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features ? incorporates the arm7tdmi ? arm ? thumb ? processor ? high-performance 32-bit risc architecture ? high-density 16-bit instruction set ? leader in mips/watt ? embeddedice ? in-circuit emulation, debug communication channel support ? internal high -speed flash ? 512 kbytes, organized in two contiguous banks of 1024 pages of 256 bytes dual plane (sam7se512) ? 256 kbytes (sam7se256) organized in one bank of 1024 pages of 256 bytes single plane (sam7se256) ? 32 kbytes (sam7se32) organized in one ba nk of 256 pages of 128 bytes single plane (sam7se32) ? single cycle access at up to 30 mhz in worst case conditions ? prefetch buffer optimizing thumb instruction executi on at maximum speed ? page programming time: 6 ms, including pa ge auto-erase, full erase time: 15 ms ? 10,000 erase cycles, 10-year data retentio n capability, sector lock capabilities, flash security bit ? fast flash programming interfa ce for high volume production ? 32 kbytes (sam7se512/256) or 8 kbytes (sam7se32) of internal high-speed sram, single-cyc le access at maximum speed ? one external bus interface (ebi) ? supports sdram, static memory, gl ueless connection to compactflash ? and ecc-enabled nand flash ? memory controller (mc) ? embedded flash controller ? memory protection unit ? abort status and mi salignment detection ? reset controller (rstc) ? based on power-on reset cells and low-power factory-calibrated brownout detector ? provides external reset signal shaping and reset source status ? clock generator (ckgr) ? low-power rc oscillator, 3 to 20 mhz on-chip oscillator and one pll ? power management controller (pmc) ? power optimization capabilities, includin g slow clock mode (down to 500 hz) and idle mode ? three programmable external clock signals ? advanced interrupt controller (aic) ? individually maskable, eight-level priority, vectored interrupt sources ? two external interrupt sources and one fa st interrupt source, spurious interrupt protected ? debug unit (dbgu) ? two-wire uart and support for debug communication channel interrupt, programmable ice access prevention ? mode for general purpose two-wi re uart serial communication ? periodic interval timer (pit) ? 20-bit programmable counter pl us 12-bit interval counter ? windowed watchdog (wdt) ? 12-bit key-protected programmable counter at91sam arm-based flash mcu sam7se512 sam7se256 sam7se32 6222f?atarm?14-jan-11
2 6222f?atarm?14-jan-11 sam7se512/256/32 ? provides reset or interru pt signals to the system ? counter may be stopped while the proces sor is in debug state or in idle mode ? real-time timer (rtt) ? 32-bit free-running counter with alarm ? runs off the internal rc oscillator ? three parallel input/output controllers (pio) ? eighty-eight programmable i/o lines multiplexed with up to two peripheral i/os ? input change interrupt ca pability on each i/o line ? individually programmable open-drain, pull-up resistor and synchronous output ? schmitt trigger on all inputs ? eleven peripheral dma controller (pdc) channels ? one usb 2.0 full speed (12 mb its per second) device port ? on-chip transceiver, eight endpoints, 2688-byte config urable integrated fifos ? one synchronous serial controller (ssc) ? independent clock and frame sync sign als for each receiver and transmitter ? i2s analog interface support, time division multiplex support ? high-speed continuous data stream ca pabilities with 32-bit data transfer ? two universal synchronous/asynchrono us receiver transmitters (usart) ? individual baud rate generator, irda ? infrared modulation/demodulation ? support for iso7816 t0/t1 smart card, hardware handshaking, rs485 support ? full modem line support on usart1 ? one master/slave serial peripheral interfaces (spi) ? 8- to 16-bit programmable da ta length, four external peripheral chip selects ? one three-channel 16-bi t timer/counter (tc) ? three external clock inputs, two multi-purpose i/o pins per channel ? double pwm generation, capture/waveform mode, up/down capability ? one four-channel 16-bit pwm controller (pwmc) ? one two-wire interface (twi) ? master, multi-master and slave mode supp ort, all two-wire atmel eeproms supported ? general call supported in slave mode ? one 8-channel 10-bit analog-to-digital converter, four channels multiplexed with digital i/os ? sam-ba ? ? default boot program ? interface with sam-ba gr aphic user interface ? ieee ? 1149.1 jtag boundary sc an on all digital pins ? four high-current drive i/o lines, up to 16 ma each ? power supplies ? embedded 1.8v regulator, drawing up to 10 0 ma for the core and external components ? 1.8v or 3,3v vddio i/o lines power supply, independent 3.3v vddflash flash power supply ? 1.8v vddcore core power supply with brownout detector ? fully static operation: ? up to 55 mhz at 1.8v and 85 ? c worst case conditions ? up to 48 mhz at 1.65v and 85 ? c worst case conditions ? available in a 128-lead lqfp green package, or a 144-ball lfbga rohs-compliant package
3 6222f?atarm?14-jan-11 sam7se512/256/32 1. description atmel's sam7se series is a member of its sm art arm microcontroller family based on the 32- bit arm7 ? risc processor and high-speed flash memory. ? sam7se512 features a 512 kbyte high-speed flash and a 32 kbyte sram. ? sam7se256 features a 256 kbyte high-speed flash and a 32 kbyte sram. ? sam7se32 features a 32 kbyte high-speed flash and an 8 kbyte sram. it also embeds a large set of peripherals, including a usb 2.0 device, an external bus interface (ebi), and a complete set of system functions minimizing the number of external components. the ebi incorporates controllers for synchr onous dram (sdram) and static memories and features specific circuitry facilitating th e interface for nand flash, smartmedia and compactflash. the device is an ideal migration path for 8/16-bit microcontroller users looking for additional per- formance, extended memory and higher levels of system integration. the embedded flash memory can be programmed in-system via the jtag-ice interface or via a parallel interface on a production programmer pr ior to mounting. built-in lock bits and a secu- rity bit protect the firmware from accidental overwrite and preserve its confidentiality. the sam7se series system controller includes a reset controller capable of managing the power-on sequence of the microcontroller and the complete system. correct device operation can be monitored by a built-in brownout detector and a watchdog running off an integrated rc oscillator. by combining the arm7tdmi processor with on-chip flash and sram, and a wide range of peripheral functions, including usart, spi, external bus interface, timer counter, rtt and analog-to-digital converters on a monolithic chip, the sam7se512/256/32 is a powerful device that provides a flexible, cost-effective solution to many embedded control applications. 1.1 configuration summary of t he sam7se512, sam7se256 and sam7se32 the sam7se512, sam7se256 and sam7se32 differ in memory sizes and organization. table 1-1 below summarizes the configurations for the three devices. table 1-1. configuration summary device flash size flash organization ram size sam7se512 512k bytes dual plane 32k bytes sam7se256 256k bytes single plane 32k bytes sam7se32 32k bytes single plane 8k bytes
4 6222f?atarm?14-jan-11 sam7se512/256/32 2. block diagram figure 2-1. sam7se512/256/32 block diagram signal description reset controller pmc apb ice jtag scan arm7tdmi processor system controller aic dbgu pdc pdc pll osc rcosc bod por pio pit wdt rtt pioa piob pioc pio pio pio usart0 usart1 spi timer counter pdc pdc pdc pdc pdc pdc pdc pdc tc0 tc1 tc2 adc advref twi ssc pwmc usb device fifo static memory controller ecc controller sdram controller ebi compactflash nand flash sram 32 kbytes (se512/256) or 8 kbytes (se32) flash 512 kbytes (se512) 256 kbytes (se256) 32 kbytes (se32) 1.8v voltage regulator memory controller embedded flash controller address decoder abort status misalignment detection memory protection unit peripheral dma controller 11 channels peripheral bridge fast flash programming interface sam-ba transciever pdc rom npcs0 npcs1 npcs2 npcs3 miso mosi spck tioa0 tiob0 tioa1 tiob1 tioa2 tiob2 adtrg ad0 ad1 ad2 ad3 ad4 ad5 ad6 ad7 tclk0 tclk1 tclk2 rxd0 txd0 sck0 rts0 cts0 rxd1 txd1 sck1 rts1 cts1 dcd1 dsr1 dtr1 ri1 nrst vddcore vddcore vddflash xin xout pllrc pck0-pck2 drxd dtxd irq0-irq1 fiq tst tdi tdo tms tck jtagsel vddin gnd vddout vddcore vddio vddflash erase pgmrdy pgmnvalid pgmnoe pgmck pgmm0-pgmm3 pgmd0-pgmd15 pgmncmd pgmen0-pgmen1 d[31:0] a0/nbs0 a1/nbs2 a[15:2], a[20:18] a21/nandale a22/reg/nandcle a16/ba0 a17/ba1 ncs0 ncs1/sdcs ncs2/cfcs1 ncs3/nandcs nrd/cfoe nwr0/nwe/cfwe nwr1/nbs1/cfior nbs3/cfiow sdcke ras cas sdwe sda10 cfrnw ncs4/cfcs0 ncs5/cfce1 ncs6/cfce2 ncs7 nandoe nandwe nwait sdck ddm ddp pwm0 pwm1 pwm2 pwm3 tf tk td rd rk rf twd twck
5 6222f?atarm?14-jan-11 sam7se512/256/32 3. signal description table 3-1. signal description list signal name function type active level comments power vddin voltage regulator and adc power supply input power 3v to 3.6v vddout voltage regulator output power 1.85v vddflash flash and usb power supply power 3v to 3.6v vddio i/o lines power supply power 3v to 3.6v or 1.65v to 1.95v vddcore core power supply power 1.65v to 1.95v vddpll pll power 1.65v to 1.95v gnd ground ground clocks, oscillators and plls xin main oscillator input input xout main oscillator output output pllrc pll filter input pck0 - pck2 programmabl e clock output output ice and jtag tck test clock input no pull-up resistor tdi test data in input no pull-up resistor tdo test data out output tms test mode select input no pull-up resistor. jtagsel jtag selection input pull-down resistor (1) flash memory erase flash and nvm configuration bits erase command input high pull-down resistor (1) reset/test nrst microcontroller reset i/o low o pen drain with pull-up resistor (1) tst test mode select input high pull-down resistor (1) debug unit drxd debug receive data input dtxd debug transmit data output aic irq0 - irq1 external interrupt inputs input fiq fast interrupt input input
6 6222f?atarm?14-jan-11 sam7se512/256/32 pio pa0 - pa31 parallel io controller a i/o pulled-up input at reset pb0 - pb31 parallel io controller b i/o pulled-up input at reset pc0 - pc23 parallel io controller c i/o pulled-up input at reset usb device port ddm usb device port data - analog ddp usb device port data + analog usart sck0 - sck1 serial clock i/o txd0 - txd1 transmit data i/o rxd0 - rxd1 receive data input rts0 - rts1 request to send output cts0 - cts1 clear to send input dcd1 data carrier detect input dtr1 data terminal ready output dsr1 data set ready input ri1 ring indicator input synchronous serial controller td transmit data output rd receive data input tk transmit clock i/o rk receive clock i/o tf transmit frame sync i/o rf receive frame sync i/o timer/counter tclk0 - tclk2 external clock inputs input tioa0 - tioa2 timer counter i/o line a i/o tiob0 - tiob2 timer counter i/o line b i/o pwm controller pwm0 - pwm3 pwm channels output serial peripheral interface miso master in slave out i/o mosi master out slave in i/o spck spi serial clock i/o npcs0 spi peripheral chip select 0 i/o low npcs1-npcs3 spi peripheral chip select 1 to 3 output low table 3-1. signal description list (continued) signal name function type active level comments
7 6222f?atarm?14-jan-11 sam7se512/256/32 two-wire interface twd two-wire serial data i/o twck two-wire serial clock i/o analog-to-digital converter ad0-ad3 analog inputs analog digital pulled-up inputs at reset ad4-ad7 analog inputs analog analog inputs adtrg adc trigger input advref adc reference analog fast flash programming interface pgmen0-pgmen2 programming enabling input pgmm0-pgmm3 programming mode input pgmd0-pgmd15 programming data i/o pgmrdy programming ready output high pgmnvalid data direction output low pgmnoe programming read input low pgmck programming clock input pgmncmd programming command input low external bus interface d[31:0] data bus i/o a[22:0] address bus output nwait external wait signal input low static memory controller ncs[7:0] chip select lines output low nwr[1:0] write signals output low nrd read signal output low nwe write enable output low nub nub: upper byte select output low nlb nlb: lower byte select output low ebi for compactflash support cfce[2:1] compactflash chip enable output low cfoe compactflash output enable output low cfwe compactflash write enable output low cfior compactflash i/o read signal output low cfiow compactflash i/o write signal output low cfrnw compactflash read not write signal output cfcs[1:0] compactflash chip select lines output low table 3-1. signal description list (continued) signal name function type active level comments
8 6222f?atarm?14-jan-11 sam7se512/256/32 note: 1. refer to section 6. ?i/o lines considerations? . ebi for nand flash support nandcs nand flash chip select line output low nandoe nand flash output enable output low nandwe nand flash write enable output low nandcle nand flash command line enable output low nandale nand flash address line enable output low sdram controller sdck sdram clock output tied low after reset sdcke sdram clock enable output high sdcs sdram controller chip select line output low ba[1:0] bank select output sdwe sdram write enable output low ras - cas row and column signal output low nbs[3:0] byte mask signals output low sda10 sdram address 10 line output table 3-1. signal description list (continued) signal name function type active level comments
9 6222f?atarm?14-jan-11 sam7se512/256/32 4. package the sam7se512/256/32 is available in: ? 20 x 14 mm 128-lead lqfp package with a 0.5 mm lead pitch. ? 10x 10 x 1.4 mm 144-ball lfbga package with a 0.8 mm lead pitch 4.1 128-lead lqfp package outline figure 4-1 shows the orientation of the 128-lead lqfp package and a detailed mechanical description is given in the mechanical characteristics section of the full datasheet. figure 4-1. 128-lead lqfp package outline (top view) 65 103 102 64 39 38 1 128
10 6222f?atarm?14-jan-11 sam7se512/256/32 4.2 128-lead lqfp pinout table 4-1. pinout in 128-lead lqfp package 1 advref 33 pb31 65 tdi 97 sdck 2 gnd 34 pb30 66 tdo 98 pc8 3 ad7 35 pb29 67 pb2 99 pc7 4 ad6 36 pb28 68 pb1 100 pc6 5 ad5 37 pb27 69 pb0 101 pc5 6 ad4 38 pb26 70 gnd 102 pc4 7 vddout 39 pb25 71 vddio 103 pc3 8 vddin 40 pb24 72 vddcore 104 pc2 9 pa20/pgmd8/ad3 41 pb23 73 nrst 105 pc1 10 pa19/pgmd7/ad2 42 pb22 74 tst 106 pc0 11 pa18/pgmd6/ad1 43 pb21 75 erase 107 pa31 12 pa17/pgmd5/ad0 44 pb20 76 tck 108 pa30 13 pa16/pgmd4 45 gnd 77 tms 109 pa29 14 pa15/pgmd3 46 vddio 78 jtagsel 110 pa28 15 pa14/pgmd2 47 vddcore 79 pc23 111 pa27/pgmd15 16 pa13/pgmd1 48 pb19 80 pc22 112 pa26/pgmd14 17 pa12/pgmd0 49 pb18 81 pc21 113 pa25/pgmd13 18 pa11/pgmm3 50 pb17 82 pc20 114 pa24/pgmd12 19 pa10/pgmm2 51 pb16 83 pc19 115 pa23/pgmd11 20 pa9/pgmm1 52 pb15 84 pc18 116 pa22/pgmd10 21 vddio 53 pb14 85 pc17 117 pa21/pgmd9 22 gnd 54 pb13 86 pc16 118 vddcore 23 vddcore 55 pb12 87 pc15 119 gnd 24 pa8/pgmm0 56 pb11 88 pc14 120 vddio 25 pa7/pgmnvalid 57 pb10 89 pc13 121 dm 26 pa6/pgmnoe 58 pb9 90 pc12 122 dp 27 pa5/pgmrdy 59 pb8 91 pc11 123 vddflash 28 pa4/pgmncmd 60 pb7 92 pc10 124 gnd 29 pa3 61 pb6 93 pc9 125 xin/pgmck 30 pa2/pgmen2 62 pb5 94 gnd 126 xout 31 pa1/pgmen1 63 pb4 95 vddio 127 pllrc 32 pa0/pgmen0 64 pb3 96 vddcore 128 vddpll
11 6222f?atarm?14-jan-11 sam7se512/256/32 4.3 144-ball lfbga package outline figure 4-2 shows the orientation of the 144-ball lfbga package and a detailed mechanical description is given in the mechanical characteristics section. figure 4-2. 144-ball lfbga package outline (top view) abcdefghjklm 12 11 10 9 8 7 6 5 4 3 2 1 ball a1
12 6222f?atarm?14-jan-11 sam7se512/256/32 4.4 144-ball lfbga pinout table 4-2. sam7se512/256/32 pinout for 144-ball lfbga package pin signal name pin signal name pin signal name pin signal name a1 pb7 d1 vddcore g1 pc18 k1 pc11 a2 pb8 d2 vddcore g2 pc16 k2 pc6 a3 pb9 d3 pb2 g3 pc17 k3 pc2 a4 pb12 d4 tdo g4 pc9 k4 pc0 a5 pb13 d5 tdi g5 vddio k5 pa27/pgmd15 a6 pb16 d6 pb17 g6 gnd k6 pa26/pgmd14 a7 pb22 d7 pb26 g7 gnd k7 gnd a8 pb23 d8 pa14/pgmd2 g8 gnd k8 vddcore a9 pb25 d9 pa12/pgmd0 g9 gnd k9 vddflash a10 pb29 d10 pa11/pgmm3 g10 ad4 k10 vddio a11 pb30 d11 pa8/pgmm0 g11 vddin k11 vddio a12 pb31 d12 pa7/pgmnvalid g12 vddout k12 pa18/pgmd6/ad1 b1 pb6 e1 pc22 h1 pc15 l1 sdck b2 pb3 e2 pc23 h2 pc14 l2 pc7 b3 pb4 e3 nrst h3 pc13 l3 pc4 b4 pb10 e4 tck h4 vddcore l4 pc1 b5 pb14 e5 erase h5 vddcore l5 pa29 b6 pb18 e6 test h6 gnd l6 pa24/pgmd12 b7 pb20 e7 vddcore h7 gnd l7 pa21/pgmd9 b8 pb24 e8 vddcore h8 gnd l8 advref b9 pb28 e9 gnd h9 gnd l9 vddflash b10 pa4/pgmncmd e10 pa9/pgmm1 h10 pa19/pgmd7/ad2 l10 vddflash b11 pa0/pgmen0 e11 pa10/pgmm2 h11 pa20/pgmd8/ad3 l11 pa17/pgmd5/ad0 b12 pa1/pgmen1 e12 pa13/pgmd1 h12 vddio l12 gnd c1 pb0 f1 pc21 j1 pc12 m1 pc8 c2 pb1 f2 pc20 j2 pc10 m2 pc5 c3 pb5 f3 pc19 j3 pa30 m3 pc3 c4 pb11 f4 jtagsel j4 pa28 m4 pa31 c5 pb15 f5 tms j5 pa23/pgmd11 m5 pa25/pgmd13 c6 pb19 f6 vddio j6 pa22/pgmd10 m6 dm c7 pb21 f7 gnd j7 ad6 m7 dp c8 pb27 f8 gnd j8 ad7 m8 gnd c9 pa6/pgmnoe f9 gnd j9 vddcore m9 xin/pgmck c10 pa5/pgmrdy f10 ad5 j10 vddcore m10 xout c11 pa2/pgmen2 f11 pa15/pgmd3 j11 vddcore m11 pllrc c12 pa3 f12 pa16/pgmd4 j12 vddio m12 vddpll
13 6222f?atarm?14-jan-11 sam7se512/256/32 5. power considerations 5.1 power supplies the sam7se512/256/32 has six types of power supply pins and integrates a voltage regulator, allowing the device to be supplied with only one voltage. the six power supply pin types are: ? vddin pin. it powers the voltage regulator and the adc; voltage ranges from 3.0v to 3.6v, 3.3v nominal. ? vddout pin. it is the output of the 1.8v voltage regulator. ? vddio pin. it powers the i/o lines; two voltage ranges are supported: ? from 3.0v to 3.6v, 3.3v nominal ? or from 1.65v to 1.95v, 1.8v nominal. ? vddflash pin. it powers the usb transceivers and a part of the flash. it is required for the flash to operate correctly; voltage ranges from 3.0v to 3.6v, 3.3v nominal. ? vddcore pins. they power the logic of the device; voltage ranges from 1.65v to 1.95v, 1.8v typical. it can be connected to the vddout pin with decoupling capacitor. vddcore is required for the device, including its embedded flash, to operate correctly. ? vddpll pin. it powers the oscillator and the pll. it can be connected directly to the vddout pin. in order to decrease current consumption, if the voltage regulator and the adc are not used, vddin, advref, ad4, ad5, ad6 and ad7 should be connected to gnd. in this case vddout should be left unconnected. no separate ground pins are provided for the diff erent power supplies. only gnd pins are pro- vided and should be connected as shortl y as possible to the system ground plane. 5.2 power consumption the sam7se512/256/32 has a static current of less than 60 a on vddcore at 25c, includ- ing the rc oscillator, the volt age regulator and the power-on reset when the brownout detector is deactivated. activating the brownout detector adds 20 a static current. the dynamic power consumption on vddcore is less than 80 ma at full speed when running out of the flash. under the sa me conditions, the power consum ption on vddflash does not exceed 10 ma. 5.3 voltage regulator the sam7se512/256/32 embeds a voltage regulator that is managed by the system controller. in normal mode, the voltage regulator consumes less than 100 a static current and draws 100 ma of output current. the voltage regulator also has a low-power mode. in this mode, it consumes less than 20 a static current and draws 1 ma of output current. adequate output supply decoupling is mandator y for vddout to reduce ripple and avoid oscil- lations. the best way to achieve this is to use two capacitors in parallel: ? one external 470 pf (or 1 nf) npo capacitor should be connected between vddout and gnd as close to the chip as possible.
14 6222f?atarm?14-jan-11 sam7se512/256/32 ? one external 2.2 f (or 3.3 f) x7r capacitor should be connected between vddout and gnd. adequate input supply decouplin g is mandatory for vddin in or der to improve startup stability and reduce source voltage drop. the input decoupling capacitor should be placed close to the chip. for example, two capacitors can be used in parallel: 100 nf npo and 4.7 f x7r. 5.4 typical powe ring schematics the sam7se512/256/32 supports a 3.3v single s upply mode. the internal regulator input con- nected to the 3.3v source and its output feeds vddcore and the vddpll. figure 5-1 shows the power schematics to be used for usb bus-powered systems. figure 5-1. 3.3v system single power supply schematic power source ranges from 4.5v (usb) to 18v 3.3v vddin voltage regulator vddout vddio dc/dc converter vddcore vddflash vddpll
15 6222f?atarm?14-jan-11 sam7se512/256/32 6. i/o lines considerations 6.1 jtag port pins tms, tdi and tck are schmitt trigger inputs. tms, tdi and tck do not integrate a pull-up resistor. tdo is an output, driven at up to vddio, and has no pull-up resistor. the jtagsel pin is used to select the jtag boundary scan when asserted at a high level. the jtagsel pin integrates a permanent pull-down resistor of about 15 k . to eliminate any risk of s puriously entering the jtag boundary scan mode due to noise on jtagsel, it should be tied externally to gn d if boundary scan is not used, or put in place an external low value resistor (such as 1 k ) . 6.2 test pin the tst pin is used for manufacturing test or fast programming mode of the sam7se512/256/32 when asserted high. the tst pi n integrates a permanent pull-down resis- tor of about 15 k to gnd. to eliminate any risk of entering the test mode due to noise on the tst pin, it should be tied to gnd if the ffpi is not used, or put in place an external low value resistor (such as 1 k ) . to enter fast programming mode, the tst pin and the pa0 and pa1 pins should be tied high and pa2 tied low. driving the tst pin at a high level while pa0 or pa1 is driven at 0 leads to unpredictable results. 6.3 reset pin the nrst pin is bidirectional with an open-drain output buffer. it is handled by the on-chip reset controller and can be driven low to provide a rese t signal to the external components or asserted low externally to reset the microcontroller. there is no constraint on the length of the reset pulse, and the reset controller can guarantee a minimum pu lse length. this allows connection of a sim- ple push-button on the nrst pin as system user reset, and the use of the nrst signal to reset all the components of the system. an external power-on reset can dr ive this pin during the start-up instead of using the internal power-on reset circuit. the nrst pin integrates a permanent pull-up of about 100 k resistor to vddio . this pin has schmitt trigger input. 6.4 erase pin the erase pin is used to re-initialize the flash content and some of its nvm bits. it integrates a permanent pull-down resistor of about 15 k to gnd. to eliminate any risk of erasing the flash due to noise on the erase pin, it sh ould be tied exter- nally to gnd, which prevents erasing the flash from the application, or put in place an external low value resistor (such as 1 k ) . this pin is debounced by the rc osc illator to improve the g litch tolerance. when the pin is tied to high during less than 100 ms, er ase pin is not taken into acc ount. the pin must be tied high during more than 220 ms to perform the re-initialization of the flash.
16 6222f?atarm?14-jan-11 sam7se512/256/32 6.5 sdck pin the sdck pin is dedicated to the sdram clock and is an output-only without pull-up. maximum output frequency of this pad is 48 mhz at 3.0v and 25 mhz at 1.65v with a maximum load of 30 pf. 6.6 pio controller lines all the i/o lines pa0 to pa31, pb0 to pb31, pc0 to pc23 integrate a programmable pull-up resistor. programming of this pull-up resistor is performed independently for each i/o line through the pio controllers. typical pull-up value is 100 k . all the i/o lines have schmitt trigger inputs. 6.7 i/o lines current drawing the pio lines pa0 to pa3 are high-drive current capable. each of these i/o lines can drive up to 16 ma permanently. the remaining i/o lines can draw only 8 ma. however, the total current drawn by all the i/o lines cannot exceed 300 ma.
17 6222f?atarm?14-jan-11 sam7se512/256/32 7. processor and architecture 7.1 arm7tdmi processor ? risc processor based on armv4t von neumann architecture ? runs at up to 55 mhz, providing 0.9 mips/mhz (core supplied with 1.8v) ? two instruction sets ?arm ? high-performance 32-bit instruction set ?thumb ? high code density 16-bit instruction set ? three-stage pipeline architecture ? instruction fetch (f) ? instruction decode (d) ? execute (e) 7.2 debug and test features ? embeddedice ? (integrated embedded in-circuit emulator) ? two watchpoint units ? test access port accessible through a jtag protocol ? debug communication channel ? debug unit ?two-pin uart ? debug communication channel interrupt handling ? chip id register ? ieee1149.1 jtag boundary-scan on all digital pins 7.3 memory controller ? programmable bus arbiter ? handles requests from the arm7tdmi and the peripheral dma controller ? address decoder provides selection signals for ? four internal 1 mbyte memory areas ? one 256-mbyte embedded peripheral area ? eight external 256-mbyte memory areas ? abort status registers ? source, type and all parameters of the access leading to an abort are saved ? facilitates debug by de tection of bad pointers ? misalignment detector ? alignment checking of all data accesses ? abort generation in case of misalignment ? remap command ? remaps the sram in place of the embedded non-volatile memory ? allows handling of dynamic exception vectors ? 16-area memory protection unit (internal memory and peripheral protection only)
18 6222f?atarm?14-jan-11 sam7se512/256/32 ? individually programmable size between 1k byte and 1m byte ? individually programmable protection against write and/or user access ? peripheral protection against write and/or user access ? embedded flash controller ? embedded flash interface, up to three programmable wait states ? prefetch buffer, buffering and anticipating the 16-bit requests, reducing the required wait states ? key-protected program, erase and lock/unlock sequencer ? single command for erasing, programming and locking operations ? interrupt generation in case of forbidden operation 7.4 external bus interface ? integrates three external memory controllers: ? static memory controller ? sdram controller ? ecc controller ? additional logic for nand flash and compactflash ? support ? nand flash support: 8-bit as well as 16-bit devices are supported ? compactflash support: all modes (attribute memory, common memory, i/o, true ide) are supported but the signals _iois16 (i/o and true ide modes) and -ata sel (true ide mode) are not handled. ? optimized external bus: ? 16- or 32-bit data bus (32-bit data bus for sdram only) ? up to 23-bit address bus, up to 8-mbytes addressable ? up to 8 chip selects, each reserved to one of the eight memory areas ? optimized pin multiplexing to re duce latencies on external memories ? configurable chip select assignment: ? static memory controller on ncs0 ? sdram controller or static memory controller on ncs1 ? static memory controller on ncs2, optional compactflash support ? static memory controller on ncs3, nc s5 - ncs6, optional nand flash support ? static memory controller on ncs4, optional compactflash support ? static memory controller on ncs7 7.5 static memory controller ? external memory mapping, 512-mbyte address space ? 8-, or 16-bit data bus ? up to 8 chip select lines ? multiple access modes supported ? byte write or byte select lines ? two different read protocols for each memory bank
19 6222f?atarm?14-jan-11 sam7se512/256/32 ? multiple device adaptability ? compliant with lcd module ? compliant with psram in synchronous operations ? programmable setup time read/write ? programmable hold time read/write ? multiple wait state management ? programmable wait state generation ? external wait request ? programmable data float time 7.6 sdram controller ? numerous configurations supported ? 2k, 4k, 8k row address memory parts ? sdram with two or four internal banks ? sdram with 16- or 32-bit data path ? programming facilities ? word, half-word, byte access ? automatic page break when memory boundary has been reached ? multibank ping-pong access ? timing parameters specified by software ? automatic refresh operation, refresh rate is programmable ? energy-saving capabilities ? self-refresh, and low-power modes supported ? error detection ? refresh error interrupt ? sdram power-up initialization by software ? latency is set to two clocks (cas latency of 1, 3 not supported) ? auto precharge command not used ? mobile sdram supported (except for low-power extended mode and deep power-down mode) 7.7 error corrected code controller ? tracking the accesses to a nand flash device by triggering on the corresponding chip select ? single bit error correction and 2-bit random detection. ? automatic hamming code calculation while writing ? ecc value available in a register ? automatic hamming code calculation while reading ? error report, including error flag, correctable error flag and word address being detected erroneous ? supports 8- or 16-bit nand flash devices with 512-, 1024-, 2048- or 4096-byte pages
20 6222f?atarm?14-jan-11 sam7se512/256/32 7.8 peripheral dma controller ? handles data transfer between peripherals and memories ? eleven channels ? two for each usart ? two for the debug unit ? two for the serial synchronous controller ? two for the serial peripheral interface ? one for the analog-to-digital converter ? low bus arbitration overhead ? one master clock cycle needed for a transfer from memory to peripheral ? two master clock cycles needed for a transfer from peripheral to memory ? next pointer management for reducing interrupt latency requirements ? peripheral dma controller (pdc) priority is as follows (from the highest priority to the lowest): receive dbgu receive usart0 receive usart1 receive ssc receive adc receive spi tr a n s m i t d b g u transmit usart0 transmit usart1 transmit ssc transmit spi
21 6222f?atarm?14-jan-11 sam7se512/256/32 8. memories ? 512 kbytes of flash memory (sam7se512) ? dual plane ? two contiguous banks of 1024 pages of 256 bytes ? fast access time, 30 mhz single-cycle access in worst case conditions ? page programming time: 6 ms, including page auto-erase ? page programming without auto-erase: 3 ms ? full chip erase time: 15 ms ? 10,000 write cycles, 10-yea r data retent ion capability ? 32 lock bits, each protecting 32 lock regions of 64 pages ? protection mode to secure contents of the flash ? 256 kbytes of flash memory (sam7se256) ? single plane ? one bank of 1024 pages of 256 bytes ? fast access time, 30 mhz single-cycle access in worst case conditions ? page programming time: 6 ms, including page auto-erase ? page programming without auto-erase: 3 ms ? full chip erase time: 15 ms ? 10,000 cycles, 10-year data retention capability ? 16 lock bits, each protecting 16 lock regions of 64 pages ? protection mode to secure contents of the flash ? 32 kbytes of flash memory (sam7se32) ? single plane ? one bank of 256 pages of 128 bytes ? fast access time, 30 mhz single-cycle access in worst case conditions ? page programming time: 6 ms, including page auto-erase ? page programming without auto-erase: 3 ms ? full chip erase time: 15 ms ? 10,000 cycles, 10-year data retention capability ? 8 lock bits, each protecting 8 lock regions of 32 pages ? protection mode to secure contents of the flash ? 32 kbytes of fast sram (sam7se512/256) ? single-cycle access at full speed ? 8 kbytes of fast sram (sam7se32) ? single-cycle access at full speed
22 6222f?atarm?14-jan-11 sam7se512/256/32 figure 8-1. sam7se memory mapping internal peripherals 0x1000 0000 0x0000 0000 0x0fff ffff 0x2000 0000 0x1fff ffff 0x3000 0000 0x2fff ffff 0x4000 0000 0x3fff ffff 0x6fff ffff 0x6000 0000 0x5fff ffff 0x5000 0000 0x4fff ffff 0x7000 0000 0x7fff ffff 0x8000 0000 0x8fff ffff 0x9000 0000 0xf000 0000 0xefff ffff 0xffff ffff 256 mbytes 256 mbytes 256 mbytes 256 mbytes 256 mbytes 256 mbytes 256 mbytes 256 mbytes 256 mbytes 256 mbytes 6 x 256 mbytes 1,536 mbytes 0x000f ffff 0x0010 0000 0x001f ffff 0x0020 0000 0x002f ffff 0x0030 0000 0x003f ffff 0x0040 0000 0x0000 0000 1 mbytes 1 mbytes 1 mbytes 1 mbytes 252 mbytes 0xfffa 0000 0xfffa 3fff 0xfffa 4000 0xf000 0000 0xfffb 8000 0xfffc 0000 0xfffc 3fff 0xfffc 4000 0xfffc 7fff 0xfffd 4000 0xfffd 7fff 0xfffd 3fff 0xfffd ffff 0xfffe 0000 0xfffe 3fff 0xffff efff 0xffff f000 0xffff ffff 0xfffe 4000 0xfffb 4000 0xfffb 7fff 0xfff9 ffff 0xfffc ffff 0xfffd 8000 0xfffd bfff 0xfffc bfff 0xfffc c000 0xfffb ffff 0xfffb c000 0xfffb bfff 0xfffa ffff 0xfffb 0000 0xfffb 3fff 0xfffd 0000 0xfffd c000 0xfffc 8000 16 kbytes 16 kbytes 16 kbytes 16 kbytes 16 kbytes 16 kbytes 16 kbytes 16 kbytes 16 kbytes 0x0fff ffff 512 bytes/128 registers 512 bytes/128 registers 512 bytes/128 registers 256 bytes/64 registers 16 bytes/4 registers 16 bytes/4 registers 16 bytes/4 registers 16 bytes/4 registers 256 bytes/64 registers 4 bytes/1 register 512 bytes/128 registers 512 bytes/128 registers 0xffff f000 0xffff f200 0xffff f1ff 0xffff f3ff 0xffff f9ff 0xffff fbff 0xffff fcff 0xffff feff 0xffff ffff 0xffff f400 0xffff fa00 0xffff fc00 0xffff fd0f 0xffff fc2f 0xffff fc3f 0xffff fd4f 0xffff fc6f 0xffff f5ff 0xffff f600 0xffff f7ff 0xffff f800 0xffff fd00 0xffff ff00 0xffff fd20 0xffff fd30 0xffff fd40 0xffff fd60 0xffff fd70 internal memories ebi chip select 0 smc ebi chip select 1/ smc or sdramc ebi chip select 2 smc ebi chip select 3 smc/nandflash/ smartmedia ebi chip select 4 smc compact flash ebi chip select 5 smc compact flash ebi chip select 6 ebi chip select 7 undefined (abort) (1) can be rom, flash or sram depending on gpnvm2 and remap flash before remap sram after remap internal flash internal sram internal rom reserved boot memory (1) address memory space internal memory mapping note: tc0, tc1, tc2 usart0 usart1 pwmc reserved reserved reserved reserved reserved reserved reserved reserved reserved reserved reserved reserved reserved reserved reserved twi ssc spi sysc udp adc aic dbgu pioa reserved pmc mc wdt pit rtt rstc vreg piob pioc peripheral mapping system controller mapping
23 6222f?atarm?14-jan-11 sam7se512/256/32 a first level of address decoding is performed by the memory controller, i.e., by the implementa- tion of the advanced sy stem bus (asb) with ad ditional features. decoding splits the 4g bytes of address space into 16 areas of 256m bytes. the areas 1 to 8 are directed to the ebi that associates these areas to the external chip selects nc0 to ncs7. the area 0 is reserved for the addressing of the internal memories, and a second level of decoding provides 1m byte of internal memory area. the area 15 is reserved for the peripherals and pro- vides access to the advanced peripheral bus (apb). other areas are unused and performing an access within them provides an abort to the master requesting such an access. 8.1 embedded memories 8.1.1 internal memories 8.1.1.1 internal sram the sam7se512/256 embeds a high-speed 32-kbyte sram bank. the sam7se32 embeds a high-speed 8-kbyte sram bank. after reset and until the remap command is performed, the sram is only accessible at address 0x0020 0000. after remap, the sram also becomes avail- able at address 0x0. 8.1.1.2 internal rom the sam7se512/256/32 embeds an internal rom. at any time, the rom is mapped at address 0x30 0000. the rom contains the ffpi and the sam-ba boot program. 8.1.1.3 internal flash ? the sam7se512 features two banks of 256 kbytes of flash. ? the sam7se256 features one bank of 256 kbytes of flash. ? the sam7se32 features one bank of 32 kbytes of flash. at any time, the flash is mapped to address 0x0010 0000. a general purpose nvm (gpnvm) bit is used to boot either on the rom (default) or from the flash. this gpnvm bit can be cleared or set respecti vely through the commands ?clear general-pur- pose nvm bit? and ?set general-purpose nvm bit? of the efc user interface. setting the gpnvm bit 2 selects the boot from the flash, clearing it selects the boot from the rom. asserting erase clears the gpnvm bit 2 and thus selects the boot from the rom by default.
24 6222f?atarm?14-jan-11 sam7se512/256/32 figure 8-2. internal memory mapping with gpnvm bit 2 = 0 (default) figure 8-3. internal memory mapping with gpnvm bit 2 = 1 8.1.2 embedded flash 8.1.2.1 flash overview the flash of the sam7se512 is organized in two banks (dual plane) of 1024 pages of 256 bytes. it reads as 131,072 32-bit words. the flash of the sam7se256 is organized in 1024 pages (single plane) of 256 bytes. it reads as 65,536 32-bit words. the flash of the sam7se32 is organized in 256 pages (single plane) of 128 bytes. it reads as 8192 32-bit words. the flash of the sam7se32 contains a 128-byte write buffer, accessible through a 32-bit interface. the flash of the sam7se512/256 contains a 256-b yte write buffer, accessible through a 32-bit interface. 256m bytes rom before remap sram after remap undefined areas (abort) 0x000f ffff 0x001f ffff 0x002f ffff 0x0fff ffff 1 m bytes 1 m bytes 1 m bytes 252 m bytes internal flash internal sram 0x0000 0000 0x0010 0000 0x0020 0000 0x0030 0000 internal rom 0x003f ffff 0x0040 0000 1 m bytes 256m bytes flash before remap sram after remap undefined areas (abort) 0x000f ffff 0x001f ffff 0x002f ffff 0x0fff ffff 1 m bytes 1 m bytes 1 m bytes 252 m bytes internal flash internal sram 0x0000 0000 0x0010 0000 0x0020 0000 0x0030 0000 internal rom 0x003f ffff 0x0040 0000 1 m bytes
25 6222f?atarm?14-jan-11 sam7se512/256/32 the flash benefits from the integration of a power reset cell and from the brownout detector. this prevents code corruption during power su pply changes, even in the worst conditions. 8.1.2.2 embedded flash controller the embedded flash controller (efc) manages accesses performed by the masters of the sys- tem. it enables reading the flash and writing the write buffer. it also contains a user interface, mapped within the memory co ntroller on the apb. the user interface allows: ? programming of the access parameters of the flash (number of wait states, timings, etc.) ? starting commands such as full erase, page erase, page program, nvm bit set, nvm bit clear, etc. ? getting the end status of the last command ? getting error status ? programming interrupts on the end of the last commands or on errors the embedded flash controller also provides a dual 32-bit prefetch buffer that optimizes 16-bit access to the flash. this is particularly efficient when the processor is running in thumb mode. ? two efcs (efc0 and efc1) are embedded in the sam7se512 to control each plane of 256 kbytes. dual plane organization allows concurrent read and program. ? one efc (efc0) is embedded in the sam7se256 to control the single plane 256 kbytes. ? one efc (efc0) is embedded in the sam7se32 to control the single plane 32 kbytes. 8.1.2.3 lock regions the sam7se512 embedded flash controller manages 32 lock bits to protect 32 regions of the flash against inadvertent flash erasing or programming commands. the sam7se512 contains 32 lock regions and each lock region contains 64 pages of 256 bytes. each lock region has a size of 16 kbytes. the sam7se256 embedded flash controller manages 16 lock bits to protect 16 regions of the flash against inadvertent flash erasing or programming commands. the sam7se256 contains 16 lock regions and each lock region contains 64 pages of 256 bytes. each lock region has a size of 16 kbytes. the sam7se32 embedded flash controller manages 8 lock bits to protect 8 regions of the flash against inadvertent flash erasing or programming commands. the sam7se32 contains 8 lock regions and each lock region contains 32 pages of 128 bytes. each lock region has a size of 4 kbytes. if a locked-region?s erase or program command occurs, the command is aborted and the efc trigs an interrupt. the 32 (sam7se512), 16 (sam7se256) or 8 (sam7se32) nvm bits are software programma- ble through the efc user interface. the command ?set lock bit? enables the protection. the command ?clear lock bit? unlocks the lock region. asserting the erase pin clears the lock bits, thus unlocking the entire flash. 8.1.2.4 security bit feature the sam7se512/256/32 features a security bit, based on a specific nvm-bit. when the security is enabled, any access to the flash, either through the ice interface or through the fast flash programming interface, is forbidden.
26 6222f?atarm?14-jan-11 sam7se512/256/32 the security bit can only be enabled through the command ?set security bit? of the efc user interface. disabling the security bit can only be achieved by asserting the erase pin at 1 and after a full flash erase is performed. when the se curity bit is deactivated, all accesses to the flash are permitted. it is important to note that the assertion of the erase pin should always be longer than 200 ms. as the erase pin integrates a permanent pull-down, it can be left unconnected during normal operation. however, it is safer to connect it directly to gnd fo r the final application. 8.1.2.5 non-volatile brownout detector control two general purpos e nvm (gpnvm) bits are used for c ontrolling the brownout detector (bod), so that even after a power loss, the brownout detector operations remain in their state. these two gpnvm bits can be cleared or set respectively through the commands ?clear gen- eral-purpose nvm bit? and ?set general-pu rpose nvm bit? of the efc user interface. ? gpnvm bit 0 is used as a brownout detector enable bit. setting the gpnvm bit 0 enables the bod, clearing it disables the bod. assert ing erase clears the gpnvm bit 0 and thus disables the brownout detector by default. ? gpnvm bit 1 is used as a brownout reset enable signal for the reset controller. setting the gpnvm bit 1 enables the brownout reset when a brownout is detected, clearing the gpnvm bit 1 disables the brownout rese t. asserting erase disables the brownout reset by default. 8.1.2.6 calibration bits sixteen nvm bits are used to calibrate the brownout detector and the voltage regulator. these bits are factory configured and cannot be changed by the user. the erase pin has no effect on the calibration bits. 8.1.3 fast flash programming interface the fast flash programming interface allows programming the device through either a serial jtag interface or through a multiplexed fully-han dshaked parallel port. it allows gang-program- ming with market-standard industrial programmers. the ffpi supports read, page program, page erase, full erase, lock, unlock and protect commands. the fast flash programming interface is enabled and the fast programming mode is entered when the tst pin and the pa0 and pa1 pins are all tied high and pa2 tied to low. ? the flash of the sam7se512 is organized in 2048 pages of 256 bytes (dual plane). it reads as 131,072 32-bit words. ? the flash of the sam7se256 is organized in 1024 pages of 256 bytes (single plane). it reads as 65,536 32-bit words. ? the flash of the sam7se32 is organized in 256 pages of 128 bytes (single plane). it reads as 32,768 32-bit words. ? the flash of the sam7se512/256 contains a 256-byte write buffer, accessible through a 32- bit interface. ? the flash of the sam7se32 contains a 128-byte write buffer, accessible through a 32-bit interface.
27 6222f?atarm?14-jan-11 sam7se512/256/32 8.1.4 sam-ba ? boot the sam-ba boot is a default boot program which provides an easy way to program in-situ the on-chip flash memory. the sam-ba boot assistant supports serial co mmunication via the dbgu or the usb device port. ? communication via the dbgu supports a wide range of crystals from 3 to 20 mhz via software auto-detection. ? communication via the usb device port is limited to an 18.432 mhz crystal. the sam-ba boot provides an interface with sam-ba graphic user interface (gui). the sam-ba boot is in rom and is mapped in flash at address 0x0 when gpnvm bit 2 is set to 0. 8.2 external memories the external memories are accessed through the external bus interface. refer to the memory map in figure 8-1 on page 22 .
28 6222f?atarm?14-jan-11 sam7se512/256/32 9. system controller the system controller manages a ll vital blocks of the microcontr oller: interrupts , clocks, power, time, debug and reset. the system controller peripherals are all mapped to the highest 4 kbytes of address space, between addresses 0xffff f000 and 0xffff ffff. figure 9-1 on page 29 shows the system controller block diagram. figure 8-1 on page 22 shows the mapping of the user interface of the system controller periph- erals. note that the memory controller configuration user interface is also mapped within this address space.
29 6222f?atarm?14-jan-11 sam7se512/256/32 figure 9-1. system controller block diagram s lck adv a nced interr u pt controller re a l-time timer periodic interv a l timer re s et controller periph_nre s et s y s tem controller w a tchdog timer wdt_f au lt wdrproc por bod rco s c gpnvm[0] c a l en power m a n a gement controller o s c pll mainck pllck pit_ir q mck proc_nre s et wdt_ir q periph_clk[2..1 8 ] pck mck pmc_ir q udpck nir q nfi q rtt_ir q pck[0- 3 ] arm7tdmi s lck s lck ir q 0-ir q 1 fi q periph_ir q [2..1 8 ] int int i h lk[4 1 8 ] em b edded fl as h fl as h_poe jt a g_nre s et fl as h_poe gpnvm[0..2] fl as h_wrdi s fl as h_wrdi s proc_nre s et periph_nre s et pit_ir q rtt_ir q d b g u _ir q pmc_ir q r s tc_ir q wdt_ir q r s tc_ir q s lck gpnvm[1] bo u nd a ry s c a n tap controller jt a g_nre s et de bu g pck de bu g idle de bu g memory controller mck proc_nre s et b od_r s t_en proc_nre s et power_on_re s et periph_nre s et idle de bu g unit d b g u _ir q mck d b g u _rxd periph_nre s et force_ntr s t d b g u _txd u s b device port udpck periph_nre s et periph_clk[11] periph_ir q [11] usb _ sus pend volt a ge reg u l a tor s t a nd b y volt a ge reg u l a tor mode controller s ec u rity_ b it c a l power_on_re s et power_on_re s et force_ntr s t c a l
30 6222f?atarm?14-jan-11 sam7se512/256/32 9.1 reset controller ? based on one power-on reset cell and a double brownout detector ? status of the last reset, either power-up reset, software reset, user reset, watchdog reset, brownout reset ? controls the internal resets and the nrst pin output ? allows to shape a signal on the nrst line, guaranteeing that the length of the pulse meets any requirement. 9.1.1 brownout detector and power on reset the sam7se512/256/32 embeds one brownout detection circuit and a power-on reset cell. the power-on reset is supplied with and monitors vddcore. both signals are provided to the flash to prev ent any code corruption during power-up or power- down sequences or if brownouts occur on the vddcore power supply. the power-on reset cell has a limited-accuracy threshold at around 1.5v. its output remains low during power-up until vddcore go es over this voltag e level. this signal goes to the reset con- troller and allows a full re-initialization of the device. the brownout detector monitors the vddcor e and vddflash levels during operation by comparing it to a fixed trigger level. it secures system operations in the most difficult environ- ments and prevents code corruption in case of brownout on the vddcore or vddflash. when the brownout detector is enabled and vddcor e decreases to a value below the trigger level (vbot18-, defined as vbot18 - hyst/2), the brownout output is immediately activated. when vddcore increases above the trigger leve l (vbot18+, defined as v bot18 + hyst/2), the reset is released. the brownout detector only detects a drop if the voltage on vddcore stays below the threshold voltage for longer than about 1s. the vddcore threshold voltage ha s a hysteresis of about 50 mv , to ensure spike free brown- out detection. the typical value of the brownout detector threshold is 1.68v with an accuracy of 2% and is factory calibrated. when the brownout detector is enabled and vddflash decreases to a value below the trigger level (vbot33-, defined as vbot33 - hyst/2), the brownout output is immediately activated. when vddflash increases above the trigger level (vbot33+, defined as vbot33 + hyst/2), the reset is released. the brownout detector only detects a drop if the voltage on vddcore stays below the threshold voltage for longer than about 1s. the vddflash threshold voltage has a hysteresis of about 50 mv, to ensure spike free brown- out detection. the typical value of the brownout detector threshold is 2.80v with an accuracy of 3.5% and is factory calibrated. the brownout detector is low-power, as it consum es less than 20 a static current. however, it can be deactivated to save its static current. in this case, it consumes less than 1a. the deac- tivation is configured through the gpnvm bit 0 of the flash. 9.2 clock generator the clock generator embeds one low-power rc oscillator, one main oscillator and one pll with the following characteristics: ? rc oscillator ranges betw een 22 khz and 42 khz
31 6222f?atarm?14-jan-11 sam7se512/256/32 ? main oscillator frequency ranges between 3 and 20 mhz ? main oscillator can be bypassed ? pll output ranges between 80 and 220 mhz it provides slck, mainck and pllck. figure 9-2. clock generator block diagram 9.3 power management controller the power management controller uses the clock generator outputs to provide: ? the processor clock pck ? the master clock mck ? the usb clock udpck ? all the peripheral clocks, independently controllable ? three programmable clock outputs the master clock (mck) is programmable from a few hundred hz to the maximum operating fre- quency of the device. the processor clock (pck) switches off when entering processor idle mode, thus allowing reduced power consumption while waiting for an interrupt. power management controller xin xout pllrc slow clock slck main clock mainck pll clock pllck control status embedded rc oscillator main oscillator pll and divider clock generator
32 6222f?atarm?14-jan-11 sam7se512/256/32 figure 9-3. power management co ntroller block diagram 9.4 advanced interrupt controller ? controls the interrupt lines (nirq and nfiq) of an arm processor ? individually maskable and vectored interrupt sources ? source 0 is reserved for the fast interrupt input (fiq) ? source 1 is reserved for system peripherals (rtt, pit, efc, pmc, dbgu, etc.) ? other sources control the peripheral interrupts or external interrupts ? programmable edge-triggered or level-sensitive internal sources ? programmable positive/negative edge-triggered or high/low level-sensitive external sources ? 8-level priority controller ? drives the normal interrupt nirq of the processor ? handles priority of the interrupt sources ? higher priority interrupts can be served during service of lower priority interrupt ? vectoring ? optimizes interrupt service routine branch and execution ? one 32-bit vector register per interrupt source ? interrupt vector register reads the corresponding current interrupt vector ?protect mode ? easy debugging by preventing automatic operations ?fast forcing ? permits redirecting any interrupt source on the fast interrupt ? general interrupt mask ? provides processor synchronization on events without triggering an interrupt mck periph_clk[2..14] int udpck slck mainck pllck prescaler /1,/2,/4,...,/64 pck processor clock controller idle mode master clock controller peripherals clock controller on/off usb clock controller on/off slck mainck pllck prescaler /1,/2,/4,...,/64 programmable clock controller pllck divider /1,/2,/4 pck[0..2] usb_suspend
33 6222f?atarm?14-jan-11 sam7se512/256/32 9.5 debug unit ? comprises: ? one two-pin uart ? one interface for the debug co mmunication channel (dcc) support ? one set of chip id registers ? one interface providing ice access prevention ?two-pin uart ? usart-compatible user interface ? programmable baud rate generator ? parity, framing and overrun error ? automatic echo, local loopback and remote loopback channel modes ? debug communication channel support ? offers visibility of commrx and commt x signals from the arm processor ? chip id registers ? identification of the device revision, sizes of the embedded memories, set of peripherals ? chip id is 0x272a 0a40 (version 0) for sam7se512 ? chip id is 0x272a 0940 (version 0) for sam7se256 ? chip id is 0x2728 0340 (version 0) for sam7se32 9.6 periodic interval timer ? 20-bit programmable counter plus 12-bit interval counter 9.7 watchdog timer ? 12-bit key-protected programmable counter running on prescaled slck ? provides reset or interrupt signals to the system ? counter may be stopped while the processor is in debug state or in idle mode 9.8 real-time timer ? 32-bit free-running counter with alarm running on prescaled slck ? programmable 16-bit prescaler for slck accuracy compensation 9.9 pio controllers ? three pio controllers. pio a and b each control 32 i/o lines and pio c controls 24 i/o lines. ? fully programmable through set/clear registers ? multiplexing of two peripheral functions per i/o line ? for each i/o line (whether assigned to a peripheral or used as general-purpose i/o) ? input change interrupt ? half a clock period glitch filter ? multi-drive option enables driving in open drain ? programmable pull-up on each i/o line ? pin data status register, supplies visib ility of the level on the pin at any time
34 6222f?atarm?14-jan-11 sam7se512/256/32 ? synchronous output, provides set and clear of several i/o lines in a single write 9.10 voltage regulator controller the purpose of this controller is to select the power mode of the voltage regulator between normal mode (bit 0 is cleared) or standby mode (bit 0 is set).
35 6222f?atarm?14-jan-11 sam7se512/256/32 10. peripherals 10.1 user interface the user peripherals are mapped in the 256 mbytes of the address space between 0xf000 0000 and 0xffff efff. each peripheral is allocated 16 kbytes of address space. a complete memory map is presented in figure 8-1 on page 22 . 10.2 peripheral identifiers the sam7se512/256/32 embeds a wide range of peripherals. table 10-1 defines the peripheral identifiers of the sam7se512/256/32. unique peripheral identifiers are defined for both the advanced interrupt controller and the power management controller. note: 1. setting sysc and adc bits in the clock set/clear registers of the pmc has no effect. the sys- tem controller is continuously clocked. the ad c clock is automatically started for the first conversion. in sleep mode the adc clock is automatically stopped after each conversion. table 10-1. peripheral identifiers peripheral id peripheral mnemonic peripheral name external interrupt 0 aic advanced interrupt controller fiq 1 sysc (1) 2 pioa parallel i/o controller a 3 piob parallel i/o controller b 4 pioc parallel i/o controller c 5 spi serial peripheral interface 0 6 us0 usart 0 7 us1 usart 1 8 ssc synchronous serial controller 9 twi two-wire interface 10 pwmc pwm controller 11 udp usb device port 12 tc0 timer/counter 0 13 tc1 timer/counter 1 14 tc2 timer/counter 2 15 adc (1) analog-to digital converter 16-28 reserved 29 aic advanced interrupt controller irq0 30 aic advanced interrupt controller irq1
36 6222f?atarm?14-jan-11 sam7se512/256/32 10.3 peripheral multiplexing on pio lines the sam7se512/256/32 features three pio controllers, pioa, piob and pioc, that multiplex the i/o lines of the peripheral set. pio controller a and b control 32 lines; pio c ontroller c controls 24 lines. each line can be assigned to one of two peripheral functions, a or b. some of them can also be multiplexed with the analog inputs of the adc controller. table 10-2 on page 37 defines how the i/o lines of the peripherals a and b or the analog inputs are multiplexed on the pio controller a, b and c. the two columns ?function? and ?comments? have been inserted for the user?s own comments; they may be used to track how pins are defined in an application. note that some peripheral functions that are output only may be duplicated in the table. at reset, all i/o lines are automatically configured as input with the programmable pull-up enabled, so that the device is maintained in a static state as soon as a reset is detected.
37 6222f?atarm?14-jan-11 sam7se512/256/32 10.4 pio controller a multiplexing table 10-2. multiplexing on pio controller a pio controller a application usage i/o line peripheral a peripheral b comments function comments pa0 pwm0 a0/nbs0 high-drive pa1 pwm1 a1/nbs2 high-drive pa2 pwm2 a2 high-drive pa3 twd a3 high-drive pa 4 t w c k a 4 pa 5 r x d 0 a 5 pa 6 t x d 0 a 6 pa 7 rt s 0 a 7 pa 8 c t s 0 a 8 pa9 drxd a9 pa 1 0 d t x d a 1 0 pa11 npcs0 a11 pa12 miso a12 pa13 mosi a13 pa14 spck a14 pa 1 5 t f a 1 5 pa16 tk a16/ba0 pa17 td a17/ba1 ad0 pa18 rd nbs3/cfiow ad1 pa 1 9 rk ncs4/cfcs0 ad2 pa 2 0 rf ncs2/cfcs1 ad3 pa21 rxd1 ncs6/cfce2 pa22 txd1 ncs5/cfce1 pa23 sck1 nwr1/nbs1/cfior pa24 rts1 sda10 pa25 cts1 sdcke pa26 dcd1 ncs1/sdcs pa27 dtr1 sdwe pa28 dsr1 cas pa 2 9 r i 1 r a s pa30 irq1 d30 pa31 npcs1 d31
38 6222f?atarm?14-jan-11 sam7se512/256/32 10.5 pio controller b multiplexing table 10-3. multiplexing on pio controller b pio controller b application usage i/o line peripheral a peripheral b comments function comments pb0 tioa0 a0/nbs0 pb1 tiob0 a1/nbs2 pb2 sck0 a2 pb3 npcs3 a3 pb4 tclk0 a4 pb5 npcs3 a5 pb6 pck0 a6 pb7 pwm3 a7 pb8 adtrg a8 pb9 npcs1 a9 pb10 npcs2 a10 pb11 pwm0 a11 pb12 pwm1 a12 pb13 pwm2 a13 pb14 pwm3 a14 pb15 tioa1 a15 pb16 tiob1 a16/ba0 pb17 pck1 a17/ba1 pb18 pck2 d16 pb19 fiq d17 pb20 irq0 d18 pb21 pck1 d19 pb22 npcs3 d20 pb23 pwm0 d21 pb24 pwm1 d22 pb25 pwm2 d23 pb26 tioa2 d24 pb27 tiob2 d25 pb28 tclk1 d26 pb29 tclk2 d27 pb30 npcs2 d28 pb31 pck2 d29
39 6222f?atarm?14-jan-11 sam7se512/256/32 10.6 pio controller c multiplexing 10.7 serial peripheral interface ? supports communication with external serial devices ? four chip selects with external decoder allow communication with up to 15 peripherals ? serial memories, such as dataflash ? and 3-wire eeproms ? serial peripherals, such as adcs, dacs, lcd controllers, can controllers and sensors ? external co-processors ? master or slave serial peripheral bus interface multiplexing on pio controller c pio controller c application usage i/o line peripheral a peripheral b comments function comments pc0 d0 pc1 d1 pc2 d2 pc3 d3 pc4 d4 pc5 d5 pc6 d6 pc7 d7 pc8 d8 rts1 pc9 d9 dtr1 pc10 d10 pck0 pc11 d11 pck1 pc12 d12 pck2 pc13 d13 pc14 d14 npcs1 pc15 d15 ncs3/nandcs pc16 a18 nwait pc17 a19 nandoe pc18 a20 nandwe pc19 a21/nandale pc20 a22/reg/nandcle ncs7 pc21 nwr0/nwe/cfwe pc22 nrd/cfoe pc23 cfrnw ncs0
40 6222f?atarm?14-jan-11 sam7se512/256/32 ? 8- to 16-bit programmable data length per chip select ? programmable phase and polarity per chip select ? programmable transfer delays per chip select, between consecutive transfers and between clock and data ? programmable delay between consecutive transfers ? selectable mode fault detection ? maximum frequency at up to master clock 10.8 two wire interface ? master, multi-master and slave mode operation ? compatibility with standard two-wire serial memories ? one, two or three bytes for slave address ? sequential read/write operations ? bit rate: up to 400 kbit/s ? general call supported in slave mode 10.9 usart ? programmable baud rate generator ? 5- to 9-bit full-duplex synchronous or asynchronous serial communications ? 1, 1.5 or 2 stop bits in asynchronous mode ? 1 or 2 stop bits in synchronous mode ? parity generation and error detection ? framing error detection, overrun error detection ? msb or lsb first ? optional break generation and detection ? by 8 or by 16 over-sampling receiver frequency ? hardware handshaking rts - cts ? modem signals management dtr-dsr-dcd-ri on usart1 ? receiver time-out and transmitter timeguard ? multi-drop mode with address generation and detection ? rs485 with driver control signal ? iso7816, t = 0 or t = 1 protocols for interfacing with smart cards ? nack handling, error counter with repetition and iteration limit ?irda ? modulation and demodulation ? communication at up to 115.2 kbps ? test modes ? remote loopback, local loopback, automatic echo 10.10 serial synchronous controller ? provides serial synchronous communication links used in audio and telecom applications ? contains an independent receiver and transmitter and a common clock divider
41 6222f?atarm?14-jan-11 sam7se512/256/32 ? offers a configurable frame sync and data length ? receiver and transmitter can be programmed to start automatically or on detection of different event on the frame sync signal ? receiver and transmitter include a data signal , a clock signal and a frame synchronization signal 10.11 timer counter ? three 16-bit timer counter channels ? two output compare or one input capture per channel ? wide range of functions including: ? frequency measurement ? event counting ? interval measurement ? pulse generation ? delay timing ? pulse width modulation ? up/down capabilities ? each channel is user-configurable and contains: ? three external clock inputs ? five internal clock inputs, as defined in table 10-4 ? two multi-purpose input/output signals ? two global registers that act on all three tc channels 10.12 pwm controller ? four channels, one 16-bit counter per channel ? common clock generator, providing thirteen different clocks ? one modulo n counter providing eleven clocks ? two independent linear dividers working on modulo n counter outputs ? independent channel programming ? independent enable/disable commands ? independent clock selection ? independent period and duty cycle, with double buffering ? programmable selection of the output waveform polarity ? programmable center or left aligned output waveform table 10-4. timer counter clocks assignment tc clock input clock timer_clock1 mck/2 timer_clock2 mck/8 timer_clock3 mck/32 timer_clock4 mck/128 timer_clock5 mck/1024
42 6222f?atarm?14-jan-11 sam7se512/256/32 10.13 usb device port ? usb v2.0 full-speed compliant,12 mbits per second. ? embedded usb v2.0 full-speed transceiver ? embedded 2688-byte dual-port ram for endpoints ? eight endpoints ? endpoint 0: 64bytes ? endpoint 1 and 2: 64 bytes ping-pong ? endpoint 3: 64 bytes ? endpoint 4 and 5: 512 bytes ping-pong ? endpoint 6 and 7: 64 bytes ping-pong ? ping-pong mode (two memory banks) for isochronous and bulk endpoints ? suspend/resume logic ? integrated pull-up on ddp 10.14 analog-to-digital converter ? 8-channel adc ? 10-bit 384 ksamples/sec. or 8-bit 583 ksam ples/sec. successive approximation register adc ? 2 lsb integral non linearity, 1 lsb differential non linearity ? integrated 8-to-1 multiplexer, offering eight independent 3.3v analog inputs ? external voltage reference for better accuracy on low voltage inputs ? individual enable and disable of each channel ? multiple trigger sources ? hardware or software trigger ? external trigger pin ? timer counter 0 to 2 outputs tioa0 to tioa2 trigger ? sleep mode and conversion sequencer ? automatic wakeup on trigger and back to sleep mode after conversions of all enabled channels ? each analog input shared with digital signals
43 6222f?atarm?14-jan-11 sam7se512/256/32 11. arm7tdmi proc essor overview 11.1 overview the arm7tdmi core executes both the 32-bit arm and 16-bit thumb instruction sets, allowing the user to trade off between high performanc e and high code density.the arm7tdmi proces- sor implements von neuman architecture, using a three-stage pipeline consisting of fetch, decode, and execute stages. the main features of the arm7tdmi processor are: ? arm7tdmi based on armv4t architecture ? two instruction sets ? arm high-performance 32-bit instruction set ? thumb high code density 16-bit instruction set ? three-stage pipeline architecture ? instruction fetch (f) ? instruction decode (d) ? execute (e)
44 6222f?atarm?14-jan-11 sam7se512/256/32 11.2 arm7tdmi processor for further details on arm7tdmi, refer to the following arm documents: arm architecture reference manual (ddi 0100e) arm7tdmi technical reference manual (ddi 0210b) 11.2.1 instruction type instructions are either 32 bits long (in arm state) or 16 bits long (in thumb state). 11.2.2 data type arm7tdmi supports byte (8-bit), half-word (16-bit) and word (32-bit) data types. words must be aligned to four-byte boundaries and half words to two-byte boundaries. unaligned data access behavior depends on which instruction is used where. 11.2.3 arm7tdmi operating mode the arm7tdmi, based on arm architecture v4t, supports seven processor modes: user : the normal arm program execution state fiq : designed to support high-speed data transfer or channel process irq : used for general-purpose interrupt handling supervisor : protected mode for the operating system abort mode : implements virtual memory and/or memory protection system : a privileged user mode for the operating system undefined : supports software emulation of hardware coprocessors mode changes may be made under software control, or may be brought about by external inter- rupts or exception processing. most application programs execute in user mode. the non-user modes, or privileged modes, are entered in order to service interrupts or exceptions, or to access protecte d resources. 11.2.4 arm7tdmi registers the arm7tdmi processor has a total of 37registers: ? 31 general-purpose 32-bit registers ? 6 status registers these registers are not accessible at the same time. the processor state and operating mode determine which registers are available to the programmer. at any one time 16 registers are visible to the user. the remainder are synonyms used to speed up exception processing. register 15 is the program counter (pc) and c an be used in all instructions to reference data relative to the current instruction. r14 holds the return address after a subroutine call. r13 is used (by software convention) as a stack pointer.
45 6222f?atarm?14-jan-11 sam7se512/256/32 registers r0 to r7 are unbanked registers. this means that each of them refers to the same 32- bit physical register in all processor modes. they are general-purpose registers, with no special uses managed by the architecture, and can be used wherever an instruction allows a general- purpose register to be specified. registers r8 to r14 are banked registers. this means that each of them depends on the current mode of the processor. 11.2.4.1 modes and exception handling all exceptions have banked registers for r14 and r13. after an exception, r14 holds the return address for exception processing. this address is used to return after the exception is processed, as well as to address the instruction that caused the exception. r13 is banked across exception modes to provide each exception handler with a private stack pointer. the fast interrupt mode also banks registers 8 to 12 so that interrupt processing can begin with- out having to save these registers. table 11-1. arm7tdmi arm modes and registers layout user and system mode supervisor mode abort mode undefined mode interrupt mode fast interrupt mode r0 r0 r0 r0 r0 r0 r1 r1 r1 r1 r1 r1 r2 r2 r2 r2 r2 r2 r3 r3 r3 r3 r3 r3 r4 r4 r4 r4 r4 r4 r5 r5 r5 r5 r5 r5 r6 r6 r6 r6 r6 r6 r7 r7 r7 r7 r7 r7 r8 r8 r8 r8 r8 r8_fiq r9 r9 r9 r9 r9 r9_fiq r10 r10 r10 r10 r10 r10_fiq r11 r11 r11 r11 r11 r11_fiq r12 r12 r12 r12 r12 r12_fiq r13 r13_svc r13_abort r13_undef r13_irq r13_fiq r14 r14_svc r14_abort r14_undef r14_irq r14_fiq pc pc pc pc pc pc cpsr cpsr cpsr cpsr cpsr cpsr spsr_svc spsr_abort spsr_undef spsr_irq spsr_fiq mode-specific banked registers
46 6222f?atarm?14-jan-11 sam7se512/256/32 a seventh processing mode, system mode, does not have any banked registers. it uses the user mode registers. system mode runs tasks that require a privileged processor mode and allows them to invoke all classes of exceptions. 11.2.4.2 status registers all other processor states are held in status registers. the current operating processor status is in the current program status register (cpsr). the cpsr holds: ? four alu flags (negative, zero, carry, and overflow) ? two interrupt disable bits (one for each type of interrupt) ? one bit to indicate arm or thumb execution ? five bits to encode the current processor mode all five exception modes also have a saved program status r egister (spsr) that holds the cpsr of the task immediately preceding the exception. 11.2.4.3 exception types the arm7tdmi supports five types of exception and a privileged processing mode for each type. the types of exceptions are: ? fast interrupt (fiq) ? normal interrupt (irq) ? memory aborts (used to implement memory protection or virtual memory) ? attempted execution of an undefined instruction ? software interrupts (swis) exceptions are generated by internal and external sources. more than one exception can occur in the same time. when an exception occurs, the banked version of r14 and the spsr for the exception mode are used to save state. to return after handling the exception, the spsr is moved to the cpsr, and r14 is moved to the pc. this can be done in two ways: ? by using a data-processing instruction with the s-bit set, and the pc as the destination ? by using the load multiple with restore cpsr instruction (ldm) 11.2.5 arm instruction set overview the arm instruction set is divided into: ? branch instructions ? data processing instructions ? status register transfer instructions ? load and store instructions ? coprocessor instructions ? exception-generating instructions arm instructions can be executed conditionally. every instruction contains a 4-bit condition code field (bit[31:28]).
47 6222f?atarm?14-jan-11 sam7se512/256/32 table 11-2 gives the arm instruction mnemonic list. 11.2.6 thumb instruction set overview the thumb instruction set is a re-encoded subset of the arm instruction set. the thumb instruction set is divided into: ? branch instructions ? data processing instructions ? load and store instructions ? load and store multiple instructions ? exception-generating instruction in thumb mode, eight general-purpose registers, r0 to r7, are available that are the same physical registers as r0 to r7 when executing arm instructions. some thumb instructions also table 11-2. arm instruction mnemonic list mnemonic operation mnemonic operation mov move cdp coprocessor data processing add add mvn move not sub subtract adc add with carry rsb reverse subtract sbc subtract with carry cmp compare rsc reverse subtract with carry tst test cmn compare negated and logical and teq test equivalence eor logical exclusiv e or bic bit clear mul multiply orr logical (inclusive) or smull sign long multiply mla multiply accumulate smlal signed long multiply accumulate umull unsigned long multiply msr move to status register umla l unsigned long multiply accumulate b branch mrs move from status register bx branch and exchange bl branch and link ldr load word swi software interrupt ldrsh load signed halfword str store word ldrsb load signed byte strh store half word ldrh load half word strb store byte ldrb load byte strbt store register byte with translation ldrbt load register byte with translati on strt store register with translation ldrt load register with translation stm store multiple ldm load multiple swpb swap byte swp swap word mrc move from coprocessor mcr move to coprocessor stc store from coprocessor ldc load to coprocessor
48 6222f?atarm?14-jan-11 sam7se512/256/32 access to the program counter (arm register 15), the link register (arm register 14) and the stack pointer (arm register 13). further instru ctions allow limited access to the arm registers 8 to 15. table 11-3 gives the thumb instruction mnemonic list. table 11-3. thumb instruction mnemonic list mnemonic operation mnemonic operation mov move mvn move not add add adc add with carry sub subtract sbc subtract with carry cmp compare cmn compare negated tst test neg negate and logical and bic bit clear eor logical exclusive or orr logical (inclusive) or lsl logical shift left lsr logical shift right asr arithmetic shift right ror rotate right mul multiply b branch bl branch and link bx branch and exchange swi software interrupt ldr load word str store word ldrh load half word strh store half word ldrb load byte strb store byte ldrsh load signed halfword ldrsb load signed byte ldmia load multiple stmia store multiple push push register to stack pop pop register from stack
49 6222f?atarm?14-jan-11 sam7se512/256/32 12. debug and test features 12.1 overview the sam7se series microcontrollers feature a number of complementary debug and test capa- bilities. a common jtag/ice (embedded ice) port is used for standard debugging functions, such as downloading code and single-stepping th rough programs. the debug unit provides a two-pin uart that can be used to upload an application into internal sram. it manages the interrupt handling of the internal commtx and co mmrx signals that trace the activity of the debug communication channel. a set of dedicated deb ug and test input/out put pins gives direct access to these capabilities from a pc-based test environment. 12.2 block diagram figure 12-1. debug and test block diagram ice pdc dbgu pio drxd dtxd tst tms tck tdi jtagsel tdo boundary ta p ice/jtag ta p arm7tdmi reset and test por
50 6222f?atarm?14-jan-11 sam7se512/256/32 12.3 application examples 12.3.1 debug environment figure 12-2 shows a complete debug environment example. the ice/jtag interface is used for standard debugging functions, such as downloading code and single-stepping through the program. figure 12-2. application debug environment example ice/jtag interface host debugger ice/jtag connector rs232 connector at91samsexx at91sam7sxx-based application board terminal
51 6222f?atarm?14-jan-11 sam7se512/256/32 12.3.2 test environment figure 12-3 shows a test environment example. test vectors are sent and interpreted by the tes- ter. in this example, the ?board in test? is des igned using a number of jtag-compliant devices. these devices can be connected to form a single scan chain. figure 12-3. application test environment example 12.4 debug and test pin description chip 2 chip n chip 1 at91sam7sexx at91sam7sexx-based application board in test ice/jtag connector tester test adaptor jtag interface table 12-1. debug and test pin list pin name function type active level reset/test nrst microcontroller reset input/output low tst test mode select input high ice and jtag tck test clock input tdi test data in input tdo test data out output tms test mode select input jtagsel jtag selection input debug unit drxd debug receive data input dtxd debug transmit data output
52 6222f?atarm?14-jan-11 sam7se512/256/32 12.5 functional description 12.5.1 test pin one dedicated pin, tst, is used to define the device operating mode. the user must make sure that this pin is tied at low level to ensure normal operating conditions. other values associated with this pin are reserved for manufacturing test. 12.5.2 embeddedice ? (embedded in-circuit emulator) the arm7tdmi embeddedice is supported via the ice/jtag port.the internal state of the arm7tdmi is examined through an ice/jtag port. the arm7tdmi processor contains hardware ex tensions for advanced debugging features: ? in halt mode, a store-multiple (stm) can be inserted into the instruction pipeline. this exports the contents of the arm7tdmi registers. this data can be serially shifted out without affecting the rest of the system. ? in monitor mode, the jtag interface is used to transfer data between the debugger and a simple monitor program running on the arm7tdmi processor. there are three scan chains inside the arm7tdmi processor that support testing, debugging, and programming of the embedded ice. the scan chains are controlled by the ice/jtag port. embedded ice mode is selected when jtagsel is low. it is not possible to switch directly between ice and jtag operations. a chip reset must be performed after jtagsel is changed. for further details on the embedded ice, see the arm7tdmi (rev4) technical reference man- ual (ddi0210b). 12.5.3 debug unit the debug unit provides a two-pin (dxrd a nd txrd) usart that can be used for several debug and trace purposes and offers an ideal means for in-situ programming solutions and debug monitor communication. moreover, the association with two peripheral data controller channels permits packet handling of these tasks with processor time reduced to a minimum. the debug unit also manages the interrupt handling of the commtx and commrx signals that come from the ice and that trace the activity of the debug communication channel.the debug unit allows blockage of access to the system through the ice interface. a specific register, the debug unit chip id register, gives information about the product version and its internal configuration. for further details on the debug unit, see the debug unit section. 12.5.4 ieee 1149.1 jtag boundary scan ieee 1149.1 jtag boundary scan allows pin-level access independent of the device packaging technology. table 12-2. at91sam7sexx chip ids chip name chip id at91sam7se32 0x27280340 at91sam7se256 0x272a0940 at91sam7se512 0x272a0a40
53 6222f?atarm?14-jan-11 sam7se512/256/32 ieee 1149.1 jtag boundary scan is enabled when jtagsel is high. the sample, extest and bypass functions are implemented. in ic e debug mode, the arm proce ssor responds with a non-jtag ch ip id that identifi es the processo r to the ice system. this is not ieee 1149.1 jtag-compliant. it is not possible to switch directly between jtag and ice operations. a chip reset must be per- formed after jtagsel is changed. a boundary-scan descriptor language (bsdl) file is provided to set up test. 12.5.4.1 jtag boundary-scan register the boundary-scan register (bsr) contains 353 bits that correspond to active pins and associ- ated control signals. each at91sam7sexx input/output pin corresponds to a 3-bit register in the bsr. the output bit contains data that can be fo rced on the pad. the input bit fac ilitates the observ ability of data applied to the pad. the control bit selects the direction of the pad. for more information, please refer to bdsl files which are available for the sam7se series.
54 6222f?atarm?14-jan-11 sam7se512/256/32 12.5.5 id code register access: read-only ? version[31:28]: product version number set to 0x0. ? part number[27:12]: product part number ? manufacturer identity[11:1] set to 0x01f. ? bit[0] required by ieee std. 1149.1. set to 0x1. 31 30 29 28 27 26 25 24 version part number 23 22 21 20 19 18 17 16 part number 15 14 13 12 11 10 9 8 part number manufacturer identity 76543210 manufacturer identity 1 chip name chip id at91sam7se32 0x5b1d at91sam7se256 0x5b15 at91sam7se512 0x5b14 chip name jtag id code at91sam7se32 05b1_d03f at91sam7se256 05b1_503f at91sam7se512 05b1_403f
55 6222f?atarm?14-jan-11 sam7se512/256/32 13. reset controller (rstc) the reset controller (rstc), based on power-on reset cells, handles all the resets of the sys- tem without any external components. it reports which reset occurred last. the reset controller also drives independently or simultaneously the external reset and the peripheral and processor resets. a brownout detection is also available to preven t the processor from falling into an unpredictable state. 13.1 block diagram figure 13-1. reset controller block diagram nrst startup counter proc_nreset wd_fault periph_nreset slck reset state manager reset controller brown_out bod_rst_en rstc_irq nrst manager exter_nreset nrst_out main supply por wdrproc user_reset brownout manager bod_reset
56 6222f?atarm?14-jan-11 sam7se512/256/32 13.2 functional description 13.2.1 reset controller overview the reset controller is made up of an nrst manager, a brownout manager, a startup counter and a reset state manager. it runs at slow clock and generates the following reset signals: ? proc_nreset: processor reset line. it also resets the watchdog timer. ? periph_nreset: affects the whole set of embedded peripherals. ? nrst_out: drives the nrst pin. these reset signals are asserted by the reset cont roller, either on external events or on soft- ware action. the reset state manager controls the generation of reset signals and provides a signal to the nrst manager when an assertion of the nrst pin is required. the nrst manager shapes the nrst assertion du ring a programmable ti me, thus controlling external device resets. the startup counter waits for the complete crystal oscillator startu p. the wait dela y is given by the crystal oscillator startup time maximum value that can be foun d in the section crystal oscil- lator characteristics in the electrical characteristics section of the product documentation. 13.2.2 nrst manager the nrst manager samples the nrst input pin and drives this pin low when required by the reset state manager. figure 13-2 shows the block diagram of the nrst manager. figure 13-2. nrst manager 13.2.2.1 nrst signal or interrupt the nrst manager samples the nrst pin at slow clock speed. when the line is detected low, a user reset is reported to the reset state manager. however, the nrst manager can be programmed to not trigger a reset when an assertion of nrst occurs. writing the bit ursten at 0 in rstc_mr disables the user reset trigger. the level of the pin nrst can be read at any ti me in the bit nrstl (nrst level) in rstc_sr. as soon as the pin nrst is asserted, the bit ur sts in rstc_sr is set. this bit clears only when rstc_sr is read. external reset timer ursts ursten erstl exter_nreset urstien rstc_mr rstc_mr rstc_mr rstc_sr nrstl nrst_out nrst rstc_irq other interrupt sources user_reset
57 6222f?atarm?14-jan-11 sam7se512/256/32 the reset controller can also be programmed to generate an interrupt instead of generating a reset. to do so, the bit urstien in rstc_mr must be written at 1. 13.2.2.2 nrst external reset control the reset state manager asserts the signal ext_nreset to assert the nrst pin. when this occurs, the ?nrst_out? signal is driven low by the nrst manager for a time programmed by the field erstl in rstc_mr. this assertion duration, named externa l_reset_length, lasts 2 (erstl+1) slow clock cycles. this gives the approx imate duration of an assertion between 60 s and 2 seconds. note that erstl at 0 defines a two-cycle duration for the nrst pulse. this feature allows the reset controller to shape the nrst pin level, and thus to guarantee that the nrst line is driven low for a time compliant with potential external devices connected on the system reset. 13.2.3 brownout manager brownout detection prevents the processor from falling into an unpredictable state if the power supply drops below a certain level. when vddcore drops below the brownout threshold, the brownout manager requests a brownout re set by asserting the bod_reset signal. the programmer can disable the brownout reset by setting low the bod_rst_en input signal, i.e.; by locking the corresponding general-purpose nvm bit in the flash. when the brownout reset is disabled, no reset is performed. instead, the br ownout detection is reported in the bit bodsts of rstc_sr. bodsts is set and clears only when rstc_sr is read. the bit bodsts can trigger an interrupt if the bit bodien is set in the rstc_mr. at factory, the brownout reset is disabled. figure 13-3. brownout manager 13.2.4 reset states the reset state manager handles the different reset sources and generates the internal reset signals. it reports the reset status in the field rsttyp of the status register (rstc_sr). the update of the field rsttyp is performed when the processor reset is released. rstc_irq brown_out bod_reset bod_rst_en bodien rstc_mr bodsts rstc_sr other interrupt sources
58 6222f?atarm?14-jan-11 sam7se512/256/32 13.2.4.1 power-up reset when vddcore is powered on, the main supply por cell output is filtered with a start-up counter that operates at slow clock. the purpose of this counter is to ensure that the slow clock oscillator is stable before starting up the device. the startup time, as shown in figure 13-4 , is hardcoded to comply wit h the slow clock oscillator startup time. after the startup time, the reset signals are released and the field rsttyp in rstc_sr reports a power-up reset. when vddcore is detected low by the main suppl y por cell, all reset signals are asserted immediately. figure 13-4. power-up reset 13.2.4.2 user reset the user reset is entered when a low level is detected on the nrst pin and the bit ursten in rstc_mr is at 1. the nrst inpu t signal is resynchronized with slck to insure proper behav- ior of the system. the user reset is entered as soon as a low level is detected on nrst. the processor reset and the peripheral reset are asserted. the user reset is left when nrst rises, afte r a two-cycle resynchroniza tion time and a three- cycle processor startup. the processor clock is re-enabled as soon as nrst is confirmed high. when the processor reset signal is released, the rsttyp field of the status register (rstc_sr) is loaded with the value 0x4, indicating a user reset. the nrst manager guarantees that the nrst line is asserted for external_reset_length slow clock cycles, as programmed in the field erstl. how- ever, if nrst does not rise after extern al_reset_length because it is driven low externally, the internal reset lines remain asserted until nrst actually rises. slck periph_nreset proc_nreset main supply por output nrst (nrst_out) external reset length = 2 cycles startup time mck processor startup = 3 cycles any freq.
59 6222f?atarm?14-jan-11 sam7se512/256/32 figure 13-5. user reset state 13.2.4.3 brownout reset when the brown_out/bod_reset signal is asserted, the reset state manager immediately enters the brownout reset. in this state, the processo r, the peripheral and the external reset lines are asserted. the brownout reset is left 3 slow clock cycles after the rising edge of brown_out/bod_reset after a two-cycle resynchronization. an external reset is also triggered. when the processor reset is released, the field rsttyp in rstc_sr is loaded with the value 0x5, thus indicating that the last reset is a brownout reset. slck periph_nreset proc_nreset nrst nrst (nrst_out) >= external reset length mck processor startup = 3 cycles any freq. resynch. 2 cycles rsttyp any xxx resynch. 2 cycles 0x4 = user reset
60 6222f?atarm?14-jan-11 sam7se512/256/32 figure 13-6. brownout reset state 13.2.4.4 software reset the reset controller offers several commands used to assert the different reset signals. these commands are performed by writing the control register (rstc_cr) with the following bits at 1: ? procrst: writing procrst at 1 resets the processor and the watchdog timer. ? perrst: writing perrst at 1 resets all the embedded peripherals, including the memory system and, in particular, the remap command. the peripheral reset is generally used for debug purposes. except for debug purposes, the perrst must always be used in conjunction with a procrst (perrst and procrst both set at 1 simultaneously). ? extrst: writing extrst at 1 asserts low the nrst pin during a time defined by the field erstl in the mode register (rstc_mr). the software reset is entered if at least one of these bits is set by the software. all these com- mands can be performed independently or simultaneously. the software reset lasts 3 slow clock cycles. the internal reset signals are asserted as soon as the register write is performed. this is detected on the master clock (mck). they are released when the software reset is left, i.e.; syn- chronously to slck. if extrst is set, the nrst_out signal is asserted depending on the programming of the field erstl. however, the result ing falling edge on nrst does not lead to a user reset. if and only if the procrst bit is set, the reset controller reports the software status in the field rsttyp of the status register (rstc_sr). other software resets are not reported in rsttyp. slck periph_nreset proc_nreset brown_out or bod_reset nrst (nrst_out) external reset length 8 cycles (erstl=2) mck processor startup = 3 cycles any freq. rsttyp any xxx 0x5 = brownout reset resynch. 2 cycles
61 6222f?atarm?14-jan-11 sam7se512/256/32 as soon as a software operation is detected, the bit srcmp (software reset command in progress) is set in the status register (rstc_sr). it is cleared as soon as the software reset is left. no other software reset can be performed while the srcmp bit is set, and writing any value in rstc_cr ha s no effect. figure 13-7. software reset 13.2.4.5 watchdog reset the watchdog reset is entered when a watchdog fault occurs. this state lasts 3 slow clock cycles. when in watchdog reset, assertion of the reset signals depends on the wdrproc bit in wdt_mr: ? if wdrproc is 0, the processor reset and the peripheral reset are asserted. the nrst line is also asserted, depending on the programming of the field erstl. however, the resulting low level on nrst does not result in a user reset state. ? if wdrproc = 1, only the processor reset is asserted. the watchdog timer is reset by the proc_nreset si gnal. as the watchdog fault always causes a processor reset if wdrsten is set, the watchd og timer is always reset after a watchdog reset, and the watchdog is enabled by default and with a period set to a maximum. when the wdrsten in wdt_mr bit is reset, the watchdog fault has no impact on the reset controller. slck periph_nreset if perrst=1 proc_nreset if procrst=1 write rstc_cr nrst (nrst_out) if extrst=1 external reset length 8 cycles (erstl=2) mck processor startup = 3 cycles any freq. rsttyp any xxx 0x3 = software reset resynch. 1 cycle srcmp in rstc_sr
62 6222f?atarm?14-jan-11 sam7se512/256/32 figure 13-8. watchdog reset 13.2.5 reset state priorities the reset state manager manages the following priorities between the different reset sources, given in descending order: ? power-up reset ?brownout reset ? watchdog reset ? software reset ? user reset particular cases are listed below: ? when in user reset: ? a watchdog event is impossible because the watchdog timer is being reset by the proc_nreset signal. ? a software reset is impossible, since the processor reset is being activated. ? when in software reset: ? a watchdog event has priority over the current state. ? the nrst has no effect. ? when in watchdog reset: ? the processor reset is active and so a software reset cannot be programmed. ? a user reset cannot be entered. 13.2.6 reset controller status register the reset controller status register (rstc_sr) provides several status fields: only if wdrproc = 0 slck periph_nreset proc_nreset wd_fault nrst (nrst_out) external reset length 8 cycles (erstl=2) mck processor startup = 3 cycles any freq. rsttyp any xxx 0x2 = watchdog reset
63 6222f?atarm?14-jan-11 sam7se512/256/32 ? rsttyp field: this field gives the type of the last reset, as explained in previous sections. ? srcmp bit: this field indicates that a software reset command is in progress and that no further software reset should be performed until the end of the current one. this bit is automatically cleared at the end of the current software reset. ? nrstl bit: the nrstl bit of the status register gives the level of the nrst pin sampled on each mck rising edge. ? ursts bit: a high-to-low transition of the nrst pin sets the ursts bit of the rstc_sr register. this transition is also detected on the master clock (mck) rising edge (see figure 13-9 ). if the user reset is disabled (ursten = 0) and if the interruption is enabled by the urstien bit in the rstc_mr register, the ursts bit triggers an interrupt. reading the rstc_sr status register resets the ursts bit and clears the interrupt. ? bodsts bit: this bit indicates a brownout detection when the brownout reset is disabled (bod_rst_en = 0). it triggers an interrupt if the bit bodien in the rstc_mr register enables the interrupt. reading the rstc_sr register resets the bodsts bit and clears the interrupt. figure 13-9. reset controller status and interrupt 13.3 reset controller (rstc) user interface mck nrst nrstl 2 cycle resynchronization 2 cycle resynchronization ursts read rstc_sr peripheral access rstc_irq if (ursten = 0) and (urstien = 1) table 13-1. reset controller (rstc) register mapping offset register name access reset value 0x00 control register rstc_cr write-only - 0x04 status register rs tc_sr read-only 0x0000_0000 0x08 mode register rstc_mr read/write 0x0000_0000
64 6222f?atarm?14-jan-11 sam7se512/256/32 13.3.1 reset controller control register name: rstc_cr access: write-only ? procrst: processor reset 0 = no effect. 1 = if key is correct, resets the processor. ? perrst: peripheral reset 0 = no effect. 1 = if key is correct, resets the peripherals. ? extrst: external reset 0 = no effect. 1 = if key is correct, asserts the nrst pin. ?key: password should be written at value 0xa5. writing any other value in this field aborts the write operation. 31 30 29 28 27 26 25 24 key 23 22 21 20 19 18 17 16 ???????? 15 14 13 12 11 10 9 8 ?????? ? 76543210 ????extrstperrst?procrst
65 6222f?atarm?14-jan-11 sam7se512/256/32 13.3.2 reset controller status register name: rstc_sr access: read-only ? ursts: user reset status 0 = no high-to-low edge on nrst happened since the last read of rstc_sr. 1 = at least one high-to-low transition of nrst has been detected since the last read of rstc_sr. ? bodsts: brownout detection status 0 = no brownout high-to-low transition happened since the last read of rstc_sr. 1 = a brownout high-to-low transition has be en detected since the last read of rstc_sr. ? rsttyp: reset type reports the cause of the last processor reset. r eading this rstc_sr does not reset this field. ? nrstl: nrst pin level registers the nrst pin level at master clock (mck). ? srcmp: software reset command in progress 0 = no software command is being performed by the reset controller. the reset controller is ready for a software command. 1 = a software reset command is being performed by the reset controller. the reset controller is busy. 13.3.3 reset controller mode register name: rstc_mr 31 30 29 28 27 26 25 24 ???????? 23 22 21 20 19 18 17 16 ??????srcmpnrstl 15 14 13 12 11 10 9 8 ????? rsttyp 76543210 ??????bodstsursts rsttyp reset type comments 0 0 0 power-up reset vddcore rising 0 1 0 watchdog reset watchdog fault occurred 0 1 1 software reset processor re set required by the software 1 0 0 user reset nrst pin detected low 1 0 1 brownout reset brownout reset occurred
66 6222f?atarm?14-jan-11 sam7se512/256/32 access: read/write ? ursten: user reset enable 0 = the detection of a low level on the pin nrst does not generate a user reset. 1 = the detection of a low level on the pin nrst triggers a user reset. ? urstien: user reset interrupt enable 0 = usrts bit in rstc_sr at 1 has no effect on rstc_irq. 1 = usrts bit in rstc_sr at 1 asserts rstc_irq if ursten = 0. ? bodien: brownout detection interrupt enable 0 = bodsts bit in rstc_sr at 1 has no effect on rstc_irq. 1 = bodsts bit in rstc_sr at 1 asserts rstc_irq. ? erstl: external reset length this field defines the external reset length. the external reset is asserted during a time of 2 (erstl+1) slow clock cycles. this allows assertion duration to be programmed between 60 s and 2 seconds. ?key: password should be written at value 0xa5. writing any other value in this field aborts the write operation. 31 30 29 28 27 26 25 24 key 23 22 21 20 19 18 17 16 ???????bodien 15 14 13 12 11 10 9 8 ???? erstl 76543210 ? ? urstien ? ? ? ursten
67 6222f?atarm?14-jan-11 sam7se512/256/32 14. real-time timer (rtt) 14.1 overview the real-time timer is built around a 32-bit coun ter and used to count elapsed seconds. it gen- erates a periodic interrupt or/and triggers an alarm on a programmed value. 14.2 block diagram figure 14-1. real-time timer 14.3 functional description the real-time timer is used to count elapsed seconds. it is built around a 32-bit counter fed by slow clock divided by a programmable 16-bit va lue. the value can be programmed in the field rtpres of the real-time mode register (rtt_mr). programming rtpres at 0x00008000 corresponds to feeding the real-time counter with a 1 hz signal (if the slow clock is 32.768 hz). the 32-bit counter can count up to 2 32 seconds, corre- sponding to more than 136 years, then roll over to 0. the real-time timer can also be used as a free -running timer with a lower time-base. the best accuracy is achieved by writing rtpres to 3. programming rtpres to 1 or 2 is possible, but may result in losing status events because the stat us register is cleared two slow clock cycles after read. thus if the rtt is configured to trigger an interrupt, the interrupt occurs during 2 slow clock cycles after reading rtt_sr. to prevent se veral executions of the interrupt handler, the interrupt must be disabled in the interrupt handl er and re-enabled when the status register is clear. slck rtpres rttinc alms 16-bit divider 32-bit counter almv = crtv rtt_mr rtt_vr rtt_ar rtt_sr rttincien rtt_mr 0 10 almien rtt_int rtt_mr set set rtt_sr read rtt_sr reset reset rtt_mr reload rtt_alarm rttrst rtt_mr rttrst
68 6222f?atarm?14-jan-11 sam7se512/256/32 the real-time timer value (crtv) can be read at any time in the register rtt_vr (real-time value register). as this value can be updated asynchronously from the master clock, it is advis- able to read this register twice at the same value to improve accuracy of the returned value. the current value of the counter is compared with the value written in the alarm register rtt_ar (real-time alarm register). if the counter value matches the alarm, the bit alms in rtt_sr is set. the alarm register is set to its maximum value, corresponding to 0xffff_ffff, after a reset. the bit rttinc in rtt_sr is set each time the real-time timer counter is incremented. this bit can be used to start a periodic interrupt, the period being one second when the rtpres is pro- grammed with 0x8000 and slow clock equal to 32.768 hz. reading the rtt_sr status register resets the rttinc and alms fields. writing the bit rttrst in rtt_mr immediately re loads and restarts the clock divider with the new programmed value. this also resets the 32-bit counter. note: because of the asynchronism between the slow clock (sclk) and the system clock (mck): 1) the restart of the counter and the reset of the rtt_vr current value register is effective only 2 slow clock cycles after the write of th e rttrst bit in the rtt_mr register. 2) the status register fl ags reset is taken into account only 2 sl ow clock cycles after the read of the rtt_sr (status register). figure 14-2. rtt counting prescaler almv almv-1 0 almv+1 0 rtpres - 1 rtt apb cycle read rtt_sr alms (rtt_sr) apb interface mck rttinc (rtt_sr) almv+2 almv+3 ... apb cycle
69 6222f?atarm?14-jan-11 sam7se512/256/32 14.4 real-time timer (rtt) user interface table 14-1. real-time timer (rtt) register mapping offset register name access reset value 0x00 mode register rtt_mr read/write 0x0000_8000 0x04 alarm register rtt_ar read/write 0xffff_ffff 0x08 value register rtt_vr read-only 0x0000_0000 0x0c status register rtt_sr read-only 0x0000_0000
70 6222f?atarm?14-jan-11 sam7se512/256/32 14.4.1 real-time timer mode register name: rtt_mr access: read/write ? rtpres: real-time timer prescaler value defines the number of slck periods required to increment the real-time timer. rtpres is defined as follows: rtpres = 0: the prescaler period is equal to 2 16 rtpres 0: the prescaler period is equal to rtpres. ? almien: alarm interrupt enable 0 = the bit alms in rtt_sr has no effect on interrupt. 1 = the bit alms in rtt_sr asserts interrupt. ? rttincien: real-time timer increment interrupt enable 0 = the bit rttinc in rtt_sr has no effect on interrupt. 1 = the bit rttinc in r tt_sr asserts interrupt. ? rttrst: real-time timer restart 1 = reloads and restarts the clock divider with the new programmed value. this also resets the 32-bit counter. 31 30 29 28 27 26 25 24 ???????? 23 22 21 20 19 18 17 16 ?????rttrstrttincienalmien 15 14 13 12 11 10 9 8 rtpres 76543210 rtpres
71 6222f?atarm?14-jan-11 sam7se512/256/32 14.4.2 real-time timer alarm register name: rtt_ar access: read/write ? almv: alarm value defines the alarm value (almv+1) compared with the real-time timer. 14.4.3 real-time timer value register name: rtt_vr access: read-only ? crtv: current real-time value returns the current value of the real-time timer. 31 30 29 28 27 26 25 24 almv 23 22 21 20 19 18 17 16 almv 15 14 13 12 11 10 9 8 almv 76543210 almv 31 30 29 28 27 26 25 24 crtv 23 22 21 20 19 18 17 16 crtv 15 14 13 12 11 10 9 8 crtv 76543210 crtv
72 6222f?atarm?14-jan-11 sam7se512/256/32 14.4.4 real-time timer status register name: rtt_sr access: read-only ? alms: real-time alarm status 0 = the real-time alarm has not occurred since the last read of rtt_sr. 1 = the real-time alarm occurred since the last read of rtt_sr. ? rttinc: real-time timer increment 0 = the real-time timer has not been incremented since the last read of the rtt_sr. 1 = the real-time timer has been incremented since the last read of the rtt_sr. 31 30 29 28 27 26 25 24 ???????? 23 22 21 20 19 18 17 16 ???????? 15 14 13 12 11 10 9 8 ???????? 76543210 ??????rttincalms
73 6222f?atarm?14-jan-11 sam7se512/256/32 15. watchdog timer (wdt) 15.1 overview the watchdog timer can be used to prevent system lock-up if the software becomes trapped in a deadlock. it features a 12-bit down counter that allows a watchdog period of up to 16 seconds (slow clock at 32.768 khz). it can generate a general reset or a processor reset only. in addition, it can be stopped while the processor is in debug mode or idle mode. 15.2 block diagram figure 15-1. watchdog timer block diagram = 0 10 set reset read wdt_sr or reset wdt_fault (to reset controller) set reset wdfien wdt_int wdt_mr slck 1/128 12-bit down counter current value wdd wdt_mr <= wdd wdv wdrstt wdt_mr wdt_cr reload wdunf wderr reload write wdt_mr wdt_mr wdrsten
74 6222f?atarm?14-jan-11 sam7se512/256/32 15.3 functional description the watchdog timer can be used to prevent system lock-up if the software becomes trapped in a deadlock. it is supplied with vddcore. it re starts with initial values on processor reset. the watchdog is built around a 12-bit down counter, which is loaded with the value defined in the field wdv of the mode register (wdt_mr). the watchdog timer uses the slow clock divided by 128 to establish the maximum watchdog period to be 16 seconds (with a typical slow clock of 32.768 khz). after a processor reset, the value of wdv is 0xfff, corresponding to the maximum value of the counter with the external reset generation enabled (field wdrsten at 1 after a backup reset). this means that a default watchdog is running at reset, i.e., at power-up. the user must either disable it (by setting the wddis bit in wd t_mr) if he does not expect to use it or must reprogram it to meet the maximum watchdog period the application requires. the watchdog mode register (wdt_mr) can be written only once. only a processor reset resets it. writing the wdt_mr register reloads the timer with the newly programmed mode parameters. in normal operation, the user reloads the watchdog at regular intervals before the timer under- flow occurs, by writing the control register (wdt_cr) with the bit wdrstt to 1. the watchdog counter is then immediately reloaded from wdt_mr and restarted, and the slow clock 128 divider is reset and restarted. the wdt_cr register is write-protected. as a result, writing wdt_cr without the correct hard-coded key has no effect. if an underflow does occur, the ?wdt_fault? signal to the reset controller is asserted if the bit wdrsten is set in the mode register (wdt_mr). moreover, the bit wdunf is set in the watchdog status register (wdt_sr). to prevent a software deadlock that continuously triggers the watchdog, the reload of the watchdog must occur while the watchdog count er is within a window between 0 and wdd, wdd is defined in the watchdog mode register wdt_mr. any attempt to restart the watchdog while the watchdog counter is between wdv and wdd results in a watchdog error, even if the watchdog is disabled. the bit wderr is updated in the wdt_sr and the ?wdt_fault? signal to the reset controller is asserted. note that this feature can be disabled by programming a wdd value greater than or equal to the wdv value. in such a configuration, restarti ng the watchdog timer is permitted in the whole range [0; wdv] and does not generate an error. this is the default configuration on reset (the wdd and wdv values are equal). the status bits wdunf (watchdog underflow ) and wderr (watchdog error) trigger an inter- rupt, provided the bit wdfien is set in the mode register. the signal ?wdt_fault? to the reset controller causes a watchdog reset if the wdrsten bit is set as already explained in the reset controller programmer datasheet. in that case, the processor and the watchdog timer are reset, and the wderr and wdunf flags are reset. if a reset is generated or if wdt_sr is read, the status bits are reset, the interrupt is cleared, and the ?wdt_fault? signal to the reset controller is deasserted. writing the wdt_mr reloads and restarts the down counter. while the processor is in debug state or in idle mode, the counter may be stopped depending on the value programmed for the bits wdidlehlt and wddbghlt in the wdt_mr.
75 6222f?atarm?14-jan-11 sam7se512/256/32 figure 15-2. watchdog behavior 0 wdv wdd wdt_cr = wdrstt watchdog fault normal behavior watchdog error watchdog underflow fff if wdrsten is 1 if wdrsten is 0 forbidden window permitted window
76 6222f?atarm?14-jan-11 sam7se512/256/32 15.4 watchdog timer (wdt) user interface 15.4.1 watchdog timer control register name: wdt_cr access: write-only ? wdrstt: watchdog restart 0: no effect. 1: restarts the watchdog. ?key: password should be written at value 0xa5. writing any other value in this field aborts the write operation. table 15-1. watchdog timer (wdt) register mapping offset register name access reset value 0x00 control register wdt_cr write-only - 0x04 mode register wdt_mr read/write once 0x3fff_2fff 0x08 status register wdt_sr read-only 0x0000_0000 31 30 29 28 27 26 25 24 key 23 22 21 20 19 18 17 16 ???????? 15 14 13 12 11 10 9 8 ???????? 76543210 ???????wdrstt
77 6222f?atarm?14-jan-11 sam7se512/256/32 15.4.2 watchdog timer mode register name: wdt_mr access: read/write once ? wdv: watchdog counter value defines the value loaded in the 12-bit watchdog counter. ? wdfien: watchdog fault interrupt enable 0: a watchdog fault (underflow or error) has no effect on interrupt. 1: a watchdog fault (underflow or error) asserts interrupt. ? wdrsten: watchdog reset enable 0: a watchdog fault (underflow or error) has no effect on the resets. 1: a watchdog fault (underflow or error) triggers a watchdog reset. ? wdrproc: watchdog reset processor 0: if wdrsten is 1, a watchdog fault (underflow or error) activates all resets. 1: if wdrsten is 1, a watchdog fault (underflow or error) activates the processor reset. ? wdd: watchdog delta value defines the permitted range for reloading the watchdog timer. if the watchdog timer value is less than or equal to w dd, writing wdt_cr with wdrs tt = 1 restarts the timer. if the watchdog timer value is greater than wdd, writing wdt_cr with wdrstt = 1 causes a watchdog error. ? wddbghlt: watchdog debug halt 0: the watchdog runs when the processor is in debug state. 1: the watchdog stops when the processor is in debug state. ? wdidlehlt: watchdog idle halt 0: the watchdog runs when the system is in idle mode. 1: the watchdog stops when the system is in idle state. 31 30 29 28 27 26 25 24 ? ? wdidlehlt wddbghlt wdd 23 22 21 20 19 18 17 16 wdd 15 14 13 12 11 10 9 8 wddis wdrproc wdrsten wdfien wdv 76543210 wdv
78 6222f?atarm?14-jan-11 sam7se512/256/32 ? wddis: watchdog disable 0: enables the watchdog timer. 1: disables the watchdog timer. 15.4.3 watchdog timer status register name: wdt_sr access: read-only ? wdunf: watchdog underflow 0: no watchdog underflow occurred since the last read of wdt_sr. 1: at least one watchdog underflow occurred since the last read of wdt_sr. ? wderr: watchdog error 0: no watchdog error occurred since the last read of wdt_sr. 1: at least one watchdog error occurred since the last read of wdt_sr. 31 30 29 28 27 26 25 24 ???????? 23 22 21 20 19 18 17 16 ???????? 15 14 13 12 11 10 9 8 ???????? 76543210 ??????wderrwdunf
79 6222f?atarm?14-jan-11 sam7se512/256/32 16. periodic interval timer (pit) 16.1 overview the periodic interval timer (pit) provides the operating system?s scheduler interrupt. it is designed to offer maximum accuracy and efficient management, even for systems with long response time. 16.2 block diagram figure 16-1. periodic interval timer 20-bit counter mck/16 piv pit_mr cpiv pit_pivr picnt 12-bit adder 0 0 read pit_pivr cpiv picnt pit_piir pits pit_sr set reset pitien pit_mr pit_irq 1 0 1 0 mck prescaler = ?
80 6222f?atarm?14-jan-11 sam7se512/256/32 16.3 functional description the periodic interval timer aims at providing pe riodic interrupts for use by operating systems. the pit provides a programmable overflow counter and a reset-on-read feature. it is built around two counters: a 20-bit cpiv counter and a 12-bit picnt counter. both counters work at master clock /16. the first 20-bit cpiv counter increments from 0 up to a programmable overflow value set in the field piv of the mode register (pit_mr). when the counter cpiv reaches this value, it resets to 0 and increments the periodic interval counter, picnt. the status bit pits in the status regis- ter (pit_sr) rises and triggers an interrupt, provided the interrupt is enabled (pitien in pit_mr). writing a new piv value in pit_mr does not reset/restart the counters. when cpiv and picnt values are obtained by reading the periodic interval value register (pit_pivr), the overflow counter (picnt) is rese t and the pits is cleared, thus acknowledging the interrupt. the value of picnt gives the number of periodic intervals elapsed since the last read of pit_pivr. when cpiv and picnt values are obtained by reading the periodic interval image register (pit_piir), there is no effect on the counters cpiv and picnt, nor on the bit pits. for exam- ple, a profiler can read pit_piir without clearing any pending interrupt, whereas a timer interrupt clears the interrupt by reading pit_pivr. the pit may be enabled/disabled using the pite n bit in the pit_mr register (disabled on reset). the piten bit only becomes effective when the cpiv value is 0. figure 16-2 illustrates the pit counting. after the pit enable bit is re set (piten= 0), the cpiv goes on counting until the piv value is reached, and is then reset. pit restarts counting, only if the piten is set again. the pit is stopped when the core enters debug state.
81 6222f?atarm?14-jan-11 sam7se512/256/32 figure 16-2. enabling/disabling pit with piten mck prescaler piv piv - 1 0 piten 10 0 15 cpiv 1 restarts mck prescaler 0 1 apb cycle read pit_pivr 0 picnt pits (pit_sr) mck apb interface apb cycle
82 6222f?atarm?14-jan-11 sam7se512/256/32 16.4 periodic interval time r (pit) user interface table 16-1. periodic interval timer (pit) register mapping offset register name access reset value 0x00 mode register pit_mr read/write 0x000f_ffff 0x04 status register pit_sr read-only 0x0000_0000 0x08 periodic interval value register pit_pivr read-only 0x0000_0000 0x0c periodic interval image register pit_piir read-only 0x0000_0000
83 6222f?atarm?14-jan-11 sam7se512/256/32 16.4.1 periodic interval timer mode register name: pit_mr access: read/write ? piv: periodic interval value defines the value compared with the primary 20-bit counter of the periodic interval timer (cpiv). the period is equal to (piv + 1). ? piten: period interval timer enabled 0 = the periodic interval timer is disabled when the piv value is reached. 1 = the periodic interval timer is enabled. ? pitien: periodic interval timer interrupt enable 0 = the bit pits in pit_sr has no effect on interrupt. 1 = the bit pits in pit_sr asserts interrupt. 16.4.2 periodic interval timer status register name: pit_sr access: read-only ? pits: periodic interval timer status 0 = the periodic interval timer has not reached piv since the last read of pit_pivr. 1 = the periodic interval timer has reached piv since the last read of pit_pivr. 31 30 29 28 27 26 25 24 ??????pitienpiten 23 22 21 20 19 18 17 16 ???? piv 15 14 13 12 11 10 9 8 piv 76543210 piv 31 30 29 28 27 26 25 24 ???????? 23 22 21 20 19 18 17 16 ???????? 15 14 13 12 11 10 9 8 ???????? 76543210 ???????pits
84 6222f?atarm?14-jan-11 sam7se512/256/32 16.4.3 periodic interval timer value register name: pit_pivr access: read-only reading this register clears pits in pit_sr. ? cpiv: current periodic interval value returns the current value of the periodic interval timer. ? picnt: periodic interval counter returns the number of occurrences of periodic intervals since the last read of pit_pivr. 16.4.4 periodic interval timer image register name: pit_piir access: read-only ? cpiv: current periodic interval value returns the current value of the periodic interval timer. ? picnt: periodic interval counter returns the number of occurrences of periodic intervals since the last read of pit_pivr. 31 30 29 28 27 26 25 24 picnt 23 22 21 20 19 18 17 16 picnt cpiv 15 14 13 12 11 10 9 8 cpiv 76543210 cpiv 31 30 29 28 27 26 25 24 picnt 23 22 21 20 19 18 17 16 picnt cpiv 15 14 13 12 11 10 9 8 cpiv 76543210 cpiv
85 6222f?atarm?14-jan-11 sam7se512/256/32 17. voltage regulator mode controller (vreg) 17.1 overview the voltage regulator mode controller contains one read/write register, the voltage regulator mode register. its offset is 0x60 with respect to the system controller offset. this register controls the voltage regulator mode. setting pstdby (bit 0) puts the voltage regulator in standby mode or low-power mode. on reset, the pstdby is reset, so as to wake up the voltage regulator in normal mode.
86 6222f?atarm?14-jan-11 sam7se512/256/32 17.2 voltage regulator power cont roller (vreg) user interface 17.2.1 voltage regulator mode register name: vreg_mr access: read/write ? pstdby: periodic interval value 0 = voltage regulator in normal mode. 1 = voltage regulator in standby mode (low-power mode). table 17-1. voltage regulator power controller register mapping offset register name access reset value 0x60 voltage regulator mode register vreg_mr read/write 0x0 31 30 29 28 27 26 25 24 ???????? 23 22 21 20 19 18 17 16 ???????? 15 14 13 12 11 10 9 8 ???????? 76543210 ???????pstdby
87 6222f?atarm?14-jan-11 sam7se512/256/32 18. memory controller (mc) 18.1 overview the memory controller (mc) manages the asb bus and controls accesses requested by the masters, typically the arm7tdmi processor and the peripheral dma controller. it features a simple bus arbiter, an address decoder, an abort status, a misalignment detector and an embedded flash controller. in addition, the mc contains a memory protection unit (mpu) con- sisting of 16 areas that can be protected against write and/or user accesses. access to peripherals can be protected in the same way. 18.2 block diagram figure 18-1. memory controlle r block diagram arm7tdmi processor bus arbiter peripheral dma controller memory controller abort asb abort status address decoder user interface peripheral 0 peripheral 1 internal ram apb apb bridge misalignment detector from master to slave peripheral n embedded flash controller internal flash memory protection unit external bus interface
88 6222f?atarm?14-jan-11 sam7se512/256/32 18.3 functional description the memory controller handles the internal asb bus and arbitrates the accesses of both masters. it is made up of: ? a bus arbiter ? an address decoder ? an abort status ? a misalignment detector ? a memory protection unit ? an embedded flash controller the mc handles only little-endian mode accesses. the masters work in little-endian mode only. 18.3.1 bus arbiter the memory controller has a simple, hard-wired priority bus arbiter that gives the control of the bus to one of the two masters. the peripheral data controller has the highest priority; the arm processor has the lowest one. 18.3.2 address decoder the memory controller features an address decoder that first decodes the four highest bits of the 32-bit address bus and defines 11 separate areas: ? one 256-mbyte address space for the internal memories ? eight 256-mbyte address spaces, each assigned to one of the eight chip select lines of the external bus interface ? one 256-mbyte address space reserved for the embedded peripherals ? an undefined address space of 1536m bytes that returns an abort if accessed
89 6222f?atarm?14-jan-11 sam7se512/256/32 18.4 external memory areas figure 18-2 shows the assignment of the 256-mbyte memory areas. figure 18-2. external memory areas 18.4.1 internal memory mapping within the internal memory address space, the address decoder of the memory controller decodes eight more address bits to allocate 1-mbyte address spaces for the embedded memories. the allocated memories are accessed all along the 1-mbyte address space and so are repeated n times within this address space, n equaling 1m bytes divided by the size of the memory. when the address of the access is undefined within the internal memory area, the address decoder returns an abort to the master. 0x0000 0000 0x0fff ffff 0x1000 0000 0x1fff ffff 0x2000 0000 0x2fff ffff 0x3000 0000 0x3fff ffff 0x4000 0000 0x4fff ffff 0x5000 0000 0x5fff ffff 0x6000 0000 0x6fff ffff 0x7000 0000 0x7fff ffff 0x8000 0000 0x8fff ffff 0x9000 0000 0xefff ffff 0xf000 0000 0xffff ffff 256m bytes 256m bytes 256m bytes 256m bytes 256m bytes 256m bytes 256m bytes 256m bytes 256m bytes 256m bytes 6 x 256m bytes 1,536 bytes internal memories chip select 0 chip select 1 chip select 2 chip select 3 chip select 4 chip select 5 chip select 6 chip select 7 undefined (abort) peripherals ebi external bus interface
90 6222f?atarm?14-jan-11 sam7se512/256/32 figure 18-3. internal memory mapping 18.4.2 internal memory area 0 the first 32 bytes of internal memory area 0 contain the arm processor exception vectors, in particular, the reset vector at address 0x0. before execution of the remap command, the internal rom or the on-chip flash is mapped into internal memory area 0, so that the arm7tdmi reaches an executable instruction contained in flash. a general purpose bit (gpnvm bit 2) is used to boot either on the rom (default) or from the flash. setting the gpnvm bit 2 selects the boot from the flash, clearing it selects the boot from the rom. asserting erase clears the gpnvm bit 2 and thus selects the boot from the rom by default. after the remap command, the internal sram at address 0x0020 0000 is mapped into internal memory area 0. the memory mapped into internal memory area 0 is access ible in both its orig- inal location and at address 0x0. 18.4.3 remap command after execution, the remap command causes the internal sram to be accessed through the internal memory area 0. as the arm vectors (reset, abort, data abort, prefetch abort, undefined instruction, interrupt, and fast interrupt) are mapped from address 0x0 to address 0x20, the remap command allows the user to redefine dynamically these vectors under software control. the remap command is accessible through the me mory controller user in terface by writing the mc_rcr (remap control regi ster) rcb field to one. the remap command can be cancelled by writing the mc_rcr rcb field to one, which acts as a toggling command. this allows easy debug of the user-defined boot sequence by offering a simple way to put the chip in the same configuration as after a reset. 256m bytes internal memory area 0 undefined areas (abort) 0x000f ffff 0x001f ffff 0x002f ffff 0x0fff ffff 1 m bytes 1 m bytes 1 m bytes 252 m bytes internal memory area 1 internal flash internal memory area 2 internal sram 0x0000 0000 0x0010 0000 0x0020 0000 0x0030 0000 internal memory area 3 internal rom 0x003f ffff 0x0040 0000 1 m bytes
91 6222f?atarm?14-jan-11 sam7se512/256/32 18.4.4 abort status there are three reasons for an abort to occur: ? access to an undefined address ? access to a protected area without the permitted state ? an access to a misaligned address. when an abort occurs, a signal is sent back to all the masters, regardless of which one has gen- erated the access. however, only the arm7tdmi can take an abort signal into account, and only under the condition that it was generating an access. the peripheral data controller does not handle the abort input signal. note that the connection is not represented in figure 18-1 . to facilitate debug or for fault analysis by an operating system, th e memory contro ller integrates an abort status register set. the full 32-bit wide abort address is saved in mc_aasr. parameters of the access are saved in mc_asr and include: ? the size of the request (field abtsz) ? the type of the access, whether it is a data read or write, or a code fetch (field abttyp) ? whether the access is due to accessing an undefined address (bit undadd), a misaligned address (bit misadd) or a protection violation (bit mpu) ? the source of the access leading to the last abort (bits mst0 and mst1) ? whether or not an abort occurred for each master since the last read of the register (bit svmst0 and svmst1) unless this information is loaded in mst bits in the case of a data abort from the processor, the address of the data access is stored. this is useful, as searching for which address generated the abort would require disassembling the instructions and full knowledge of the processor context. in the case of a prefetch abort, the address may have changed, as the prefetch abort is pipe- lined in the arm processor. the arm processor takes the prefetch abort into account only if the read instruction is executed and it is probable th at several aborts have occurred during this time. thus, in this case, it is preferable to use the content of the abort link register of the arm processor. 18.4.5 memory protection unit the memory protection unit allows definition of up to 16 memory spaces within the internal memories. note that the external memories can not be protected. after reset, the memory protection unit is dis abled. enabling it requires writing the protection unit enable register (mc_puer) with the pueb at 1. programming of the 16 memory spaces is done in the registers mc_puia0 to mc_puia15. the size of each of the memory spaces is pr ogrammable by a power of 2 between 1k bytes and 4m bytes. the base address is also programmable on a number of bits according to the size. the memory protection unit also allows the protection of the peripherals by programming the protection unit peripheral register (mc_pup) with the field prot at the appropriate value. the peripheral address space and each internal memory area can be protected against write and non-privileged access of one of the masters. when one of the masters performs a forbidden access, an abort is generated and the abort status traces what has happened.
92 6222f?atarm?14-jan-11 sam7se512/256/32 there is no priority in the protection of the me mory spaces. in case of overlap between several memory spaces, the strongest protection is tak en into account. if an access is performed to an address which is not contained in any of the 16 memory spaces, the memory protection unit generates an abort. the reset value of mc_puiax registers is 0, whic h blocks all access to the first 1k of memory starting at address 0, which prevents the core from reading exception vectors. therefore, all regions must be programmed to allow read/write access on the first 4m bytes of the memory range during mpu initialization. 18.4.6 embedded flash controller the embedded flash controller is added to the memory controller and ensures the interface of the flash block with the 32-bit internal bus. it allows an increase of performance in thumb mode for code fetch with its system of 32-bit buffers. it also manages with the programming, erasing, locking and unlocking sequences th anks to a full set of commands. 18.4.7 misalignment detector the memory controller features a misalignment detector that checks the consistency of the accesses. for each access, regardless of the master, the size of the access and the bits 0 and 1 of the address bus are checked. if the type of access is a word (32-bit) and the bits 0 and 1 are not 0, or if the type of the access is a half-word (16-bit) and the bit 0 is not 0, an abort is returned to the master and the access is cancelled. note that the accesses of the arm processor when it is fetching instructions are not checked. the misalignments are generally due to software bugs leading to wrong pointer handling. these bugs are particularly difficult to detect in the debug phase. as the requested address is saved in the abort status register and the address of the instruc- tion generating the misalignment is saved in the abort link register of the processor, detection and fix of this kind of software bugs is simplified.
93 6222f?atarm?14-jan-11 sam7se512/256/32 18.5 memory controller (mc) user interface base address : 0xffffff00 table 18-1. memory controller (mc) memory mapping offset register name access reset state 0x00 mc remap control register mc_rcr write-only 0x04 mc abort status register mc_asr read-only 0x0 0x08 mc abort address status register mc_aasr read-only 0x0 0x0c reserved 0x10 mc protection unit area 0 mc_puia0 read/write 0x0 0x14 mc protection unit area 1 mc_puia1 read/write 0x0 0x18 mc protection unit area 2 mc_puia2 read/write 0x0 0x1c mc protection unit area 3 mc_puia3 read/write 0x0 0x20 mc protection unit area 4 mc_puia4 read/write 0x0 0x24 mc protection unit area 5 mc_puia5 read/write 0x0 0x28 mc protection unit area 6 mc_puia6 read/write 0x0 0x2c mc protection unit area 7 mc_puia7 read/write 0x0 0x30 mc protection unit area 8 mc_puia8 read/write 0x0 0x34 mc protection unit area 9 mc_puia9 read/write 0x0 0x38 mc protection unit area 10 mc_puia10 read/write 0x0 0x3c mc protection unit area 11 mc_puia11 read/write 0x0 0x40 mc protection unit area 12 mc_puia12 read/write 0x0 0x44 mc protection unit area 13 mc_puia13 read/write 0x0 0x48 mc protection unit area 14 mc_puia14 read/write 0x0 0x4c mc protection unit area 15 mc_puia15 read/write 0x0 0x50 mc protection unit peripherals mc_pup read/write 0x0 0x54 mc protection unit enable register mc_puer read/write 0x0 0x60 efc0 configuration registers see efc0 user interface 0x70 efc1 configuration registers see efc1 user interface 0x80 external bus interface registers see ebi user interface 0x90 smc configuration registers see smc user interface 0xb0 sdramc configuration registers see sdramc user interface 0xdc ecc configuration registers see ecc user interface
94 6222f?atarm?14-jan-11 sam7se512/256/32 18.5.1 mc remap control register name: mc_rcr access: write-only absolute address : 0xffff ff00 ? rcb: remap command bit 0: no effect. 1: this command bit acts on a toggle basis: writing a 1 altern atively cancels and restores the remapping of the page zero memory devices. 31 30 29 28 27 26 25 24 ???????? 23 22 21 20 19 18 17 16 ???????? 15 14 13 12 11 10 9 8 ???????? 76543210 ???????rcb
95 6222f?atarm?14-jan-11 sam7se512/256/32 18.5.2 mc abort status register name: mc_asr access: read-only reset value :0x0 absolute address : 0xffff ff04 ? undadd: undefined address abort status 0: the last abort was not due to the access of an undefined address in the address space. 1: the last abort was due to the access of an undefined address in the address space. ? misadd: misaligned address abort status 0: the last aborted access was not due to an address misalignment. 1: the last aborted access was due to an address misalignment. ? mpu: memory protection unit abort status 0: the last aborted access was not due to the memory protection unit. 1: the last aborted access was due to the memory protection unit. ? abtsz: abort size status ? abttyp: abort type status 31 30 29 28 27 26 25 24 ??????svmst1svmst0 23 22 21 20 19 18 17 16 ??????mst1mst0 15 14 13 12 11 10 9 8 ? ? ? ? abttyp abtsz 76543210 ?????mpumisaddundadd abtsz abort size 00 byte 0 1 half-word 10 word 11 reserved abttyp abort type 0 0 data read 0 1 data write 1 0 code fetch 11 reserved
96 6222f?atarm?14-jan-11 sam7se512/256/32 ? mst0: pdc abort source 0: the last aborted access was not due to the pdc. 1: the last aborted access was due to the pdc. ? mst1: arm7tdmi abort source 0: the last aborted access was not due to the arm7tdmi. 1: the last aborted access was due to the arm7tdmi. ? svmst0: saved pdc abort source 0: no abort due to the pdc occurred. 1: at least one abort due to the pdc occurred. ? svmst1: saved arm7tdmi abort source 0: no abort due to the arm7tdmi occurred. 1: at least one abort due to the arm7tdmi occurred.
97 6222f?atarm?14-jan-11 sam7se512/256/32 18.5.3 mc abort address status register name: mc_aasr access: read-only reset value :0x0 absolute address : 0xffff ff08 ? abtadd: abort address this field contains the address of the last aborted access. 31 30 29 28 27 26 25 24 abtadd 23 22 21 20 19 18 17 16 abtadd 15 14 13 12 11 10 9 8 abtadd 76543210 abtadd
98 6222f?atarm?14-jan-11 sam7se512/256/32 18.5.4 mc protection unit area 0 to 15 registers name: mc_puia0 - mc_puia15 access: read/write reset value :0x0 absolute address : 0xffffff10 - 0xffffff4c ?prot: protection ? size: internal area size ? ba: internal area base address these bits define the base address of the area. note that only th e most significant bits of ba are significant. the number of significant bits are in respect with the size of the area. 31 30 29 28 27 26 25 24 ???????? 23 22 21 20 19 18 17 16 ?? ba 15 14 13 12 11 10 9 8 ba ? ? 76543210 size ? ? prot prot processor mode privilege user 0 0 no access no access 0 1 read/write no access 1 0 read/write read-only 1 1 read/write read/write size area size lsb of ba 0000 1 kb 10 0001 2 kb 11 0010 4 kb 12 0011 8 kb 13 010016 kb 14 010132 kb 15 011064 kb 16 0111128 kb 17 1000256 kb 18 1001512 kb 19 10101 mb 20 10112 mb 21 11014 mb 22
99 6222f?atarm?14-jan-11 sam7se512/256/32 18.5.5 mc protection unit peripheral name: mc_pup access: read/write reset value : 0x000000000 absolute address : 0xffffff50 ?prot: protection 31 30 29 28 27 26 25 24 ???????? 23 22 21 20 19 18 17 16 ???????? 15 14 13 12 11 10 9 8 ???????? 76543210 ?????? prot prot processor mode privilege user 0 0 read/write no access 0 1 read/write no access 1 0 read/write read-only 1 1 read/write read/write
100 6222f?atarm?14-jan-11 sam7se512/256/32 18.5.6 mc protection unit enable register name: mc_puer access: read/write reset value : 0x000000000 absolute address : 0xffffff54 ? pueb: protection unit enable bit 0: the memory controller protection unit is disabled. 1: the memory controller protection unit is enabled. 31 30 29 28 27 26 25 24 ???????? 23 22 21 20 19 18 17 16 ???????? 15 14 13 12 11 10 9 8 ???????? 76543210 ???????pueb
101 6222f?atarm?14-jan-11 sam7se512/256/32 19. embedded flash controller (efc) 19.1 overview the embedded flash controller (efc ) is a part of the memory controller and ensures the inter- face of the flash block with the 32-bit internal bus. it increases performance in thumb mode for code fetch with its system of 32-bit buffers. it also manages the programming, erasing, locking and unlocking sequences using a full set of commands. the sam7se512 is equipped with two efcs, efc0 and efc1. efc1 does not feature the security bit and gpnvm bits. the security bit and gpnvm bits embedded only on efc0 apply to the two blocks in the sam7se512. the sam7se256/32 is equipped with one efc (efc0). 19.2 functional description 19.2.1 embedded flash organization the embedded flash interfaces directly to the 32- bit internal bus. it is composed of several interfaces: ? one memory plane organized in several pages of the same size ? two 32-bit read buffers used for code read optimization (see ?read operations? on page 102 ). ? one write buffer that manages page programming. the write buffer size is equal to the page size. this buffer is write-only and accessible all along the 1 mbyte address space, so that each word can be written to its final address (see ?write operations? on page 104 ). ? several lock bits used to protect write and erase operations on lock regions. a lock region is composed of several consecutive pages, and each lock region has its associated lock bit. ? several general-purpose nvm bits. each bit controls a specific feature in the device. refer to the product definition section to get the gpnvm assignment. the embedded flash size, the page size and the lock region organization are described in the product definition section.
102 6222f?atarm?14-jan-11 sam7se512/256/32 figure 19-1. embedded flash memory mapping 19.2.2 read operations an optimized controller manages embedded flash reads. a system of 2 x 32-bit buffers is added in order to start access at following address during the second read, thus increasing perfor- mance when the processor is running in thumb mode (16-bit instruction set). see figure 19-2 , figure 19-3 and figure 19-4 . this optimization concerns only code fetch and not data. the read operations can be performed with or without wait state. up to 3 wait states can be pro- grammed in the field fws (flash wait state) in the flash mode register mc_fmr (see ?mc flash mode register? on page 111 ). defining fws to be 0 enables the single-cycle access of the embedded flash. the flash memory is accessible through 8-, 16- and 32-bit reads. as the flash block size is smaller than the addr ess space reserved for the internal memory area, the embedded flash wraps around the address space and appears to be repeated within it. lock region 0 lock region (n-1) page 0 page (m-1) start address 32-bit wide flash memory page ( (n-1)*m ) page (n*m-1) lock bit 0 lock region 1 lock bit 1 lock bit n-1
103 6222f?atarm?14-jan-11 sam7se512/256/32 figure 19-2. code read optimization in thumb mode for fws = 0 note: when fws is equal to 0, all accesse s are performed in a single-cycle access . figure 19-3. code read optimization in thumb mode for fws = 1 note: when fws is equal to 1, in case of sequential re ads, all the accesses are performed in a single-cycle access (except for t he first one). flash access buffer (32 bits) master clock arm request (16-bit) code fetch data to arm bytes 0-3 bytes 4-7 bytes 0-3 bytes 0-1 bytes 2-3 bytes 4-5 bytes 6-7 bytes 8-9 bytes 10-11 bytes 12-13 @byte 0 @byte 2 @byte 4 @byte 6 @byte 8 @byte 10 @byte 12 @byte 14 @byte 16 bytes 14-15 bytes 4-7 bytes 8-11 bytes 8-11 bytes 12-15 bytes 16-19 bytes 12-15 flash access buffer (32 bits) master clock arm request (16-bit) code fetch data to arm bytes 0-3 bytes 4-7 bytes 0-3 bytes 2-3 bytes 4-5 bytes 6-7 bytes 8-9 bytes 10-11 @byte 0 @byte 4 @byte 6 @byte 8 @byte 10 @byte 12 @byte 14 bytes 4-7 bytes 8-11 bytes 8-11 bytes 12-15 1 wait state cycle bytes 0-1 1 wait state cycle 1 wait state cycle 1 wait state cycle @byte 2 bytes 12-13
104 6222f?atarm?14-jan-11 sam7se512/256/32 figure 19-4. code read optimization in thumb mode for fws = 3 note: when fws is equal to 2 or 3, in case of sequential r eads, the first access takes fws cycles, the second access one cycle, the third access fws cycles, the fourth access one cycle, etc. 19.2.3 write operations the internal memory area reserved for the embedded flash can also be written through a write- only latch buffer. write operations take into account only the 8 lowest address bits and thus wrap around within the internal memory area address space and appear to be repeated 1024 times within it. write operations can be prevented by programming the memory protection unit of the product. writing 8-bit and 16-bit data is not allowed and may lead to unpredictable data corruption. write operations are performed in the number of wait states equal to the number of wait states for read operations + 1, except for fws = 3 (see ?mc flash mode register? on page 111 ). 19.2.4 flash commands the efc offers a command set to manage programming the memory flash, locking and unlock- ing lock sectors, consecutive programming and locking, and full flash erasing. flash access master clock data to arm 0-1 @byte 0 @2 bytes 0-3 bytes 4-7 bytes 8-11 bytes 12-15 bytes 0-3 2-3 6-7 @4 8-9 10-11 4-5 @8 @12 bytes 4-7 3 wait state cycles buffer (32 bits) arm request (16-bit) code fetch bytes 8-11 3 wait state cycles 3 wait state cycles 3 wait state cycles @6 @10 12-13 table 19-1. set of commands command value mnemonic write page 0x01 wp set lock bit 0x02 slb write page and lock 0x03 wpl clear lock bit 0x04 clb erase all 0x08 ea set general-purpose nvm bit 0x0b sgpb clear general-purpose nvm bit 0x0d cgpb set security bit 0x0f ssb
105 6222f?atarm?14-jan-11 sam7se512/256/32 to run one of these commands, the field fcmd of the mc_fcr register has to be written with the command number. as soon as the mc_fcr register is written, the frdy flag is automati- cally cleared. once the current command is achieved, then the frdy flag is automatically set. if an interrupt has been enabled by setting the bit frdy in mc_fmr, the interrupt line of the mem- ory controller is activated. all the commands are protected by the same keyword, which has to be written in the eight high- est bits of the mc_fcr register. writing mc_fcr with data that does not contain the correct key and/or with an invalid command has no effect on the memory plane; however, the proge flag is set in the mc_fsr register. this flag is automatically cleared by a read access to the mc_fsr register. when the current command writes or erases a page in a locked region, the command has no effect on the whole memory plane; however, the locke flag is set in the mc_fsr register. this flag is automatically cleared by a read access to the mc_fsr register.
106 6222f?atarm?14-jan-11 sam7se512/256/32 figure 19-5. command state chart in order to guarantee valid operations on the fl ash memory, the field flash microsecond cycle number (fmcn) in the flash mode register mc_fmr must be correctly programmed (see ?mc flash mode register? on page 111 ). 19.2.4.1 flash programming several commands can be used to program the flash. the flash technology requires that an erase must be done before programming. the entire memory plane can be erased at the same time, or a page can be automatically erased by clear- ing the nebp bit in the mc_fmr register before writing the command in the mc_fcr register. by setting the nebp bit in the mc_fmr register , a page can be programme d in several steps if it has been erased before (see figure 19-6 ). check if frdy flag set no yes read status: mc_fsr write fcmd and pagenb in mc_fcr check if locke flag set check if frdy flag set no read status: mc_fsr yes yes locking region violation no check if proge flag set yes no bad keyword violation and/or invalid command command successful
107 6222f?atarm?14-jan-11 sam7se512/256/32 figure 19-6. example of partial page programming: the partial programming mode works only with 32-bit (or higher) boundaries. it cannot be used with boundaries lower than 32 bits (8 or 16-bit for example). after programming, the page (the whole lock r egion) can be locked to prevent miscellaneous write or erase sequences. the lock bit can be automatically set after page programming using wpl. data to be written is stored in an internal latch buffer. the size of the latch buffer corresponds to the page size. the latch buffer wraps around within the internal memory area address space and appears to be repeated by the number of pages in it. note: writing of 8-bit and 16-bit data is not allowed and may lead to unpredictable data corruption. data is written to the latch buffer before the programming command is written to the flash com- mand register mc_fcr. the sequence is as follows: ? write the full page, at any page address, within the internal memory area address space using only 32-bit access. ? programming starts as soon as the page number and the programming command are written to the flash command register. the frdy bit in the flash programming status register (mc_fsr) is automatically cleared. ? when programming is completed, the bit frdy in the flash programming status register (mc_fsr) rises. if an interrupt was enabled by setting the bit frdy in mc_fmr, the interrupt line of the memory controller is activated. two errors can be detected in the mc_fsr register after a programming sequence: ? programming error: a bad keyword and/or an invalid command have been written in the mc_fcr register. ? lock error: the page to be programmed belongs to a locked region. a command must be previously run to unlock the corresponding region. 19.2.4.2 erase all command the entire memory can be erased if the erase all command (ea) in the flash command regis- ter mc_fcr is written. erase all flash programming of the second part of page 7 programming of the third part of page 7 32 bits wide 32 bits wide 32 bits wide 16 words ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ... ca fe ca fe ca fe ca fe ca fe ca fe ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ca fe ca fe ca fe ca fe ca fe ca fe de ca de ca de ca de ca de ca de ca ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff step 1. step 2. step 3. ... ... ... ... ... ... ... ... ... ... ... (nebp = 1) (nebp = 1) 16 words 16 words 16 words page 7 erased
108 6222f?atarm?14-jan-11 sam7se512/256/32 erase all operation is allowed only if there are no lock bits set. thus, if at least one lock region is locked, the bit locke in mc_fsr rises and the command is cancelled. if the bit locke has been written at 1 in mc_fmr, the interrupt line rises. when programming is complete, the bit frdy bit in the flash programming status register (mc_fsr) rises. if an interrupt has been enabled by setting the bit frdy in mc_fmr, the inter- rupt line of the memory controller is activated. two errors can be detected in the mc_fsr register after a programming sequence: ? programming error: a bad keyword and/or an invalid command have been written in the mc_fcr register. ? lock error: at least one lock region to be erased is protected. the erase command has been refused and no page has been erased. a clear lock bit command must be executed previously to unlock the corresponding lock regions. 19.2.4.3 lock bit protection lock bits are associated with several pages in the embedded flash memory plane. this defines lock regions in the embedded flash memory plane. they prevent writing/erasing protected pages. after production, the device may have some embedded flash lock regions locked. these locked regions are reserved for a default application. refer to the product definition section for the default embedded flash mapping. locked sectors can be unlocked to be erased and then pro- grammed with another application or other data. the lock sequence is: ? the flash command register must be written with the following value: (0x5a << 24) | (lockpagenumber << 8 & pagen) | slb lockpagenumber is a page of the corresponding lock region. ? when locking completes, the bit frdy in the flash programming status register (mc_fsr) rises. if an interrupt has been enabled by setting the bit frdy in mc_fmr, the interrupt line of the memory controller is activated. a programming error, where a bad keyword and/or an invalid command have been written in the mc_fcr register, may be detected in the mc _fsr register after a programming sequence. it is possible to clear lock bits that were set previously. then the locked region can be erased or programmed. the unlock sequence is: ? the flash command register must be written with the following value: (0x5a << 24) | (lockpagenumber << 8 & pagen) | clb lockpagenumber is a page of the corresponding lock region. ? when the unlock completes, the bit frdy in the flash programming status register (mc_fsr) rises. if an interrupt has been enabled by setting the bit frdy in mc_fmr, the interrupt line of the memory controller is activated. a programming error, where a bad keyword and/or an invalid command have been written in the mc_fcr register, may be detected in the mc_fsr register after a programming sequence. the unlock command programs the lock bit to 1; the corresponding bit locksx in mc_fsr reads 0. the lock command programs the lock bit to 0; the corresponding bit locksx in mc_fsr reads 1. note: access to the flash in read mode is permitted when a lock or unlock command is performed.
109 6222f?atarm?14-jan-11 sam7se512/256/32 19.2.4.4 general-purpose nvm bits general-purpose nvm bits do not interfere wi th the embedded flash memory plane. (does not apply to efc1 on the sam7se512.) these general-purpose bits are dedicated to protect other parts of the product. they can be set (activated) or cleared individually. refer to the product def- inition section for the general-purpose nvm bit action. the activation sequence is: ? start the set general purpose bit command (sgpb) by writing the flash command register with the sel command and the number of the general-purpose bit to be set in the pagen field. ? when the bit is set, the bit frdy in the flash programming status register (mc_fsr) rises. if an interrupt has been enabled by setting the bit frdy in mc_fmr, the interrupt line of the memory controller is activated. two errors can be detected in the mc_fsr register after a programming sequence: ? programming error: a bad keyword and/or an invalid command have been written in the mc_fcr register ? if the general-purpose bit number is greater than the total number of general-purpose bits, then the command has no effect. it is possible to deactivate a general-purpose nvm bit set previously. the clear sequence is: ? start the clear general-purpose bit command (cgpb) by writing the flash command register with cgpb and the number of the general-purpose bit to be cleared in the pagen field. ? when the clear completes, the bit frdy in the flash programming status register (mc_fsr) rises. if an interrupt has been enabled by setting the bit frdy in mc_fmr, the interrupt line of the memory controller is activated. two errors can be detected in the mc_fsr register after a programming sequence: ? programming error: a bad keyword and/or an invalid command have been written in the mc_fcr register ? if the number of the general-purpose bit set in the pagen field is greater than the total number of general-purpose bits, then the command has no effect. the clear general-purpose bit command programs the general-purpose nvm bit to 0; the corre- sponding bit gpnvm0 to gpnvmx in mc_fsr reads 0. the set general-purpose bit command programs the general-purpose nvm bit to 1; the corresponding bit gpnvmx in mc_fsr reads 1. note: access to the flash in read mode is permitt ed when a set, clear or get general-purpose nvm bit command is performed. 19.2.4.5 security bit the goal of the security bit is to prevent extern al access to the internal bus system. (does not apply to efc1 on the sam7se512.) jtag, fast flash programming and flash serial test inter- face features ar e disabled. once set, this bit can be re set only by an external hardware erase request to the chip. refer to the product definition section for the pin name that controls the erase. in this case, the full memory plane is erased and all lock and general-purpose nvm bits are cleared. the security bit in the mc_fsr is cleared only after these operations. the activa- tion sequence is: ? start the set security bit command (ssb) by writing the flash command register.
110 6222f?atarm?14-jan-11 sam7se512/256/32 ? when the locking completes, the bit frdy in the flash programming status register (mc_fsr) rises. if an interrupt has been enabled by setting the bit frdy in mc_fmr, the interrupt line of the memory controller is activated. when the security bit is active, the security bit in the mc_fsr is set. 19.3 embedded flash controll er (efc ) user interface the user interface of the efc is integrated wi thin the memory controller with base address: 0xffff ff00. the sam7se512 is equipped with two efcs, efc0 and efc1, as described in the register mapping tables and register descriptions that follow. the sam7se256/32 is equipped with one efc (efc0). table 19-2. embedded flash controller (efc0) register mapping offset register name access reset state 0x60 mc flash mode register mc_fmr read/write 0x0 0x64 mc flash command register mc_fcr write-only ? 0x68 mc flash status register mc_fsr read-only ? 0x6c reserved ? ? ? table 19-3. embedded flash controller (efc1) register mapping offset register name access reset state 0x70 mc flash mode register mc_fmr read/write 0x0 0x74 mc flash command register mc_fcr write-only ? 0x78 mc flash status register mc_fsr read-only ? 0x7c reserved ? ? ?
111 6222f?atarm?14-jan-11 sam7se512/256/32 19.3.1 mc flash mode register name: mc_fmr access: read/write offset : (efc0) 0x60 offset : (efc1) 0x70 ? frdy: flash ready interrupt enable 0: flash ready does not generate an interrupt. 1: flash ready generates an interrupt. ? locke: lock error interrupt enable 0: lock error does not generate an interrupt. 1: lock error generates an interrupt. ? proge: programming error interrupt enable 0: programming error does not generate an interrupt. 1: programming error generates an interrupt. ? nebp: no erase before programming 0: a page erase is performed before programming. 1: no erase is performed before programming. ? fws: flash wait state this field defines the number of wait states for read and write operations: 31 30 29 28 27 26 25 24 ???????? 23 22 21 20 19 18 17 16 fmcn 15 14 13 12 11 10 9 8 ?????? fws 76543210 nebp ? ? ? proge locke ? frdy fws read operations write operations 0 1 cycle 2 cycles 1 2 cycles 3 cycles 2 3 cycles 4 cycles 3 4 cycles 4 cycles
112 6222f?atarm?14-jan-11 sam7se512/256/32 ? fmcn: flash microsecond cycle number before writing non volatile memo ry bits (lock bits, general purpose nvm bit and security bits), this field must be set to the number of master clock cycles in one microsecond. when writing the rest of the flash, this field defines the numb er of master clock cycles in 1.5 microseconds. this number must be rounded up. warning : the value 0 is only allowed for a master clock period superior to 30 microseconds. warning: in order to guarantee valid operations on the flash memory, the field flash microsecond cycle number (fmcn) must be correctly programmed.
113 6222f?atarm?14-jan-11 sam7se512/256/32 19.3.2 mc flash command register name: mc_fcr access: write-only offset : (efc0) 0x64 offset : (efc1) 0x74 ? fcmd: flash command this field defines the flash commands: 31 30 29 28 27 26 25 24 key 23 22 21 20 19 18 17 16 ?????? pagen 15 14 13 12 11 10 9 8 pag e n 76543210 ???? fcmd fcmd operations 0000 no command. does not raise the programming error status flag in the flash status register mc_fsr. 0001 write page command (wp): starts the programming of the page specified in the pagen field. 0010 set lock bit command (slb): starts a set lock bit sequence of the lo ck region specified in the pagen field. 0011 write page and lock command (wpl): the lock sequence of the lock region associated with the page specified in the field pagen occurs automatically after completion of the programming sequence . 0100 clear lock bit command (clb): starts a clear lock bit sequence of the lock region specified in the pagen field. 1000 erase all command (ea): starts the erase of the entire flash. if at least one page is locked, the command is cancelled. 1011 set general-purpose nvm bit (sgpb): activates the general-purpose nvm bit corresponding to the number specified in the pagen field. 1101 clear general purpose nvm bit (cgpb): deactivates the general-purpose nvm bit corres ponding to the number specified in the pagen field. 1111 set security bit command (ssb): sets security bit. others reserved. raises the programming error status flag in the flash status register mc_fsr.
114 6222f?atarm?14-jan-11 sam7se512/256/32 ?pagen: page number note: depending on the command, all the possible unused bits of pagen are meaningless. ? key: write protection key this field should be written with the value 0x5a to enable the command defined by the bits of the register. if the field is wri t- ten with a different value, the write is not performed and no action is started. command pagen description write page command pagen defines the page number to be written. write page and lock command pagen defines the page number to be written and its associated lock region. erase all command this field is meaningless set/clear lock bit command pagen defines one page number of the lock region to be locked or unlocked. set/clear general purpose nvm bit command pa gen defines the general-purpose bit number. set security bit command this field is meaningless
115 6222f?atarm?14-jan-11 sam7se512/256/32 19.3.3 mc flash status register name: mc_fsr access: read-only offset : (efc0) 0x68 offset : (efc1) 0x78 ? frdy: flash ready status 0: the efc is busy and the application must wait before running a new command. 1: the efc is ready to run a new command. ? locke: lock error status 0: no programming of at least one locked lock region has happened since the last read of mc_fsr. 1: programming of at least one locked lock regi on has happened since the last read of mc_fsr. ? proge: programming error status 0: no invalid commands and no bad keywords were written in the flash command register mc_fcr. 1: an invalid command and/or a bad keyword was/were written in the flash command register mc_fcr. ? security: security bit status (does not apply to efc1 on the sam7se512.) 0: the security bit is inactive. 1: the security bit is active. ? gpnvmx: general-purpose nvm bit status (does not apply to efc1 on the sam7se512.) 0: the corresponding general- purpose nvm bit is inactive. 1: the corresponding general-purpose nvm bit is active. ? efc locksx: lock region x lock status 0: the corresponding lock region is not locked. 1: the corresponding lock region is locked. locks 8-15 do not apply to sam7se32. 31 30 29 28 27 26 25 24 locks15 locks14 locks13 locks12 locks11 locks10 locks9 locks8 23 22 21 20 19 18 17 16 locks7 locks6 locks5 locks4 locks3 locks2 locks1 locks0 15 14 13 12 11 10 9 8 ?????gpnvm2 gpnvm1 gpnvm0 76543210 ? ? ? security proge locke ? frdy
116 6222f?atarm?14-jan-11 sam7se512/256/32
117 6222f?atarm?14-jan-11 sam7se512/256/32 20. fast flash programming interface (ffpi) 20.1 overview the fast flash programming interface provides tw o solutions - parallel or serial - for high-vol- ume programming using a standard gang programmer. the parallel interface is fully handshaked and the device is considered to be a standard eeprom. additionally, the parallel protocol offers an optimized access to all t he embedded flash functionalities. the serial inter- face uses the standard ieee 1149.1 jtag protocol. it offers an optimized access to all the embedded flash functionalities. although the fast flash programming mode is a dedicated mode for high volume programming, this mode not designed for in-situ programming.
118 6222f?atarm?14-jan-11 sam7se512/256/32 20.2 parallel fast flash programming 20.2.1 device configuration in fast flash programming mode, the device is in a specific test mode. only a certain set of pins is significant. other pins must be left unconnected. figure 20-1. parallel programming interface ncmd pgmncmd rdy pgmrdy noe pgmnoe nvalid pgmnvalid mode[3:0] pgmm[3:0] data[15:0] pgmd[15:0] xin tst vddio pgmen0 pgmen1 0 - 50mhz vddio vddcore vddio vddpll vddflash gnd vddio table 20-1. signal description list signal name function type active level comments power vddflash flash power supply power vddio i/o lines power supply power vddcore core power supply power vddpll pll power supply power gnd ground ground clocks xin main clock input. this input can be tied to gnd. in this case, the device is clocked by the internal rc oscillator. input 32khz to 50mhz test tst test mode select input high must be connected to vddio pgmen0 test mode select input high must be connected to vddio pgmen1 test mode select input high must be connected to vddio
119 6222f?atarm?14-jan-11 sam7se512/256/32 20.2.2 signal names depending on the mode settings, data is latched in different internal registers. pio pgmncmd valid command available input low pulled-up input at reset pgmrdy 0: device is busy 1: device is ready for a new command output high pulled-up input at reset pgmnoe output enable (active high) input low pulled-up input at reset pgmnvalid 0: data[15:0] is in input mode 1: data[15:0] is in output mode output low pulled-up input at reset pgmm[3:0] specifies data type (see table 20-2 ) input pulled-up input at reset pgmd[15:0] bidirectional data bus input/output pulled-up input at reset table 20-1. signal description list (continued) signal name function type active level comments table 20-2. mode coding mode[3:0] symbol data 0000 cmde command register 0001 addr0 address register lsbs 0010 addr1 0101 data data register default idle no register
120 6222f?atarm?14-jan-11 sam7se512/256/32 when mode is equal to cmde, then a new command (strobed on data[15:0] signals) is stored in the command register. note: 1. applies to sam7se512. 20.2.3 entering programming mode the following algorithm puts the devi ce in parallel programming mode: ? apply gnd, vddio, vddcore, vddflash and vddpll. ? apply xin clock within t por_reset if an external clock is available. ?wait for t por_reset ? start a read or write handshaking. note: after reset, the device is clocked by the internal rc oscillator. before clearing rdy signal, if an external clock (> 32 khz) is connected to xin, th en the device switches on the external clock. else, xin input is not considered. a highe r frequency on xin speeds up the programmer handshake. 20.2.4 programmer handshaking an handshake is defined for read and write operations. when the device is ready to start a new operation (rdy signal set), the programmer star ts the handshake by clearing the ncmd signal. the handshaking is achieved once nc md signal is high and rdy is high. table 20-3. command bit coding data[15:0] symbol command executed 0x0011 read read flash 0x0012 wp write page flash 0x0022 wpl write page and lock flash 0x0032 ewp erase page and write page 0x0042 ewpl erase page and write page then lock 0x0013 ea erase all 0x0014 slb set lock bit 0x0024 clb clear lock bit 0x0015 glb get lock bit 0x0034 sfb set general purpose nvm bit 0x0044 cfb clear general purpose nvm bit 0x0025 gfb get general purpose nvm bit 0x0054 sse set security bit 0x0035 gse get security bit 0x001f wram write memory 0x0016 sefc select efc controller (1) 0x001e gve get version
121 6222f?atarm?14-jan-11 sam7se512/256/32 20.2.4.1 write handshaking for details on the write handshaking sequence, refer to figure 20-2 and table 20-4 . figure 20-2. parallel programming timing, write sequence ncmd rdy noe nvalid data[15:0] mode[3:0] 1 2 3 4 5 table 20-4. write handshake step programmer action device action data i/o 1 sets mode and data signals waits for ncmd low input 2 clears ncmd signal latches mode and data input 3 waits for rdy low clears rdy signal input 4 releases mode and data signals executes command and polls ncmd high input 5 sets ncmd signal executes command and polls ncmd high input 6 waits for rdy high sets rdy input
122 6222f?atarm?14-jan-11 sam7se512/256/32 20.2.4.2 read handshaking for details on the read handshaking sequence, refer to figure 20-3 and table 20-5 . figure 20-3. parallel programming timing, read sequence ncmd rdy noe nvalid data[15:0] mode[3:0] 1 2 3 4 5 6 7 9 8 addr adress in z data out 10 11 xin 12 13 table 20-5. read handshake step programmer action device action data i/o 1 sets mode and data signals waits for ncmd low input 2 clears ncmd signal latch mode and data input 3 waits for rdy low clears rdy signal input 4 sets data signal in tristate waits for noe low input 5 clears noe signal tristate 6 waits for nvalid low sets data bus in output mode and outputs the flash contents. output 7 clears nvalid signal output 8 reads value on data bus waits for noe high output 9 sets noe signal output 10 waits for nvalid high sets data bus in input mode x 11 sets data in output mode sets nvalid signal input 12 sets ncmd signal waits for ncmd high input 13 waits for rdy high sets rdy signal input
123 6222f?atarm?14-jan-11 sam7se512/256/32 20.2.5 device operations several commands on the flash memory are available. these commands are summarized in table 20-3 on page 120 . each command is driven by the programmer through the parallel inter- face running several read/write handshaking sequences. when a new command is executed, the previous one is automatically achieved. thus, chaining a read command after a write automatically flushes the load buffer in the flash. 20.2.5.1 flash read command this command is used to read the contents of the flash memory. the read command can start at any valid address in the memory plane and is optimized for consecutive reads. read hand- shaking can be chained; an internal address buffer is automatically increased. 20.2.5.2 flash write command this command is used to write the flash contents. the flash memory plane is organized into several pages. data to be written are stored in a load buffer that corresponds to a flash memory page. the load buffer is automatically flushed to the flash: ? before access to any page other than the current one ? when a new command is validated (mode = cmde) table 20-6. read command step handshake sequence mode[3:0] data[15:0] 1 write handshaking cmde read 2 write handshaking addr0 32-bit memory address first byte 3 write handshaking addr1 32-bit flash address 6 read handshaking data *memory address++ 7 read handshaking data *memory address++ ... ... ... ... n write handshaking addr0 32-bit memory address first byte n+1 write handshaking addr1 32-bit flash address n+2 write handshaking addr2 32-bit flash address n+3 write handshaking addr3 32-bit flash address last byte n+4 read handshaking data *memory address++ n+5 read handshaking data *memory address++ ... ... ... ...
124 6222f?atarm?14-jan-11 sam7se512/256/32 the write page command (wp) is optimized for consecutive wr ites. write handshaking can be chained; an internal address buffer is automatically increased. the flash command write page and lock (wpl) is equivalent to the flash write command. however, the lock bit is automatically set at the end of the flash write operation. as a lock region is composed of several pages, the programmer writes to the first pages of the lock region using flash write commands and writes to the last page of the lock region using a flash write and lock command. the flash command erase page and write (ewp) is equivalent to the flash write command. however, before programming the load buffer, the page is erased. the flash command erase page and write the lock (ewpl) combines ewp and wpl commands. 20.2.5.3 flash full erase command this command is used to erase the flash memory planes. all lock regions must be unlocked before the full erase command by using the clb command. otherwise, the erase command is aborted and no page is erased. table 20-7. write command step handshake sequence mode[3:0] data[15:0] 1 write handshaking cmde wp or wpl or ewp or ewpl 2 write handshaking addr0 32-bit memory address first byte 3 write handshaking addr1 32-bit flash address 4 write handshaking addr2 32-bit flash address 5 write handshaking addr3 32-bit flash address last byte 6 write handshaking data *memory address++ 7 write handshaking data *memory address++ ... ... ... ... n write handshaking addr0 32-bit memory address first byte n+1 write handshaking addr1 32-bit flash address n+2 write handshaking addr2 32-bit flash address n+3 write handshaking addr3 32-bit flash address last byte n+4 write handshaking data *memory address++ n+5 write handshaking data *memory address++ ... ... ... ... table 20-8. full erase command step handshake sequence mode[3:0] data[15:0] 1 write handshaking cmde ea 2 write handshaking data 0
125 6222f?atarm?14-jan-11 sam7se512/256/32 20.2.5.4 flash lock commands lock bits can be set using wpl or ewpl co mmands. they can also be set by using the set lock command (slb) . with this command, several lock bits can be activated. a bit mask is pro- vided as argument to the command. when bit 0 of the bit mask is set, then the first lock bit is activated. in the same way, the clear lock command (clb) is used to clear lock bits. all the lock bits are also cleared by the ea command. lock bits can be read using get lock bit command (glb) . the n th lock bit is active when the bit n of the bit mask is set.. 20.2.5.5 flash general-purpose nvm commands general-purpose nvm bits (gp nvm bits) can be set using the set fuse command (sfb) . this command also activates gp nvm bits. a bit mask is provided as argument to the command. when bit 0 of the bit mask is set, then the first gp nvm bit is activated. in the same way, the clear fuse command (cfb) is used to clear general-purpose nvm bits. all the general-purpose nvm bits are also cleared by the ea command. the general-purpose nvm bit is deactivated when the corresponding bit in the pattern value is set to 1. general-purpose nvm bits can be read using the get fuse bit command (gfb) . the n th gp nvm bit is active when bit n of the bit mask is set.. table 20-9. set and clear lock bit command step handshake sequence mode[3:0] data[15:0] 1 write handshaking cmde slb or clb 2 write handshaking data bit mask table 20-10. get lock bit command step handshake sequen ce mode[3:0] data[15:0] 1 write handshaking cmde glb 2 read handshaking data lock bit mask status 0 = lock bit is cleared 1 = lock bit is set table 20-11. set/clear gp nvm command step handshake sequen ce mode[3:0] data[15:0] 1 write handshaking cmde sfb or cfb 2 write handshaking data gp nvm bit pattern value table 20-12. get gp nvm bit command step handshake sequen ce mode[3:0] data[15:0] 1 write handshaking cmde gfb 2 read handshaking data gp nvm bit mask status 0 = gp nvm bit is cleared 1 = gp nvm bit is set
126 6222f?atarm?14-jan-11 sam7se512/256/32 20.2.5.6 flash security bit command a security bit can be set using the set security bit command (sse). once the security bit is active, the fast flash programming is disabled. no other command can be run. an event on the erase pin can erase the security bit once th e contents of the flash have been erased. the sam7se512 security bit is controlled by the efc0. to use the set security bit command, the efc0 must be selected using the select efc command. 20.2.5.7 sam7se512 select efc command the commands wpx, ea, xlb, xfb are executed using the current efc controller. the default efc controller is efc0. the select efc command (sefc) allows se lection of the current efc controller. 20.2.5.8 memory write command this command is used to perform a write access to any memory location. the memory write command (wram) is optimized for consecutive writes. write handshaking can be chained; an internal address buffer is automatically increased. table 20-13. set security bit command step handshake sequen ce mode[3:0] data[15:0] 1 write handshaking cmde sse 2 write handshaking data 0 table 20-14. select efc command step handshake sequen ce mode[3:0] data[15:0] 1 write handshaking cmde sefc 2 write handshaking data 0 = select efc0 1 = select efc1 table 20-15. write command step handshake sequence mode[3:0] data[15:0] 1 write handshaking cmde wram 2 write handshaking addr0 32-bit memory address first byte 3 write handshaking addr1 32-bit flash address 4 write handshaking addr2 32-bit flash address 5 write handshaking addr3 32-bit flash address last byte 6 write handshaking data *memory address++ 7 write handshaking data *memory address++ ... ... ... ... n write handshaking addr0 32-bit memory address first byte n+1 write handshaking addr1 32-bit flash address n+2 write handshaking addr2 32-bit flash address n+3 write handshaking addr3 32-bit flash address last byte
127 6222f?atarm?14-jan-11 sam7se512/256/32 20.2.5.9 get version command the get version (gve) command retrieves the version of the ffpi interface. n+4 write handshaking data *memory address++ n+5 write handshaking data *memory address++ ... ... ... ... table 20-15. write command (continued) step handshake sequence mode[3:0] data[15:0] table 20-16. get version command step handshake sequen ce mode[3:0] data[15:0] 1 write handshaking cmde gve 2 write handshaking data version
128 6222f?atarm?14-jan-11 sam7se512/256/32 20.3 serial fast flash programming the serial fast flash programming interface is based on ieee std. 1149.1 ?standard test access port and boundary-scan architecture?. refe r to this standard for an explanation of terms used in this chapter and for a description of the tap controller states. in this mode, data read/written from/to the embedded flash of the device are transmitted through the jtag interface of the device. 20.3.1 device configuration in serial fast flash programming mode, the device is in a specific test mode. only a distinct set of pins is significant. other pins must be left unconnected. figure 20-4. serial programing tdi tdo tms tck xin tst vddio pgmen0 pgmen1 0-50mhz vddio vddcore vddio vddpll vddflash gnd vddio table 20-17. signal description list signal name function type active level comments power vddflash flash power supply power vddio i/o lines power supply power vddcore core power supply power vddpll pll power supply power gnd ground ground clocks xin main clock input. this input can be tied to gnd. in this case, the device is clocked by the internal rc oscillator. input 32 khz to 50 mhz
129 6222f?atarm?14-jan-11 sam7se512/256/32 20.3.2 entering serial programming mode the following algorithm puts the device in serial programming mode: ? apply gnd, vddio, vddcore, vddflash and vddpll. ? apply xin clock within t por_reset + 32(t sclk ) if an external clock is available. ?wait for t por_reset . ? reset the tap controller clocking 5 tck pulses with tms set. ? shift 0x2 into the ir register (ir is 4 bits long, lsb first) without going through the run-test- idle state. ? shift 0x2 into the dr register (dr is 4 bits long, lsb first) without going through the run- test-idle state. ? shift 0xc into the ir register (ir is 4 bits long, lsb first) without going through the run-test- idle state. note: after reset, the device is clocked by the internal rc oscillator. before clearing rdy signal, if an external clock (> 32 khz) is connected to xin, th en the device will switch on the external clock. else, xin input is not considered. an high er frequency on xin speeds up the programmer handshake. test tst test mode select input high must be connected to vddio. pgmen0 test mode select input high must be connected to vddio pgmen1 test mode select input high must be connected to vddio jtag tck jtag tck input - pulled-up input at reset tdi jtag test data in input - pulled-up input at reset tdo jtag test data out output - tms jtag test mode select input - pulled-up input at reset table 20-17. signal description list (continued) signal name function type active level comments table 20-18. reset tap controller and go to select-dr-scan tdi tms tap controller state x1 x1 x1 x1 x 1 test-logic reset x 0 run-test/idle xt 1 select-dr-scan
130 6222f?atarm?14-jan-11 sam7se512/256/32 20.3.3 read/write handshake the read/write handshake is done by carrying out read/write operations on two registers of the device that are accessible through the jtag: ? debug comms control register: dccr ? debug comms data register: dcdr access to these registers is done through the ta p 38-bit dr register comprising a 32-bit data field, a 5-bit address field and a read/write bit. the data to be written is scanned into the 32-bit data field with the address of the register to the 5-bit address field and 1 to the read/write bit. a register is read by scanning its address into th e address field and 0 into the read/write bit, going through the update-dr tap state, then scanning out the data. refer to the arm7tdmi reference manuel for more information on comm channel operations. figure 20-5. tap 8-bit dr register a read or write takes place when the tap contro ller enters update-dr st ate. refer to the ieee 1149.1 for more details on jtag operations. ? the address of the debug comms control register is 0x04. ? the address of the debug comms data register is 0x05. the debug comms control register is read-only and allows synchronized handshaking between the processor and the debugger. ? bit 1 (w): denotes whether the programmer can read a data through the debug comms data register. if the device is busy w = 0, then the programmer must poll until w = 1. ? bit 0 (r): denotes whether the programmer can send data from the debug comms data register. if r = 1, data previously placed there through the scan chain has not been collected by the device and so the programmer must wait. the write handshake is done by polling the debug comms control register until the r bit is cleared. once cleared, data can be written to the debug comms data register. the read handshake is do ne by polling the debug co mms control register until the w bit is set. once set, data can be read in the debug comms data register. 20.3.4 device operations several commands on the flash memory are available. these commands are summarized in table 20-3 on page 120 . commands are run by the programmer through the serial interface that is reading and writing the debug comms registers. tdi tdo 4 0 r/w address 31 data 0 address decoder debug comms control register debug comms data register 32 5
131 6222f?atarm?14-jan-11 sam7se512/256/32 20.3.4.1 flash read command this command is used to read the flash contents. the memory map is accessible through this command. memory is seen as an array of words (32-bit wide). the read command can start at any valid address in the memory plane. this address must be word-aligned . the address is automatically incremented. 20.3.4.2 flash write command this command is used to write the flash contents. the address transmitted must be a valid flash address in the memory plane. the flash memory plane is organized into several pages. data to be written is stored in a load buffer that corresponds to a flash memory page. the load buffer is automatically flushed to the flash: ? before access to any page than the current one ? at the end of the number of words transmitted the write page command (wp) is optimized for consecutive wr ites. write handshaking can be chained; an internal address buffer is automatically increased. flash write page and lock command (wpl) is equivalent to the flash write command. how- ever, the lock bit is automatically set at the end of the flash write operation. as a lock region is composed of several pages, the programmer writes to the first pages of the lock region using flash write commands and writes to the last page of the lock region using a flash write and lock command. flash erase page and write command (ewp) is equivalent to the flash write command. how- ever, before programming the load buffer, the page is erased. flash erase page and write the lock command (ewpl) combines ewp and wpl commands. table 20-19. read command read/write dr data write (number of words to read) << 16 | read write address read memory [address] read memory [address+4] ... ... read memory [address+(number of words to read - 1)* 4] table 20-20. write command read/write dr data write (number of words to write) << 16 | (wp or wpl or ewp or ewpl) write address write memory [address] write memory [address+4] write memory [address+8] write memory [address+(number of words to write - 1)* 4]
132 6222f?atarm?14-jan-11 sam7se512/256/32 20.3.4.3 flash full erase command this command is used to erase the flash memory planes. all lock bits must be deactivated before using the full erase command. this can be done by using the clb command. 20.3.4.4 flash lock commands lock bits can be set using wpl or ewpl co mmands. they can also be set by using the set lock command (slb) . with this command, several lock bits can be activated at the same time. bit 0 of bit mask corresponds to the first lock bit and so on. in the same way, the clear lock command (clb) is used to clear lock bits. all the lock bits can also be cleared by the ea command. lock bits can be read using get lock bit command (glb) . when a bit set in the bit mask is returned, then the corresponding lock bit is active. 20.3.4.5 flash general-purpose nvm commands general-purpose nvm bits (gp nvm) can be set with the set fuse command (sfb) . using this command, several gp nvm bits can be activated at the same time. bit 0 of bit mask corre- sponds to the first fuse bit and so on. in the same way, the clear fuse command (cfb) is used to clear gp nvm bits. all the general- purpose nvm bits are also cleared by the ea command. table 20-21. full erase command read/write dr data write ea table 20-22. set and clear lock bit command read/write dr data write slb or clb write bit mask table 20-23. get lock bit command read/write dr data write glb read bit mask table 20-24. set and clear general-purpose nvm bit command read/write dr data write sfb or cfb write bit mask
133 6222f?atarm?14-jan-11 sam7se512/256/32 gp nvm bits can be read using get fuse bit command (gfb) . when a bit set in the bit mask is returned, then the corresponding fuse bit is set. 20.3.4.6 flash security bit command security bits can be set using set security bit command (sse). once the security bit is active, the fast flash programming is disabled. no othe r command can be run. only an event on the erase pin can erase the security bit once th e contents of the flash have been erased. the sam7se512 security bit is controlled by the efc0. to use the set security bit command, the efc0 must be selected using the select efc command. 20.3.4.7 sam7se512 select efc command the commands wpx, ea, xlb, xfb are executed using the current efc controller. the default efc controller is efc0. the select efc command (sefc) allows se lection of the current efc controller. 20.3.4.8 memory write command this command is used to perform a write access to any memory location. the memory write command (wram) is optimized for consecutive writes. an internal address buffer is automatically increased. table 20-25. get general-purpose nvm bit command read/write dr data write gfb read bit mask table 20-26. set security bit command read/write dr data write sse table 20-27. select efc command step handshake sequence mode[3:0] data[15:0] 1 write handshaking cmde sefc 2 write handshaking data 0 = select efc0 1 = select efc1 table 20-28. write command read/write dr data write (number of words to write) << 16 | (wram) write address write memory [address] write memory [address+4] write memory [address+8] write memory [address+(number of words to write - 1)* 4]
134 6222f?atarm?14-jan-11 sam7se512/256/32 20.3.4.9 get version command the get version (gve) command retrieves the version of the ffpi interface. table 20-29. get version command read/write dr data write gve read version
135 6222f?atarm?14-jan-11 sam7se512/256/32 21. external bus interface (ebi) 21.1 overview the external bus interface (ebi) is designed to ensure the successful data transfer between several external devices and the embedded memo ry controller of an arm-based device. the static memory, sdram and ecc controllers are all featured external memory controllers on the ebi. these external memory controllers are capable of handling several types of external memory and peripheral devices, such as sram, prom, eprom, eeprom, flash, and sdram. the ebi also supports the compactflash ? and the nand flash protocols via integrated circuitry that greatly reduces the requirements for external components. furthermore, the ebi handles data transfers with up to eight external devices , each assigned to eight address spaces defined by the embedded memory controller. data transfers are performed through a 16-bit or 32-bit data bus, an address bus of up to 23 bits, up to ei ght chip select lines (ncs[7:0]) and several control pins that are generally multiplexed betw een the different external memory controllers.
136 6222f?atarm?14-jan-11 sam7se512/256/32 21.2 block diagram figure 21-1. organization of the external bus interface external bus interface d[31:0] a[15:2], a[20:18] mux logic nand flash logic compactflash logic user interface chip select assignor static memory controller sdram controller memory controller apb asb address decoder a16/ba0 a0/nbs0 a1/nbs2 a17/ba1 ncs0/cfrnw ncs3/nandcs nrd/cfoe ncs1/sdcs ncs2/cfcs1 nwr0/nwe/cfwe nwr1/nbs1/cfior nbs3/cfiow sdcke ras cas sdwe ncs4/cfcs0 ncs5/cfce1 ncs6/cfce2 ncs7 nandoe nandwe nwait sda10 pio ecc controller a22/reg/nandcle a21/nandale sdck
137 6222f?atarm?14-jan-11 sam7se512/256/32 21.3 i/o lines description table 21-1. i/o lines description name function type active level ebi d[31:0] data bus i/o a[22:0] address bus output nwait external wait signal input low smc ncs[7:0] chip select lines output low nwr[1:0] write signals output low nrd read signal output low nwe write enable output low nub nub: upper byte select output low nlb nlb: lower byte select output low ebi for compactflash support cfce[2:1] compactflash chip enable output low cfoe compactflash output enable output low cfwe compactflash write enable output low cfior compactflash i/o read signal output low cfiow compactflash i/o write signal output low cfrnw compactflash read not write signal output cfcs[1:0] compactflash chip select lines output low ebi for nand flash support nandcs nand flash chip select line output low nandoe nand flash output enable output low nandwe nand flash write enable output low nandcle nand flash command line enable output low nandale nand flash address line enable output low sdram controller sdck sdram clock output sdcke sdram clock enable output high sdcs sdram controller chip select line output low ba[1:0] bank select output sdwe sdram write enable output low ras - cas row and column signal output low nbs[3:0] byte mask signals output low sda10 sdram address 10 line output
138 6222f?atarm?14-jan-11 sam7se512/256/32 the connection of some signals through the mux logic is not direct and depends on the memory controller in use at the moment. table 21-2 details the connections between the tw o memory controllers and the ebi pins. 21.4 application example 21.4.1 hardware interface table 21-3 details the connections to be applied betw een the ebi pins and the external devices for each memory controller table 21-2. ebi pins and memory controllers i/o lines connections ebi pins sdramc i/o lines smc i/o lines nwr1/nbs1/cfior nbs1 nwr1/nub a0/nbs0 not supported a0/nlb a1/nbs2 not supported a1 a[11:2] a[9:0] a[11:2] sda10 a10 not supported a12 not supported a12 a[14:13] a[12:11] a[14:13] a[22:15] not supported a[22:15] d[31:16] d[31:16] not supported d[15:0] d[15:0] d[15:0] table 21-3. ebi pins and external static device connections pin pins of the interfaced device 8-bit static device 2 x 8-bit static devices 16-bit static device sdram (1) compactflash compactflash true ide mode nand flash (2) controller smc sdramc smc d0 - d7 d0 - d7 d0 - d7 d0 - d7 d0 - d7 d0 - d7 d0 - d7 i/o0 - i/o7 d8 - d15 ? d8 - d15 d8 - d15 d8 - d15 d8 - 15 d8 - 15 i/o8 - i/o15 (3) d16 - d31 ? ? ? d16 - d31 ? ? ? a0/nbs0 a0 ? nlb dqm0 a0 a0 ? a1/nbs2 a1 a0 a0 dqm2 a1 a1 ? a2 - a9 a2 - a9 a1 - a8 a1 - a8 a0 - a7 a2 - a9 a2 - a9 ? a10 a10 a9 a9 a8 a10 a10 ? a11 a11 a10 a10 a9 ? ? ? sda10 ? ? ? a10 ? ? ? a12 a12 a11 a11 ? ? ? ? a13 - a14 a13 - a14 a12 - a13 a12 - a13 a11 - a12 ? ? ? a15 a15 a14 a14 ? ? ? ? a16/ba0 a16 a15 a15 ba0 ? ? ? a17/ba1 a17 a16 a16 ba1 ? ? ?
139 6222f?atarm?14-jan-11 sam7se512/256/32 notes: 1. for sdram connection examples, refer to ?using sdram on at91sam 7se microcontrollers?, application note. 2. for nand flash connection examples, refer to ?nand flash support on at91sam7se microcontrollers?, application note. 3. i/o8 - i/o15 bits used only for 16-bit nand flash. 4. not directly connected to the compactflash slot. permits the control of the bidirect ional buffer between the ebi data bus and the compactflash slot. 5. nwr1 enables upper byte writes. nwr0 enables lower byte writes. 6. any free pio line. 7. ce connection depends on the nand flash. for standard nand flash devices, it must be connected to any free pio line. for ?ce don?t care? 8-bit nand flash devices, it can be either connected to ncs3/na ndcs or to any free pio line. for ?ce don?t care? 16-bit nand flash devices, it must be connected to any free pio line. a18 - a20 a18 - a20 a17 - a19 a17 - a19 ? ? ? ? a21/nandale a21 a20 a20 ? ? ? ale a22/reg/nandcle a22 a21 a21 ? reg ? cle ncs0 cs cs cs ? cfrnw (4) cfrnw (4) ? ncs1/sdcs cs cs cs cs ? ? ? ncs2/cfcs1 cs cs cs ? cfcs1 (4) cfcs1 (4) ? ncs3/nandcs cs cs cs ? ? ? ce (7) ncs4/cfcs0 cs cs cs ? cfcs0 (4) cfcs0 (4) ? ncs5/cfce1 cs cs cs ? ce1 cs0 ? ncs6/cfce2 cs cs cs ? ce2 cs1 ? ncs7 cs cs cs ? ? ? ? nandoe ? ? ? ? ? ? re nandwe ? ? ? ? ? ? we nrd/cfoe oe oe oe ? oe ? nwr0/nwe/cfwe we we (5) we ? we ? (8) nwr1/nbs1/cfior we we (5) nub dqm1 ior ior ? nbs3/cfiow ? ? ? dqm3 iow iow ? sdck ? ? ? clk ? ? ? sdcke ? ? ? cke ? ? ? ras ? ? ? ras ? ? ? cas ? ? ? cas ? ? ? sdwe ? ? ? we ? ? ? nwait ? ? ? ? wait wait ? pxx (6) ? ? ? ? cd1 or cd2 cd1 or cd2 ? pxx (6) ???? ? ? ce (7) pxx (6) ???? ? ? rdy table 21-3. ebi pins and external static device connections (continued) pin pins of the interfaced device 8-bit static device 2 x 8-bit static devices 16-bit static device sdram (1) compactflash compactflash true ide mode nand flash (2) controller smc sdramc smc
140 6222f?atarm?14-jan-11 sam7se512/256/32 8. when the nand flash logic is used, nwr0/nwe/cfwe must be kept as pio input mode with pull-up enabled (default state after reset) or as pio output set at logi c level 1. the pio cannot be used in pio mode. 21.4.2 connection examples figure 21-2 shows an example of connections be tween the ebi and external devices. figure 21-2. ebi connections to memory devices ebi d0-d31 a2-a15 ras cas sdck sdcke sdwe a0/nbs0 2m x 8 sdram d0-d7 a0-a9, a11 ras cas clk cke we dqm cs ba0 ba1 nwr1/nbs1 a1/nbs2 nbs3 ncs1/sdcs d0-d7 d8-d15 a16/ba0 a17/ba1 a18-a22 a10 sda10 sda10 a2-a11, a13 ncs0 ncs2 ncs3 ncs4 ncs5 ncs6 ncs7 a16/ba0 a17/ba1 2m x 8 sdram d0-d7 a0-a9, a11 ras cas clk cke we dqm cs ba0 ba1 a10 sda10 a2-a11, a13 a16/ba0 a17/ba1 2m x 8 sdram d0-d7 a0-a9, a11 ras cas clk cke we dqm cs ba0 ba1 d16-d23 d24-d31 a10 sda10 a2-a11, a13 a16/ba0 a17/ba1 2m x 8 sdram d0-d7 a0-a9, a11 ras cas clk cke we dqm cs ba0 ba1 a10 sda10 a2-a11, a13 a16/ba0 a17/ba1 nbs0 nbs1 nbs3 nbs2 nrd nwr0/nwe 128k x 8 sram 128k x 8 sram d0-d7 d0-d7 a0-a16 a0-a16 a1-a17 a1-a17 cs cs oe we d0-d7 d8-d15 oe we nrd/noe a0/nwr0/nbs0 nrd/noe nwr1/nbs1 sdwe sdwe sdwe sdwe
141 6222f?atarm?14-jan-11 sam7se512/256/32 21.5 product dependencies 21.5.1 i/o lines the pins used for interfacing the external bus interface may be multiplexed with the pio lines. the programmer must first program the pio controller to assign the external bus interface pins to their peripheral function. if i/o lines of the external bus interface are not used by the applica- tion, they can be used for other purposes by the pio controller. 21.6 functional description the ebi transfers data between the internal asb bus ( handled by the memo ry controller) and the external memories or peripheral devices. it controls the waveforms and the parameters of the external address, data and control busses and is composed of the following elements: ? the static memory controller (smc) ? the sdram controller (sdramc) ? the ecc controller (ecc) ? a chip select assignment feature that assigns an asb address space to the external devices ? a multiplex controller circuit that shares the pins between the different memory controllers ? programmable compactflash support logic ? programmable nand flash support logic 21.6.1 bus multiplexing the ebi offers a complete set of control signal s that share the 32-bit data lines, the address lines of up to 23 bits and the control signals through a multiplex logic operating in function of the memory area requests. multiplexing is specifically organized in order to guarantee the maintenance of the address and output control lines at a stable state while no ex ternal access is being perf ormed. multip lexing is also designed to respect the data float times defined in the memory controllers. furthermore, refresh cycles of the sdram are executed i ndependently by the sdram controller without delaying the other external memory controller accesses. 21.6.2 static memory controller for information on the static memory controller, refer to the static memory controller section. 21.6.3 sdram controller for information on the sdram controlle r, refer to the sdramc section. 21.6.4 ecc controller for information on the ecc contro ller, refer to the eccc section. 21.6.5 compactflash support the external bus interface integrates circuitry that interfaces to compactflash devices. the compactflash logic is driven by the stat ic memory controller (smc) on the ncs4 and/or ncs2 address space. programming the cs4a and/or cs2a bit of the chip select assignment register ( see ?ebi chip select assignment register? on page 158. ) to the appropriate value enables this logic. access to an external compactflash device is then made by accessing the
142 6222f?atarm?14-jan-11 sam7se512/256/32 address space reserved to ncs4 and/or ncs2 (i.e., between 0x5000 0000 and 0x5fff ffff for ncs4 and between 0x3000 0000 and 0x3fff ffff for ncs2). when multiplexed with cfce1 and cfce2 si gnals, the ncs5 and ncs6 signals become unavailable. performing an access within the a ddress space reserved to ncs5 and ncs6 (i.e., between 0x6000 0000 and 0x7fff ffff) may lead to an unpredictable outcome. all compactflash modes (attribute memory, common memory, i/o and true ide) are sup- ported but the signals _iois16 (i/o and true ide modes) and _ata sel (true ide mode) are not handled. 21.6.5.1 i/o mode, common memory mode, attribute memory and true ide mode within the ncs4 and/or ncs2 address space, the current transfer address is used to distinguish i/o mode, common memory mode, attribute memory mode and true ide mode. the different modes are accessed through a s pecific memory mapping as illustrated in figure 21-3 . figure 21-3. compactflash memory mapping note: the a22 pin of the ebi is used to drive the reg signal of the compactflash device (except in true ide mode). 21.6.5.2 cfce1 and cfce2 signals to cover all types of access, the smc must be alternatively set to drive the 8-bit data bus or 16- bit data bus. the odd byte access on the d[7:0] bus is only possible when the smc is configured to drive 8-bit memory devices on the corr esponding ncs pin (ncs4 and/ or ncs2). the dbw field in the corresponding chip select register of the ncs4 and/or ncs2 address space must be set as shown in table 21-4 to enable the required access type. nub and nlb are the byte selection signals from smc and are available when the smc is set in byte select mode on the corresponding chip select. the cfce1 and cfce2 waveforms are identical to the corresponding ncsx waveform. for details on these waveforms and timings, refer to the static memory controller section. cf address space attribute memory mode space common memory mode space i/o mode space true ide mode space true ide alternate mode space offset 0x00e0 0000 offset 0x00c0 0000 offset 0x0080 0000 offset 0x0040 0000 offset 0x0000 0000
143 6222f?atarm?14-jan-11 sam7se512/256/32 21.6.5.3 read/write signals in i/o mode and true ide mode, the compactflash logic drives the read and write command signals of the smc on cfior and cfiow signals, while the cfoe and cfwe signals are deac- tivated. likewise, in common memory mode and attribute memory mode, the smc signals are driven on the cfoe and cfwe signals, while the cfior and cfiow are deactivated. figure 21-4 on page 144 shows a schematic representation of this logic and table 21-5 on page 144 presents the signal decoding. attribute memory mode, common memory mode and i/o mode are supported by setting the address setup and hold time on the ncs4 (and/or ncs2) chip select to the appropriate values. for details on these signal waveforms, please refer to the section: setup and hold cycles of the static memory controller section. table 21-4. cfce1 and cfce2 truth table mode cfce2 cfce1 dbw comment smc access mode attribute memory nub nlb 16 bits access to even byte on d[7:0] byte select common memory nub nlb 16bits access to even byte on d[7:0] access to odd byte on d[15:8] byte select 1 0 8 bits access to odd byte on d[7:0] don?t care i/o mode nub nlb 16 bits access to even byte on d[7:0] access to odd byte on d[15:8] byte select 1 0 8 bits access to odd byte on d[7:0] don?t care true ide mode task file 1 0 8 bits access to even byte on d[7:0] access to odd byte on d[7:0] don?t care data register 1 0 16 bits access to even byte on d[7:0] access to odd byte on d[15:8] byte select alternate true ide mode control register alternate status read 01 don?t care access to even byte on d[7:0] don?t care drive address 0 1 8 bits access to odd byte on d[7:0] don?t care standby mode or address space is not assigned to cf 11 don?t care don?t care don?t care
144 6222f?atarm?14-jan-11 sam7se512/256/32 figure 21-4. compactflash read/write control signals 21.6.5.4 multiplexing of compactflash signals on ebi pins table 21-6 and table 21-7 on page 145 describe the multiplexing of the compactflash logic sig- nals with other ebi signals on the ebi pins. the ebi pins in table 21-6 are strictly dedicated to the compactflash interface as soon as the cs4a and/or cs2a field of the chip select assign- ment register is set ( see ?ebi chip select assignment register? on page 158. ). these pins must not be used to drive any other memory devices. the ebi pins in table 21-7 remain shared between all memory areas when the corresponding compactflash interface is enabled (cs4a = 1 and/or cs2a = 1). smc nrd nwr0_nwe a22 cfior cfiow cfoe cfwe 1 1 compactflash logic external bus interface 1 1 1 0 a21 1 0 1 0 1 0 table 21-5. compactflash mode selection mode base address cfoe cfwe cfior cfiow attribute memory common memory nrd nwr0_nwe 1 1 i/o mode 1 1 nrd nwr0_nwe true ide mode 0 1 nrd nwr0_nwe table 21-6. dedicated compactflash interface multiplexing pins compactflash sign als ebi signals cs4a = 1 cs2a = 1 cs4a = 0 cs2a = 0 ncs4/cfcs0 cfcs0 ncs4 ncs2/cfcs1 cfcs1 ncs2
145 6222f?atarm?14-jan-11 sam7se512/256/32 21.6.5.5 application example figure 21-5 on page 145 illustrates an example of a comp actflash application. cfcs0 and cfrnw signals are not directly connected to the compactflash slot 0, but do control the direc- tion and the output enable of the buffers between the ebi and the compactflash device. the timing of the cfcs0 signal is identical to the ncs4 signal. moreover, the cfrnw signal remains valid throughout the transfer, as does the address bus. the compactflash _wait sig- nal is connected to the nwait input of the static memory controller. for details on these waveforms and timings, refer to the static memory controller section. figure 21-5. compactflash application example table 21-7. shared compactflash interface mu ltiplexing pins access to compactflash device access to other ebi devices compactflash sign als ebi signals nrd/cfoe cfoe nrd nwr0/nwe/cfwe cfwe nwr0/nwe nwr1/nbs1/cfior cfior nwr1/nbs1 nbs3/cfiow cfiow nbs3 ncs0/cfrnw cfrnw ncs0 d[15:0] /oe dir _cd1 _cd2 /oe d[15:0] ncs0/cfrnw ncs4/cfcs0 cd (pio) a[10:0] a22/reg nrd/cfoe a[10:0] _reg _oe _we _iord _iowr _ce1 _ce2 nwe/cfwe nwr1/cfior cfiow ncs5/cfce1 ncs6/cfce2 _wait nwait
146 6222f?atarm?14-jan-11 sam7se512/256/32 21.6.6 nand flash support the ebi integrates circuitry that interfaces to nand flash devices. the nand flash logic is driven by the static memory controller on the ncs3 address space. programming the cs3a field in the chip select assignment register to the appropriate value enables the nand flash logic ( see ?ebi chip select assignment register? on page 158. ). access to an external nand flash device is then made by accessing the address space reserved to ncs3 (i.e., between 0x4000 0000 and 0x4fff ffff). the nand flash logic drives the read and write command signals of the smc on the nandoe and nandwe signals when the ncs3 signal is active. nandoe and nandwe are invalidated as soon as the transfer address fails to lie in the ncs3 address space. for details on these waveforms, refer to the stat ic memory controller section. figure 21-6. nand flash signal multiplexing on ebi pins (1) when the nand flash logic is used, nwr0/nwe/cfw e must be kept as pio input mode with pull-up enabled (default state after reset) or as pio output set at logic level 1. the pio cannot be used in pio mode. the address latch enable and command latch enable signals on the nand flash device are driven respectively by address bits a21 and a22 of the ebi address bus. the command, address or data words on the data bus of the na nd flash device are distinguished by using their address within the ncs3 address space. the chip enable (ce) signal of the device and the ready/busy (r/b) signals are connected to pio lines. the ce signal then remains asserted even when ncs3 is not selected, preventing the device from returning to standby mode. s mc nrd nwr0_nwe (1) nandoe nandwe nand fl as h logic nc s3 mux logic c s3 a nandwe nandoe c s3 a
147 6222f?atarm?14-jan-11 sam7se512/256/32 figure 21-7. nand flash application example note: the external bus interface is also able to support 16-bit devices. d[7:0] cle nandwe nandoe noe nwe a22/reg/nandcle ale ad[7:0] pio r/b ebi ce nand flash pio ncs3/nandcs not connected a21/nandale
148 6222f?atarm?14-jan-11 sam7se512/256/32 21.7 implementation examples 21.7.1 16-bit sdram 21.7.1.1 hardware configuration 21.7.1.2 software configuration the following configuration must be respected: ? address lines a[0..11], a[13-14], ba0, ba1 , sda10, sdcs_ncs1, sdwe, sdcke, nbs1, ras, cas, and data lines d[8..15] are multip lexed with pio lines and thus dedicated pios must be programmed in peripheral mode in the pio controller. ? assign the ebi cs1 to the sdram controller by setting the bit ebi_cs1a in the ebi chip select assignment register. ? initialize the sdram controller depending on the sdram device and system bus frequency. the data bus width is to be programmed to 16 bits. the sdram initialization sequence is described in the ?sdram device initialization? section of the sdram controller. d13 d12 d8 d7 d3 d11 d2 d14 d4 d0 ras d1 d10 cas sda10 sdck d9 sdwe sdcke d5 d15 d6 a4 a9 a14 a5 a2 a6 a3 ba0 a10 a13 a8 ba1 a7 a11 a0 ras cas sda10 sdwe sdcke sdck cfior_nbs1_nwr1 sdcs_ncs1 ba0 ba1 d[0..15] a[0..14] 3v3 256 mbits (not used a12) tsop54 package c1 100nf c1 100nf c7 100nf c7 100nf c2 100nf c2 100nf mt48lc16m16a2 u1 mt48lc16m16a2 u1 a0 23 a1 24 a2 25 a3 26 a4 29 a5 30 a6 31 a7 32 a8 33 a9 34 a10 22 ba0 20 a12 36 dq0 2 dq1 4 dq2 5 dq3 7 dq4 8 dq5 10 dq6 11 dq7 13 dq8 42 dq9 44 dq10 45 dq11 47 dq12 48 dq13 50 dq14 51 dq15 53 vdd 1 vss 28 vss 41 vddq 3 vdd 27 n.c 40 clk 38 cke 37 dqml 15 dqmh 39 cas 17 ras 18 we 16 cs 19 vddq 9 vddq 43 vddq 49 vssq 6 vssq 12 vssq 46 vssq 52 vdd 14 vss 54 a11 35 ba1 21 c3 100nf c3 100nf c4 100nf c4 100nf c5 100nf c5 100nf c6 100nf c6 100nf
149 6222f?atarm?14-jan-11 sam7se512/256/32 21.7.2 32-bit sdram 21.7.2.1 hardware configuration 21.7.2.2 software configuration the following configuration must be respected: ? address lines a[0..11], a[13-14], ba0, ba1 , sda10, sdcs_ncs1, sdwe, sdcke, nbs1, ras, cas, and data lines d[8..31] are multip lexed with pio lines and thus dedicated pios must be programmed in peripheral mode in the pio controller. ? assign the ebi cs1 to the sdram controller by setting the bit ebi_cs1a in the ebi chip select assignment register locate d in the bus matrix memory space. ? initialize the sdram controller depending on the sdram device and system bus frequency. the data bus width is to be programmed to 32 bits. the sdram initialization sequence is described in the ?sdram device initialization? section of the sdram controller. cas sdcke sdck ras sdwe sda10 d13 d18 d12 d22 d8 d7 d3 d28 d11 d26 d21 d2 d14 d4 d24 d0 d23 ras d27 d1 d19 d10 d31 d17 cas sda10 d25 d29 d16 sdck d9 d20 sdwe sdcke d5 d30 d15 d6 a5 ba0 a2 a11 a7 a4 a9 a14 a8 a1 a5 a2 ba1 a13 a6 a3 a3 a10 ba0 a10 a13 a8 ba1 a6 a4 a14 a9 a7 a11 a0 ras cas sda10 sdwe sdcke sdck cfiow_nbs3_nwr3 cfior_nbs1_nwr1 sdcs_ncs1 ba0 ba1 d[0..31] a[0..14] 3v3 3v3 256 mbits 256 mbits (not used a12) tsop54 package c11 100nf c11 100nf c9 100nf c9 100nf c1 100nf c1 100nf c12 100nf c12 100nf mt48lc16m16a2 u2 mt48lc16m16a2 u2 a0 23 a1 24 a2 25 a3 26 a4 29 a5 30 a6 31 a7 32 a8 33 a9 34 a10 22 ba0 20 a12 36 dq0 2 dq1 4 dq2 5 dq3 7 dq4 8 dq5 10 dq6 11 dq7 13 dq8 42 dq9 44 dq10 45 dq11 47 dq12 48 dq13 50 dq14 51 dq15 53 vdd 1 vss 28 vss 41 vddq 3 vdd 27 n.c 40 clk 38 cke 37 dqml 15 dqmh 39 cas 17 ras 18 we 16 cs 19 vddq 9 vddq 43 vddq 49 vssq 6 vssq 12 vssq 46 vssq 52 vdd 14 vss 54 a11 35 ba1 21 c7 100nf c7 100nf c13 100nf c13 100nf c8 100nf c8 100nf c14 100nf c14 100nf mt48lc16m16a2 u1 mt48lc16m16a2 u1 a0 23 a1 24 a2 25 a3 26 a4 29 a5 30 a6 31 a7 32 a8 33 a9 34 a10 22 ba0 20 a12 36 dq0 2 dq1 4 dq2 5 dq3 7 dq4 8 dq5 10 dq6 11 dq7 13 dq8 42 dq9 44 dq10 45 dq11 47 dq12 48 dq13 50 dq14 51 dq15 53 vdd 1 vss 28 vss 41 vddq 3 vdd 27 n.c 40 clk 38 cke 37 dqml 15 dqmh 39 cas 17 ras 18 we 16 cs 19 vddq 9 vddq 43 vddq 49 vssq 6 vssq 12 vssq 46 vssq 52 vdd 14 vss 54 a11 35 ba1 21 c2 100nf c2 100nf c3 100nf c3 100nf c4 100nf c4 100nf c5 100nf c5 100nf c6 100nf c6 100nf c10 100nf c10 100nf
150 6222f?atarm?14-jan-11 sam7se512/256/32 21.7.3 8-bit nand flash 21.7.3.1 hardware configuration 21.7.3.2 software configuration the following configuration must be respected: ? cle, ale, nandoe and nandwe signals are multiplexed with pio lines and thus the dedicated pios must be programmed in peripheral mode in the pio controller. ? assign the ebi cs3 to the nand flash by setting the bit ebi_cs3a in the ebi chip select assignment register. ? reserve a21/a22 for ale/cle functions. address and command latches are controlled respectively by setting to 1 the address bit a21 and a22 during accesses. ? configure a pio line as an input to manage the ready/busy signal. ? configure static memory controller cs3 setup, pulse, cycle and mode according to nand flash timings, the data bus width and the system bus frequency. d6 d0 d3 d4 d2 d1 d5 d7 nandoe nandwe (any pio) (any pio) ale cle d[0..7] 3v3 3v3 2 gb tsop48 package u1 k9f2g08u0m u1 k9f2g08u0m we 18 n.c 6 vcc 37 ce 9 re 8 n.c 20 wp 19 n.c 5 n.c 1 n.c 2 n.c 3 n.c 4 n.c 21 n.c 22 n.c 23 n.c 24 r/b 7 n.c 26 n.c 27 n.c 28 i/o0 29 n.c 34 n.c 35 vss 36 pre 38 n.c 39 vcc 12 vss 13 ale 17 n.c 11 n.c 10 n.c 14 n.c 15 cle 16 n.c 25 n.c 33 i/o1 30 i/o3 32 i/o2 31 n.c 47 n.c 46 n.c 45 i/o7 44 i/o6 43 i/o5 42 i/o4 41 n.c 40 n.c 48 r2 10k r2 10k c2 100nf c2 100nf r1 10k r1 10k c1 100nf c1 100nf
151 6222f?atarm?14-jan-11 sam7se512/256/32 21.7.4 16-bit nand flash 21.7.4.1 hardware configuration 21.7.4.2 software configuration the software configuration is the same as for an 8-bit nand flash except the data bus width programmed in the mode register of the static memory controller and the selection of d[8..15] in the pio controller. d6 d0 d3 d4 d2 d1 d5 d7 d14 d8 d11 d12 d10 d9 d13 d15 nandoe nandwe (any pio) ale cle d[0..15] (any pio) 3v3 3v3 2 gb tsop48 package r1 10k r1 10k r2 10k r2 10k c2 100nf c2 100nf c1 100nf c1 100nf u1 mt29f2g16aabwp-et u1 mt29f2g16aabwp-et we 18 n.c 6 vcc 37 ce 9 re 8 n.c 20 wp 19 n.c 5 n.c 1 n.c 2 n.c 3 n.c 4 n.c 21 n.c 22 n.c 23 n.c 24 r/b 7 i/o0 26 i/o8 27 i/o1 28 i/o9 29 n.c 34 n.c 35 n.c 36 pre 38 n.c 39 vcc 12 vss 13 ale 17 n.c 11 n.c 10 n.c 14 n.c 15 cle 16 vss 25 i/o11 33 i/o2 30 i/o3 32 i/o10 31 i/o15 47 i/o7 46 i/o14 45 i/o6 44 i/o13 43 i/o5 42 i/o12 41 i/o4 40 vss 48
152 6222f?atarm?14-jan-11 sam7se512/256/32 21.7.5 nor flash on ncs0 21.7.5.1 hardware configuration 21.7.5.2 software configuration ? address lines a[1..22], ncs0, nrd, nwe and da ta lines d[8..15] ar e multiplexed with pio lines and thus dedicated pios must be programmed in peripheral mode in the pio controller. the default configuration for the static memory controller, byte select mode, 16-bit data bus, read/write controlled by chip se lect, allows access on 16-bit non-volatile memory at slow clock. for another configuration, configure the static memory controller cs0 setup, pulse, cycle and mode depending on flash timings and system bus frequency. a21 a22 a1 a2 a3 a4 a5 a6 a7 a8 a15 a9 a12 a13 a11 a10 a14 a16 d6 d0 d3 d4 d2 d1 d5 d7 d14 d8 d11 d12 d10 d9 d13 d15 a17 a20 a18 a19 d[0..15] a[1..22] nrst nwe ncs0 nrd 3v3 3v3 tsop48 package c2 100nf c2 100nf c1 100nf c1 100nf at49bv6416 u1 at49bv6416 u1 a0 25 a1 24 a2 23 a3 22 a4 21 a5 20 a6 19 a7 18 a8 8 a9 7 a10 6 a11 5 a12 4 a13 3 a14 2 a15 1 a16 48 a17 17 a18 16 a21 9 a20 10 a19 15 we 11 reset 12 wp 14 oe 28 ce 26 vpp 13 dq0 29 dq1 31 dq2 33 dq3 35 dq4 38 dq5 40 dq6 42 dq7 44 dq8 30 dq9 32 dq10 34 dq11 36 dq12 39 dq13 41 dq14 43 dq15 45 vccq 47 vss 27 vss 46 vcc 37
153 6222f?atarm?14-jan-11 sam7se512/256/32 21.7.6 compactflash 21.7.6.1 hardware configuration d15 d14 d13 d12 d10 d11 d9 d8 d7 d6 d5 d4 d2 d1 d0 d3 a10 a9 a8 a7 a3 a4 a5 a6 a0 a2 a1 cd1 cd2 cd2 cd1 we oe iowr iord ce2 ce1 reg wait# reset cf_d3 cf_d2 cf_d1 cf_d0 cf_d7 cf_d6 cf_d5 cf_d4 cf_d11 cf_d10 cf_d9 cf_d8 cf_d15 cf_d14 cf_d13 cf_d12 cf_a10 cf_a9 cf_a8 cf_a7 cf_a6 cf_a5 cf_a4 cf_a3 cf_a2 cf_a1 cf_a0 reg we oe iowr iord cf_a10 cf_a9 cf_a8 cf_a7 cf_a6 cf_a5 cf_a4 cf_a3 cf_a2 cf_a1 cf_a0 cf_d4 cf_d13 cf_d15 cf_d14 cf_d12 cf_d11 cf_d10 cf_d9 cf_d8 cf_d7 cf_d6 cf_d5 cf_d3 cf_d2 cf_d1 cf_d0 ce2 ce1 reset rdy/bsy rdy/bsy wait# cfwe (any pio) cfrnw d[0..15] a[0..10] cfcsx a22/reg cfoe cfiow cfior nwait (any pio) cfce2 cfce1 (any pio) 3v3 3v3 3v3 3v3 3v3 3v3 card detect cfirq cfrst memory & i/o mode (cfcs0 or cfcs1) mn2a sn74alvc32 mn2a sn74alvc32 3 1 2 c2 100nf c2 100nf mn1d 74alvch32245 mn1d 74alvch32245 4dir t3 4oe t4 4a1 n5 4a2 n6 4a3 p5 4a4 p6 4a5 r5 4a6 r6 4a7 t6 4a8 t5 4b1 n2 4b2 n1 4b3 p2 4b4 p1 4b5 r2 4b6 r1 4b7 t1 4b8 t2 mn1c 74alvch32245 mn1c 74alvch32245 3dir j3 3oe j4 3a1 j5 3a2 j6 3a3 k5 3a4 k6 3a5 l5 3a6 l6 3a7 m5 3a8 m6 3b1 j2 3b2 j1 3b3 k2 3b4 k1 3b5 l2 3b6 l1 3b7 m2 3b8 m1 r2 47k r2 47k mn3b sn74alvc125 mn3b sn74alvc125 6 4 5 r1 47k r1 47k mn1b 74alvch32245 mn1b 74alvch32245 2dir h3 2oe h4 2a1 e5 2a2 e6 2a3 f5 2a4 f6 2a5 g5 2a6 g6 2a7 h5 2a8 h6 2b1 e2 2b2 e1 2b3 f2 2b4 f1 2b5 g2 2b6 g1 2b7 h2 2b8 h1 vcc gnd mn4 sn74lvc1g125-q1 vcc gnd mn4 sn74lvc1g125-q1 5 1 2 3 4 mn3a sn74alvc125 mn3a sn74alvc125 3 1 2 r3 10k r3 10k mn2b sn74alvc32 mn2b sn74alvc32 6 4 5 mn3c sn74alvc125 mn3c sn74alvc125 8 9 10 r4 10k r4 10k c1 100nf c1 100nf j1 n7e50-7516vy-20 j1 n7e50-7516vy-20 gnd 1 d3 2 d4 3 d5 4 d6 5 d7 6 ce1# 7 a10 8 oe# 9 a9 10 a8 11 a7 12 vcc 13 a6 14 a5 15 a4 16 a3 17 a2 18 a1 19 a0 20 d0 21 d1 22 d2 23 wp 24 cd2# 25 cd1# 26 d11 27 d12 28 d13 29 d14 30 d15 31 ce2# 32 vs1# 33 iord# 34 iowr# 35 we# 36 rdy/bsy 37 vcc 38 csel# 39 vs2# 40 reset 41 wait# 42 inpack# 43 reg# 44 bvd2 45 bvd1 46 d8 47 d9 48 d10 49 gnd 50 mn1a 74alvch32245 mn1a 74alvch32245 1a1 a5 1a2 a6 1a3 b5 1a4 b6 1a5 c5 1a6 c6 1a7 d5 1a8 d6 1dir a3 1oe a4 1b1 a2 1b2 a1 1b3 b2 1b4 b1 1b5 c2 1b6 c1 1b7 d2 1b8 d1 mn3d sn74alvc125 mn3d sn74alvc125 11 12 13
154 6222f?atarm?14-jan-11 sam7se512/256/32 21.7.6.2 software configuration the following configuration must be respected: ? assign the ebi cs4 and/or ebi_cs5 to the compactflash slot 0 and/or slot 1 by setting the bit ebi_cs4a and/or ebi_cs5a in the ebi chip select assignment register. ? select the mode by using the correspond ing address (refer to figure 21.3). ? address lines a[0..10], a22, cfwe, cf oe, cfiow, cfior, nwait, cfrnw, cfs0, cfcs1, cfce1, cfce2 and data lines d[8..15] are multiplex ed with pio lines and thus the dedicated pios must be programmed in peripheral mode in the pio controller. ? configure a pio line as an output for cfrst and two others as an input for cfirq and card detect functions respectively. ? configure smc cs4 and/or smc_cs5 (for slot 0 or 1) setup, pulse, cycle and mode accordingly to compactflash timings and system bus frequency.
155 6222f?atarm?14-jan-11 sam7se512/256/32 21.7.7 compactflash true ide 21.7.7.1 hardware configuration d15 d14 d13 d12 d10 d11 d9 d8 d7 d6 d5 d4 d2 d1 d0 d3 a10 a9 a8 a7 a3 a4 a5 a6 a0 a2 a1 cd1 cd2 cf_d3 cf_d2 cf_d1 cf_d0 cf_d7 cf_d6 cf_d5 cf_d4 cf_d11 cf_d10 cf_d9 cf_d8 cf_d15 cf_d14 cf_d13 cf_d12 reset# cf_a10 cf_a9 cf_a8 cf_a7 cf_a6 cf_a5 cf_a4 cf_a3 cf_a2 cf_a1 cf_a0 cd2 cd1 iowr iord ce2 ce1 reg we oe iowr iord iordy cf_a0 cf_a2 cf_a1 cf_d4 cf_d13 cf_d15 cf_d14 cf_d12 cf_d11 cf_d10 cf_d9 cf_d8 cf_d7 cf_d6 cf_d5 cf_d3 cf_d2 cf_d1 cf_d0 ce2 ce1 reset# intrq iordy intrq cfwe (any pio) cfrnw d[0..15] a[0..10] cfcsx a22/reg cfoe cfiow cfior nwait (any pio) cfce2 cfce1 (any pio) 3v3 3v3 3v3 3v3 3v3 3v3 3v3 card detect cfirq cfrst true ide mode (cfcs0 or cfcs1) c2 100nf c2 100nf mn1d 74alvch32245 mn1d 74alvch32245 4dir t3 4oe t4 4a1 n5 4a2 n6 4a3 p5 4a4 p6 4a5 r5 4a6 r6 4a7 t6 4a8 t5 4b1 n2 4b2 n1 4b3 p2 4b4 p1 4b5 r2 4b6 r1 4b7 t1 4b8 t2 vcc gnd mn4 sn74lvc1g125-q1 vcc gnd mn4 sn74lvc1g125-q1 5 1 2 3 4 mn3c sn74alvc125 mn3c sn74alvc125 8 9 10 r4 10k r4 10k mn1c 74alvch32245 mn1c 74alvch32245 3dir j3 3oe j4 3a1 j5 3a2 j6 3a3 k5 3a4 k6 3a5 l5 3a6 l6 3a7 m5 3a8 m6 3b1 j2 3b2 j1 3b3 k2 3b4 k1 3b5 l2 3b6 l1 3b7 m2 3b8 m1 r3 10k r3 10k j1 n7e50-7516vy-20 j1 n7e50-7516vy-20 gnd 1 d3 2 d4 3 d5 4 d6 5 d7 6 cs0# 7 a10 8 ata sel # 9 a9 10 a8 11 a7 12 vcc 13 a6 14 a5 15 a4 16 a3 17 a2 18 a1 19 a0 20 d0 21 d1 22 d2 23 iois16# 24 cd2# 25 cd1# 26 d11 27 d12 28 d13 29 d14 30 d15 31 cs1# 32 vs1# 33 iord# 34 iowr# 35 we# 36 intrq 37 vcc 38 csel# 39 vs2# 40 reset# 41 iordy 42 inpack# 43 reg# 44 dasp# 45 pdiag# 46 d8 47 d9 48 d10 49 gnd 50 mn1a 74alvch32245 mn1a 74alvch32245 1a1 a5 1a2 a6 1a3 b5 1a4 b6 1a5 c5 1a6 c6 1a7 d5 1a8 d6 1dir a3 1oe a4 1b1 a2 1b2 a1 1b3 b2 1b4 b1 1b5 c2 1b6 c1 1b7 d2 1b8 d1 mn1b 74alvch32245 mn1b 74alvch32245 2dir h3 2oe h4 2a1 e5 2a2 e6 2a3 f5 2a4 f6 2a5 g5 2a6 g6 2a7 h5 2a8 h6 2b1 e2 2b2 e1 2b3 f2 2b4 f1 2b5 g2 2b6 g1 2b7 h2 2b8 h1 mn2a sn74alvc32 mn2a sn74alvc32 3 1 2 c1 100nf c1 100nf r2 47k r2 47k r1 47k r1 47k mn3b sn74alvc125 mn3b sn74alvc125 6 4 5 mn3d sn74alvc125 mn3d sn74alvc125 11 12 13 mn2b sn74alvc32 mn2b sn74alvc32 6 4 5 mn3a sn74alvc125 mn3a sn74alvc125 3 1 2
156 6222f?atarm?14-jan-11 sam7se512/256/32 21.7.7.2 software configuration the following configuration must be respected: ? address lines a[0..10], a22, cfwe, cf oe, cfiow, cfior, nwait, cfrnw, cfs0, cfcs1, cfce1, cfce2 and data lines d[8..15] are multiplex ed with pio lines and thus the dedicated pios must be programmed in peripheral mode in the pio controller. ? assign the ebi cs4 and/or ebi cs5 to the compactflash slot 0 or/and slot 1 by setting the bit ebi_cs4a and/or ebi_cs5a in the ebi chip select assignment register. ? select the mode by using the corresponding address (refer to figure 21-3 ). ? configure a pio line as an output for cfrst and two others as an input for cfirq and card detect functions respectively. ? configure smc cs4 and/or smc_cs5 (for slot 0 or 1) setup, pulse, cycle and mode according to compactflash timings and system bus frequency.
157 6222f?atarm?14-jan-11 sam7se512/256/32 21.8 external bus interfac e (ebi) user interface ebi user interface base address: 0xffff ff80 table 21-8. external bus interface memory map offset register name access reset state 0x00 chip select assignment register ebi_csa read/write 0x0 0x04 reserved ? 0x08 reserved ? 0x0c reserved ? 0x10 - 0x2c smc user interface refer to t he static memory controller user interface 0x30 - 0x58 sdramc user interface refer to the sdram controller user interface 0x5c - 0x6c ecc user interface refer to the e rror code corrected cont roller user interface 0x70 - 0x7c reserved ?
158 6222f?atarm?14-jan-11 sam7se512/256/32 21.8.1 ebi chip select assignment register name: ebi_csa access: read/write reset value: 0x0 offset: 0x0 absolute address: 0xffff ff80 ? cs1a: chip select 1 assignment 0 = chip select 1 is assigned to the static memory controller. 1 = chip select 1 is assigned to the sdram controller. ? cs2a: chip select 2 assignment 0 = chip select 2 is assigned to the static memory controller and ncs2, ncs5 and ncs6 behave as defined by the smc. 1 = chip select 2 is assigned to the static memory controller and the compactflash logic (second slot) is activated. accessing the address space reserved to ncs5 an d ncs6 may lead to an unpredictable outcome. ? cs3a: chip select 3 assignment 0 = chip select 3 is only assigned to the static memory controller and ncs3 behave as defined by the smc. 1 = chip select 3 is assigned to the static memo ry controller and the nand flash logic is activated. ? cs4a: chip select 4 assignment 0 = chip select 4 is assigned to the static memory controller and ncs4, ncs5 and ncs6 behave as defined by the smc. 1 = chip select 4 is assigned to the static memory controller and the compactflash logic (first slot) is activated. accessing the address space reserved to ncs5 an d ncs6 may lead to an unpredictable outcome. ? nwpc: nwait pin configuration 0 = the nwait device pin is not connected to the external wait request input of the static memory controller, this multi- plexed pin can be used as a pio. 1 = the nwait device pin is connected to the external wait request input of the static memory controller. 31 30 29 28 27 26 25 24 ???????? 23 22 21 20 19 18 17 16 ???????nwpc 15 14 13 12 11 10 9 8 ???????? 76543210 ? ? ? cs4a cs3a cs2a cs1a ?
159 6222f?atarm?14-jan-11 sam7se512/256/32
160 6222f?atarm?14-jan-11 sam7se512/256/32
161 6222f?atarm?14-jan-11 sam7se512/256/32 22. static memory controller (smc) 22.1 overview the static memory controller (smc) generates t he signals that control the access to external static memory or peripheral devices. the smc is fully programmable. it has eight chip selects and a 23-bit address bus. the 16-bit data bus can be configured to interface with 8- or 16-bit external devices. separate read and write control signals allow for direct memory and peripheral interfacing. the smc supports different access protocols allowing single clock cycle memory accesses. it also provides an ex ternal wait request capability. 22.2 block diagram figure 22-1. static memory cont roller block diagram apb ncs[7:0] nwr0/nwe smc pio controller nwr1/nub nrd a0/nlb a[22:1] d[15:0] nwait user interface pmc mck memory controller smc chip select
162 6222f?atarm?14-jan-11 sam7se512/256/32 22.3 i/o lines description 22.4 multiplexed signals table 22-1. i/o lines description name description type active level ncs[7:0] static memory controller chip select lines output low nrd read signal output low nwr0/nwe write 0/write enable signal output low nwr1/nub write 1/upper byte select signal output low a0/nlb address bit 0/lower byte select signal output low a[22:1] address bus output d[15:0] data bus i/o nwait external wait signal input low table 22-2. static memory contro ller multiplexed signals multiplexed signals related function a0 nlb 8-bit or 16-bit data bus, see 22.6.1.3 ?data bus width? on page 164 . nwr0 nwe byte-write or byte-select access, see 22.6.2.1 ?write access type? on page 165 . nwr1 nub byte-write or byte-select access, see 22.6.2.1 ?write access type? on page 165 .
163 6222f?atarm?14-jan-11 sam7se512/256/32 22.5 product dependencies 22.5.1 i/o lines the pins used for interfacing the static memory controller may be multiplexed with the pio lines. the programmer must first program the pio controller to assign the static memory con- troller pins to their peripheral function. if i/o lines of the static memory controller are not used by the application, they can be used for other purposes by the pio controller. 22.6 functional description 22.6.1 external memory interface 22.6.1.1 external memory mapping the memory map is defined by hardware and asso ciates the internal 32-bit address space with the external 23-bit address bus. note that a[22:0 ] is only significant for 8-bit memory. a[22:1] is used for 16-bit memory. if the physical memory device is smaller than the page size, it wraps around and appears to be repeated within the page. the smc correctly handles any valid access to the memory devi ce within the page. see figure 22-2 . figure 22-2. case of an external memory smaller than page size 1m byte device 1m byte device 1m byte device 1m byte device memory map hi low hi low hi low hi low base base + 1m byte base + 2m bytes base + 3m bytes base + 4m bytes repeat 1 repeat 2 repeat 3
164 6222f?atarm?14-jan-11 sam7se512/256/32 22.6.1.2 chip select lines the static memory controller provides up to eight chip select lines: ncs0 to ncs7. figure 22-3. memory connections for eight external devices (1) note: 1. the maximum address space per device is 8 mbytes. 22.6.1.3 data bus width a data bus width of 8 or 16 bits can be selected for each chip select. this option is controlled by the dbw field in the smc_csr for the corresponding chip select. see ?smc chip select regis- ters? on page 196 . figure 22-4 shows how to connect a 512k x 8-bit memory on ncs2 (dbw = 10). figure 22-4. memory connection for an 8-bit data path device figure 22-5 shows how to connect a 512k x 16-bit memory on ncs2 (dbw = 01). nrd nwr[1:0] a[22:0] d[15:0] 8 or 16 memory enable memory enable memory enable memory enable memory enable memory enable memory enable memory enable output enable write enable a[22:0] d[15:0] or d[7:0] ncs3 ncs0 ncs1 ncs2 ncs7 ncs4 ncs5 ncs6 ncs[7:0] smc smc a0 nwr0 nrd ncs2 a0 write enable output enable memory enable nwr1 d[7:0] d[7:0] d[15:8] a[22:1] a[22:1]
165 6222f?atarm?14-jan-11 sam7se512/256/32 figure 22-5. memory connection for a 16-bit data path device 22.6.2 write access 22.6.2.1 write access type each chip select with a 16-bit data bus can operate with one of two different types of write access: ? byte write access supports two byte write and a single read signal. ? byte select access selects upper and/or lower byte with two byte select lines, and separate read and write signals. this option is controlled by the bat field in the smc_csr for the corresponding chip select. see ?smc chip select re gisters? on page 196 . 22.6.2.2 byte write access byte write access is used to connect 2 x 8-bit devices as a 16-bit memory page. ? the signal a0/nlb is not used. ? the signal nwr1/nub is used as nwr1 and enables upper byte writes. ? the signal nwr0/nwe is used as nwr0 and enables lower byte writes. ? the signal nrd enables half-word and byte reads. figure 22-6 shows how to connect two 512k x 8-bit devices in parallel on ncs2 (bat = 0) smc nlb nwe nrd ncs2 low byte enable write enable output enable memory enable nub high byte enable d[7:0] d[7:0] d[15:8] d[15:8] a[22:1] a[22:0]
166 6222f?atarm?14-jan-11 sam7se512/256/32 figure 22-6. memory connection for 2 x 8-bit data path devices 22.6.2.3 byte select access byte select access is used to connect 16-bit devices in a memory page. ? the signal a0/nlb is used as nlb and enables the lower byte for both read and write operations. ? the signal nwr1/nub is used as nub and enables the upper byte for both read and write operations. ? the signal nwr0/nwe is used as nwe and enables writing for byte or half-word. ? the signal nrd enables reading for byte or half-word. figure 22-7 shows how to connect a 16-bit device with byte and half-word access (e.g., sram device type) on ncs2 (bat = 1). figure 22-7. connection to a 16-bit data path device with byte and half-word access smc a0 nwr0 nrd ncs2 write enable read enable memory enable nwr1 write enable read enable memory enable d[7:0] d[7:0] d[15:8] d[15:8] a[22:1] a[18:0] a[18:0] smc nlb nwe nrd ncs2 low byte enable write enable output enable memory enable nub high byte enable d[7:0] d[7:0] d[15:8] d[15:8] a[19:1] a[18:0]
167 6222f?atarm?14-jan-11 sam7se512/256/32 figure 22-8 shows how to connect a 16-bit device without byte access (e.g., flash device type) on ncs2 (bat = 1). figure 22-8. connection to a 16-bit data path de vice without byte write capability 22.6.2.4 write data hold time during write cycles, data output becomes valid a fter the rising edge of mck and remains valid after the rising edge of nwe. during a write access, the data remain on the bus 1/2 period of mck after the rising edge of nwe. see figure 22-9 and figure 22-10 . figure 22-9. write access with 0 wait state smc d[7:0] d[7:0] d[15:8] d[15:8] a[19:1] nlb nwe nrd ncs2 write enable output enable memory enable nub a[18:0] a[22:0] ncs mck nwe d[15:0]
168 6222f?atarm?14-jan-11 sam7se512/256/32 figure 22-10. write access with 1 wait state 22.6.3 read access 22.6.3.1 read protocols the smc provides two alternative protocols for external memory read accesses: standard and early read. the difference between the two protocols lies in the behavior of the nrd signal. for write accesses, in both protocols, nwe has the same behavior. in the second half of the master clock cycle, nwe always goes low (see figure 22-18 on page 173 ). the protocol is selected by the drp field in smc_csr ( see ?smc chip select registers? on page 196. ). standard read protocol is the default protocol after reset. note: in the following waveforms and descriptions nwe represents nwe, nwr0 and nwr1 unless nwr0 and nwr1 are otherwise represented. in addition, ncs represents ncs[7:0] (see 22.5.1 ?i/o lines? on page 163 , table 22-1 and table 22-2 ). 22.6.3.2 standard read protocol standard read protocol implements a read cycle during which nrd and nwe are similar. both are active during the second half of the clock cycle. the first half of the clock cycle allows time to ensure completion of the previous access as well as the output of address lines and ncs before the read cycle begins. during a standard read protocol, ncs is set low a nd address lines are valid at the beginning of the external memory access, while nrd goes low only in the second half of the master clock cycle to avoid bus conflict. see figure 22-11 . a[22:0] ncs nwe mck d[15:0]
169 6222f?atarm?14-jan-11 sam7se512/256/32 figure 22-11. standard read protocol 22.6.3.3 early read protocol early read protocol provides more time for a read access from the memory by asserting nrd at the beginning of the clock cycle. in the case of successive read cycles in the same memory, nrd remains active continuously . since a read cycle normally lim its the speed of operation of the external memory system, early read protocol can allow a faster clock frequency to be used. however, an extra wait state is required in some cases to avoid contentions on the external bus. figure 22-12. early read protocol 22.6.4 wait state management the smc can automatically insert wait states. the different types of wait states managed are listed below: ? standard wait states ? external wait states ? data float wait states ? chip select change wait states ? early read wait states a[22:0] ncs mck nrd d[15:0] a[22:0] ncs mck nrd d[15:0]
170 6222f?atarm?14-jan-11 sam7se512/256/32 22.6.4.1 standard wait states each chip select can be programmed to insert one or more wait states during an access on the corresponding memory area. this is done by setting the wsen field in the corresponding smc_csr ( ?smc chip select registers? on page 196 ). the number of cycles to insert is pro- grammed in the nws field in the same register. below is the correspondence between the number of standard wait states programmed and the number of clock cycles during which the nwe pulse is held low: 0 wait states 1/2 clock cycle 1 wait state 1 clock cycle for each additional wait state programmed, an additional cycle is added. figure 22-13. one standard wait state access notes: 1. early read protocol 2. standard read protocol 22.6.4.2 external wait states the nwait input pin is used to insert wait states beyond the maximum standard wait states pro- grammable or in addition to. if nwait is asserted low, then the smc adds a wait state and no changes are made to the output signals, the internal counters or the state. when nwait is de- asserted, the smc comple tes the access sequence. warning: asserting nwait low stops the core?s clock and thus stops program execution. the input of the nwait signal is an asynchronous input. to avoid any metast ability problems, nwait is synchronized before using it. this operation results in a two-cycle delay. nws must be programmed as a function of synchronization time and delay between nwait fall- ing and control signals fa lling (nrd/nwe), otherwise smc will not function correctly. note: where external nwait synchronization is equal to 2 cycles. the minimum value for nws if nwait is used, is 3. warning: if nwait is asserted during a setup or hold timing, the smc does not function correctly. a[22:0] ncs nwe mck 1 wait state access nrd (1) (2) nws wait delay from nrd/nwe external_nwait synchronization delay 1 ++
171 6222f?atarm?14-jan-11 sam7se512/256/32 figure 22-14. nwait behavior in read access [nws = 3] notes: 1. early read protocol 2. standard read protocol figure 22-15. nwait behavior in write access [nws = 3] 22.6.4.3 data float wait states some memory devices are slow to release the exte rnal bus. for such devices, it is necessary to add wait states (data float wait states) after a read access before starting a write access or a read access to a different external memory. the data float output time (t df ) for each external memory dev ice is programmed in the tdf field of the smc_csr register for the corresponding chip select ( ?smc chip select registers? on page 196 ). the value of tdf indicates the number of data float wait cycles (between 0 and a[22:0] nwait nwait internally synchronized nrd ncs (1) (2) wait delay from nrd nwait synchronization delay mck a[22:0] nwait nwait internally synchronized nwe d[15:0] wait delay from nwe nwait synchronization delay mck
172 6222f?atarm?14-jan-11 sam7se512/256/32 15) to be inserted and represents the time allowed for the data output to go to high impedance after the memory is disabled. data float wait states do not delay internal memory accesses. hence, a single access to an external memory with long t df will not slow down the executio n of a program from internal memory. to ensure that the exte rnal memory system is not accessed wh ile it is still bu sy, the smc keeps track of the programmed external data float time during internal accesses. internal memory accesses and consecutive read accesses to the same external memory do not add data float wait states. figure 22-16. data float output delay notes: 1. early read protocol 2. standard read protocol 22.6.4.4 chip select change wait state a chip select wait state is automatically inse rted when consecutive accesses are made to two different external memories (if no other type of wait state has already been inserted). if a wait state has already been inserted (e.g., data float wait state), then no more wait states are added. a[22:0] nrd d[15:0] mck t df (1) (2) ncs
173 6222f?atarm?14-jan-11 sam7se512/256/32 figure 22-17. chip select wait state notes: 1. early read protocol 2. standard read protocol 22.6.4.5 early read wait state in early read protocol, an early read wait state is automatically inserted when an external write cycle is followed by a read cycle to allow time for the write cycle to end before the subsequent read cycle begins (see figure 22-18 ). this wait state is generated in addition to any other pro- grammed wait states (i.e., data float wait state). no wait state is added when a read cycle is followed by a write cycle, between consecutive accesses of the same type, or between external and internal memory accesses. figure 22-18. early read wait states ncs1 ncs2 mck mem 1 chip select wait mem 2 nrd nwe (1) (2) a[22:0] addr mem 1 addr mem 2 a[22:0] ncs nwe mck write cycle early read wait read cycle nrd d[15:0]
174 6222f?atarm?14-jan-11 sam7se512/256/32 22.6.5 setup and hold cycles the smc allows some memory devices to be interfaced with different setup, hold and pulse delays. these parameters are programmable and define the timing of each portion of the read and write cycles. however, it is not possible to use this feature in early read protocol. if an attempt is made to program the setup parameter as not equal to zero and the hold parame- ter as equal to zero with wsen = 0 (0 standard wait state), the smc does not operate correctly. if consecutive accesses are made to two different external memories and the second memory is programmed with setup cycles, then no chip select change wait state is inserted (see figure 22- 23 on page 176 ). when a data float wait state (t df ) is programmed on the first memory bank and when the second memory bank is programmed with setu p cycles, the smc behaves as follows: ? if the number of t df is higher or equal to the number of setup cycles, the number of setup cycles inserted is equal to 0 (see figure 22-24 on page 176 ). ? if the number of the setup cycle is higher than the number of t df, the number of t df inserted is 0 (see figure 22-25 on page 177 ). 22.6.5.1 read access the read cycle can be divided into a setup, a pulse length and a hold. the setup parameter can have a value between 1.5 and 7.5 clock cycles, the hold parameter between 0 and 7 clock cycles and the pulse length between 1.5 and 128.5 clock cycles, by increments of one. figure 22-19. read access with setup and hold figure 22-20. read access with setup nrd setup pulse length nrd a[22:0] nrd hold mck nrd setup pulse length nrd a[22:0] mck
175 6222f?atarm?14-jan-11 sam7se512/256/32 22.6.5.2 write access the write cycle can be divided into a setup, a pulse length and a hold. the setup parameter can have a value between 1.5 and 7.5 clock cycles, the hold parameter between 0.5 and 7 clock cycles and the pulse length between 1 and 128 clock cycles by increments of one. figure 22-21. write access with setup and hold figure 22-22. write access with setup nwr setup pulse length nwe a[22:0] nwr hold d[15:0] mck nwr setup pulse length nwe a[22:0] nwr hold d[15:0] mck
176 6222f?atarm?14-jan-11 sam7se512/256/32 22.6.5.3 data float wait states with setup cycles figure 22-23. consecutive accesses with setup programmed on the second access figure 22-24. first access with data float wait states (tdf = 2) and second access with setup (nrdsetup = 1) setup ncs1 a[22:0] mck ncs2 nrd nwe setup ncs1 a[22:0] mck ncs2 d[15:0] nrd data float time
177 6222f?atarm?14-jan-11 sam7se512/256/32 figure 22-25. first access with data float wait states (tdf = 2) and second access with setup (nrdsetup = 3) setup ncs1 a[22:0] mck ncs2 d[15:0] nrd data float time
178 6222f?atarm?14-jan-11 sam7se512/256/32 22.6.6 lcd interface mode the smc can be configured to work with an external liquid crystal display (lcd) controller by setting the acss (address to chip select setup) bit in the smc_csr registers ( ?smc chip select registers? on page 196 ). in lcd mode, ncs is shortened by one/two/three clock cycles at the leading and trailing edges, providing positive address setup and hold. for read accesses, the data is latched in the smc when ncs is raised at the end of the access. additionally, wsen must be set and nws programm ed with a value of two or more superior to acss. in lcd mode, it is not recommended to use rwhold or rwsetup. if the above condi- tions are not satisfied, smc does not operate correctly. figure 22-26. read access in lcd interface mode figure 22-27. write access in lcd interface mode nrd a[22:0] ncs data from lcd controller acss acss = 3, nwen = 1, nws = 10 acss mck nwe a[22:0] accs = 2, nwen = 1, nws = 10 accs accs ncs d[15:0] mck
179 6222f?atarm?14-jan-11 sam7se512/256/32 22.6.7 memory access waveforms 22.6.7.1 read accesses in standard and early protocols figure 22-28 on page 179 through figure 22-31 on page 182 show examples of the alternatives for external memory read protocol. figure 22-28. standard read protocol without t df read mem 1 write mem 1 read mem 1 read mem 2 write mem 2 read mem 2 chip select change wait a[22:0] nrd nwe ncs1 ncs2 d[15:0] (mem 1) d[15:0] (mem 2) d[15:0] (to write) mck t whdx t whdx
180 6222f?atarm?14-jan-11 sam7se512/256/32 figure 22-29. early read protocol without t df read mem 1 write mem 1 early read wait cycle read mem 1 read mem 2 write mem 2 early read wait cycle read mem 2 chip select change wait long t whdx a[22:0] nrd nwe ncs1 ncs2 d[15:0] (mem 1) d[15:0] (mem 2) d[15:0] (to write) mck t whdx
181 6222f?atarm?14-jan-11 sam7se512/256/32 figure 22-30. standard read protocol with t df read mem 1 write mem 1 data float wait read mem 1 data float wait read mem 2 read mem 2 data float wait write mem 2 write mem 2 t whdx t df t df t df a[22:0] nrd nwe ncs1 ncs2 d[15:0] (mem 1) d[15:0] (mem 2) d[15:0] mck (t df = 2) (t df = 1) (t df = 1 ) (to write)
182 6222f?atarm?14-jan-11 sam7se512/256/32 figure 22-31. early read protocol with t df read mem 2 a[22:0] nrd nwe ncs1 ncs2 d[15:0] (mem 1) d[15:0] (mem 2) d[15:0] mck (t df = 2) (to write) read mem 1 write mem 1 data float wait early read wait read mem 1 data float wait read mem 2 data float wait write mem 2 write mem 2 t df t df t df
183 6222f?atarm?14-jan-11 sam7se512/256/32 22.6.7.2 accesses with setup and hold figure 22-32 and figure 22-33 show an example of read and write accesses with setup and hold cycles. figure 22-32. read accesses in standard read protocol with setup and hold (1) note: 1. read access, memory data bus width = 8, rwsetup = 1, rwhold = 1,wsen= 1, nws = 0 figure 22-33. write accesses with setup and hold (1) note: 1. write access, memory data bus width = 8, rwsetup = 1, rwhold = 1, wsen = 1, nws = 0 mck a[22:1] a0/nlb nrd nwr0/nwe nwr1/nub ncs d[15:0] 00d2b 00028 00d2c e59f 0001 0002 hold setup setup hold mck a[22:1] a0/nlb nrd nwr0/nwe nwr1/nub ncs d[15:0] 008cb 00082 008cc 3000 e3a0 0605 0606 setup hold setup hold
184 6222f?atarm?14-jan-11 sam7se512/256/32 22.6.7.3 accesses using nwait input signal figure 22-34 on page 184 through figure 22-37 on page 187 show examples of accesses using nwait. figure 22-34. write access using nwait in byte select type access (1) note: 1. write access memory, data bus width = 16 bits, wsen = 1, nws = 6 a[22:1] nrd nwr0/nwe a0/nlb nwr1/nub ncs d[15:0] mck nwait nwait internally synchronized 000008a 1312 wait delay falling from nwr0/nwe chip select wait
185 6222f?atarm?14-jan-11 sam7se512/256/32 figure 22-35. write access using nwait in byte write type access (1) note: 1. write access memory, data bus width = 16 bits, wsen = 1, nws = 5 a[22:1] nrd nwr0/nwe a0/nlb nwr1/nub ncs d[15:0] mck nwait nwait internally synchronized 000008c 1716 wait delay falling from nwr0/nwe/nwr1/nub chip select wait
186 6222f?atarm?14-jan-11 sam7se512/256/32 figure 22-36. write access using nwait (1) note: 1. write access memory, data bus width = 8 bits, wsen = 1, nws = 4 ncs a[22:1] nrd nwr0/nwe a0/nlb nwr1/nub d[15:0] mck nwait nwait internally synchronized 0000033 0403 wait delay falling from nwr0/nwe chip select wait
187 6222f?atarm?14-jan-11 sam7se512/256/32 figure 22-37. read access in standard protocol using nwait (1) note: 1. read access, memory data bus width = 16, nws = 5, wsen = 1 22.6.7.4 memory access example waveforms figure 22-38 on page 188 through figure 22-44 on page 194 show the wavefo rms for read and write accesses to the various associated ex ternal memory devices. the configurations described are shown in table 22-3 . ncs a[22:1] nrd nwr0/nwe a0/nlb nwr1/nub d[15:0] mck nwait nwait internally synchronized 0002c44 0003 wait delay falling from nrd/noe table 22-3. memory access waveforms figure number number of wait states bus width size of data transfer figure 22-38 016word figure 22-39 116word figure 22-40 116half-word figure 22-41 08word figure 22-42 18half-word figure 22-43 18byte figure 22-44 0 16 byte
188 6222f?atarm?14-jan-11 sam7se512/256/32 figure 22-38. 0 wait state, 16-bit bus width, word transfer b 2 b 1 b 4 b 3 b 2 b 1 b 4 b 3 b 2 b 1 b 4 b 3 mck ncs nrd read access nrd write access nwe d[15:0] nlb nub standard read protocol early read protocol byte write/ byte select option d[15:0] d[15:0] a[22:1] addr addr+1
189 6222f?atarm?14-jan-11 sam7se512/256/32 figure 22-39. 1 wait state, 16-bit bus width, word transfer b 2 b 1 b 4 b 3 1 wait state 1 wait state b 4 b 3 b 2 b 1 b 4 b 3 b 2 b 1 mck ncs nrd read access nrd write access nwe d[15:0] nlb nub standard read protocol early read protocol byte write/ byte select option d[15:0] d[15:0] a[22:1] addr addr+1
190 6222f?atarm?14-jan-11 sam7se512/256/32 figure 22-40. 1 wait state, 16-bit bus width, half-word transfer b 2 b 1 1 wait state b 2 b 1 b 2 b 1 mck ncs nrd read access nrd write access nwe d[15:0] nlb nub standard read protocol early read protocol byte write/ byte select option d[15:0] d[15:0] a[22:1]
191 6222f?atarm?14-jan-11 sam7se512/256/32 figure 22-41. 0 wait state, 8-bit bus width, word transfer addr x b 1 addr+2 addr+3 x b 2 x b 3 x b 4 x b 1 x b 2 x b 3 x b 4 x b 1 x b 2 x b 3 x b 4 addr+1 mck ncs nrd read access nrd write access nwr1 d[15:0] standard read protocol early read protocol d[15:0] d[15:0] a[22:0] nwr0
192 6222f?atarm?14-jan-11 sam7se512/256/32 figure 22-42. 1 wait state, 8-bit bus width, half-word transfer addr x b 1 1 wait state addr+1 1 wait state x b 2 x b 1 x b 2 x b 1 x b 2 mck ncs nrd read access nrd write access nwr1 d[15:0] standard read, protocol early read protocol d[15:0] d[15:0] a[22:0] nwr0
193 6222f?atarm?14-jan-11 sam7se512/256/32 figure 22-43. 1 wait state, 8-bit bus width, byte transfer xb 1 1 wait state x b 1 x b 1 mck ncs nrd read access nrd write access nwr1 d[15:0] standard read protocol early read protocol d[15:0] d[15:0] a[22:0] nwr0
194 6222f?atarm?14-jan-11 sam7se512/256/32 figure 22-44. 0 wait state, 16-bit bus width, byte transfer x b 1 b 2 x addr x x x 0 addr x x x 0 addr x x x 0 addr x x x 1 xb 1 b 2 x b 1 b 1 b 2 b 2 mck ncs nrd read access nrd write access nwr1 d[15:0] standard read protocol early read protocol d[15:0] d[15:0] a[22:1] nwr0 byte write option byte select option internal address bus nlb nub nwe
195 6222f?atarm?14-jan-11 sam7se512/256/32 22.7 static memory controll er (smc) user interface the static memory controller is programmed using the registers listed in table 22-4 . eight chip select registers (smc_csr0 to smc_csr7) are used to program the parameters for the individual external memories. table 22-4. static memory controller register mapping offset register name access reset state 0x00 smc chip select register 0 smc_csr0 read/write 0x00002000 0x04 smc chip select register 1 smc_csr1 read/write 0x00002000 0x08 smc chip select register 2 smc_csr2 read/write 0x00002000 0x0c smc chip select register 3 smc_csr3 read/write 0x00002000 0x10 smc chip select register 4 smc_csr4 read/write 0x00002000 0x14 smc chip select register 5 smc_csr5 read/write 0x00002000 0x18 smc chip select register 6 smc_csr6 read/write 0x00002000 0x1c smc chip select register 7 smc_csr7 read/write 0x00002000
196 6222f?atarm?14-jan-11 sam7se512/256/32 22.7.1 smc chip select registers name: smc_csr0..smc_csr7 access: read/write reset value: see table 22-4 on page 195 ? nws: number of wait states this field defines the read and write signal pulse length from 1 cycle up to 128 cycles. note: when wsen is 0, nws will be read to 0 whichever the previous programmed value should be. note: 1. assuming wsen field = 0. ? wsen: wait state enable 0: wait states are disabled. 1: wait states are enabled. ? tdf: data float time the external bus is marked occupied and cannot be used by an other chip select during tdf cycles. up to 15 cycles can be defined and represents the time allowed for the data output to go to high impedance after the memory is disabled. ? bat: byte access type this field is used only if dbw defines a 16-bit data bus. 0: chip select line is connected to two 8-bit wide devices. 1: chip select line is connect ed to a 16-bit wide device. 31 30 29 28 27 26 25 24 ?rwhold?rwsetup 23 22 21 20 19 18 17 16 ?????? acss 15 14 13 12 11 10 9 8 drp dbw bat tdf 76543210 wsen nws number of wait states nws field nrd pulse length standard read protocol nrd pulse length early read protocol nwr pulse length 0 (1) don?t care ? cycle 1 cycle ? cycle 1 0 1 + ? cycles 2 cycles 1 cycle 2 1 2 + ? cycles 3 cycles 2 cycles x + 1 up to x = 127 x + 1+ ? cycles x + 2 cycles x + 1 cycle
197 6222f?atarm?14-jan-11 sam7se512/256/32 ? dbw: data bus width ? drp: data read protocol 0: standard read protocol is used. 1: early read protocol is used. ? acss: address to chip select setup ? rwsetup: read and write signal setup time see definition and description below. ? rwhold: read and write signal hold time see definition and description below . notes: 1. for a visual description, please refer to ?setup and hold cycles? on page 174 and the diagrams in figure 22-45 and figure 22-46 and figure 22-47 on page 198 . 2. in standard read protocol. 3. in early read protocol. (it is not possible to use the parameters rwsetup or rwhold in this mode.) 4. when the ecc controller is used, rwho ld must be programmed to 1 at least. dbw data bus width 0 0 reserved 0116-bit 108-bit 11reserved acss chip select waveform 0 0 standard, asserted at the beginning of the access and deasserted at the end. 0 1 one cycle less at the beginning and the end of the access. 1 0 two cycles less at the beginning and the end of the access. 1 1 three cycles less at the beginning and the end of the access. rwsetup (1) nrd setup nwr setup rwhold (1) (4) nrd hold nwr hold 000 ? cycle (2) or 0 cycles (3) ? cycle 0 0 0 0 ? cycle 0 0 1 1 + ? cycles 1 + ? cycles 0 0 1 1 cycles 1 cycle 0 1 0 2 + ? cycles 2 + ? cycles 0 1 0 2 cycles 2 cycles 0 1 1 3 + ? cycles 3 + ? cycles 0 1 1 3 cycles 3 cycles 1 0 0 4 + ? cycles 4 + ? cycles 1 0 0 4 cycles 4 cycles 1 0 1 5 + ? cycles 5 + ? cycles 1 0 1 5 cycles 5 cycles 1 1 0 6 + ? cycles 6 + ? cycles 1 1 0 6 cycles 6 cycles 1 1 1 7 + ? cycles 7 + ? cycles 1 1 1 7 cycles 7 cycles
198 6222f?atarm?14-jan-11 sam7se512/256/32 figure 22-45. read/write setup figure 22-46. read hold figure 22-47. write hold nrd a[22:0] mck rwsetup nwe nrd a[22:0] mck rwhold nwe a[22:0] mck rwhold d[15:0]
199 6222f?atarm?14-jan-11 sam7se512/256/32 23. sdram controller (sdramc) 23.1 overview the sdram controller (sdramc) extends the memory capabilities of a chip by providing the interface to an external 16-bit or 32-bit sdram device. the page size supports ranges from 2048 to 8192 and the number of columns from 256 to 2048. it supports byte (8-bit), half-word (16-bit) and word (32-bit) accesses. the sdram controller supports a read or write burst length of one location. it does not support byte read/write bursts or half-word write bursts . it keeps track of the active row in each bank, thus maximizing sdram performance, e.g., the ap plication may be placed in one bank and data in the other banks. so as to optimize performance, it is advisable to avoid accessing different rows in the same bank. the sdram controller also supports mobile sdram if vddio is set at 1.8v with the frequency limitation as given in the product electrical characteristics. however, the sdramc does not support the low-power extended mode register and deep power-down mode. 23.2 block diagram figure 23-1. sdram controller block diagram memory controller apb sdramc interrupt sdck sdcs a[12:0] sdramc pio controller ba[1:0] sdcke ras cas sdwe nbs[3:0] user interface pmc mck d[31:0] sdramc chip select
200 6222f?atarm?14-jan-11 sam7se512/256/32 23.3 i/o lines description note: 1. sdck is tied low after reset. 23.4 application example 23.4.1 software interface the sdram controller?s function is to make t he sdram device access protocol transparent to the user. table 23-2 to table 23-7 illustrate the sdram device me mory mapping t herefore seen by the user in correlation with the device st ructure. various config urations are illustrated. 23.4.1.1 32-bit memory data bus width table 23-1. i/o line description name description type active level sdck sdram clock output (1) sdcke sdram clock enable output high sdcs sdram controller chip select output low ba[1:0] bank select signals output ras row signal output low cas column signal output low sdwe sdram write enable output low nbs[3:0] data mask enable signals output low a[12:0] address bus output d[31:0] data bus i/o table 23-2. sdram configuration mapping: 2k rows, 256/512/1024/2048 columns cpu address line 2 7 2 6 2 5 2 4 2 3 2 2 2 1 2 0 1 9 1 8 1 7 1 6 1 5 1 4 1 3 1 2 1 1 1 09876543210 bk[1:0] row[10:0] column[7:0] m[1:0] bk[1:0] row[10:0] column[8:0] m[1:0] bk[1:0] row[10:0] column[9:0] m[1:0] bk[1:0] row[10:0] column[10:0] m[1:0] table 23-3. sdram configuration mapping: 4k rows, 256/512/1024/2048 columns cpu address line 2 7 2 6 2 5 2 4 2 3 2 2 2 1 2 0 1 9 1 8 1 7 1 6 1 5 1 4 1 3 1 2 1 1 1 09876543210 bk[1:0] row[11:0] column[7:0] m[1:0] bk[1:0] row[11:0] column[8:0] m[1:0] bk[1:0] row[11:0] column[9:0] m[1:0] bk[1:0] row[11:0] column[10:0] m[1:0]
201 6222f?atarm?14-jan-11 sam7se512/256/32 notes: 1. m[1:0] is the byte address inside a 32-bit word. 2. bk[1] = ba1, bk[0] = ba0. 23.4.1.2 16-bit memory data bus width notes: 1. m0 is the byte address inside a 16-bit half-word. 2. bk[1] = ba1, bk[0] = ba0. table 23-4. sdram configuration mapping: 8k rows, 256/512/1024/2048 columns cpu address line 2 7 2 6 2 5 2 4 2 3 2 2 2 1 2 0 1 9 1 8 1 7 1 6 1 5 1 4 1 3 1 2 1 1 1 09876543210 bk[1:0] row[12:0] column[7:0] m[1:0] bk[1:0] row[12:0] column[8:0] m[1:0] bk[1:0] row[12:0] column[9:0] m[1:0] bk[1:0] row[12:0] column[10:0] m[1:0] table 23-5. sdram configuration mapping: 2k rows, 256/512/1024/2048 columns cpu address line 272625242322212019181716151413121110987654321 0 bk[1:0] row[10:0] column[7:0] m0 bk[1:0] row[10:0] column[8:0] m0 bk[1:0] row[10:0] column[9:0] m0 bk[1:0] row[10:0] column[10:0] m0 table 23-6. sdram configuration mapping: 4k rows, 256/512/1024/2048 columns cpu address line 27 26 25 24 23 22 21 20 19 18 17 16 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0 bk[1:0] row[11:0] column[7:0] m0 bk[1:0] row[11:0] column[8:0] m0 bk[1:0] row[11:0] column[9:0] m0 bk[1:0] row[11:0] column[10:0] m0 table 23-7. sdram configuration mapping: 8k rows, 256/512/1024/2048 columns cpu address line 27 26 25 24 23 22 21 20 19 18 17 16 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0 bk[1:0] row[12:0] column[7:0] m0 bk[1:0] row[12:0] column[8:0] m0 bk[1:0] row[12:0] column[9:0] m0 bk[1:0] row[12:0] column[10:0] m0
202 6222f?atarm?14-jan-11 sam7se512/256/32 23.5 product dependencies 23.5.1 sdram device initialization the initialization sequence is generated by software. the sdram devices are initialized by the following sequence: 1. sdram characteristics must be set in the configuration register: asynchronous tim- ings (trc, tras,...), number of columns, rows, and cas latency. the data bus width must be set in the mode register. 2. a minimum pause of 200 s is provided to precede any signal toggle. 3. (1) a nop command is issued to the sdram devices. the application must set mode to 1 in the mode register and perform a write access to any sdram address. 4. an all banks precharge command is issued to the sdram devices. the application must set mode to 2 in the mode register and perform a write access to any sdram address. 5. eight auto-refresh (cbr) cycles are provided. the application must set the mode to 4 in the mode register and performs a write access to any sdram location height times. 6. a mode register set (mrs) cycle is issued to program the parameters of the sdram devices, in particular cas latency and burst length. the application must set mode to 3 in the mode register and perform a write access to the sdram. 7. the application must go into normal mode, setting mode to 0 in the mode register and performing a write access at any location in the sdram. 8. write the refresh rate into the count field in the sdramc refresh timer register. (refresh rate = delay between refresh cycles). the sdram device requires a refresh every 15.625 s or 7.81 s. with a 100 mhz frequency, the refresh timer counter register must be set with the value 1562(15.652 s x 100 mhz) or 781(7.81 s x 100 mhz). after initialization, the sdram devices are fully functional. note: 1. it is strongly recommended to res pect the instructions stated in step 3 of the initialization pro- cess in order to be certain that the following commands issued by the sdramc will be well taken into account.
203 6222f?atarm?14-jan-11 sam7se512/256/32 figure 23-2. sdram devices initialization sequence 23.5.2 i/o lines the pins used for interfacing the sdram cont roller may be multiplexed with the pio lines. the programmer must first program the pio controller to assign the sdram controller pins to their peripheral function. if i/o lines of the sdram controller are not used by the application, they can be used for other purposes by the pio controller. 23.5.3 interrupt the sdram controller interrupt (refresh error notification) is connected to the memory control- ler. this interrupt may be ored with other syst em peripheral interrupt lines and is finally provided as the system interrupt source (source 1) to the aic (advanced interrupt controller). using the sdram controller interrupt requ ires the aic to be programmed first. sdck sdramc_a[9:0] a10 sdramc_a[12:11] sdcs ras cas sdwe nbs inputs stable for 200 sec precharge all banks 1st auto-refresh 8th auto-refresh mrs command valid command sdcke t rp t rc t mrd
204 6222f?atarm?14-jan-11 sam7se512/256/32 23.6 functional description 23.6.1 sdram controller write cycle the sdram controller allows burst access or si ngle access. to initiate a burst access, the sdram controller uses the transfer type signal provided by the master requesting the access. if the next access is a sequential write access, writ ing to the sdram device is carried out. if the next access is a write-sequential access, but the current access is to a boundary page, or if the next access is in another row, then the sdram controller generates a precharge command, activates the new row and initiates a write comm and. to comply with sdram timing parameters, additional clock cycles are inserted between precharge/active (t rp ) commands and active/write (t rcd ) commands. for definition of these timing parameters, refer to the ?sdramc configuration register? on page 213 . this is described in figure 23-3 below. figure 23-3. write burst, 32-bit sdram access sdck sdcs ras cas a[12:0] d[31:0] t rcd = 3 dna sdwe dnb dnc dnd dne dnf dng dnh dni dnj dnk dnl row n col a col b col c col d col e col f col g col h col i col j col k col l
205 6222f?atarm?14-jan-11 sam7se512/256/32 23.6.2 sdram controller read cycle the sdram controller allows burst access or si ngle access. to initiate a burst access, the sdram controller uses the transfer type signal provided by the master requesting the access. if the next access is a sequential read access, read ing to the sdram device is carried out. if the next access is a sequential read access, but the current access is to a boundary page, or if the next access is in another row, then the sdram controller generates a precharge command, activates the new row and initiates a read command. to comply with sdram timing parameters, an additional clock cycle is insert ed between the precharge/active (t rp ) command and the active/read (t rcd ) command, after a read command, additional wait states are generated to com- ply with cas latency. the sdram controller supports a cas latency of two. for definition of these timing parameters, refer to ?sdramc configuration register? on page 213 . this is described in figure 23-4 below. figure 23-4. read burst, 32-bit sdram access sdck sdcs ras cas a[12:0] d[31:0] (input) t rcd = 3 dna sdwe dnb dnc dnd dne dnf row n col a col b col c col d col e col f cas = 2
206 6222f?atarm?14-jan-11 sam7se512/256/32 23.6.3 border management when the memory row boundary has been reached, an automatic page break is inserted. in this case, the sdram controller generates a precharge command, activates the new row and ini- tiates a read or write command. to comply with sdram timing parameters, an additional clock cycle is inserted between the precharge/active (t rp ) command and the active/read (t rcd ) com- mand. this is described in figure 23-5 below. figure 23-5. read burst with boundary row access sdck sdcs ras cas a[12:0] d[31:0] t rp = 3 sdwe row m col a col a col b col c col d col e dna dnb dnc dnd t rcd = 3 cas = 3 col b col c col d dma dmb dmc dmd row n dme
207 6222f?atarm?14-jan-11 sam7se512/256/32 23.6.4 sdram controller refresh cycles an auto-refresh command is used to refresh the sdram device. refresh addresses are gener- ated internally by the sdram device and incremented after each auto-refresh automatically. the sdram controller generates these auto-refresh commands periodically. a timer is loaded with the value in the register sdramc_tr that indicates the number of clock cycles between refresh cycles. a refresh error interrupt is generated when the previous auto-refresh command did not perform. it will be acknowledged by re ading the interrupt status register (sdramc_isr). when the sdram controller initiates a refresh of the sdram device, internal memory accesses are not delayed. howeve r, if the cpu tries to access the sdram, the slave will indi- cate that the device is busy and the arm bwait signal will be asserted. see figure 23-6 below. figure 23-6. refresh cycle followed by a read access sdck sdcs ras cas a[12:0] d[31:0] (input) t rp = 3 sdwe dnb dnc dnd col c col d cas = 2 row m col a t rc = 8 t rcd = 3 dma row n
208 6222f?atarm?14-jan-11 sam7se512/256/32 23.6.5 power management 23.6.5.1 self-refresh mode self-refresh mode is used in power-down mode, i.e., when no access to the sdram device is possible. in this case, power consumption is very low. the mode is activated by programming the self-refresh command bit (srcb) in sdramc_srr. in self-refresh mode, the sdram device retains data without external clocking and provides its own internal clocking, thus per- forming its own auto-refresh cycles. all the i nputs to the sdram device become ?don?t care? except sdcke, which remains low. as soon as the sdram device is selected, the sdram controller provides a sequence of commands and exits self-refresh mode, so the self-refresh command bit is disabled. to re-activate this mode, the self-refresh command bit must be re-programmed. the sdram device must remain in self-refresh mode for a minimum period of t ras and may remain in self-refresh mode for an in definite period. this is described in figure 23-7 below. figure 23-7. self-refresh mode behavior sdck sdcs ras cas a[12:0] self refresh mode sdwe row t xsr = 3 sdcke write sdramc_srr srcb = 1 access request to the sdram controller
209 6222f?atarm?14-jan-11 sam7se512/256/32 23.6.5.2 low-power mode low-power mode is used in power-down mode, i.e., when no access to the sdram device is possible. in this mode, power consumption is greate r than in self-refresh mode. this state is sim- ilar to normal mode (no low-power mode/no self-refresh mode), but the sdcke pin is low and the input and output buffers are deactivated as soon as the sdram device is no longer accessi- ble. in contrast to self-refresh mode, the sdram device cannot remain in low-power mode longer than the refresh period (64 ms for a whol e device refresh operation). as no auto-refresh operations are performed in this mode, the sdram controller carries out the refresh operation. in order to exit low-power mode, a nop command is required. the exit procedure is faster than in self-refresh mode. when self-refresh mode is enabled, it is recommended to avoid enabling low-power mode. when low-power mode is enabled, it is recommended to avoid enabling self-refresh mode. this is described in figure 23-8 below. figure 23-8. low-power mode behavior sdck sdcs ras cas a[12:0] d[31:0] (input) t rcd = 3 dna dnb dnc dnd dne dnf row n col a col b col c col d col e col f cas = 2 sdcke low power mode
210 6222f?atarm?14-jan-11 sam7se512/256/32 23.7 sdram controller ( sdramc) user interface table 23-8. sdram controller memory mapping offset register name access reset state 0x00 sdramc mode register sdramc_mr read/write 0x00000010 0x04 sdramc refresh timer regist er sdramc_tr read/write 0x00000800 0x08 sdramc configuration register sdramc_cr read/write 0x2a99c140 0x0c sdramc self refresh register sdramc_srr write-only ? 0x10 sdramc low power register sdramc_lpr read/write 0x0 0x14 sdramc interrupt enable register sdramc_ier write-only ? 0x18 sdramc interrupt disable register sdramc_idr write-only ? 0x1c sdramc interrupt mask re gister sdramc_imr read-only 0x0 0x20 sdramc interrupt status register sdramc_isr read-only 0x0 0x24 - 0xfc reserved ? ? ?
211 6222f?atarm?14-jan-11 sam7se512/256/32 23.7.1 sdramc mode register name: sdramc_mr access: read/write reset value : 0x00000010 ? mode: sdramc command mode this field defines the command issued by the sdram controller when the sdram device is accessed. ? dbw: data bus width 0: data bus width is 32 bits. 1: data bus width is 16 bits. 31 30 29 28 27 26 25 24 ???????? 23 22 21 20 19 18 17 16 ???????? 15 14 13 12 11 10 9 8 ???????? 76543210 ???dbw mode mode description 0000normal mode. any access to the sdram is decoded normally. 0001 the sdram controller issues a nop command when the sdram device is accessed regardless of the cycle. 0010 the sdram controller issues an ?all banks prec harge? command when the sdram device is accessed regardless of the cycle. 0011 the sdram controller issues a ?load mode registe r? command when the sdram device is accessed regardless of the cycle. the address offset with respect to the sdram device base address is used to program the mode register. for instance, when this mode is activated, an access to the ?sdram_base + offset? address generates a ?load mode register? comm and with the value ?offset? written to the sdram device mode register. 0100 the sdram controller issues a ?refresh? command when the sdram device is accessed regardless of the cycle. previously, an ?all banks precharge? command must be issued.
212 6222f?atarm?14-jan-11 sam7se512/256/32 23.7.2 sdramc refresh timer register name: sdramc_tr access: read/write reset value : 0x00000800 ? count: sdramc refresh timer count this 12-bit field is loaded into a timer that generates the refr esh pulse. each time the refresh pulse is generated, a refresh burst is initiated. the value to be loaded depends on the sdramc clock frequency (mck: master clock), the refresh rate of the sdram device and the refresh burst length where 15.6 s per row is a typical value for a burst of length one. to refresh the sdram device even if the reset value is not equal to 0, this 12-bit field must be written. if this condition is not satisfied, no refresh command is issued and no refresh of the sdram device is carried out. 31 30 29 28 27 26 25 24 ???????? 23 22 21 20 19 18 17 16 ???????? 15 14 13 12 11 10 9 8 ???? count 76543210 count
213 6222f?atarm?14-jan-11 sam7se512/256/32 23.7.3 sdramc configuration register name: sdramc_cr access: read/write reset value : 0x2a99c140 ? nc: number of column bits reset value is 8 column bits. ? nr: number of row bits reset value is 11 row bits. ? nb: number of banks reset value is two banks. ? cas: cas latency reset value is two cycles. in the sdramc, only a cas latency of two cycles is managed. in any case, another value must be programmed. 31 30 29 28 27 26 25 24 ? txsr tras 23 22 21 20 19 18 17 16 tras trcd trp 15 14 13 12 11 10 9 8 trp trc twr 76543210 twr cas nb nr nc nc column bits 008 019 1010 1111 nr row bits 00 11 01 12 10 13 11 reserved nb number of banks 02 14
214 6222f?atarm?14-jan-11 sam7se512/256/32 ? twr: write recovery delay reset value is two cycles. this field defines the write recovery time in numb er of cycles. number of cycles is between 2 and 15. if twr is less than or equal to 2, two clock periods are inserted by default. ? trc: row cycle delay reset value is eight cycles. this field defines the delay between a refresh and an activate command in numbe r of cycles. number of cycles is between 2 and 15. if trc is less than or equal to 2, two clock periods are inserted by default. ? trp: row precharge delay reset value is three cycles. this field defines the delay between a precharge command and another command in number of cycles. number of cycles is between 2 and 15. if trp is less than or equal to 2, two clock periods are inserted by default. ? trcd: row to column delay reset value is three cycles. this field defines the delay between an activate command and a read/write co mmand in number of cycles. number of cycles is between 2 and 15. if trcd is less than or equal to 2, tw o clock periods are inserted by default. ? tras: active to precharge delay reset value is five cycles. this field defines the delay between an activate command and a precharge command in number of cycles. number of cycles is between 2 and 15. if tras is less than or equal to 2, two clock periods are inserted by default. ? txsr: exit self refresh to active delay reset value is five cycles. this field defines the delay between scke set high and an activate command in numb er of cycles. number of cycles is between 1/2 and 15.5. if txsr is equal to 0, 1/2 clock period is inserted by default. cas cas latency (cycles) 00 reserved 01 reserved 10 2 11 reserved
215 6222f?atarm?14-jan-11 sam7se512/256/32 23.7.4 sdramc self-refresh register name: sdramc_srr access: write-only ? srcb: self-ref resh command bit 0: no effect. 1: the sdram controller issues a self-refresh command to the sdram device, the sdck clock is inactivated and the sdcke signal is set low. the sdram device leaves self-refresh mode when accessed again. 23.7.5 sdramc low-power register name: sdramc_lpr access: read/write reset value :0x0 ? lpcb: low-power command bit 0: the sdram controller low-power feat ure is inhibited: no low-power command is issued to the sdram device. 1: the sdram controller issues a low- power command to the sdram device after each burst access, the sdcke signal is set low. the sdram device w ill leave low-power mode when access ed and enter it after the access. 31 30 29 28 27 26 25 24 ???????? 23 22 21 20 19 18 17 16 ???????? 15 14 13 12 11 10 9 8 ???????? 76543210 ???????srcb 31 30 29 28 27 26 25 24 ???????? 23 22 21 20 19 18 17 16 ???????? 15 14 13 12 11 10 9 8 ???????? 76543210 ???????lpcb
216 6222f?atarm?14-jan-11 sam7se512/256/32 23.7.6 sdramc interrupt enable register name: sdramc_ier access: write-only ? res: refresh error status 0: no effect. 1: enables the refresh error interrupt. 23.7.7 sdramc interrupt disable register name: sdramc_idr access: write-only ? res: refresh error status 0: no effect. 1: disables the refresh error interrupt. 31 30 29 28 27 26 25 24 ???????? 23 22 21 20 19 18 17 16 ???????? 15 14 13 12 11 10 9 8 ???????? 76543210 ???????res 31 30 29 28 27 26 25 24 ???????? 23 22 21 20 19 18 17 16 ???????? 15 14 13 12 11 10 9 8 ???????? 76543210 ???????res
217 6222f?atarm?14-jan-11 sam7se512/256/32 23.7.8 sdramc interrupt mask register name: sdramc_imr access: read-only ? res: refresh error status 0: the refresh error interrupt is disabled. 1: the refresh error interrupt is enabled. 31 30 29 28 27 26 25 24 ???????? 23 22 21 20 19 18 17 16 ???????? 15 14 13 12 11 10 9 8 ???????? 76543210 ???????res
218 6222f?atarm?14-jan-11 sam7se512/256/32 23.7.9 sdramc interrupt status register name: sdramc_isr access: read-only ? res: refresh error status 0: no refresh error has been detected since the register was last read. 1: a refresh error has been detected since the register was last read. 31 30 29 28 27 26 25 24 ???????? 23 22 21 20 19 18 17 16 ???????? 15 14 13 12 11 10 9 8 ???????? 76543210 ???????res
219 6222f?atarm?14-jan-11 sam7se512/256/32 24. error corrected co de controller (ecc) 24.1 overview nand flash/smartmedia devices contain by default invalid blocks which have one or more invalid bits. over the nand flash/smartmedia lifetime, additional invalid blocks may occur which can be detected/corrected by ecc code. the ecc controller is a mechanism that encodes data in a manner that makes possible the identification and correction of certain errors in data. the ecc controller is capable of single bit error correction and 2-bit random detection. w hen nand flash/smartmedia have more than 2 bits of errors, the data cannot be corrected. the ecc user interfac e is compliant with the arm adv anced peripheral bus (apb rev2). 24.2 block diagram figure 24-1. block diagram user interface ctrl/ecc algorithm static memory controller apb nand flash smartmedia logic ecc controller
220 6222f?atarm?14-jan-11 sam7se512/256/32 24.3 functional description a page in nand flash and smartmedia memories contains an area for main data and an addi- tional area used for redundancy (ecc). the page is organized in 8-bit or 16-bit words. the page size corresponds to the number of words in the main area plus the number of words in the extra area used for redundancy. the only configuration requir ed for ecc is the nand flash or the smartmedia page size (528/1056/2112/4224). page size is configured setting the pagesize field in the ecc mode register (ecc_mr). ecc is automatically computed as soon as a read (00h)/write (80h) command to the nand flash or the smartmedia is detected. read and write access must start at a page boundary. ecc results are available as soon as the counte r reaches the end of the main area. values in the ecc parity register (ecc_pr) and ecc np arity register (ecc_npr) are then valid and locked until a new start condit ion occurs (read/write command followed by address cycles). 24.3.1 write access once the flash memory page is written, the com puted ecc code is available in the ecc parity error (ecc_pr) and ecc_nparit y error (ecc_npr) registers. the ecc code value must be written by the software application in the extra area used for redundancy. 24.3.2 read access after reading the whole data in the main area, the application must perform read accesses to the extra area where ecc code has been previously stored. error detection is automatically per- formed by the ecc controller. please note that it is mandatory to read consecutively the entire main area and the locations where parity and nparity values have been previously stored to let the ecc controller perform error detection. the application can check the ecc status register (ecc_sr) for any detected errors. it is up to the application to correct any detected error. ecc computation can detect four differ- ent circumstances: ? no error: xor between the ecc computation and the ecc code stored at the end of the nand flash or smartmedia page is equal to 0. no error flags in the ecc status register (ecc_sr). ? recoverable error: only the recerr flag in the ecc status register (ecc_sr) is set. the corrupted word offset in the read page is defined by the wordaddr field in the ecc parity register (ecc_pr). the corrupted bit position in the concerned word is defined in the bitaddr field in the ecc parity register (ecc_pr). ? ecc error: the eccerr flag in the ecc status register is set. an error has been detected in the ecc code stored in the flash memory. the position of the corrupted bit can be found by the application performing an xor between the parity and the nparity contained in the ecc code stored in the flash memory. ? non correctable error: the mulerr flag in the ecc status register is set. several unrecoverable errors have been detected in the flash memory page. ecc status register, ecc parity register and ecc nparity register are cleared when a read/write command is detected or a software reset is performed. for single-bit error correction and double-bit er ror detection (sec-ded) hsiao code is used. 32-bit ecc is generated in order to perform one bit correction per 512/1024/2048/4096 8- or 16-
221 6222f?atarm?14-jan-11 sam7se512/256/32 bit words. of the 32 ecc bits, 26 bits are for line parity and 6 bits are for column parity. they are generated according to the schemes shown in figure 24-2 and figure 24-3 . figure 24-2. parity generation for 512/1024/2048/4096 8-bit words1 to calculate p8? to px? and p8 to px, apply the algorithm that follows. page size = 2 n for i =0 to n begin for (j = 0 to page_size_byte) begin if(j[i] ==1) p[2 i+3 ]=bit7(+)bit6(+)bit5(+)bit4(+)bit3(+) bit2(+)bit1(+)bit0(+)p[2 i+3 ] else p[2 i+3 ]?=bit7(+)bit6(+)bit5(+)bit4(+)bit3(+) bit2(+)bit1(+)bit0(+)p[2 i+3 ]' end end bit7 bit6 bit5 bit4 bit3 bit2 bit1 bit0 bit7 bit6 bit5 bit4 bit3 bit2 bit1 bit0 p8 p8' bit7 bit6 bit5 bit4 bit3 bit2 bit1 bit0 bit7 bit6 bit5 bit4 bit3 bit2 bit1 bit0 p8 p8' p16 p16' bit7 bit6 bit5 bit4 bit3 bit2 bit1 bit0 bit7 bit6 bit5 bit4 bit3 bit2 bit1 bit0 p8 p8' bit7 bit6 bit5 bit4 bit3 bit2 bit1 bit0 bit7 bit6 bit5 bit4 bit3 bit2 bit1 bit0 p8 p8' p16 p16' p32 p32 1st byte p32 2nd byte 3rd byte 4 th byte page size th byte (page size -1 )th byte px px' page size = 512 px = 2048 page size = 1024 px = 4096 page size = 2048 px = 8192 page size = 4096 px = 16384 (page size -2 )th byte (page size -3 )th byte p1 p1' p1' p1 p1 p1' p1' p1 p2 p2' p2 p2' p4 p4' p1=bit7(+)bit5(+)bit3(+)bit1(+)p1 p2=bit7(+)bit6(+)bit3(+)bit2(+)p2 p4=bit7(+)bit6(+)bit5(+)bit4(+)p4 p1'=bit6(+)bit4(+)bit2(+)bit0(+)p1' p2'=bit5(+)bit4(+)bit1(+)bit0(+)p2' p4'=bit7(+)bit6(+)bit5(+)bit4(+)p4'
222 6222f?atarm?14-jan-11 sam7se512/256/32 figure 24-3. parity generation for 512/1024/2048/4096 16-bit words 1st word 2nd word 3rd word 4th word (page size -3 )th word (page size -2 )th word (page size -1 )th word page size th word (+) (+)
223 6222f?atarm?14-jan-11 sam7se512/256/32 to calculate p8? to px? and p8 to px, apply the algorithm that follows. page size = 2 n for i =0 to n begin for (j = 0 to page_size_word) begin if(j[i] ==1) p[2 i+3 ]= bit15(+)bit14(+)bit13(+)bit12(+) bit11(+)bit10(+)bit9(+)bit8(+) bit7(+)bit6(+)bit5(+)bit4(+)bit3(+) bit2(+)bit1(+)bit0(+)p[2 n+3 ] else p[2 i+3 ]?=bit15(+)bit14(+)bit13(+)bit12(+) bit11(+)bit10(+)bit9(+)bit8(+) bit7(+)bit6(+)bit5(+)bit4(+)bit3(+) bit2(+)bit1(+)bit0(+)p[2 i+3 ]' end end
224 6222f?atarm?14-jan-11 sam7se512/256/32 24.4 ecc user interface table 24-1. ecc register mapping offset register register name access reset 0x00 ecc control register ecc_cr write-only 0x0 0x04 ecc mode register ecc_mr read/write 0x0 0x8 ecc status register ecc_sr read-only 0x0 0x0c ecc parity register ecc_pr read-only 0x0 0x10 ecc nparity register ecc_npr read-only 0x0 0x14 - 0xfc reserved ? ? ?
225 6222f?atarm?14-jan-11 sam7se512/256/32 24.4.1 ecc control register name: ecc_cr access: write-only ? rst: reset parity provides reset to current ecc by software. 1: reset secc parity and ecc nparity register 0: no effect 24.4.2 ecc mode register name: ecc_mr access: read/write ? pagesize: page size this field defines the page size of the nand flash device. a word has a value of 8 bits or 16 bits, depending on the nand flash or smartmedia memory organization. 31 30 29 28 27 26 25 24 ???????? 23 22 21 20 19 18 17 16 ???????? 15 14 13 12 11 10 9 8 ???????? 76543210 ???????rst 31 30 29 28 27 26 25 24 ???????? 23 22 21 20 19 18 17 16 ???????? 15 14 13 12 11 10 9 8 ???????? 76543210 ?????? pagesize page size description 00 528 words 01 1056 words 10 2112 words 11 4224 words
226 6222f?atarm?14-jan-11 sam7se512/256/32 24.4.3 ecc status register name: ecc_sr access: read-only ? recerr: recoverable error 0 = no errors detected 1 = errors detected. if mul_error is 0, a single correctable error was detected. otherwise multiple uncorrected errors were detected ? eccerr: ecc error 0 = no errors detected 1 = a single bit error occurred in the ecc bytes. read both ecc parity and ecc nparity register, the error occurr ed at the location which contains a 1 in the least signifi- cant 16 bits. ? mulerr: multiple error 0 = no multiple errors detected 1 = multiple errors detected 31 30 29 28 27 26 25 24 ???????? 23 22 21 20 19 18 17 16 ???????? 15 14 13 12 11 10 9 8 ???????? 76543210 ?????mulerreccerrrecerr
227 6222f?atarm?14-jan-11 sam7se512/256/32 24.4.4 ecc parity register name: ecc_pr access: read-only once the entire main area of a page is written with data, the register content must be stored at any free location of the spare area. ? bitaddr during a page read, this value contains the corrupted bit offset where an error occurred, if a single error was detected. if multiple errors were detected, this value is meaningless. ? wordaddr during a page read, this value contains the word address (8-bit or 16-bit word depending on the memory plane organiza- tion) where an error occurred, if a single error was detected. if multiple errors were detected, this value is meaningless. 31 30 29 28 27 26 25 24 ???????? 23 22 21 20 19 18 17 16 ???????? 15 14 13 12 11 10 9 8 wordaddr 76543210 wordaddr bitaddr
228 6222f?atarm?14-jan-11 sam7se512/256/32 24.4.5 ecc nparity register name: ecc_npr access: read-only ? nparity: once the entire main area of a page is written with data, the register content must be stored at any free location of the spare area. 31 30 29 28 27 26 25 24 ???????? 23 22 21 20 19 18 17 16 ???????? 15 14 13 12 11 10 9 8 nparity 76543210 nparity
229 6222f?atarm?10-jan-11 sam7se512/256/32 preliminary 25. at91sam boot program 25.1 overview the boot program integrates different programs permitting download and/or upload into the dif- ferent memories of the product. first, it initializes the debug unit serial port (dbgu) and the usb device port. sam-ba ? boot is then executed. it waits for transactions either on the usb device, or on the dbgu serial port. 25.2 flow diagram the boot program implements the algorithm in figure 25-1 . figure 25-1. boot program algorithm flow diagram 25.3 device initialization initialization follows the steps described below: 1. fiq initialization 1. stack setup for arm supervisor mode 2. setup the embedded flash controller 3. external clock detection 4. main oscillator frequ ency detection if no external clock detected 5. switch master clock on main oscillator 6. copy code into sram 7. c variable initialization 8. pll setup: pll is initialized to generate a 48 mhz clock necessary to use the usb device 9. disable of the watchdog and enable of the user reset 10. initialization of the usb device port 11. jump to sam-ba boot sequence (see ?sam-ba boot? on page 230 ) device setup autobaudrate sequence successful ? run sam-ba boot run sam-ba boot usb enumeration successful ? yes yes no no
230 6222f?atarm?10-jan-11 sam7se512/256/32 preliminary 25.4 sam-ba boot the sam-ba boot principle is to: ? check if usb device enumeration has occurred ? check if the autobaudrate sequence has succeeded (see figure 25-2 ) figure 25-2. autobaudrate flow diagram ? once the communication interface is identified, the application runs in an infinite loop waiting for different commands as in table 25-1 . device setup character '0x80' received ? no ye s character '0x80' received ? no ye s character '#' received ? ye s run sam-ba boot send character '>' no 1st measurement 2nd measurement test communication uart operational
231 6222f?atarm?10-jan-11 sam7se512/256/32 preliminary ? write commands: write a byte ( o ), a halfword ( h ) or a word ( w ) to the target. ? address : address in hexadecimal. ? value : byte, halfword or word to write in hexadecimal. ? output : ?>?. ? read commands: read a byte ( o ), a halfword ( h ) or a word ( w ) from the target. ? address : address in hexadecimal ? output : the byte, halfword or word read in hexadecimal following by ?>? ? send a file ( s ): send a file to a specified address ? address : address in hexadecimal ? output : ?>?. note: there is a time-out on this command which is reached when the prompt ?>? appears before the end of the command execution. ? receive a file ( r ): receive data into a file from a specified address ? address : address in hexadecimal ? nbofbytes : number of bytes in hexadecimal to receive ? output : ?>? ?go ( g ): jump to a specified address and execute the code ? address : address to jump in hexadecimal ? output : ?>? ? get version ( v ): return the sam-ba boot version ? output : ?>? 25.4.1 dbgu serial port communication is performed through the dbgu serial port initialized to 115200 baud, 8, n, 1. the send and receive file commands use the xmodem protocol to communicate. any terminal performing this protocol can be used to send th e application file to the target. the size of the binary file to send depends on the sram size embedded in the product. in all cases, the size of table 25-1. commands available through the sam-ba boot command action argument(s) example o write a byte address, value# o 200001,ca# o read a byte address,# o 200001,# h write a half word address, value# h 200002,cafe# h read a half word address,# h 200002,# w write a word address, value# w 200000,cafedeca# w read a word address,# w 200000,# s send a file address,# s 200000,# r receive a file address, nbofbytes# r 200000,1234# g go address# g 200200# v display version no argument v #
232 6222f?atarm?10-jan-11 sam7se512/256/32 preliminary the binary file must be lower than the sram si ze because the xmodem protocol requires some sram memory to work. 25.4.2 xmodem protocol the xmodem protocol supported is the 128-byte l ength block. this protocol uses a two-charac- ter crc-16 to guarantee detection of a maximum bit error. xmodem protocol with crc is accurate provided both sender and receiver report successful transmission. each block of the transfer looks like: <255-blk #><--128 da ta bytes--> in which: ? = 01 hex ? = binary number, starts at 01, increments by 1, and wraps 0ffh to 00h (not to 01) ? <255-blk #> = 1?s complement of the blk#. ? = 2 bytes crc16 figure 25-3 shows a transmission using this protocol. figure 25-3. xmodem transfer example 25.4.3 usb device port a 48 mhz usb clock is necessary to use the usb device port. it has been programmed earlier in the device initia lization procedure with pllb configuration. the device uses the usb communication device class (cdc) drivers to take advantage of the installed pc rs-232 software to talk over the usb. the cdc class is implemented in all releases of windows ? , from windows 98se to windows xp ? . the cdc document, available at www.usb.org, describes a way to implement devices such as isdn modems and virtual com ports. the vendor id is atmel?s vendor id 0x03eb. the product id is 0x6124. these references are used by the host operating system to mount the correct driver. on windows systems, the inf files contain the correspondence between vendor id and product id. host device soh 01 fe data[128] crc crc c ack soh 02 fd data[128] crc crc ack soh 03 fc data[100] crc crc ack eot ack
233 6222f?atarm?10-jan-11 sam7se512/256/32 preliminary 25.4.3.1 enumeration process the usb protocol is a master/slave protocol. th is is the host that starts the enumeration send- ing requests to the device through the control endpoint. the device handles standard requests as defined in the usb specification. the device also handles some class requests defined in the cdc class. unhandled requests are stalled. 25.4.3.2 communication endpoints there are two communication endpoints and endpoint 0 is used for the enumeration process. endpoint 1 is a 64-byte bulk out endpoint and endpoint 2 is a 64-byte bulk in endpoint. sam- ba boot commands are sent by the host through the endpoint 1. if required, the message is split by the host into several data payloads by the host driver. if the command requires a response, the host can send in transactions to pick up the response. 25.5 hardware and software constraints ? sam-ba boot copies itself in the sram and uses a block of internal sram for variables and stacks. the remaining available size for the user code is 24576 bytes for sam7se512/256, 8192 bytes for sam7se32. ? the sam7se512/256 user area extends from address 0x202000 to address 0x208000. ? the sam7se32 user area extends from address 0x201400 to address 0x201c00. ? usb requirements: ? 18.432 mhz quartz table 25-2. handled standard requests request definition get_descriptor returns the current device configuration value. set_address sets the device address for all future device access. set_configuration sets the device configuration. get_configuration returns the curr ent device configuration value. get_status returns status for the specified recipient. set_feature used to set or enable a specific feature. clear_feature used to clear or disable a specific feature. table 25-3. handled class requests request definition set_line_coding configures dte rate, stop bits, parity and number of character bits. get_line_coding requests current dte rate, stop bits, parity and number of character bits. set_control_line_state rs-232 signal used to tell the dce device the dte device is now present.
234 6222f?atarm?10-jan-11 sam7se512/256/32 preliminary table 25-4. pins driven during boot program execution peripheral pin pio line dbgu drxd pa9 dbgu dtxd pa10
235 6222f?atarm?14-jan-11 sam7se512/256/32 26. peripheral dma controller (pdc) 26.1 overview the peripheral dma controller (pdc) transfers data between on-chip serial peripherals such as the uart, usart, ssc, spi, mci and the on- and off-chip memories. using the peripheral dma controller avoids processor intervention and removes the processor interrupt-handling overhead. this significantly reduces the number of clock cycles requ ired for a data transfer and, as a result, improves the performance of the microcontroller and makes it more power efficient. the pdc channels are implemented in pairs, each pair being dedicated to a particular periph- eral. one channel in the pair is dedicated to the receiving channel and one to the transmitting channel of each uart, usart, ssc and spi. the user interface of a pdc channel is integrated in the memory space of each peripheral. it contains: ? two 32-bit memory pointer registers (send and receive) ? two 16-bit transfer count register (send and receive) ? two 32-bit register for next memory pointer (send and receive) ? two 16-bit register for next transfer count (send and receive) the peripheral triggers pdc transfers usin g transmit and receive signals. when the pro- grammed data is transferred, an end of trans fer interrupt is generated by the corresponding peripheral. 26.2 block diagram figure 26-1. block diagram control pdc channel 0 pdc channel 1 thr rhr control status & control peripheral peripheral dma controller memory controller
236 6222f?atarm?14-jan-11 sam7se512/256/32 26.3 functional description 26.3.1 configuration the pdc channels user interface enables the user to configure and control the data transfers for each channel. the user interface of a pdc channel is integrated into the user interface of the peripheral (offset 0x100), which it is related to. per peripheral, it contains four 32-bit pointer registers (rpr, rnpr, tpr, and tnpr) and four 16-bit counter re gisters (rcr, rncr, tcr, and tncr). the size of the buffer (number of transfers) is configured in an internal 16-bit transfer counter register, and it is possible, at any moment, to read the number of transfers left for each channel. the memory base address is configured in a 32-bit memory pointer by defining the location of the first address to access in the memory. it is possible, at any moment, to read the location in memory of the current transfer and the number of remaining transfers. the pdc has dedicated status registers which indicate if the transfer is enabled or disabled for each channel. the status for each channel is located in the peripheral status register. transfers can be enabled and/or disabled by setting txten/txtdis and rxten/rx tdis in pdc transfer control register. these control bits enable reading the pointer and counter registers safely without any risk of their changing between both reads. the pdc sends status flags to the peripheral vi sible in its status-register (endrx, endtx, rxbuff, and txbufe). endrx flag is set when the periph_rcr register reaches zero. rxbuff flag is set when both pe riph_rcr and periph_rncr reach zero. endtx flag is set when the per iph_tcr register reaches zero. txbufe flag is set when both pe riph_tcr and periph_tncr reach zero. these status flags are described in the peripheral status register. 26.3.2 memory pointers each peripheral is connected to the pdc by a receiver data channel and a transmitter data channel. each channel has an internal 32-bit memory pointer. each memory pointer points to a location anywhere in the memory space (on-chip memory or external bus interface memory). depending on the type of transfer (byte, half-word or word), the memory pointer is incremented by 1, 2 or 4, respectively for peripheral transfers. if a memory pointer is reprogrammed while the pdc is in operation, the transfer address is changed, and the pdc performs transfers using the new address. 26.3.3 transfer counters there is one internal 16-bit transfer counter for each channel used to count the size of the block already transferred by its associated peripheral. these counters are decremented after each data transfer. when the counter reaches zero, the transfer is complete and the pdc stops trans- ferring data. if the next counter register is equal to zero, the pdc disables the trigger while activating the related peripheral end flag.
237 6222f?atarm?14-jan-11 sam7se512/256/32 if the counter is reprogrammed while the pdc is operating, the number of transfers is updated and the pdc counts transfers from the new value. programming the next counter/pointer register s chains the buffers. the counters are decre- mented after each data transfer as stated above, but when the transfer counter reaches zero, the values of the next counter/pointer are loaded into the counter/pointer registers in order to re-enable the triggers. for each channel, two status bits indicate the end of the current buffer (endrx, endtx) and the end of both current and next buffer (rxbuff, tx bufe). these bits are directly mapped to the peripheral status register and can trigger an interrupt request to the aic. the peripheral end flag is automatically cleared when one of the counter-registers (counter or next counter regi ster) is written. note: when the next counter register is loaded into the counter register, it is set to zero. 26.3.4 data transfers the peripheral triggers pdc transfers using transmit (txrdy) and receive (rxrdy) signals. when the peripheral receives an external characte r, it sends a receive ready signal to the pdc which then requests access to the system bus. when access is granted, the pdc starts a read of the peripheral receive holding register (rhr) and then triggers a write in the memory. after each transfer, the relevant pdc memory pointer is incremented and the number of trans- fers left is decremented. when the memory bl ock size is reached, a signal is sent to the peripheral and the transfer stops. the same procedure is followed, in reverse, for transmit transfers. 26.3.5 priority of pdc transfer requests the peripheral dma controller handles transfer requests from the channel according to priori- ties fixed for each product.these prioriti es are defined in the product datasheet. if simultaneous requests of the same type (receiver or transmitter) occur on identical peripher- als, the priority is determined by the numbering of the peripherals. if transfer requests are not simultaneous, they are treated in the order they occurred. requests from the receivers are handled first and then followed by transmitter requests.
238 6222f?atarm?14-jan-11 sam7se512/256/32 26.4 peripheral dma controll er (pdc) user interface note: 1. periph: ten registers are mapped in the peripheral memory space at the same offset. these can be defined by the user according to the function and the peripheral desired (dbgu, usart, ssc, spi, mci, etc). table 26-1. register mapping offset register register name read/write reset 0x100 receive pointer register periph (1) _rpr read/write 0x0 0x104 receive counter register periph_rcr read/write 0x0 0x108 transmit pointer register periph_tpr read/write 0x0 0x10c transmit counter register periph_tcr read/write 0x0 0x110 receive next pointer register periph_rnpr read/write 0x0 0x114 receive next counter register periph_rncr read/write 0x0 0x118 transmit next pointer register periph_tnpr read/write 0x0 0x11c transmit next counter register periph_tncr read/write 0x0 0x120 pdc transfer control register periph_ptcr write-only - 0x124 pdc transfer status r egister periph_ptsr read-only 0x0
239 6222f?atarm?14-jan-11 sam7se512/256/32 26.4.1 pdc receive pointer register name: periph _ rpr access: read/write ? rxptr: receive pointer address address of the next receive transfer. 26.4.2 pdc receive counter register name: periph _ rcr access: read/write ? rxctr: receive counter value number of receive transfers to be performed. 31 30 29 28 27 26 25 24 rxptr 23 22 21 20 19 18 17 16 rxptr 15 14 13 12 11 10 9 8 rxptr 76543210 rxptr 31 30 29 28 27 26 25 24 -- 23 22 21 20 19 18 17 16 -- 15 14 13 12 11 10 9 8 rxctr 76543210 rxctr
240 6222f?atarm?14-jan-11 sam7se512/256/32 26.4.3 pdc transmit pointer register name: periph _ tpr access: read/write ? txptr: transmit pointer address address of the transmit buffer. 26.4.4 pdc transmit counter register name: periph _ tcr access: read/write ? txctr: transmit counter value txctr is the size of the transmit transfer to be performed. at zero, the peripheral data transfer is stopped. 31 30 29 28 27 26 25 24 txptr 23 22 21 20 19 18 17 16 txptr 15 14 13 12 11 10 9 8 txptr 76543210 txptr 31 30 29 28 27 26 25 24 -- 23 22 21 20 19 18 17 16 -- 15 14 13 12 11 10 9 8 txctr 76543210 txctr
241 6222f?atarm?14-jan-11 sam7se512/256/32 26.4.5 pdc receive next pointer register name: periph _ rnpr access: read/write ? rxnptr: receive next pointer address rxnptr is the address of the next buffer to fill with received data when th e current buffer is full. 26.4.6 pdc receive next counter register name: periph _ rncr access: read/write ? rxncr: receive next counter value rxncr is the size of the next buffer to receive. 31 30 29 28 27 26 25 24 rxnptr 23 22 21 20 19 18 17 16 rxnptr 15 14 13 12 11 10 9 8 rxnptr 76543210 rxnptr 31 30 29 28 27 26 25 24 -- 23 22 21 20 19 18 17 16 -- 15 14 13 12 11 10 9 8 rxncr 76543210 rxncr
242 6222f?atarm?14-jan-11 sam7se512/256/32 26.4.7 pdc transmit next pointer register name: periph _ tnpr access: read/write ? txnptr: transmit next pointer address txnptr is the address of the next buffer to transmit when the current buffer is empty. 26.4.8 pdc transmit next counter register name: periph _ tncr access: read/write ? txncr: transmit next counter value txncr is the size of the next buffer to transmit. 31 30 29 28 27 26 25 24 txnptr 23 22 21 20 19 18 17 16 txnptr 15 14 13 12 11 10 9 8 txnptr 76543210 txnptr 31 30 29 28 27 26 25 24 -- 23 22 21 20 19 18 17 16 -- 15 14 13 12 11 10 9 8 txncr 76543210 txncr
243 6222f?atarm?14-jan-11 sam7se512/256/32 26.4.9 pdc transfer control register name: periph_ptcr access: write - only ? rxten: receiver transfer enable 0 = no effect. 1 = enables the receiver pdc transfer requests if rxtdis is not set. ? rxtdis: receiver transfer disable 0 = no effect. 1 = disables the receiver pdc transfer requests. ? txten: transmitter transfer enable 0 = no effect. 1 = enables the transmitter pdc transfer requests. ? txtdis: transmitter transfer disable 0 = no effect. 1 = disables the transmitter pdc transfer requests. 31 30 29 28 27 26 25 24 ???????? 23 22 21 20 19 18 17 16 ???????? 15 14 13 12 11 10 9 8 ??????txtdistxten 76543210 ??????rxtdisrxten
244 6222f?atarm?14-jan-11 sam7se512/256/32 26.4.10 pdc transfer status register name: periph _ ptsr access: read-only ? rxten: receiver transfer enable 0 = receiver pdc transfer requests are disabled. 1 = receiver pdc transfer requests are enabled. ? txten: transmitter transfer enable 0 = transmitter pdc transfer requests are disabled. 1 = transmitter pdc transfer requests are enabled. 31 30 29 28 27 26 25 24 ???????? 23 22 21 20 19 18 17 16 ???????? 15 14 13 12 11 10 9 8 ???????txten 76543210 ???????rxten
245 6222f?atarm?14-jan-11 sam7se512/256/32 27. advanced interrupt controller (aic) 27.1 overview the advanced interrupt controller (aic) is an 8-level priority, individually maskable, vectored interrupt controller, providing handling of up to thirty-two interrupt sources. it is designed to sub- stantially reduce the software and real-time overhead in handling internal and external interrupts. the aic drives the nfiq (fast interrupt request) and the nirq (standard interrupt request) inputs of an arm processor. inputs of the aic are either internal peripheral interrupts or external inter- rupts coming from the product's pins. the 8-level priority controller allows the user to define the priority for each interrupt source, thus permitting higher priority interrupts to be serviced even if a lower priority interrupt is being treated. internal interrupt sources can be programmed to be level sensitive or edge triggered. external interrupt sources can be programmed to be positive-edge or negative-edge triggered or high- level or low-level sensitive. the fast forcing feature redirects any internal or external interrupt source to provide a fast inter- rupt rather than a normal interrupt. 27.2 block diagram figure 27-1. block diagram aic apb arm processor fiq irq0-irqn embedded peripheralee peripheral embedded peripheral embedded up to thirty-two sources nfiq nirq
246 6222f?atarm?14-jan-11 sam7se512/256/32 27.3 application block diagram figure 27-2. description of the application block 27.4 aic detailed block diagram figure 27-3. aic detailed block diagram 27.5 i/o line description advanced interrupt controller embedded peripherals external peripherals (external interrupts) standalone applications rtos drivers hard real time tasks os-based applications os drivers general os interrupt handler fiq pio controller advanced interrupt controller irq0-irqn pioirq embedded peripherals external source input stage internal source input stage fast forcing interrupt priority controller fast interrupt controller arm processor nfiq nirq power management controller wake up user interface apb processor clock table 27-1. i/o line description pin name pin description type fiq fast interrupt input irq0 - irqn interrupt 0 - interrupt n input
247 6222f?atarm?14-jan-11 sam7se512/256/32 27.6 product dependencies 27.6.1 i/o lines the interrupt signals fiq and irq0 to irqn are normally multiplexed through the pio control- lers. depending on the features of the pio controller used in the product, the pins must be programmed in accordance with their assigned interrupt function. this is not applicable when the pio controller used in the product is transparent on the input path. 27.6.2 power management the advanced interrupt controller is continuously clocked. the power management controller has no effect on the advanced interrupt controller behavior. the assertion of the advanced interrupt controller outputs, either nirq or nfiq, wakes up the arm processor while it is in idle mode. the general interrupt mask feature enables the aic to wake up the processor without asserting the interr upt line of the processor, thus providing syn- chronization of the processor on an event. 27.6.3 interrupt sources the interrupt source 0 is always located at fiq. if the product does not feature an fiq pin, the interrupt source 0 cannot be used. the interrupt source 1 is always located at system interrupt. this is the result of the or-wiring of the system peripheral interrupt lines, such as the system timer, the real time clock, the power management controller and the memory controller. when a system interrupt occurs, the service routine must first distinguish the cause of the interrupt. this is performed by reading suc- cessively the status registers of the above mentioned system peripherals. the interrupt sources 2 to 31 can either be connected to the interrupt outputs of an embedded user peripheral or to external interrupt lines . the external interrupt lines can be connected directly, or through the pio controller. the pio controllers are considered as user peripherals in the scope of interrupt handling. accordingly, the pio controller interrupt lines are connected to the interrupt sources 2 to 31. the peripheral identification defined at the product level corresponds to the interrupt source number (as well as the bit number controlling the clock of the peri pheral). conseq uently, to sim- plify the description of the functional operations and the user interface, the interrupt sources are named fiq, sys, and pid2 to pid31.
248 6222f?atarm?14-jan-11 sam7se512/256/32 27.7 functional description 27.7.1 interrupt source control 27.7.1.1 interrupt source mode the advanced interrupt controller independently programs each interrupt source. the src- type field of the corresponding aic_smr (source mode register) selects the interrupt condition of each source. the internal interrupt sources wired on the interrupt outputs of the embedded peripherals can be programmed either in level-sensitive mode or in edge-triggered mode. the active level of the internal interrupts is not important for the user. the external interrupt sources can be programmed either in high level-sensitive or low level-sen- sitive modes, or in positive edge-triggered or negative edge-triggered modes. 27.7.1.2 interrupt source enabling each interrupt source, including the fiq in source 0, can be enabled or disabled by using the command registers; aic_iecr (interrupt enable command register) and aic_idcr (interrupt disable command register). this set of registers conducts enabling or disabling in one instruc- tion. the interrupt mask can be read in the aic_imr register. a disabled interrupt does not affect servicing of other interrupts. 27.7.1.3 interrupt clearing and setting all interrupt sources programmed to be edge-triggered (including the fiq in source 0) can be individually set or cleared by writing respectively the aic_iscr and aic_iccr registers. clear- ing or setting interrupt sources programmed in level-sensitive mode has no effect. the clear operation is perfunctory, as the softwa re must perform an acti on to reinitialize the ?memorization? circuitry activated when the source is programmed in edge-triggered mode. however, the set operation is available for auto-test or software debug purposes. it can also be used to execute an aic-implementation of a software interrupt. the aic features an automatic clear of the current interrupt when the aic_ivr (interrupt vector register) is read. only the interrupt source being detected by the aic as the current interrupt is affected by this operation. ( see ?priority controller? on page 252. ) the automatic clear reduces the operations required by the interrupt service routine entry code to reading the aic_ivr. note that the automatic interrupt clear is disabled if the interrupt source has the fast forcing feature enabled as it is considered uniquely as a fiq source. (for further details, see ?fast forcing? on page 256. ) the automatic clear of the interrupt source 0 is performed when aic_fvr is read. 27.7.1.4 interrupt status for each interrupt, the aic operation originates in aic_ipr (interrupt pending register) and its mask in aic_imr (interrupt mask register). aic_ipr enables the actual activity of the sources, whether masked or not. the aic_isr register reads the number of the current interrupt (see ?priority controller? on page 252 ) and the register aic_cisr gives an image of the signals nirq and nfiq driven on the processor. each status referred to above can be used to optimize the interrupt handling of the systems.
249 6222f?atarm?14-jan-11 sam7se512/256/32 27.7.1.5 internal interrupt source input stage figure 27-4. internal interrupt source input stage 27.7.1.6 external interrupt source input stage figure 27-5. external interrupt source input stage edge detector clear set source i aic_ipr aic_imr aic_iecr aic_idcr aic_iscr aic_iccr fast interrupt controller or priority controller ff level/ edge aic_smri (srctype) edge detector clear set pos./neg. aic_iscr aic_iccr source i ff level/ edge high/low aic_smri srctype aic_ipr aic_imr aic_iecr aic_idcr fast interrupt controller or priority controller
250 6222f?atarm?14-jan-11 sam7se512/256/32 27.7.2 interrupt latencies global interrupt latencies depend on several parameters, including: ? the time the software masks the interrupts. ? occurrence, either at the processor level or at the aic level. ? the execution time of the instruction in progress when the interrupt occurs. ? the treatment of higher priority interrupts and the resynchronization of the hardware signals. this section addresses only the hardware resync hronizations. it gives details of the latency times between the event on an external interrupt leading in a valid interrupt (edge or level) or the assertion of an internal interrupt source and the assertion of the nirq or nfiq line on the pro- cessor. the resynchronization time depends on the programming of the interrupt source and on its type (internal or external). for the standard interrupt, resynchronization times are given assuming there is no higher priority in progress. the pio controller multiplexing has no effect on the interrupt latencies of the external interrupt sources. 27.7.2.1 external interrupt edge triggered source figure 27-6. external interrupt edge triggered source maximum fiq latency = 4 cycles maximum irq latency = 4 cycles nfiq nirq mck irq or fiq (positive edge) irq or fiq (negative edge)
251 6222f?atarm?14-jan-11 sam7se512/256/32 27.7.2.2 external interrupt level sensitive source figure 27-7. external interrupt level sensitive source 27.7.2.3 internal interrupt edge triggered source figure 27-8. internal interrupt edge triggered source 27.7.2.4 internal interrupt level sensitive source figure 27-9. internal interrupt level sensitive source maximum irq latency = 3 cycles maximum fiq latency = 3 cycles mck irq or fiq (high level) irq or fiq (low level) nirq nfiq mck nirq peripheral interrupt becomes active maximum irq latency = 4.5 cycles mck nirq maximum irq latency = 3.5 cycles peripheral interrupt becomes active
252 6222f?atarm?14-jan-11 sam7se512/256/32 27.7.3 normal interrupt 27.7.3.1 priority controller an 8-level priority controller drives the nirq line of the processor, depending on the interrupt conditions occurring on the interrupt sources 1 to 31 (except for those programmed in fast forcing). each interrupt source has a programmable priority le vel of 7 to 0, which is user-definable by writ- ing the prior field of the corresponding aic_smr (source mode register). level 7 is the highest priority and level 0 the lowest. as soon as an interrupt condition occurs, as defined by the srctype field of the aic_smr (source mode register), the nirq line is asserted. as a new interrupt condition might have hap- pened on other interrupt sources since the nirq has been asserted, the priority controller determines the current interrupt at the time the aic_ivr (interrupt vector register) is read. the read of aic_ivr is the entry point of the interrupt handling which allows the aic to consider that the interrupt has been taken into account by the software. the current priority level is defined as the priority level of the current interrupt. if several interrupt sources of equal priority are pending and enabled when the aic_ivr is read, the interrupt with the lowest interrupt source number is serviced first. the nirq line can be asserted only if an interrupt cond ition occurs on an in terrupt source with a higher priority. if an interrupt condition happens (or is pending) during the interrupt treatment in progress, it is delayed until the software indicates to the aic the end of the current service by writing the aic_eoicr (end of interrupt command register). the write of aic_eoicr is the exit point of the interrupt handling . 27.7.3.2 interrupt nesting the priority controller utilizes interr upt nesting in order for the high priority interrup t to be handled during the service of lower priority interrupts. this requires the interrupt service routines of the lower interrupts to re-enable the interrupt at the processor level. when an interrupt of a higher priority happens during an already occurring interrupt service rou- tine, the nirq line is re-asserted. if the interrupt is enabled at the core level, the current execution is interrupted and the new interrupt service routine should read the aic_ivr. at this time, the current interrupt number and its priority level are pushed into an embedded hardware stack, so that they are saved and restored when the higher priority interrupt servicing is finished and the aic_eoicr is written. the aic is equipped with an 8-leve l wide hardware stack in order to support up to eight interrupt nestings pursuant to having eight priority levels. 27.7.3.3 interrupt vectoring the interrupt handler addresses corresponding to each interrupt source can be stored in the reg- isters aic_svr1 to aic_svr31 (source vector register 1 to 31). when the processor reads aic_ivr (interrupt vector register), the value written into aic_svr corresponding to the cur- rent interrupt is returned. this feature offers a way to branch in one single instruction to the handler corresponding to the current interrupt, as aic_ivr is mapped at the absolute address 0xffff f100 and thus acces- sible from the arm interrupt vector at address 0x0000 0018 through the following instruction: ldr pc,[pc,# -&f20]
253 6222f?atarm?14-jan-11 sam7se512/256/32 when the processor executes this instruction, it loads the read value in aic_ivr in its program counter, thus branching the execution on the correct interrupt handler. this feature is often not used when the application is based on an operating system (either real time or not). operating systems often have a single entry point for all the interrupts and the first task performed is to discern the source of the interrupt. however, it is strongly recommended to port the operating system on at91 products by support- ing the interrupt vectoring. this can be performed by defining all the aic_svr of the interrupt source to be handled by the operating system at the address of its interrupt handler. when doing so, the interrupt vectoring permits a critical interr upt to transfer the execution on a specific very fast handler and not onto the operating system?s general interrupt handler. this facilitates the support of hard real-time tasks (input/outputs of voice/audio buffers and software peripheral han- dling) to be handled efficiently and independently of the application running under an operating system. 27.7.3.4 interrupt handlers this section gives an overview of the fast interrupt handling sequence when using the aic. it is assumed that the programmer understands the architecture of the arm processor, and espe- cially the processor interrupt mode s and the associated status bits. it is assumed that: 1. the advanced interrupt controller has been programmed, aic_svr registers are loaded with corresponding interrupt service routine addresses and interrupts are enabled. 2. the instruction at the arm interrupt exception vector address is required to work with the vectoring ldr pc, [pc, # -&f20] when nirq is asserted, if the bit ?i? of cpsr is 0, the sequence is as follows: 1. the cpsr is stored in spsr_i rq, the current value of the program coun ter is loaded in the interrupt link register (r14_irq) and the program counter (r15) is loaded with 0x18. in the following cycle during fetch at address 0x1c, the arm core adjusts r14_irq, dec- rementing it by four. 2. the arm core enters interrupt mode, if it has not already done so. 3. when the instruction loaded at address 0x18 is executed, the program counter is loaded with the value read in aic_ivr. reading the aic_ivr has the following effects: ? sets the current interrupt to be the pending and enabled interrupt with the highest priority. the current level is the priority level of the current interrupt. ? de-asserts the nirq line on the processor. even if vectoring is not used, aic_ivr must be read in order to de-assert nirq. ? automatically clears the interrupt, if it has been programmed to be edge-triggered. ? pushes the current level and the current interrupt number on to the stack. ? returns the value written in the aic_svr corresponding to the current interrupt. 4. the previous step has the effect of branc hing to the corresponding interrupt service routine. this should start by saving the link register (r14_irq) and spsr_irq. the link register must be decremented by four when it is saved if it is to be restored directly into the program counter at the end of the interrupt. for example, the instruction sub pc, lr, #4 may be used.
254 6222f?atarm?14-jan-11 sam7se512/256/32 5. further interrupts can then be unmasked by clearing the ?i? bit in cpsr, allowing re- assertion of the nirq to be taken into account by the core. this can happen if an inter- rupt with a higher priority than the current interrupt occurs. 6. the interrupt handler can th en proceed as required, savi ng the registers that will be used and restoring them at the end. during this phase, an interrupt of higher priority than the current leve l will restart the sequence from step 1. note: if the interrupt is programmed to be level sensitiv e, the source of the interrupt must be cleared dur- ing this phase. 7. the ?i? bit in cpsr must be set in order to mask interrupts before exiting to ensure that the interrupt is completed in an orderly manner. 8. the end of interrupt command register (aic_eoicr) must be written in order to indi- cate to the aic that the current interrupt is finished. this causes the current level to be popped from the stack, restoring the previous current level if one exists on the stack. if another interrupt is pending, with lower or equal priority than the old current level but with higher priority than the new current level, the nirq line is re-asserted, but the inter- rupt sequence does not immediately start because the ?i? bit is set in the core. spsr_irq is restored. fina lly, the saved value of the link regi ster is restored directly into the pc. this has the effect of returning from the interrupt to whatever was being exe- cuted before, and of loading the cpsr with the stored spsr, masking or unmasking the interrupts depending on the state saved in spsr_irq. note: the ?i? bit in spsr is significant. if it is set, it indicates that the arm core was on the verge of masking an interrupt when the mask instruction was in terrupted. hence, when spsr is restored, the mask instruction is comple ted (interrupt is masked).
255 6222f?atarm?14-jan-11 sam7se512/256/32 27.7.4 fast interrupt 27.7.4.1 fast interrupt source the interrupt source 0 is the only source which can raise a fast interrupt request to the processor except if fast forcing is used. the interrupt so urce 0 is generally connected to a fiq pin of the product, either directly or through a pio controller. 27.7.4.2 fast interrupt control the fast interrupt logic of the aic has no priority controller. the mode of interrupt source 0 is programmed with the aic_smr0 and the field prior of this register is not used even if it reads what has been written. the fi eld srctype of aic_smr0 enable s programming the fast inter- rupt source to be positive-edge triggered or negative-edge triggered or high-level sensitive or low-level sensitive writing 0x1 in the aic_iecr (interrupt enable command register) and aic_idcr (interrupt disable command register) respectively enables and disables the fast interrupt. the bit 0 of aic_imr (interrupt mask register) indicates whet her the fast interrupt is enabled or disabled. 27.7.4.3 fast interrupt vectoring the fast interrupt handler address can be stored in aic_svr0 (source vector register 0). the value written into this register is returned when the processor reads aic_fvr (fast vector reg- ister). this offers a way to branch in one single instruction to the interrupt handler, as aic_fvr is mapped at the absolute address 0xffff f104 and thus accessible from the arm fast inter- rupt vector at address 0x0000 001c through the following instruction: ldr pc,[pc,# -&f20] when the processor executes this instruction it loads the value read in aic_fvr in its program counter, thus branching the execution on the fast interrupt handler. it also automatically per- forms the clear of the fast interrupt source if it is programmed in edge-triggered mode. 27.7.4.4 fast interrupt handlers this section gives an overview of the fast interrupt handling sequence when using the aic. it is assumed that the programmer understands the architecture of the arm processor, and espe- cially the processor interrupt modes and associated status bits. assuming that: 1. the advanced interrupt controller has been programmed, aic_svr0 is loaded with the fast interrupt service routine address, and the interrupt source 0 is enabled. 2. the instruction at address 0x1c (fiq exception vector address) is required to vector the fast interrupt: ldr pc, [pc, # -&f20] 3. the user does not need nested fast interrupts. when nfiq is asserted, if the bit ?f? of cpsr is 0, the sequence is: 1. the cpsr is stored in spsr_fiq, the current value of the program counter is loaded in the fiq link register (r14_fiq) and the program counter (r15) is loaded with 0x1c. in the following cycle, during fetch at address 0x20, the arm core ad justs r14_fiq, decre- menting it by four. 2. the arm core enters fiq mode. 3. when the instruction loaded at address 0x1c is executed, the program counter is loaded with the value read in aic_fvr. re ading the aic_fvr has effect of automati-
256 6222f?atarm?14-jan-11 sam7se512/256/32 cally clearing the fast interrupt, if it has been programmed to be edge triggered. in this case only, it de-asserts the nfiq line on the processor. 4. the previous step enables branching to the corresponding interrupt service routine. it is not necessary to save the link register r14_fiq and spsr_fiq if nested fast interrupts are not needed. 5. the interrupt handler can then proceed as required. it is not necessary to save regis- ters r8 to r13 because fiq mode has its own dedicated registers and the user r8 to r13 are banked. the other registers, r0 to r7, must be saved before being used, and restored at the end (before the next step). note that if the fast interrupt is programmed to be level sensitive, the source of the interrupt must be cleared during this phase in order to de-assert the interrupt source 0. 6. finally, the link register r14_fiq is restored into the pc after decrementing it by four (with instruction sub pc, lr, #4 for example). this has the effect of returning from the interrupt to whatever was being exec uted before, loading the cpsr with the spsr and masking or unmasking the fast interrupt depending on the state saved in the spsr. note: the ?f? bit in spsr is significan t. if it is set, it indicates that the arm core was just about to mask fiq interrupts when the mask instru ction was interrupted. hence wh en the spsr is restored, the interrupted instruction is completed (fiq is masked). another way to handle the fast interrupt is to map the interrupt service routine at the address of the arm vector 0x1c. this method does not use the vectoring, so that reading aic_fvr must be performed at the very beginning of the handler operation. however, this method saves the execution of a branch instruction. 27.7.4.5 fast forcing the fast forcing feature of the advanced interrupt controller provides redirection of any normal interrupt source on the fast interrupt controller. fast forcing is enabled or disabl ed by writing to the fast forcing enable register (aic_ffer) and the fast forcing disable register (aic_ff dr). writing to these re gisters results in an update of the fast forcing status register (aic _ffsr) that controls the feature for each inter- nal or external interrupt source. when fast forcing is disabled, the interrupt sources are handled as described in the previous pages. when fast forcing is enabled, the edge/level programming and, in certain cases, edge detec- tion of the interrupt s ource is still active but the source c annot trigger a normal interrupt to the processor and is not seen by the priority handler. if the interrupt source is programmed in level- sensitive mode and an active level is sampled, fast forcing results in the assertion of the nfiq line to the core. if the interrupt source is programmed in edge-triggered mode and an active edge is detected, fast forcing results in the assertion of the nfiq line to the core. the fast forcing feature does not affect the source 0 pending bit in the interrupt pending reg- ister (aic_ipr). the fiq vector register (aic_fvr) reads the contents of the source vector register 0 (aic_svr0), whatever the source of the fast interrupt may be. the read of the fvr does not clear the source 0 when the fast forcing feature is used and the interrupt source should be cleared by writing to the interrupt cl ear command register (aic_iccr).
257 6222f?atarm?14-jan-11 sam7se512/256/32 all enabled and pending interrupt sources that have the fast forcing feature enabled and that are programmed in edge-triggered mode must be cleared by writing to the interrupt clear command register. in doing so, they are cleared independently and thus lost interrupts are prevented. the read of aic_ivr does not clear the source that has the fast forcing feature enabled. the source 0, reserved to the fast interrupt, continues operating normally and becomes one of the fast interrupt sources. figure 27-10. fast forcing source 0 _ fiq input stage automatic clear input stage automatic clear source n aic_ipr aic_imr aic_ffsr aic_ipr aic_imr priority manager nfiq nirq read ivr if source n is the current interrupt and if fast forcing is disabled on source n. read fvr if fast forcing is disabled on sources 1 to 31.
258 6222f?atarm?14-jan-11 sam7se512/256/32 27.7.5 protect mode the protect mode permits reading the interrupt vector register without performing the associ- ated automatic operations. this is necessary when working with a debug system. when a debugger, working either with a debug monitor or the arm processor's ic e, stops the applica- tions and updates the opened windows, it might read the aic user interface and thus the ivr. this has undesirable consequences: ? if an enabled interrupt with a higher priority than the current one is pending, it is stacked. ? if there is no enabled pending interrupt, the spurious vector is returned. in either case, an end of interrupt command is necessary to acknowledge and to restore the context of the aic. this operation is generally not performed by the debug system as the debug system would become strongly intrusive and caus e the application to enter an undesired state. this is avoided by using the protect mode. writing dbgm in aic_dcr (debug control register) at 0x1 enables the protect mode. when the protect mode is enabled, the aic performs interrupt stacking only when a write access is performed on the aic_ivr. therefore, the interrupt service routines must write (arbitrary data) to the aic_ivr just after reading it. the new context of the aic, including the value of the interrupt status register (aic_isr), is updated with the current interrupt only when aic_ivr is written. an aic_ivr read on its own (e.g., by a debugger), modifies neither the aic context nor the aic_isr. extra aic_ivr reads perform the same operations. however, it is recommended to not stop the processor between the read and the write of aic_ivr of the interrupt service routine to make sure the debugger does not modify the aic context. to summarize, in normal operating mode, the read of aic_ivr performs the following opera- tions within the aic: 1. calculates active interrupt (higher than current or spurious). 2. determines and returns the vector of the active interrupt. 3. memorizes the interrupt. 4. pushes the current priority level onto the internal stack. 5. acknowledges the interrupt. however, while the protect mode is activated, only operations 1 to 3 are performed when aic_ivr is read. operations 4 and 5 are only performed by the aic when aic_ivr is written. software that has been written and debugged using the protect mode runs correctly in normal mode without modification. however, in normal mode the aic_ivr write has no effect and can be removed to optimize the code. 27.7.6 spurious interrupt the advanced interrupt controller features protec tion against spurious interrupts. a spurious interrupt is defined as being the assertion of an interrupt source long enough for the aic to assert the nirq, but no longer present when aic_ivr is read. this is most prone to occur when: ? an external interrupt source is programmed in level-sensitive mode and an active level occurs for only a short time.
259 6222f?atarm?14-jan-11 sam7se512/256/32 ? an internal interrupt source is programmed in level sensitive and the output signal of the corresponding embedded peripheral is activated for a short time. (as in the case for the watchdog.) ? an interrupt occurs just a few cycles before the software begins to mask it, thus resulting in a pulse on the interrupt source. the aic detects a spurious interrupt at the time the aic_ivr is read while no enabled interrupt source is pending. when this happens, the aic returns the value stored by the programmer in aic_spu (spurious vector register). the progr ammer must store the address of a spurious interrupt handler in aic_spu as part of the application, to enable an as fast as possible return to the normal execution flow. this handler writes in aic_eoicr and performs a return from interrupt. 27.7.7 general interrupt mask the aic features a general interrupt mask bit to prevent interrupts from reaching the processor. both the nirq and the nfiq lines are driven to thei r inactive state if the bit gmsk in aic_dcr (debug control register) is set. however, this mask does not prevent waking up the processor if it has entered idle mode. this function facilitates synchronizi ng the processor on a next event and, as soon as the event occurs, performs su bsequent operations without having to handle an interrupt. it is strongly recommended to use this mask with caution.
260 6222f?atarm?14-jan-11 sam7se512/256/32 27.8 advanced interrupt controll er (aic) user interface 27.8.1 base address the aic is mapped at the address 0xffff f000 . it has a total 4-kbyte addressing space. this permits the vectoring feature, as the pc-relative load/store instructions of the arm processor support only an 4-kbyte offset. 27.8.2 register mapping notes: 1. the reset value of this register depends on the level of the external interrupt source. all other sources are cleared a t reset, thus not pending. 2. pid2...pid31 bit fields refer to the identifiers as defined in the peripheral identifiers se ction of the product datasheet. table 27-2. register mapping offset register name access reset value 0000 source mode register 0 aic_smr0 read/write 0x0 0x04 source mode register 1 aic_smr1 read/write 0x0 --- --- --- --- --- 0x7c source mode register 31 aic_smr31 read/write 0x0 0x80 source vector register 0 aic_svr0 read/write 0x0 0x84 source vector register 1 aic_svr1 read/write 0x0 --- --- --- --- --- 0xfc source vector register 31 aic_svr31 read/write 0x0 0x100 interrupt vector register aic_ivr read-only 0x0 0x104 fiq interrupt vector register aic_fvr read-only 0x0 0x108 interrupt status register aic_isr read-only 0x0 0x10c interrupt pending register (2) aic_ipr read-only 0x0 (1) 0x110 interrupt mask register (2) aic_imr read-only 0x0 0x114 core interrupt status register aic_cisr read-only 0x0 0x118 reserved --- --- --- 0x11c reserved --- --- --- 0x120 interrupt enable command register (2) aic_iecr write-only --- 0x124 interrupt disable command register (2) aic_idcr write-only --- 0x128 interrupt clear command register (2) aic_iccr write-only --- 0x12c interrupt set command register (2) aic_iscr write-only --- 0x130 end of interrupt command register aic_eoicr write-only --- 0x134 spurious interrupt vector register aic_spu read/write 0x0 0x138 debug control register aic_dcr read/write 0x0 0x13c reserved --- --- --- 0x140 fast forcing enable register (2) aic_ffer write-only --- 0x144 fast forcing disable register (2) aic_ffdr write-only --- 0x148 fast forcing status register (2) aic_ffsr read-only 0x0
261 6222f?atarm?14-jan-11 sam7se512/256/32 27.8.3 aic source mode register name: aic_smr0..aic_smr31 access: read/write reset value: 0x0 ? prior: priority level programs the priority level for all sources except fiq source (source 0). the priority level can be between 0 (lowest) and 7 (highest). the priority level is not used for the fi q in the related smr register aic_smrx. ? srctype: interrupt source type the active level or edge is not programmable for the internal interrupt sources. 31 30 29 28 27 26 25 24 ???????? 23 22 21 20 19 18 17 16 ???????? 15 14 13 12 11 10 9 8 ???????? 76543210 ? srctype ? ? prior srctype internal interrupt sources external interrupt sources 0 0 high level sensitive low level sensitive 0 1 positive edge triggered negative edge triggered 1 0 high level sensitive high level sensitive 1 1 positive edge triggered positive edge triggered
262 6222f?atarm?14-jan-11 sam7se512/256/32 27.8.4 aic source vector register name: aic_svr0..aic_svr31 access: read/write reset value: 0x0 ? vector: source vector the user may store in these registers the addresses of the corresponding handler for each interrupt source. 27.8.5 aic interrupt vector register name: aic_ivr access: read-only reset value: 0x0 ? irqv: interrupt vector register the interrupt vector register contains the vector programmed by the user in the source vector register corresponding to the current interrupt. the source vector register is indexed using the current interrupt number when the interrupt vector register is read. when there is no current interrupt, the interrupt vector register reads the value stored in aic_spu. 31 30 29 28 27 26 25 24 vector 23 22 21 20 19 18 17 16 vector 15 14 13 12 11 10 9 8 vector 76543210 vector 31 30 29 28 27 26 25 24 irqv 23 22 21 20 19 18 17 16 irqv 15 14 13 12 11 10 9 8 irqv 76543210 irqv
263 6222f?atarm?14-jan-11 sam7se512/256/32 27.8.6 aic fiq vector register name: aic_fvr access: read-only reset value: 0 x0 ? fiqv: fiq vector register the fiq vector register contains the vector programmed by the user in the source vector register 0. when there is no fast interrupt, the fiq vector register reads the value stored in aic_spu. 27.8.7 aic interrupt status register name: aic_isr access: read-only reset value: 0x0 ? irqid: current interrupt identifier the interrupt status register returns the current interrupt source number. 31 30 29 28 27 26 25 24 fiqv 23 22 21 20 19 18 17 16 fiqv 15 14 13 12 11 10 9 8 fiqv 76543210 fiqv 31 30 29 28 27 26 25 24 ???????? 23 22 21 20 19 18 17 16 ???????? 15 14 13 12 11 10 9 8 ???????? 76543210 ??? irqid
264 6222f?atarm?14-jan-11 sam7se512/256/32 27.8.8 aic interrupt pending register name: aic_ipr access: read-only reset value: 0x0 ? fiq, sys, pid2-pid31: interrupt pending 0 = corresponding interrupt is not pending. 1 = corresponding interrupt is pending. 27.8.9 aic interrupt mask register name: aic_imr access: read-only reset value: 0x0 ? fiq, sys, pid2-pid31: interrupt mask 0 = corresponding interrupt is disabled. 1 = corresponding interrupt is enabled. 31 30 29 28 27 26 25 24 pid31 pid30 pid29 pid28 pid27 pid26 pid25 pid24 23 22 21 20 19 18 17 16 pid23 pid22 pid21 pid20 pid19 pid18 pid17 pid16 15 14 13 12 11 10 9 8 pid15 pid14 pid13 pid12 pid11 pid10 pid9 pid8 76543210 pid7 pid6 pid5 pid4 pid3 pid2 sys fiq 31 30 29 28 27 26 25 24 pid31 pid30 pid29 pid28 pid27 pid26 pid25 pid24 23 22 21 20 19 18 17 16 pid23 pid22 pid21 pid20 pid19 pid18 pid17 pid16 15 14 13 12 11 10 9 8 pid15 pid14 pid13 pid12 pid11 pid10 pid9 pid8 76543210 pid7 pid6 pid5 pid4 pid3 pid2 sys fiq
265 6222f?atarm?14-jan-11 sam7se512/256/32 27.8.10 aic core interrupt status register name: aic_cisr access: read-only reset value: 0x0 ? nfiq: nfiq status 0 = nfiq line is deactivated. 1 = nfiq line is active. ? nirq: nirq status 0 = nirq line is deactivated. 1 = nirq line is active. 27.8.11 aic interrupt enable command register name: aic_iecr access: write-only ? fiq, sys, pid2-pid3: interrupt enable 0 = no effect. 1 = enables corresponding interrupt. 31 30 29 28 27 26 25 24 ???????? 23 22 21 20 19 18 17 16 ???????? 15 14 13 12 11 10 9 8 ???????? 76543210 ??????nirqnifq 31 30 29 28 27 26 25 24 pid31 pid30 pid29 pid28 pid27 pid26 pid25 pid24 23 22 21 20 19 18 17 16 pid23 pid22 pid21 pid20 pid19 pid18 pid17 pid16 15 14 13 12 11 10 9 8 pid15 pid14 pid13 pid12 pid11 pid10 pid9 pid8 76543210 pid7 pid6 pid5 pid4 pid3 pid2 sys fiq
266 6222f?atarm?14-jan-11 sam7se512/256/32 27.8.12 aic interrupt disable command register name: aic_idcr access: write-only ? fiq, sys, pid2-pid31: interrupt disable 0 = no effect. 1 = disables corresponding interrupt. 27.8.13 aic interrupt clear command register name: aic_iccr access: write-only ? fiq, sys, pid2-pid31: interrupt clear 0 = no effect. 1 = clears corresponding interrupt. 31 30 29 28 27 26 25 24 pid31 pid30 pid29 pid28 pid27 pid26 pid25 pid24 23 22 21 20 19 18 17 16 pid23 pid22 pid21 pid20 pid19 pid18 pid17 pid16 15 14 13 12 11 10 9 8 pid15 pid14 pid13 pid12 pid11 pid10 pid9 pid8 76543210 pid7 pid6 pid5 pid4 pid3 pid2 sys fiq 31 30 29 28 27 26 25 24 pid31 pid30 pid29 pid28 pid27 pid26 pid25 pid24 23 22 21 20 19 18 17 16 pid23 pid22 pid21 pid20 pid19 pid18 pid17 pid16 15 14 13 12 11 10 9 8 pid15 pid14 pid13 pid12 pid11 pid10 pid9 pid8 76543210 pid7 pid6 pid5 pid4 pid3 pid2 sys fiq
267 6222f?atarm?14-jan-11 sam7se512/256/32 27.8.14 aic interrupt set command register name: aic_iscr access: write-only ? fiq, sys, pid2-pid31: interrupt set 0 = no effect. 1 = sets corresponding interrupt. 27.8.15 aic end of interrupt command register name: aic_eoicr access: write-only the end of interrupt command register is used by the interrupt routine to indicate that the interrupt treatment is complete. any value can be written because it is only necessary to make a write to this register location to signal the end of interrupt treatment. 31 30 29 28 27 26 25 24 pid31 pid30 pid29 pid28 pid27 pid26 pid25 pid24 23 22 21 20 19 18 17 16 pid23 pid22 pid21 pid20 pid19 pid18 pid17 pid16 15 14 13 12 11 10 9 8 pid15 pid14 pid13 pid12 pid11 pid10 pid9 pid8 76543210 pid7 pid6 pid5 pid4 pid3 pid2 sys fiq 31 30 29 28 27 26 25 24 ???????? 23 22 21 20 19 18 17 16 ???????? 15 14 13 12 11 10 9 8 ???????? 76543210 ????????
268 6222f?atarm?14-jan-11 sam7se512/256/32 27.8.16 aic spurious interrupt vector register name: aic_spu access: read/write reset value: 0x0 ? siqv: spurious interrupt vector register the user may store the address of a spurious interrupt handler in this register. the written value is returned in aic_ivr in case of a spurious interrupt and in aic_fvr in case of a spurious fast interrupt. 27.8.17 aic debug control register name: aic_debug access: read/write reset value: 0x0 ? prot: protection mode 0 = the protection mode is disabled. 1 = the protection mode is enabled. ? gmsk: general mask 0 = the nirq and nfiq lines are normally controlled by the aic. 1 = the nirq and nfiq lines are tied to their inactive state. 31 30 29 28 27 26 25 24 siqv 23 22 21 20 19 18 17 16 siqv 15 14 13 12 11 10 9 8 siqv 76543210 siqv 31 30 29 28 27 26 25 24 ???????? 23 22 21 20 19 18 17 16 ???????? 15 14 13 12 11 10 9 8 ???????? 76543210 ??????gmskprot
269 6222f?atarm?14-jan-11 sam7se512/256/32 27.8.18 aic fast forcing enable register name: aic_ffer access: write-only ? sys, pid2-pid31: fast forcing enable 0 = no effect. 1 = enables the fast forcing feature on the corresponding interrupt. 27.8.19 aic fast forcing disable register name: aic_ffdr access: write-only ? sys, pid2-pid31: fast forcing disable 0 = no effect. 1 = disables the fast forcing feature on the corresponding interrupt. 31 30 29 28 27 26 25 24 pid31 pid30 pid29 pid28 pid27 pid26 pid25 pid24 23 22 21 20 19 18 17 16 pid23 pid22 pid21 pid20 pid19 pid18 pid17 pid16 15 14 13 12 11 10 9 8 pid15 pid14 pid13 pid12 pid11 pid10 pid9 pid8 76543210 pid7 pid6 pid5 pid4 pid3 pid2 sys ? 31 30 29 28 27 26 25 24 pid31 pid30 pid29 pid28 pid27 pid26 pid25 pid24 23 22 21 20 19 18 17 16 pid23 pid22 pid21 pid20 pid19 pid18 pid17 pid16 15 14 13 12 11 10 9 8 pid15 pid14 pid13 pid12 pid11 pid10 pid9 pid8 76543210 pid7 pid6 pid5 pid4 pid3 pid2 sys ?
270 6222f?atarm?14-jan-11 sam7se512/256/32 27.8.20 aic fast forcing status register name: aic_ffsr access: read-only ? sys, pid2-pid31: fast forcing status 0 = the fast forcing feature is disabled on the corresponding interrupt. 1 = the fast forcing feature is enabled on the corresponding interrupt. 31 30 29 28 27 26 25 24 pid31 pid30 pid29 pid28 pid27 pid26 pid25 pid24 23 22 21 20 19 18 17 16 pid23 pid22 pid21 pid20 pid19 pid18 pid17 pid16 15 14 13 12 11 10 9 8 pid15 pid14 pid13 pid12 pid11 pid10 pid9 pid8 76543210 pid7 pid6 pid5 pid4 pid3 pid2 sys ?
271 6222f?atarm?14-jan-11 sam7se512/256/32 28. clock generator 28.1 overview the clock generator is made up of 1 pll, a main oscillato r, as well as an rc oscillator. it provides the following clocks: ? slck, the slow clock, which is the only permanent clock within the system ? mainck is the output of the main oscillator ? pllck is the output of the divider and pll block the clock generator user interface is embedded within the power management controller and is described in section 29.9 . however, the clock generator registers are named ckgr_. 28.2 slow clock rc oscillator the user has to take into accoun t the possible drifts of the rc oscillator. more details are given in the section ?dc characteristics? of the product datasheet. 28.3 main oscillator figure 28-1 shows the main oscillator block diagram. figure 28-1. main oscillator block diagram 28.3.1 main oscillator connections the clock generator integr ates a main oscillator that is desi gned for a 3 to 20 mhz fundamental crystal. the typical crystal c onnection is illustrated in figure 28-2 . for further details on the elec- trical characteristics of the main oscillator, se e the section ?dc characte ristics? of the product datasheet. xin xout moscen main oscillator counter oscount moscs mainck main clock main clock frequency counter mainf mainrdy slck slow clock main oscillator
272 6222f?atarm?14-jan-11 sam7se512/256/32 figure 28-2. typical crystal connection 28.3.2 main oscillator startup time the startup time of the main oscillator is given in the dc characteristics section of the product datasheet. the startup time depends on the crystal frequency and decreases when the fre- quency rises. 28.3.3 main oscillator control to minimize the power required to start up the sy stem, the main oscillator is disabled after reset and slow clock is selected. the software enable s or disables the main oscillator so as to reduce powe r consumption by clearing the moscen bit in the ma in oscillator regi ster (ckgr_mor). when disabling the main oscillator by clearin g the moscen bit in ckgr_mor, the moscs bit in pmc_sr is automatica lly cleared, indicating the main clock is off. when enabling the main oscillator, the user must initiate the ma in oscillator coun ter with a value corresponding to the startup time of the oscillat or. this startup time depends on the crystal fre- quency connected to the main oscillator. when the moscen bit and the oscount are written in ckgr_mor to enable the main oscil- lator, the moscs bit in pmc_sr (status register) is cleared and the counter starts counting down on the slow clock divided by 8 from the oscount value. since the oscount value is coded with 8 bits, the maximum startup time is about 62 ms. when the counter reaches 0, the moscs bit is set, indicating that the main clock is valid. set- ting the moscs bit in pmc_imr can trigger an interrupt to the processor. 28.3.4 main clock frequency counter the main oscillator feat ures a main clock frequen cy counter that provides the quartz frequency connected to the main oscillator. generally, this value is know n by the system designer; how- ever, it is useful for the boot program to c onfigure the device with the correct clock speed, independently of the application. the main clock frequency counter starts incrementing at the main clock speed after the next ris- ing edge of the slow clock as soon as the main oscillator is stab le, i.e., as soon as the moscs bit is set. then, at th e 16th falling edge of slow clock, the mainrdy bit in ckgr_mcfr (main clock frequency register) is set and the counter stops counting. its value can be read in the mainf field of ckgr_mcfr and gives the number of main clock cycles during 16 periods of 1k xin xout gnd at91sam7se microcontroller
273 6222f?atarm?14-jan-11 sam7se512/256/32 slow clock, so that the frequency of the crystal connected on the main oscillator can be determined. 28.3.5 main oscillator bypass the user can input a clock on the device instead of connecting a crystal. in this case, the user has to provide the external clock signal on the xi n pin. the input characteristics of the xin pin under these conditions are given in the product el ectrical characteristics section. the program- mer has to be sure to set the oscbypass bit to 1 and the moscen bit to 0 in the main osc register (ckgr_mor) for the external clock to operate properly. 28.4 divider and pll block the pll embeds an input divider to increase the accuracy of the resulting clock signals. how- ever, the user must respect the pll minimum input frequency when programming the divider. figure 28-3 shows the block diagram of the divider and pll block. figure 28-3. divider and pll block diagram 28.4.1 pll filter the pll requires connection to an external sec ond-order filter through the pllrc pin. figure 28-4 shows a schematic of these filters. figure 28-4. pll capacitors and resistors values of r, c1 and c2 to be connected to the pllrc pin must be calculated as a function of the pll input frequency, the pll output frequency and the phase margin. a trade-off has to be found between output signal overshoot and startup time. divider pllrc div pll mul pllcount lock out slck mainck pllck pll counter gnd c1 c2 pll pllrc r
274 6222f?atarm?14-jan-11 sam7se512/256/32 28.4.2 divider and phase lock loop programming the divider can be set between 1 and 255 in steps of 1. when a divider field (div) is set to 0, the output of the corresponding divider and the pll out put is a continuous signal at level 0. on reset, each div field is set to 0, thus the corresponding pll input clock is set to 0. the pll allows multiplication of the divider?s out puts. the pll clock signal has a frequency that depends on the respective source signal frequency and on the parameters div and mul. the factor applied to the source signal frequency is (mul + 1)/div. when mul is written to 0, the corresponding pll is disabled and its power consumption is saved. re-enabling the pll can be performed by writing a value higher than 0 in the mul field. whenever the pll is re-enabled or one of its parameters is changed, the lock bit in pmc_sr is automatically cleared. the values written in the pllcount field in ckgr_pllr are loaded in the pll counter. the pll counter then decrements at the speed of the slow clock until it reaches 0. at this time, the lock bit is set in pmc_sr and can trigger an interrupt to the pro- cessor. the user has to load the number of slow clock cycles required to cover the pll transient time into the pllcount field. the transient time depends on the pll filter. the initial state of the pll and its target frequency can be calculated using a specific tool provided by atmel.
275 6222f?atarm?14-jan-11 sam7se512/256/32 29. power management controller (pmc) 29.1 overview the power management controller (pmc) optimizes power consumption by controlling all sys- tem and user peripheral clocks. the pmc enables/disables the clock inputs to many of the peripherals and the arm processor. the power management controller provides the following clocks: ? mck, the master clock, programmable from a few hundred hz to the maximum operating frequency of the device. it is available to the modules running permanently, such as the aic and the memory controller. ? processor clock (pck), switched off wh en entering processor in idle mode. ? peripheral clocks, typically mck, provided to the embedded peripherals (usart, ssc, spi, twi, tc, mci, etc.) and independently controllable. in order to reduce the number of clock names in a product, the peripheral clocks are named mck in the product datasheet. ? udp clock (udpck), required by usb device port operations. ? programmable clock outputs can be selected from the clocks provided by the clock generator and driven on the pckx pins. 29.2 master clock controller the master clock controller provides selection and division of the master clock (mck). mck is the clock provided to all the peripherals and the memory controller. the master clock is selected from one of the clocks provided by the clock generator. selecting the slow clock provides a slow clock signal to the whole device. selecting the main clock saves power consumption of the pll. the master clock controller is made up of a clock selector and a prescaler. the master clock selection is made by writing the css field (clock source selection) in pmc_mckr (master clock register). the prescaler supports the division by a power of 2 of the selected clock between 1 and 64. the pres field in pmc_mckr programs the prescaler. each time pmc_mckr is written to define a ne w master clock, the mckr dy bit is cleared in pmc_sr. it reads 0 until the master clock is es tablished. then, the mckrdy bit is set and can trigger an interrupt to the processor. this feature is useful when switching from a high-speed clock to a lower one to inform the software when the change is actually done. figure 29-1. master clock controller slck master clock prescaler mck pres css mainck pllck to the processor clock controller (pck) pmc_mckr pmc_mckr
276 6222f?atarm?14-jan-11 sam7se512/256/32 29.3 processor clock controller the pmc features a processor clock controller (pck) that implements the processor idle mode. the processor clock can be disabled by writing the system cl ock disable register (pmc_scdr). the status of this clock (at least for debug purpose) can be read in the system clock status register (pmc_scsr). the processor clock pck is enabled after a reset and is automatically re-enabled by any enabled interrupt. the processor idle mode is ac hieved by disabling the processor clock, which is automatically re-enabled by any enabled fast or normal interrupt, or by the reset of the product. when the processor clock is disabled, the current instruction is finished before the clock is stopped, but this does not prevent data transfers from other masters of the system bus. 29.4 usb clock controller the usb source clock is the pll output. if using the usb, the user must program the pll to generate a 48 mhz, a 96 mhz or a 192 mhz signal with an accuracy of 0.25% depending on the usbdiv bit in ckgr_pllr. when the pll output is stable, i.e., the lock bit is set: ? the usb device clock can be enabled by setting the udp bit in pmc_scer. to save power on this peripheral when it is not used, the user can set the udp bit in pmc_scdr. the udp bit in pmc_scsr gives the activity of this clock. the usb device port require both the 48 mhz signal and the master clock. the master clock may be controlled via the master clock controller. figure 29-2. usb clock controller 29.5 peripheral clock controller the power management controller controls the clocks of each embedded peripheral by the way of the peripheral clock controller. the user can individually enable and disable the master clock on the peripherals by writing into the peripheral clock enable (pmc_pcer) and periph- eral clock disable (pmc_pcdr) registers. the status of the peripheral clock activity can be read in the peripheral clock status register (pmc_pcsr). when a peripheral clock is disabled, the clock is immediately stopped. the peripheral clocks are automatically disabled after a reset. in order to stop a peri pheral, it is recommended that the syst em software wait until the peripheral has executed its last programmed operation before disabling the clock. this is to avoid data cor- ruption or erroneous behavior of the system. usb source clock udp clock (udpck) udp usbdiv divider /1,/2,/4
277 6222f?atarm?14-jan-11 sam7se512/256/32 the bit number within the peripheral clock control registers (pmc_pcer, pmc_pcdr, and pmc_pcsr) is the peripheral identifier defined at the product level. generally, the bit number corresponds to the interrupt source number assigned to the peripheral. 29.6 programmable clock output controller the pmc controls 3 signals to be output on external pins pckx. each signal can be indepen- dently programmed via the pmc_pckx registers. pckx can be independently selected between the sl ow clock, the pll output and the main clock by writing the css field in pmc_pckx. each output signal can also be divided by a power of 2 between 1 and 64 by writing the pres (prescaler) field in pmc_pckx. each output signal can be enabled and disabled by writing 1 in the corresponding bit, pckx of pmc_scer and pmc_scdr, respectively. status of the active programmable output clocks are given in the pckx bits of pmc_scsr (system clock status register). moreover, like the pck, a status bit in pmc_sr indicates that the programmable clock is actu- ally what has been programmed in the programmable clock registers. as the programmable clock controller does not manage with glitch prevention when switching clocks, it is strongly recommended to disable the programmable clock before any configuration change and to re-enable it after the change is actually performed. 29.7 programming sequence 1. enabling the main oscillator: the main oscillator is enabled by setting the moscen field in the ckgr_mor register. in some cases it may be advantageous to define a st art-up time. this can be achieved by writ- ing a value in the oscount field in the ckgr_mor register. once this register has been correctly configured, the user must wait for moscs field in the pmc_sr register to be se t. this can be done either by pollin g the status regist er or by wait- ing the interrupt line to be raised if the associated interrupt to moscs has been enabled in the pmc_ier register. code example: write_register(ckgr_mor,0x00000701) start up time = 8 * oscount / slck = 56 slow clock cycles. so, the main oscillator will be enabled (moscs bit set) after 56 slow clock cycles. 2. checking the main oscilla tor frequency (optional): in some situations the user may need an accu rate measure of the ma in oscillator frequency. this measure can be accomplished via the ckgr_mcfr register. once the mainrdy field is set in ckgr_mcfr register, the user may read the mainf field in ckgr_mcfr register. this provides the num ber of main clock cycles within sixteen slow clock cycles.
278 6222f?atarm?14-jan-11 sam7se512/256/32 3. setting pll and divider: all parameters needed to configure pll and the divider are located in the ckgr_pllr register. the div field is used to control divider itself. a value between 0 and 255 can be pro- grammed. divider output is divider input divided by div parameter. by default div parameter is set to 0 which means that divider is turned off. the out field is used to select the pll b output frequency range. the mul field is the pll multiplier factor. this parameter can be programmed between 0 and 2047. if mul is set to 0, pll will be turn ed off, otherwise the pll output fr equency is pll input frequency mult iplied by (mul + 1). the pllcount field specifies the number of sl ow clock cycles before lock bit is set in the pmc_sr register after ckgr_pllr register has been written. once the pmc_pll register has been written, the user must wait for the lock bit to be set in the pmc_sr register. this ca n be done either by polling the st atus register or by waiting the interrupt line to be raised if the associated interrupt to lock has been enabled in the pmc_ier register. all parameters in ckgr_pllr can be programmed in a single write operation. if at some stage one of the following parameters, mul, div is modified, lock bit will go low to indicate that pl l is not ready yet. when pll is locked, lock will be set again. the user is constrained to wait for lock bi t to be set before using the pll output clock. the usbdiv field is used to control the additional divider by 1, 2 or 4, which generates the usb clock(s). code example: write_register(ckgr_pllr,0x00040805) if pll and divider are enabled, the pll input clock is the main clock. pll output clock is pll input clock multiplied by 5. on ce ckgr_pllr has been written, lock bit will be set after eight slow clock cycles. 4. selection of master clock and processor clock the master clock and the processor clock are configurable via the pmc_mckr register. the css field is used to select the master clock divider source. by default, the selected clock source is slow clock. the pres field is used to control the master clo ck prescaler. the user can choose between different values (1, 2, 4, 8, 16, 32, 64). master clock output is prescaler input divided by pres parameter. by default, pres parameter is set to 1 which means that master clock is equal to slow clock. once the pmc_mckr register has been written, the user must wait for the mckrdy bit to be set in the pmc_sr register. this can be done either by polling the status register or by waiting for the interrupt line to be raised if the associated interrupt to mckrdy has been enabled in the pmc_ier register. the pmc_mckr register must not be programmed in a single write operation. the pre- ferred programming sequence for the pmc_mckr register is as follows:
279 6222f?atarm?14-jan-11 sam7se512/256/32 ? if a new value for css field corresponds to pll clock, ? program the pres field in the pmc_mckr register. ? wait for the mckrdy bit to be set in the pmc_sr register. ? program the css field in the pmc_mckr register. ? wait for the mckrdy bit to be set in the pmc_sr register. ? if a new value for css field corresponds to main clock or slow clock, ? program the css field in the pmc_mckr register. ? wait for the mckrdy bit to be set in the pmc_sr register. ? program the pres field in the pmc_mckr register. ? wait for the mckrdy bit to be set in the pmc_sr register. if at some stage one of the following parameters, css or pres, is modified, the mckrdy bit will go low to indicate that the master clock and the processor clock are not ready yet. the user must wait for mckrdy bit to be set again before using the master and processor clocks. note: if pllx clock was selected as the master clock and the user decides to modify it by writing in ckgr_pllr, the mckrdy flag will go low while pll is unlocked. once pll is locked again, lock goes high and mckrdy is set. while pll is unlocked, the master clock selection is automatically changed to main clock. for fur- ther information, see section 29.8.2 . ?clock switching waveforms? on page 281 . code example: write_register(pmc_mckr,0x00000001) wait (mckrdy=1) write_register(pmc_mckr,0x00000011) wait (mckrdy=1) the master clock is main clock divided by 16. the processor clock is the master clock. 5. selection of programmable clocks programmable clocks are controlled via registers; pmc_scer, pmc_scdr and pmc_scsr. programmable clocks can be enabled and/or disabled via the pmc_scer and pmc_scdr registers. depending on the system used, 3 programmable clocks can be enabled or dis- abled. the pmc_scsr provides a clear indi cation as to which programmable clock is enabled. by default all programmable clocks are disabled. pmc_pckx registers are used to configure programmable clocks. the css field is used to select the programm able clock divider source . four clock options are available: main clock, slow clock, pllck. by default, the clock source selected is slow clock. the pres field is used to control the programmable clock prescaler. it is possible to choose between different values (1, 2, 4, 8, 16, 32, 64). programmable clock output is prescaler
280 6222f?atarm?14-jan-11 sam7se512/256/32 input divided by pres parameter. by default, the pres parameter is set to 1 which means that master clock is equal to slow clock. once the pmc_pckx register has been programmed, the corresponding programmable clock must be enabled and the user is constrai ned to wait for the pckrdyx bit to be set in the pmc_sr register. this can be done either by polling the status register or by waiting the interrupt line to be raised if the associated interrupt to pckrdyx has been enabled in the pmc_ier register. all parameters in pmc_ pckx can be programmed in a single write operation. if the css and pres parameters are to be modified, the corresponding programmable clock must be disabled first. the parameters can then be modified. once this has been done, the user must re-enable the programmable clock and wait for the pckrdyx bit to be set. code example: write_register(pmc_pck0,0x00000015) programmable clock 0 is main clock divided by 32. 6. enabling peripheral clocks once all of the previous steps have been completed, the peripheral clocks can be enabled and/or disabled via registers pmc_pcer and pmc_pcdr. depending on the system used, at91sam7se512,14 peripheral clocks and for at91sam7se256/32,12 peripheral clocks can be enabled or disabled. the pmc_pcsr provides a clear view as to which peripheral clock is enabled. note: each enabled peripheral clock corresponds to master clock. code examples: write_register(pmc_pcer,0x00000110) peripheral clocks 4 and 8 are enabled. write_register(pmc_pcdr,0x00000010) peripheral clock 4 is disabled.
281 6222f?atarm?14-jan-11 sam7se512/256/32 29.8 clock switching details 29.8.1 master clock switching timings table 29-1 gives the worst case timings required fo r the master clock to switch from one selected clock to another one. this is in the event that the prescaler is de-activated. when the prescaler is activated, an additional time of 64 cl ock cycles of the new selected clock has to be added. 29.8.2 clock switching waveforms figure 29-3. switch master clock from slow clock to pll clock table 29-1. clock switching timings (worst case) from main clock slck pll clock to main clock ? 4 x slck + 2.5 x main clock 3 x pll clock + 4 x slck + 1 x main clock slck 0.5 x main clock + 4.5 x slck ? 3 x pll clock + 5 x slck pll clock 0.5 x main clock + 4 x slck + pllcount x slck + 2.5 x pllx clock 2.5 x pll clock + 5 x slck + pllcount x slck 2.5 x pll clock + 4 x slck + pllcount x slck slow clock lock mckrdy master clock write pmc_mckr pll clock
282 6222f?atarm?14-jan-11 sam7se512/256/32 figure 29-4. switch master clock from main clock to slow clock figure 29-5. change pll programming slow clock main clock mckrdy master clock write pmc_mckr main clock main clock pll clock lock mckrdy master clock write ckgr_pllr
283 6222f?atarm?14-jan-11 sam7se512/256/32 figure 29-6. programmable clock output programming pll clock pckrdy pckx output write pmc_pckx write pmc_scer write pmc_scdr pckx is disabled pckx is enabled pll clock is selected
284 6222f?atarm?14-jan-11 sam7se512/256/32 29.9 power management contro ller (pmc) user interface table 29-2. register mapping offset register name access reset value 0x0000 system clock enable register pmc_scer write-only ? 0x0004 system clock disable register pmc_scdr write-only ? 0x0008 system clock status register pmc _scsr read-only 0x01 0x000c reserved ? ? ? 0x0010 peripheral clock enable register pmc _pcer write-only ? 0x0014 peripheral clock disable register pmc_pcdr write-only ? 0x0018 peripheral clock status register pmc_pcsr read-only 0x0 0x001c reserved ? ? ? 0x0020 main oscillator register ckgr_mor read-write 0x0 0x0024 main clock frequency register ckgr_mcfr read-only 0x0 0x0028 reserved ? ? ? 0x002c pll register ckgr_pllr read-write 0x3f00 0x0030 master clock register pmc_mckr read-write 0x0 0x0038 reserved ? ? ? 0x003c reserved ? ? ? 0x0040 programmable clock 0 register pmc_pck0 read-write 0x0 0x0044 programmable clock 1 register pmc_pck1 read-write 0x0 ... ... ... ... ... 0x0060 interrupt enable register pmc_ier write-only -- 0x0064 interrupt disable register pmc_idr write-only -- 0x0068 status register pmc_sr read-only 0x08 0x006c interrupt mask register pmc_imr read-only 0x0 0x0070 - 0x007c reserved ? ? ?
285 6222f?atarm?14-jan-11 sam7se512/256/32 29.9.1 pmc system clock enable register name: pmc_scer access: write-only ? udp: usb device port clock enable 0 = no effect. 1 = enables the 48 mhz clock of the usb device port. ? pckx: programmable clock x output enable 0 = no effect. 1 = enables the corresponding programmable clock output. 31 30 29 28 27 26 25 24 ???????? 23 22 21 20 19 18 17 16 ???????? 15 14 13 12 11 10 9 8 ?????pck2pck1pck0 76543210 udp???????
286 6222f?atarm?14-jan-11 sam7se512/256/32 29.9.2 pmc system clock disable register name: pmc_scdr access: write-only ? pck: processor clock disable 0 = no effect. 1 = disables the processor clock. this is used to enter the processor in idle mode. ? udp: usb device port clock disable 0 = no effect. 1 = disables the 48 mhz clock of the usb device port. ? pckx: programmable clock x output disable 0 = no effect. 1 = disables the corresponding programmable clock output. 31 30 29 28 27 26 25 24 ???????? 23 22 21 20 19 18 17 16 ???????? 15 14 13 12 11 10 9 8 ?????pck2pck1pck0 76543210 udp??????pck
287 6222f?atarm?14-jan-11 sam7se512/256/32 29.9.3 pmc system clock status register name: pmc_scsr access: read-only ? pck: processor clock status 0 = the processor clock is disabled. 1 = the processor clock is enabled. ? udp: usb device port clock status 0 = the 48 mhz clock (udpck) of th e usb device port is disabled. 1 = the 48 mhz clock (udpck) of the usb device port is enabled. ? pckx: programmable clock x output status 0 = the corresponding programmable clock output is disabled. 1 = the corresponding programmable clock output is enabled. 31 30 29 28 27 26 25 24 ???????? 23 22 21 20 19 18 17 16 ???????? 15 14 13 12 11 10 9 8 ?????pck2pck1pck0 76543210 udp??????pck
288 6222f?atarm?14-jan-11 sam7se512/256/32 29.9.4 pmc peripheral clock enable register name: pmc_pcer access: write-only ? pidx: peripheral clock x enable 0 = no effect. 1 = enables the corresponding peripheral clock. note: pid2 to pid31 refer to identifiers as defined in the section ?peripheral identifiers ? in the product datasheet. note: programming the control bits of the peripheral id that ar e not implemented has no effect on the behavior of the pmc. 31 30 29 28 27 26 25 24 pid31 pid30 pid29 pid28 pid27 pid26 pid25 pid24 23 22 21 20 19 18 17 16 pid23 pid22 pid21 pid20 pid19 pid18 pid17 pid16 15 14 13 12 11 10 9 8 pid15 pid14 pid13 pid12 pid11 pid10 pid9 pid8 76543210 pid7 pid6 pid5 pid4 pid3 pid2 ? ?
289 6222f?atarm?14-jan-11 sam7se512/256/32 29.9.5 pmc peripheral clock disable register name: pmc_pcdr access: write-only ? pidx: peripheral clock x disable 0 = no effect. 1 = disables the corresponding peripheral clock. note: pid2 to pid31 refer to identifiers as defined in the section ?peripheral identifiers ? in the product datasheet. 29.9.6 pmc peripheral clock status register name: pmc_pcsr access: read-only ? pidx: peripheral clock x status 0 = the corresponding peripheral clock is disabled. 1 = the corresponding peripheral clock is enabled. note: pid2 to pid31 refer to identifiers as defined in the section ?peripheral identifiers ? in the product datasheet. 31 30 29 28 27 26 25 24 pid31 pid30 pid29 pid28 pid27 pid26 pid25 pid24 23 22 21 20 19 18 17 16 pid23 pid22 pid21 pid20 pid19 pid18 pid17 pid16 15 14 13 12 11 10 9 8 pid15 pid14 pid13 pid12 pid11 pid10 pid9 pid8 76543210 pid7 pid6 pid5 pid4 pid3 pid2 ? ? 31 30 29 28 27 26 25 24 pid31 pid30 pid29 pid28 pid27 pid26 pid25 pid24 23 22 21 20 19 18 17 16 pid23 pid22 pid21 pid20 pid19 pid18 pid17 pid16 15 14 13 12 11 10 9 8 pid15 pid14 pid13 pid12 pid11 pid10 pid9 pid8 76543210 pid7 pid6 pid5 pid4 pid3 pid2 ? ?
290 6222f?atarm?14-jan-11 sam7se512/256/32 29.9.7 pmc clock generator main oscillator register name: ckgr_mor access: read-write ? moscen: main oscillator enable a crystal must be connected between xin and xout. 0 = the main oscillator is disabled. 1 = the main oscillator is enabl ed. oscbypass must be set to 0. when moscen is set, the moscs flag is set once the main oscillator startup time is achieved. ? oscbypass: oscillator bypass 0 = no effect. 1 = the main oscillator is bypassed. moscen must be set to 0. an exter nal clock must be connected on xin. when oscbypass is set, th e moscs flag in pmc_sr is automatically set. clearing moscen and oscbypass bits allows resetting the moscs flag. ? oscount: main oscillator start-up time specifies the number of slow clock cycles multip lied by 8 for the main o scillator start-up time. 31 30 29 28 27 26 25 24 ???????? 23 22 21 20 19 18 17 16 ???????? 15 14 13 12 11 10 9 8 oscount 76543210 ??????oscbypassmoscen
291 6222f?atarm?14-jan-11 sam7se512/256/32 29.9.8 pmc clock generator main clock frequency register name: ckgr_mcfr access: read-only ? mainf: main clock frequency gives the number of main clock cycles within 16 slow clock periods. ? mainrdy: main clock ready 0 = mainf value is not valid or the main oscillator is disabled. 1 = the main oscillator has been enabled pr eviously and mainf value is available. 31 30 29 28 27 26 25 24 ???????? 23 22 21 20 19 18 17 16 ???????mainrdy 15 14 13 12 11 10 9 8 mainf 76543210 mainf
292 6222f?atarm?14-jan-11 sam7se512/256/32 29.9.9 pmc clock generator pll register name: ckgr_pllr access: read-write possible limitations on pll input frequencies and multiplier factors should be checked before using the pmc. ?div: divider ? pllcount: pll counter specifies the number of slow clock cycles before the lo ck bit is set in pmc_sr after ckgr_pllr is written. ? out: pll clock frequency range to optimize clock performance, this field must be programmed as specified in ?pll characteristics? in the electrical char- acteristics section of the product datasheet. ? mul: pll multiplier 0 = the pll is deactivated. 1 up to 2047 = the pll clock frequency is the pll input frequency multiplied by mul+ 1. ? usbdiv: divider for usb clock 31 30 29 28 27 26 25 24 ? ? usbdiv ? mul 23 22 21 20 19 18 17 16 mul 15 14 13 12 11 10 9 8 out pllcount 76543210 div div divider selected 0 divider output is 0 1 divider is bypassed 2 - 255 divider output is the selected clock divided by div. usbdiv divider for usb clock(s) 0 0 divider output is pll clock output. 0 1 divider output is pll clock output divided by 2. 1 0 divider output is pll clock output divided by 4. 1 1 reserved.
293 6222f?atarm?14-jan-11 sam7se512/256/32 29.9.10 pmc master clock register name: pmc_mckr access: read-write ? css: master clock selection ? pres: processor clock prescaler 31 30 29 28 27 26 25 24 ???????? 23 22 21 20 19 18 17 16 ???????? 15 14 13 12 11 10 9 8 ???????? 76543210 ? ? ? pres css css clock source selection 0 0 slow clock is selected 0 1 main clock is selected 10reserved 1 1 pll clock is selected. pres processor clock 0 0 0 selected clock 0 0 1 selected clock divided by 2 0 1 0 selected clock divided by 4 0 1 1 selected clock divided by 8 1 0 0 selected clock divided by 16 1 0 1 selected clock divided by 32 1 1 0 selected clock divided by 64 111reserved
294 6222f?atarm?14-jan-11 sam7se512/256/32 29.9.11 pmc programmable clock register name: pmc_pckx access: read-write ? css: master clock selection ? pres: programmable clock prescaler 31 30 29 28 27 26 25 24 ???????? 23 22 21 20 19 18 17 16 ???????? 15 14 13 12 11 10 9 8 ???????? 76543210 ? ? ? pres css css clock source selection 0 0 slow clock is selected 0 1 main clock is selected 10reserved 1 1 pll clock is selected pres programmable clock 0 0 0 selected clock 0 0 1 selected clock divided by 2 0 1 0 selected clock divided by 4 0 1 1 selected clock divided by 8 1 0 0 selected clock divided by 16 1 0 1 selected clock divided by 32 1 1 0 selected clock divided by 64 111reserved
295 6222f?atarm?14-jan-11 sam7se512/256/32 29.9.12 pmc interrupt enable register name: pmc_ier access: write-only ? moscs: main oscillator status interrupt enable ? lock: pll lock interrupt enable ? mckrdy: master clock ready interrupt enable ? pckrdyx: programmable clock ready x interrupt enable 0 = no effect. 1 = enables the corresponding interrupt. 31 30 29 28 27 26 25 24 ???????? 23 22 21 20 19 18 17 16 ???????? 15 14 13 12 11 10 9 8 ?????pckrdy2pckrdy1pckrdy0 76543210 ????mckrdylock?moscs
296 6222f?atarm?14-jan-11 sam7se512/256/32 29.9.13 pmc interrupt disable register name: pmc_idr access: write-only ? moscs: main oscillator status interrupt disable ? lock: pll lock interrupt disable ? mckrdy: master clock ready interrupt disable ? pckrdyx: programmable clock ready x interrupt disable 0 = no effect. 1 = disables the corresponding interrupt. 31 30 29 28 27 26 25 24 ???????? 23 22 21 20 19 18 17 16 ???????? 15 14 13 12 11 10 9 8 ?????pckrdy2pckrdy1pckrdy0 76543210 ? ???mckrdy lock ? moscs
297 6222f?atarm?14-jan-11 sam7se512/256/32 29.9.14 pmc status register name: pmc_sr access: read-only ? moscs: moscs flag status 0 = main oscillator is not stabilized. 1 = main oscillator is stabilized. ? lock: pll lock status 0 = pll is not locked 1 = pll is locked. ? mckrdy: master clock status 0 = master clock is not ready. 1 = master clock is ready. ? pckrdyx: programmable clock ready status 0 = programmable clock x is not ready. 1 = programmable clock x is ready. 31 30 29 28 27 26 25 24 ???????? 23 22 21 20 19 18 17 16 ???????? 15 14 13 12 11 10 9 8 ?????pckrdy2pckrdy1pckrdy0 76543210 ????mckrdy lock ? moscs
298 6222f?atarm?14-jan-11 sam7se512/256/32 29.9.15 pmc interrupt mask register name: pmc_imr access: read-only ? moscs: main oscillator status interrupt mask ? lock: pll lock interrupt mask ? mckrdy: master clock ready interrupt mask ? pckrdyx: programmable clock ready x interrupt mask 0 = the corresponding interrupt is enabled. 1 = the corresponding interrupt is disabled. 31 30 29 28 27 26 25 24 ???????? 23 22 21 20 19 18 17 16 ???????? 15 14 13 12 11 10 9 8 ?????pckrdy2pckrdy1pckrdy0 76543210 ? ???mckrdy lock ? moscs
299 6222f?atarm?14-jan-11 sam7se512/256/32 30. debug unit (dbgu) 30.1 overview the debug unit provides a single entry point from the processor for access to all the debug capabilities of atmel?s arm-based systems. the debug unit features a two-pin uart that can be used for several debug and trace purposes and offers an ideal medium for in-situ programming solutions and debug monitor communica- tions. the debug unit two-pin uart can be used stand-alone for general purpose serial communication. moreover, the association with two peripheral data controller channels permits packet handling for these tasks with processor time reduced to a minimum. the debug unit also makes the debug communication channel (dcc) signals provided by the in-circuit emulator of the arm processor visible to the software. these signals indicate the sta- tus of the dcc read and write regi sters and generate an interrupt to the arm processor, making possible the handling of the dcc under interrupt control. chip identifier registers permit recognition of the device and its revision. these registers inform as to the sizes and types of the on-chip memori es, as well as the set of embedded peripherals. finally, the debug unit features a force ntrst capability that enables the software to decide whether to prevent access to the system via the in-circuit emulator. this permits protection of the code, stored in rom.
300 6222f?atarm?14-jan-11 sam7se512/256/32 30.2 block diagram figure 30-1. debug unit functional block diagram debug unit application example peripheral dma controller baud rate generator dcc handler ice access handler transmit receive chip id interrupt control peripheral bridge parallel input/ output dtxd drxd power management controller arm processor force_ntrst commrx commtx mck ntrst power-on reset dbgu_irq apb debug unit r table 30-1. debug unit pin description pin name description type drxd debug receive data input dtxd debug transmit data output debug unit rs232 drivers programming tool trace console debug console boot program debug monitor trace manager
301 6222f?atarm?14-jan-11 sam7se512/256/32 30.3 product dependencies 30.3.1 i/o lines depending on product integration, the debug unit pins may be multiplexed with pio lines. in this case, the programmer must first configure t he corresponding pio controller to enable i/o lines operations of the debug unit. 30.3.2 power management depending on product integration, the debug unit clock may be controllable through the power management controller. in this case, the programmer must first configure the pmc to enable the debug unit clock. usually, the peripheral identifier used for this purpose is 1. 30.3.3 interrupt source depending on product integration, the debug unit interrupt line is connected to one of the inter- rupt sources of the advanced interrupt controller. interrupt handling requires programming of the aic before configuring the de bug unit. usually, the debug unit interrupt line connects to the interrupt source 1 of the aic, which may be shared with the real-time clock, the system timer interrupt lines and other system peripheral interrupts, as shown in figure 30-1 . this sharing requires the programmer to determine the source of the interrupt when the source 1 is triggered. 30.4 uart operations the debug unit operates as a uart, (asynchro nous mode only) and supports only 8-bit charac- ter handling (with parity). it has no clock pin. the debug unit's uart is made up of a receiver and a transmitter that operate independently, and a common baud rate generator. receiver timeout and transmitter time guard are not imple- mented. however, all the implemented features are compatible with those of a standard usart. 30.4.1 baud rate generator the baud rate generator provides the bit period clock named baud rate clock to both the receiver and the transmitter. the baud rate clock is the master clock divided by 16 times the value (cd) written in dbgu_brgr (baud rate generator register). if dbgu_brgr is set to 0, the baud rate clock is disabled and the debug unit's uart remains inactive. the maximum allowable baud rate is master clock divided by 16. the minimum allowable baud rate is master clock divided by (16 x 65536). baud rate mck 16 cd ---------------------- =
302 6222f?atarm?14-jan-11 sam7se512/256/32 figure 30-2. baud rate generator 30.4.2 receiver 30.4.2.1 receiver rese t, enable and disable after device reset, the debug unit receiver is disabled and must be enabled before being used. the receiver can be enabled by writing the control register dbgu_cr with the bit rxen at 1. at this command, the receiver starts looking for a start bit. the programmer can disable the receiver by writ ing dbgu_cr with the bit rxdis at 1. if the receiver is waiting for a start bit, it is immedi ately stopped. however, if the receiver has already detected a start bit and is receiving the data, it waits for the stop bit before actually stopping its operation. the programmer can also put the receiver in it s reset state by writing dbgu_cr with the bit rstrx at 1. in doing so, the receiver immediat ely stops its current operations and is disabled, whatever its current state. if rstrx is applied wh en data is being processed, this data is lost. 30.4.2.2 start detection and data sampling the debug unit only supports asynchronous operations, and this affects only its receiver. the debug unit receiver detects the start of a rece ived character by samplin g the drxd signal until it detects a valid start bit. a low level (space) on drxd is interpreted as a valid start bit if it is detected for more than 7 cycles of the sampling clock, which is 16 times the baud rate. hence, a space that is longer than 7/16 of the bit period is detected as a valid start bit. a space which is 7/16 of a bit period or shorter is ignored and the receiver continues to wait for a valid start bit. when a valid start bit has been detected, the receiver samples the drxd at the theoretical mid- point of each bit. it is assumed that each bit last s 16 cycles of the sampling clock (1-bit period) so the bit sampling point is eight cycles (0.5-bit period) after the start of the bit. the first sampling point is therefore 24 cycles (1.5 -bit periods) after t he falling edge of the st art bit was detected. each subsequent bit is sampled 16 cycles (1-bit period) after the previous one. mck 16-bit counter 0 baud rate clock cd cd out divide by 16 0 1 >1 receiver sampling clock
303 6222f?atarm?14-jan-11 sam7se512/256/32 figure 30-3. start bit detection figure 30-4. character reception 30.4.2.3 receiver ready when a complete character is received, it is transferred to the dbgu_rhr and the rxrdy sta- tus bit in dbgu_sr (status register) is set. the bit rxrdy is automatically cleared when the receive holding register dbgu_rhr is read. figure 30-5. receiver ready 30.4.2.4 receiver overrun if dbgu_rhr has not been read by the software (o r the peripheral data controller) since the last transfer, the rxrdy bit is still set and a ne w character is received, the ovre status bit in dbgu_sr is set. ovre is cleared when the soft ware writes the control register dbgu_cr with the bit rststa (reset status) at 1. figure 30-6. receiver overrun 30.4.2.5 parity error each time a character is received, the receiver calculates the parity of the received data bits, in accordance with the field par in dbgu_mr. it then compares the result with the received parity sampling clock drxd true start detection d0 baud rate clock d0 d1 d2 d3 d4 d5 d6 d7 drxd true start detection sampling parity bit stop bit example: 8-bit, parity enabled 1 stop 1 bit period 0.5 bit period d0 d1 d2 d3 d4 d5 d6 d7 p s s d0 d1 d2 d3 d4 d5 d6 d7 p drxd read dbgu_rhr rxrdy d0 d1 d2 d3 d4 d5 d6 d7 p s s d0 d1 d2 d3 d4 d5 d6 d7 p drxd rststa rxrdy ovre stop stop
304 6222f?atarm?14-jan-11 sam7se512/256/32 bit. if different, the parity error bit pare in dbgu_sr is set at the same time the rxrdy is set. the parity bit is cleared when the control register dbgu_cr is written with the bit rststa (reset status) at 1. if a new character is received before the reset status command is written, the pare bit remains at 1. figure 30-7. parity error 30.4.2.6 receiver framing error when a start bit is detected, it generates a character reception when all the data bits have been sampled. the stop bit is also sampled and when it is detected at 0, the frame (framing error) bit in dbgu_sr is set at the same time the rxrdy bit is set. the bit frame remains high until the control register dbgu_cr is written with the bit rststa at 1. figure 30-8. receiver framing error 30.4.3 transmitter 30.4.3.1 transmitter reset, enable and disable after device reset, the debug unit transmitter is disabled and it must be enabled before being used. the transmitter is enabled by writing the co ntrol register dbgu_cr with the bit txen at 1. from this command, the transmitter waits for a ch aracter to be written in the transmit holding register dbgu_thr before actually starting the transmission. the programmer can disable the transmitter by writing dbgu_cr with the bit txdis at 1. if the transmitter is not operating, it is immediately stopped. however, if a character is being pro- cessed into the shift register and/or a character has been written in the transmit holding register, the characters are completed before the transmitter is actually stopped. the programmer can also put the transmitter in its reset state by writing the dbgu_cr with the bit rsttx at 1. this immediately stops the transmitter, whether or not it is processing characters. 30.4.3.2 transmit format the debug unit transmitter drives the pin dtxd at the baud rate clock speed. the line is driven depending on the format defined in the mode register and the data stored in the shift register. one start bit at level 0, then the 8 data bits, from the lowest to the highest bit, one optional parity bit and one stop bit at 1 are consecutively shifte d out as shown on the following figure. the field stop d0 d1 d2 d3 d4 d5 d6 d7 p s drxd rststa rxrdy pare wrong parity bit d0 d1 d2 d3 d4 d5 d6 d7 p s drxd rststa rxrdy frame stop bit detected at 0 stop
305 6222f?atarm?14-jan-11 sam7se512/256/32 pare in the mode register dbgu_mr defines whether or not a parity bit is shifted out. when a parity bit is enabled, it can be selected between an odd parity, an even parity, or a fixed space or mark bit. figure 30-9. character transmission 30.4.3.3 transmitter control when the transmitter is enabled, the bit txrdy (transmitter ready) is set in the status register dbgu_sr. the transmission starts when the prog rammer writes in the transmit holding regis- ter dbgu_thr, and after the written character is transferred from dbgu_thr to the shift register. the bit txrdy remains high until a se cond character is written in dbgu_thr. as soon as the first character is completed, the last character written in dbgu_thr is transferred into the shift register and txrdy rises again, showing that the holding register is empty. when both the shift register and the dbgu_thr are empty, i.e., all the characters written in dbgu_thr have been processed, the bit txempty rises after the last stop bit has been completed. figure 30-10. transmitter control 30.4.4 peripheral data controller both the receiver and the transmitter of the debug unit's uart are generally connected to a peripheral data controller (pdc) channel. the peripheral data controller channels are programmed via registers that are mapped within the debug unit user interface from the offset 0x100. the status bits are reported in the debug unit status register dbgu_sr and can generate an interrupt. d0 d1 d2 d3 d4 d5 d6 d7 dtxd start bit parity bit stop bit example: parity enabled baud rate clock dbgu_thr shift register dtxd txrdy txempty data 0 data 1 data 0 data 0 data 1 data 1 s s p p write data 0 in dbgu_thr write data 1 in dbgu_thr stop stop
306 6222f?atarm?14-jan-11 sam7se512/256/32 the rxrdy bit triggers the pdc channel data transfer of the receiver. this results in a read of the data in dbgu_rhr. the txrdy bit triggers t he pdc channel data tran sfer of the transmit- ter. this results in a writ e of a data in dbgu_thr. 30.4.5 test modes the debug unit supports three tests modes. these modes of operation are programmed by using the field chmode (channel mode) in the mode register dbgu_mr. the automatic echo mode allows bit-by-bit retr ansmission. when a bit is received on the drxd line, it is sent to the dtxd line. the transm itter operates normally, but has no effect on the dtxd line. the local loopback mode allows the transmitted characters to be received. dtxd and drxd pins are not used and the output of the transmitter is internally connected to the input of the receiver. the drxd pin level has no effect and th e dtxd line is held high , as in idle state. the remote loopback mode directly connects the drxd pin to the dtxd line. the transmitter and the receiver are disabled and have no effec t. this mode allows a bit-by-bit retransmission. figure 30-11. test modes 30.4.6 debug communication channel support the debug unit handles the signals commrx and commtx that come from the debug com- munication channel of the arm processor and are driven by the in-circuit emulator. receiver transmitter disabled rxd txd receiver transmitter disabled rxd txd v dd disabled receiver transmitter disabled rxd txd disabled automatic echo local loopback remote loopback v dd
307 6222f?atarm?14-jan-11 sam7se512/256/32 the debug communication channel contains two registers that are accessible through the ice breaker on the jtag side and through the coprocessor 0 on the arm processor side. as a reminder, the following instructions ar e used to read and write the debug communication channel: mrc p14, 0, rd, c1, c0, 0 returns the debug communication data read register into rd mcr p14, 0, rd, c1, c0, 0 writes the value in rd to the debug communication data write register. the bits commrx and commtx, which indicate, respectively, that the read register has been written by the debugger but not yet read by the processor, and that the write register has been written by the processor and not yet read by the debugger, are wired on the two highest bits of the status register dbgu_sr. these bits can generate an interrupt. this feature permits han- dling under interrupt a debug link between a debug monitor running on the target system and a debugger. 30.4.7 chip identifier the debug unit features two chip identifier registers, dbgu_cidr (chip id register) and dbgu_exid (extension id). both registers contain a hard-wired value that is read-only. the first register contains the following fields: ? ext - shows the use of the extension identifier register ? nvptyp and nvpsiz - identifies the type of embedded non-volatile memory and its size ? arch - identifies the set of embedded peripheral ? sramsiz - indicates the size of the embedded sram ? eproc - indicates the embedded arm processor ? version - gives the revision of the silicon the second register is device-dependent and reads 0 if the bit ext is 0. 30.4.8 ice access prevention the debug unit allows blockage of access to the system through the arm processor's ice interface. this feature is implemented via the register force ntrst (dbgu_fnr), that allows assertion of the ntrst signal of the ice interface. writing the bit fntrst (force ntrst) to 1 in this register prevents any activity on the tap controller. on standard devices, the fntrst bit resets to 0 and thus does not prevent ice access. this feature is especially useful on custom rom devices for customers who do not want their on-chip code to be visible.
308 6222f?atarm?14-jan-11 sam7se512/256/32 30.5 debug unit user interface table 30-2. debug unit memory map offset register name access reset value 0x0000 control register dbgu_cr write-only ? 0x0004 mode register dbgu_mr read/write 0x0 0x0008 interrupt enable register dbgu_ier write-only ? 0x000c interrupt disable register dbgu_idr write-only ? 0x0010 interrupt mask register dbgu_imr read-only 0x0 0x0014 status register dbgu_sr read-only ? 0x0018 receive holding register dbgu_rhr read-only 0x0 0x001c transmit holding register dbgu_thr write-only ? 0x0020 baud rate generator register dbgu_brgr read/write 0x0 0x0024 - 0x003c reserved ? ? ? 0x0040 chip id register dbgu_cidr read-only ? 0x0044 chip id extension register dbgu_exid read-only ? 0x0048 force ntrst register dbgu_fnr read/write 0x0 0x004c - 0x00fc reserved ? ? ? 0x0100 - 0x0124 pdc area ? ? ?
309 6222f?atarm?14-jan-11 sam7se512/256/32 30.5.1 debug unit control register name: dbgu_cr access: write-only ? rstrx: reset receiver 0 = no effect. 1 = the receiver logic is reset and disabled. if a ch aracter is being received, the reception is aborted. ? rsttx: reset transmitter 0 = no effect. 1 = the transmitter logic is reset and disabled. if a character is being transmitted, the transmission is aborted. ? rxen: receiver enable 0 = no effect. 1 = the receiver is enabled if rxdis is 0. ? rxdis: receiver disable 0 = no effect. 1 = the receiver is disabled. if a character is being processe d and rstrx is not set, the character is completed before the receiver is stopped. ? txen: transmitter enable 0 = no effect. 1 = the transmitter is ena bled if txdis is 0. ? txdis: transmitter disable 0 = no effect. 1 = the transmitter is disabled. if a character is being processed and a charac ter has been written the dbgu_thr and rsttx is not set, both characters are completed before the transmitter is stopped. ? rststa: reset status bits 0 = no effect. 1 = resets the status bits pare, frame and ovre in the dbgu_sr. 31 30 29 28 27 26 25 24 ???????? 23 22 21 20 19 18 17 16 ???????? 15 14 13 12 11 10 9 8 ??????? rststa 76543210 txdis txen rxdis rxen rsttx rstrx ??
310 6222f?atarm?14-jan-11 sam7se512/256/32 30.5.2 debug unit mode register name: dbgu_mr access: read/write ? par: parity type parity type ? chmode: channel mode 31 30 29 28 27 26 25 24 ???????? 23 22 21 20 19 18 17 16 ???????? 15 14 13 12 11 10 9 8 chmode ?? pa r ? 76543210 ???????? pa r 0 0 0 even parity 00 1o d d p a r i t y 0 1 0 space: parity forced to 0 0 1 1 mark: parity forced to 1 1 x x no parity chmode mode description 00n o r m a l m o d e 0 1 automatic echo 1 0 local loopback 1 1 remote loopback
311 6222f?atarm?14-jan-11 sam7se512/256/32 30.5.3 debug unit interrupt enable register name: dbgu_ier access: write-only ? rxrdy: enable rxrdy interrupt ? txrdy: enable txrdy interrupt ? endrx: enable end of receive transfer interrupt ? endtx: enable end of transmit interrupt ? ovre: enable overrun error interrupt ? frame: enable framing error interrupt ? pare: enable parity error interrupt ? txempty: enable txempty interrupt ? txbufe: enable buffer empty interrupt ? rxbuff: enable buffer full interrupt ? commtx: enable commtx (from arm) interrupt ? commrx: enable commrx (from arm) interrupt 0 = no effect. 1 = enables the corresponding interrupt. 31 30 29 28 27 26 25 24 commrx commtx ?????? 23 22 21 20 19 18 17 16 ???????? 15 14 13 12 11 10 9 8 ??? rxbuff txbufe ? txempty ? 76543210 pare frame ovre endtx endrx ? txrdy rxrdy
312 6222f?atarm?14-jan-11 sam7se512/256/32 30.5.4 debug unit interrupt disable register name: dbgu_idr access: write-only ? rxrdy: disable rxrdy interrupt ? txrdy: disable txrdy interrupt ? endrx: disable end of receive transfer interrupt ? endtx: disable end of transmit interrupt ? ovre: disable overrun error interrupt ? frame: disable framing error interrupt ? pare: disable parity error interrupt ? txempty: disable txempty interrupt ? txbufe: disable buffer empty interrupt ? rxbuff: disable buffer full interrupt ? commtx: disable commtx (from arm) interrupt ? commrx: disable commrx (from arm) interrupt 0 = no effect. 1 = disables the corresponding interrupt. 31 30 29 28 27 26 25 24 commrx commtx ?????? 23 22 21 20 19 18 17 16 ???????? 15 14 13 12 11 10 9 8 ??? rxbuff txbufe ? txempty ? 76543210 pare frame ovre endtx endrx ? txrdy rxrdy
313 6222f?atarm?14-jan-11 sam7se512/256/32 30.5.5 debug unit interrupt mask register name: dbgu_imr access: read-only ? rxrdy: mask rxrdy interrupt ? txrdy: disable txrdy interrupt ? endrx: mask end of receive transfer interrupt ? endtx: mask end of transmit interrupt ? ovre: mask overrun error interrupt ? frame: mask framing error interrupt ? pare: mask parity error interrupt ? txempty: mask txempty interrupt ? txbufe: mask txbufe interrupt ? rxbuff: mask rxbuff interrupt ? commtx: mask commtx interrupt ? commrx: mask commrx interrupt 0 = the corresponding interrupt is disabled. 1 = the corresponding interrupt is enabled. 31 30 29 28 27 26 25 24 commrx commtx ?????? 23 22 21 20 19 18 17 16 ???????? 15 14 13 12 11 10 9 8 ??? rxbuff txbufe ? txempty ? 76543210 pare frame ovre endtx endrx ? txrdy rxrdy
314 6222f?atarm?14-jan-11 sam7se512/256/32 30.5.6 debug unit status register name: dbgu_sr access: read-only ? rxrdy: receiver ready 0 = no character has been received since the last re ad of the dbgu_rhr or the receiver is disabled. 1 = at least one complete character has been received, transferred to dbgu_rhr and not yet read. ? txrdy: transmitter ready 0 = a character has been written to dbgu_thr and not yet transferred to the shift register, or the transmitter is disabled. 1 = there is no character written to dbgu_thr not yet transferred to the shift register. ? endrx: end of receiver transfer 0 = the end of transfer signal from the receiver peripheral data controller channel is inactive. 1 = the end of transfer signal from the receiver peripheral data controller channel is active. ? endtx: end of transmitter transfer 0 = the end of transfer signal from the transmitter peripheral data controller channel is inactive. 1 = the end of transfer signal from the transmitter peripheral data controller channel is active. ? ovre: overrun error 0 = no overrun error has occurred since the last rststa. 1 = at least one overrun error has occurred since the last rststa. ? frame: framing error 0 = no framing error has occurred since the last rststa. 1 = at least one framing error has occurred since the last rststa. ? pare: parity error 0 = no parity error has occurred since the last rststa. 1 = at least one parity error has occurred since the last rststa. ? txempty: transmitter empty 0 = there are characters in dbgu_thr, or characters being processed by the transmitter, or the transmitter is disabled. 1 = there are no characters in dbgu_thr and there ar e no characters being processed by the transmitter. 31 30 29 28 27 26 25 24 commrx commtx ?????? 23 22 21 20 19 18 17 16 ???????? 15 14 13 12 11 10 9 8 ??? rxbuff txbufe ? txempty ? 76543210 pare frame ovre endtx endrx ? txrdy rxrdy
315 6222f?atarm?14-jan-11 sam7se512/256/32 ? txbufe: transmission buffer empty 0 = the buffer empty signal from the transmitter pdc channel is inactive. 1 = the buffer empty signal from the transmitter pdc channel is active. ? rxbuff: receive buffer full 0 = the buffer full signal from the receiver pdc channel is inactive. 1 = the buffer full signal from the receiver pdc channel is active. ? commtx: debug communication channel write status 0 = commtx from the arm processor is inactive. 1 = commtx from the arm processor is active. ? commrx: debug communication channel read status 0 = commrx from the arm processor is inactive. 1 = commrx from the arm processor is active.
316 6222f?atarm?14-jan-11 sam7se512/256/32 30.5.7 debug unit receiver holding register name: dbgu_rhr access: read-only ? rxchr: received character last received character if rxrdy is set. 31 30 29 28 27 26 25 24 ???????? 23 22 21 20 19 18 17 16 ???????? 15 14 13 12 11 10 9 8 ???????? 76543210 rxchr
317 6222f?atarm?14-jan-11 sam7se512/256/32 30.5.8 debug unit transmit holding register name: dbgu_thr access: write-only ? txchr: character to be transmitted next character to be transmitted after the current character if txrdy is not set. 31 30 29 28 27 26 25 24 ???????? 23 22 21 20 19 18 17 16 ???????? 15 14 13 12 11 10 9 8 ???????? 76543210 txchr
318 6222f?atarm?14-jan-11 sam7se512/256/32 30.5.9 debug unit baud ra te generator register name: dbgu_brgr access: read/write ? cd: clock divisor 31 30 29 28 27 26 25 24 ???????? 23 22 21 20 19 18 17 16 ???????? 15 14 13 12 11 10 9 8 cd 76543210 cd cd baud rate clock 0 disabled 1mck 2 to 65535 mck / (cd x 16)
319 6222f?atarm?14-jan-11 sam7se512/256/32 30.5.10 debug unit chip id register name: dbgu_cidr access: read-only ? version: version of the device ? eproc: embedded processor ? nvpsiz: nonvolatile program memory size 31 30 29 28 27 26 25 24 ext nvptyp arch 23 22 21 20 19 18 17 16 arch sramsiz 15 14 13 12 11 10 9 8 nvpsiz2 nvpsiz 76543210 eproc version eproc processor 0 0 1 arm946es ? 0 1 0 arm7tdmi ? 100arm920t ? 1 0 1 arm926ejs ? nvpsiz size 0000none 00018k bytes 001016k bytes 001132k bytes 0100reserved 010164k bytes 0110reserved 0111128k bytes 1000reserved 1001256k bytes 1010512k bytes 1011reserved 11001024k bytes 1101reserved 11102048k bytes 1111reserved
320 6222f?atarm?14-jan-11 sam7se512/256/32 ? nvpsiz2 second nonvolatile program memory size ? sramsiz: internal sram size nvpsiz2 size 0000none 00018k bytes 001016k bytes 001132k bytes 0100reserved 010164k bytes 0110reserved 0111128k bytes 1000reserved 1001256k bytes 1010512k bytes 1011reserved 11001024k bytes 1101reserved 11102048k bytes 1111reserved sramsiz size 0000reserved 00011k bytes 00102k bytes 00116k bytes 0100112k bytes 01014k bytes 011080k bytes 0111160k bytes 10008k bytes 100116k bytes 101032k bytes 101164k bytes 1100128k bytes 1101256k bytes 111096k bytes 1111512k bytes
321 6222f?atarm?14-jan-11 sam7se512/256/32 ? arch: architecture identifier ? nvptyp: nonvolatile program memory type ? ext: extension flag 0 = chip id has a single register definition without extension 1 = an extended chip id exists. arch architecture hex bin 0x19 0001 1001 at91sam9xx series 0x29 0010 1001 at91sam9xexx series 0x34 0011 0100 at91x34 series 0x37 0011 0111 cap7 series 0x39 0011 1001 cap9 series 0x3b 0011 1011 cap11 series 0x40 0100 0000 at91x40 series 0x42 0100 0010 at91x42 series 0x55 0101 0101 at91x55 series 0x60 0110 0000 at91sam7axx series 0x61 0110 0001 at91sam7aqxx series 0x63 0110 0011 at91x63 series 0x70 0111 0000 at91sam7sxx series 0x71 0111 0001 at91sam7xcxx series 0x72 0111 0010 at91sam7sexx series 0x73 0111 0011 at91sam lxx series 0x75 0111 0101 at91sam7xxx series 0x92 1001 0010 at91x92 series 0xf0 1111 0000 at75cxx series nvptyp memory 000rom 0 0 1 romless or on-chip flash 1 0 0 sram emulating rom 0 1 0 embedded flash memory 011 rom and embedded flash memory nvpsiz is rom size nvpsiz2 is flash size
322 6222f?atarm?14-jan-11 sam7se512/256/32 30.5.11 debug unit chip id extension register name: dbgu_exid access: read-only ? exid: chip id extension reads 0 if the bit ext in dbgu_cidr is 0. 30.5.12 debug unit force ntrst register name: dbgu_fnr access: read/write ? fntrst: force ntrst 0 = ntrst of the arm processor?s tap controller is driven by the power_on_reset signal. 1 = ntrst of the arm processor?s tap controller is held low. 31 30 29 28 27 26 25 24 exid 23 22 21 20 19 18 17 16 exid 15 14 13 12 11 10 9 8 exid 76543210 exid 31 30 29 28 27 26 25 24 ??????? ? 23 22 21 20 19 18 17 16 ??????? ? 15 14 13 12 11 10 9 8 ??????? ? 7654321 0 ??????? fntrst
323 6222f?atarm?14-jan-11 sam7se512/256/32 31. serial peripheral interface (spi) 31.1 overview the serial peripheral interface (spi) circuit is a synchronous serial data link that provides com- munication with external devices in master or slave mode. it also enables communication between processors if an external processor is connected to the system. the serial peripheral interface is essentially a shift register that serially transmits data bits to other spis. during a data transfer, one spi system acts as the ?master?' which controls the data flow, while the other devices act as ?slaves'' whic h have data shifted into and out by the master. different cpus can take turn being masters (multiple master protocol opposite to single master protocol where one cpu is always the master while all of the others are always slaves) and one master may simultaneously shift da ta into multiple slaves. howeve r, only one slave may drive its output to write data back to the master at any given time. a slave device is selected when the master asse rts its nss signal. if multiple slave devices exist, the master generates a separate slav e select signal for each slave (npcs). the spi system consists of two data lines and two control lines: ? master out slave in (mosi): this data line supplies the output data from the master shifted into the input(s) of the slave(s). ? master in slave out (miso): this data line supplies the output data from a slave to the input of the master. there may be no more than one slave transmitting data during any particular transfer. ? serial clock (spck): this control line is driven by the master and regulates the flow of the data bits. the master may transmit data at a variety of baud rates; the spck line cycles once for each bit that is transmitted. ? slave select (nss): this control line allows slaves to be turned on and off by hardware.
324 6222f?atarm?14-jan-11 sam7se512/256/32 31.2 block diagram figure 31-1. block diagram 31.3 application block diagram figure 31-2. application block diagram: single master/multiple slave implementation spi interface interrupt control pio pdc pmc mck spi interrupt spck miso mosi npcs0/nss npcs1 npcs2 npcs3 apb spi master spck miso mosi npcs0 npcs1 npcs2 spck miso mosi nss slave 0 spck miso mosi nss slave 1 spck miso mosi nss slave 2 nc npcs3
325 6222f?atarm?14-jan-11 sam7se512/256/32 31.4 signal description 31.5 product dependencies 31.5.1 i/o lines the pins used for interfacing the compliant ex ternal devices may be multiplexed with pio lines. the programmer must first program the pio controllers to assign the spi pins to their peripheral functions. 31.5.2 power management the spi may be clocked through the power management controller (pmc), thus the program- mer must first configure the pmc to enable the spi clock. 31.5.3 interrupt the spi interface has an interrupt line connected to the advanced interrupt controller (aic). handling the spi interrupt requires programming the aic before configuring the spi. table 31-1. signal description pin name pin description type master slave miso master in slave out input output mosi master out slave in output input spck serial clock output input npcs1-npcs3 peripheral chip selects output unused npcs0/nss peripheral chip select/slave select output input
326 6222f?atarm?14-jan-11 sam7se512/256/32 31.6 functional description 31.6.1 modes of operation the spi operates in master mode or in slave mode. operation in master mode is programmed by writing at 1 the mstr bit in the mode register. the pins npcs0 to npcs3 are all configured as outputs, the spck pin is driven, the miso line is wired on the receiver input and the mosi line driven as an output by the transmitter. if the mstr bit is written at 0, the spi operates in slave mode. the miso line is driven by the transmitter output, the mosi line is wired on the re ceiver input, the spck pin is driven by the transmitter to synchronize the receiver. the npcs0 pin becomes an input, and is used as a slave select signal (nss). the pins npcs1 to npcs3 are not driven and can be used for other purposes. the data transfers are identically programmable for both modes of operations. the baud rate generator is activated only in master mode. 31.6.2 data transfer four combinations of polarity and phase are available for data transfers. the clock polarity is programmed with the cpol bit in the chip select register. the clock phase is programmed with the ncpha bit. these two parameters determine th e edges of the clock signal on which data is driven and sampled. each of the two parameters has two possible states, resulting in four possi- ble combinations that are incompatible with one another. thus, a master/slave pair must use the same parameter pair values to communicate. if multiple slaves are used and fixed in different configurations, the master must reconfigure itself each time it needs to communicate with a dif- ferent slave. table 31-2 shows the four modes and corresponding parameter settings. figure 31-3 and figure 31-4 show examples of data transfers. table 31-2. spi bus protocol mode spi mode cpol ncpha 001 100 211 310
327 6222f?atarm?14-jan-11 sam7se512/256/32 figure 31-3. spi transfer format (ncpha = 1, 8 bits per transfer) figure 31-4. spi transfer format (ncpha = 0, 8 bits per transfer) 6 * spck (cpol = 0) spck (cpol = 1) mosi (from master) miso (from slave) nss (to slave) spck cycle (for reference) msb msb lsb lsb 6 6 5 5 4 4 3 3 2 2 1 1 * not defined, but normally msb of previous character received. 1 2345 78 6 * spck (cpol = 0) spck (cpol = 1) 1 2345 7 mosi (from master) miso (from slave) nss (to slave) spck cycle (for reference) 8 msb msb lsb lsb 6 6 5 5 4 4 3 3 1 1 * not defined but normally lsb of previous character transmitted. 2 2 6
328 6222f?atarm?14-jan-11 sam7se512/256/32 31.6.3 master mode operations when configured in master mode, the spi operates on the clock generated by the internal pro- grammable baud rate generator. it fully controls the data transfers to and from the slave(s) connected to the spi bus. the spi drives the chip select line to the slave and the serial clock signal (spck). the spi features two holding registers, the transmit data register and the receive data regis- ter, and a single shift register. the holding registers maintain the data flow at a constant rate. after enabling the spi, a data transfer begins when the processor writes to the spi_tdr (trans- mit data register). the written data is immediat ely transferred in the shift register and transfer on the spi bus starts. while the data in the shift register is shifted on the mosi line, the miso line is sampled and shifted in the shift register. transmission cannot occur without reception. before writing the tdr, the pcs field must be set in order to select a slave. if new data is written in spi_tdr during the transfe r, it stays in it until the current transfer is completed. then, the received data is transferred from the shift register to spi_rdr, the data in spi_tdr is loaded in the shift register and a new transfer starts. the transfer of a data written in spi_tdr in t he shift register is indicated by the tdre bit (transmit data register empty) in the status register (spi_sr). when new data is written in spi_tdr, this bit is cleared. the tdre bit is used to trigger the transmit pdc channel. the end of transfer is indicated by the txempty flag in the spi_sr register. if a transfer delay (dlybct) is greater than 0 for the last transfer, txempty is set after the completion of said delay. the master clock (mck) can be switched off at this time. the transfer of received data from the shift register in spi_rdr is indicated by the rdrf bit (receive data register full) in the status register (spi_sr). when the received data is read, the rdrf bit is cleared. if the spi_rdr (receive data register) has not been read before new data is received, the overrun error bit (ovres) in spi_sr is set. as long as this flag is set, data is loaded in spi_rdr. the user has to read the status register to clear the ovres bit. figure 31-5 on page 329 shows a block diagram of the spi when operating in master mode. fig- ure 31-6 on page 330 shows a flow chart describing how transfers are handled.
329 6222f?atarm?14-jan-11 sam7se512/256/32 31.6.3.1 master mode block diagram figure 31-5. master mode block diagram shift register spck mosi lsb msb miso spi_rdr rd spi clock tdre spi_tdr td rdrf ovres spi_csr0..3 cpol ncpha bits mck baud rate generator spi_csr0..3 scbr npcs3 npcs0 npcs2 npcs1 npcs0 0 1 ps spi_mr pcs spi_tdr pcs modf current peripheral spi_rdr pcs spi_csr0..3 csaat pcsdec modfdis mstr
330 6222f?atarm?14-jan-11 sam7se512/256/32 31.6.3.2 master mode flow diagram figure 31-6. master mode flow diagram s spi enable csaat ? ps ? 1 0 0 1 1 npcs = spi_tdr(pcs) npcs = spi_mr(pcs) delay dlybs serializer = spi_tdr(td) tdre = 1 data transfer spi_rdr(rd) = serializer rdrf = 1 tdre ? npcs = 0xf delay dlybcs fixed peripheral variable peripheral delay dlybct 0 1 csaat ? 0 tdre ? 1 0 ps ? 0 1 spi_tdr(pcs) = npcs ? no yes spi_mr(pcs) = npcs ? no npcs = 0xf delay dlybcs npcs = spi_tdr(pcs) npcs = 0xf delay dlybcs npcs = spi_mr(pcs), spi_tdr(pcs) fixed peripheral variable peripheral - npcs defines the current chip select - csaat, dlybs, dlybct refer to the fields of the chip select register corresponding to the current chip select - when npcs is 0xf, csaat is 0.
331 6222f?atarm?14-jan-11 sam7se512/256/32 31.6.3.3 clock generation the spi baud rate clock is generated by dividing the master clock (mck), by a value between 1 and 255. this allows a maximum operating baud rate at up to master clock and a minimum operating baud rate of mck divided by 255. programming the scbr field at 0 is forbidden. tri ggering a transfer while scbr is at 0 can lead to unpredictable results. at reset, scbr is 0 and the user has to program it at a valid value before performing the first transfer. the divisor can be defined independently for each chip select, as it has to be programmed in the scbr field of the chip select registers. this allows the spi to automatically adapt the baud rate for each interfaced peripheral without reprogramming. 31.6.3.4 transfer delays figure 31-7 shows a chip select transfer change and consecutive transfers on the same chip select. three delays can be programmed to modify the transfer waveforms: ? the delay between chip selects, programmable only once for all the ch ip selects by writing the dlybcs field in the mode register. allows insertion of a delay between release of one chip select and before assertion of a new one. ? the delay before spck, independently programmable for each chip select by writing the field dlybs. allows the start of spck to be delayed after the chip select has been asserted. ? the delay between consecutive transfers, independently programmable for each chip select by writing the dlybct field. allows insertion of a delay between two transfers occurring on the same chip select these delays allow the spi to be adapted to the interfaced peripherals and their speed and bus release time. figure 31-7. programmable delays 31.6.3.5 peripheral selection the serial peripherals are selected through the as sertion of the npcs0 to npcs3 signals. by default, all the npcs signals are high before and after each transfer. the peripheral selection can be performed in two different ways: ? fixed peripheral select: spi exchanges data with only one peripheral dlybcs dlybs dlybct dlybct chip select 1 chip select 2 spck
332 6222f?atarm?14-jan-11 sam7se512/256/32 ? variable peripheral select: data can be exchanged with more than one peripheral fixed peripheral select is activated by writing the ps bit to zero in spi_mr (mode register). in this case, the current peripheral is defined by the pcs field in spi_mr and the pcs field in the spi_tdr has no effect. variable peripheral select is ac tivated by setting ps bit to one. the pcs field in spi_tdr is used to select the current peripheral. this means that the peripheral selection can be defined for each new data. the fixed peripheral selection allows buffer transfers with a single peripheral. using the pdc is an optimal means, as the size of the data transfer between the memory and the spi is either 8 bits or 16 bits. however, changing the peripheral selection requires the mode register to be reprogrammed. the variable peripheral selection allows buffer transfers with multiple peripherals without repro- gramming the mode register. data written in spi_tdr is 32 bits wide and defines the real data to be transmitted and the peripheral it is desti ned to. using the pdc in th is mode requires 32-bit wide buffers, with the data in the lsbs and the pcs and lastxfer fields in the msbs, how- ever the spi still controls the number of bits (8 to16) to be transferred through miso and mosi lines with the chip select configuration registers. this is not the optimal means in term of mem- ory size for the buffers, but it provides a very effective means to exchange data with several peripherals without any intervention of the processor. 31.6.3.6 peripheral chip select decoding the user can program the spi to operate with up to 15 peripherals by decoding the four chip select lines, npcs0 to npcs3 with an external l ogic. this can be enabled by writing the pcs- dec bit at 1 in the mode register (spi_mr). when operating without decoding, the spi makes sure that in any case only one chip select line is activated, i.e. driven low at a time. if two bits are defined low in a pcs field, only the lowest numbered chip select is driven low. when operating with decoding, the spi directly outputs the value defined by the pcs field of either the mode register or the transmit data register (depending on ps). as the spi sets a default value of 0xf on the chip select lines (i.e. all chip select lines at 1) when not processing any transfer, only 15 peripherals can be decoded. the spi has only four chip select registers, not 15. as a result, when decoding is activated, each chip select defines the characteristics of up to four peripherals. as an example, spi_crs0 defines the characteristics of the externally decoded peripherals 0 to 3, corresponding to the pcs values 0x0 to 0x3. thus, the user has to make sure to connect compatible peripherals on the decoded chip select lines 0 to 3, 4 to 7, 8 to 11 and 12 to 14. 31.6.3.7 peripheral deselection when operating normally, as soon as the transfer of the last data written in spi_tdr is com- pleted, the npcs lines all rise. this might lead to runtime error if the processor is too long in responding to an interrupt, and thus might lead to difficulties for interfacing with some serial peripherals requiring the chip select line to remain active during a full set of transfers. to facilitate interfacing with such devices, the chip select regist er can be prog rammed with the csaat bit (chip select active after transfer) at 1. this allows the chip select lines to remain in their current state (low = active) until transfer to another peripheral is required.
333 6222f?atarm?14-jan-11 sam7se512/256/32 figure 31-8 shows different peripheral deselection cases and the effect of the csaat bit. figure 31-8. peripheral deselection 31.6.3.8 mode fault detection a mode fault is detected when the spi is programmed in master mode and a low level is driven by an external master on the npcs0/nss sign al. npcs0, mosi, miso and spck must be con- figured in open drain through the pio controller, so that external pull up resistors are needed to guarantee high level. when a mode fault is detected, the modf bit in the spi_sr is set until the spi_sr is read and the spi is automatically disabl ed until re-enabled by writing t he spien bit in the spi_cr (con- trol register) at 1. by default, the mode fault detection circuitr y is enabled. the user can disable mode fault detection by setting the modfdis bit in the spi mode register (spi_mr). 31.6.4 spi slave mode when operating in slave mode, the spi processes data bits on the clock provided on the spi clock pin (spck). the spi waits for nss to go active before receiving the serial clock from an external master. when nss falls, the clock is validated on the serializer, which processes the number of bits a npcs[0..3] write spi_tdr tdre npcs[0..3] write spi_tdr tdre npcs[0..3] write spi_tdr tdre dlybcs pcs = a dlybcs dlybct a pcs = b b dlybcs pcs = a dlybcs dlybct a pcs = b b dlybcs dlybct pcs=a a dlybcs dlybct a pcs = a a a dlybct aa csaat = 0 dlybct aa csaat = 1 a
334 6222f?atarm?14-jan-11 sam7se512/256/32 defined by the bits field of the chip select register 0 (spi_csr0). these bits are processed following a phase and a polarity defined respectively by the ncpha and cpol bits of the spi_csr0. note that bits, cpol and ncpha of the other chip select registers have no effect when the spi is programmed in slave mode. the bits are shifted out on the miso line and sampled on the mosi line. when all the bits are processed, the received data is transferred in the receive data register and the rdrf bit rises. if rdrf is already high wh en the data is transf erred, the overrun bit rises and the data transfer to spi_rdr is aborted. when a transfer starts, the data shifted out is the data present in the shift register. if no data has been written in the transmit data register (spi_tdr), the la st data received is transferred. if no data has been received since the last reset, all bits are transmitted low, as the shift regis- ter resets at 0. when a first data is written in sp i_tdr, it is transferred immediat ely in the shift register and the tdre bit rises. if new data is wri tten, it remains in spi_tdr until a transfer occurs, i.e. nss falls and there is a valid clock on the spck pin. w hen the transfer occurs, the last data written in spi_tdr is transferred in the shift register and the tdre bit rises. this enables frequent updates of critical variables with single transfers. then, a new data is loaded in the shift register from the transmit data register. in case no character is ready to be transmitted, i.e. no character has been written in spi_tdr since the last load from spi_tdr to the shift register, the shift register is not modified and the last received character is retransmitted. figure 31-9 shows a block diagram of the spi when operating in slave mode. figure 31-9. slave mode functional block diagram shift register spck spiens lsb msb nss mosi spi_rdr rd spi clock tdre spi_tdr td rdrf ovres spi_csr0 cpol ncpha bits spien spidis miso
335 6222f?atarm?14-jan-11 sam7se512/256/32 31.7 serial peripheral inte rface (spi) user interface table 31-3. spi register mapping offset register register name access reset 0x00 control register spi_cr write-only --- 0x04 mode register spi_mr read/write 0x0 0x08 receive data register spi_rdr read-only 0x0 0x0c transmit data register spi_tdr write-only --- 0x10 status register spi_sr read-only 0x000000f0 0x14 interrupt enable register spi_ier write-only --- 0x18 interrupt disable register spi_idr write-only --- 0x1c interrupt mask register spi_imr read-only 0x0 0x20 - 0x2c reserved 0x30 chip select register 0 spi_csr0 read/write 0x0 0x34 chip select register 1 spi_csr1 read/write 0x0 0x38 chip select register 2 spi_csr2 read/write 0x0 0x3c chip select register 3 spi_csr3 read/write 0x0 0x004c - 0x00f8 reserved ? ? ? 0x004c - 0x00fc reserved ? ? ? 0x100 - 0x124 reserved for the pdc
336 6222f?atarm?14-jan-11 sam7se512/256/32 31.7.1 spi control register name: spi_cr access: write-only ? spien: spi enable 0 = no effect. 1 = enables the spi to transfer and receive data. ? spidis: spi disable 0 = no effect. 1 = disables the spi. as soon as spidis is set, spi finishes its transfer. all pins are set in input mode and no data is received or transmitted. if a transfer is in progress, the transfer is finished before the spi is disabled. if both spien and spidis are equal to one when the control register is written, the spi is disabled. ? swrst: spi software reset 0 = no effect. 1 = reset the spi. a software-triggered hardware reset of the spi interface is performed. the spi is in slave mode after software reset. pdc channels are not affected by software reset. ? lastxfer: last transfer 0 = no effect. 1 = the current npcs will be deasserted afte r the character written in td has been tr ansferred. when c saat is set, this allows to close the communication with the current serial periph eral by raising the correspondi ng npcs line as soon as td transfer has completed. 31 30 29 28 27 26 25 24 ???????lastxfer 23 22 21 20 19 18 17 16 ???????? 15 14 13 12 11 10 9 8 ???????? 76543210 swrst?????spidisspien
337 6222f?atarm?14-jan-11 sam7se512/256/32 31.7.2 spi mode register name: spi_mr access: read/write ? mstr: master/slave mode 0 = spi is in slave mode. 1 = spi is in master mode. ? ps: peripheral select 0 = fixed peripheral select. 1 = variable peripheral select. ? pcsdec: chip select decode 0 = the chip selects are directly connected to a peripheral device. 1 = the four chip select lines are connected to a 4- to 16-bit decoder. when pcsdec equals one, up to 15 chip select signals can be generated with the four lines using an external 4- to 16-bit decoder. the chip select registers define the characteristics of the 15 chip selects according to the following rules: spi_csr0 defines peripheral chip select signals 0 to 3. spi_csr1 defines peripheral chip select signals 4 to 7. spi_csr2 defines peripheral chip select signals 8 to 11. spi_csr3 defines peripheral chip select signals 12 to 14. ? modfdis: mode fault detection 0 = mode fault detection is enabled. 1 = mode fault detection is disabled. ? llb: local loopback enable 0 = local loopback path disabled. 1 = local loopback path enabled. llb controls the local loopback on the data serializer for te sting in master mode only. (miso is internally connected on mosi.) 31 30 29 28 27 26 25 24 dlybcs 23 22 21 20 19 18 17 16 ???? pcs 15 14 13 12 11 10 9 8 ???????? 76543210 llb ? ? modfdis pcsdec ps mstr
338 6222f?atarm?14-jan-11 sam7se512/256/32 ? pcs: peripheral chip select this field is only used if fixed peripheral select is active (ps = 0). if pcsdec = 0: pcs = xxx0 npcs[3:0] = 1110 pcs = xx01 npcs[3:0] = 1101 pcs = x011 npcs[3:0] = 1011 pcs = 0111 npcs[3:0] = 0111 pcs = 1111 forbidden (no peripheral is selected) (x = don?t care) if pcsdec = 1: npcs[3:0] output signals = pcs. ? dlybcs: delay between chip selects this field defines the delay from npcs inactive to the ac tivation of another npcs. the dlybcs time guarantees non-over- lapping chip selects and solves bus contentions in case of peripherals having long data float times. if dlybcs is less than or eq ual to six, six mck periods will be inserted by default. otherwise, the following equat ion determines the delay: delay between chip selects dlybcs mck ---------------------- - =
339 6222f?atarm?14-jan-11 sam7se512/256/32 31.7.3 spi receive data register name: spi_rdr access: read-only ? rd: receive data data received by the spi interface is stored in this register right-justified. unused bits read zero. ? pcs: peripheral chip select in master mode only, these bits indicate the value on the npcs pins at the end of a transfer. otherwise, these bits read zero. 31 30 29 28 27 26 25 24 ???????? 23 22 21 20 19 18 17 16 ???? pcs 15 14 13 12 11 10 9 8 rd 76543210 rd
340 6222f?atarm?14-jan-11 sam7se512/256/32 31.7.4 spi transmit data register name: spi_tdr access: write-only ? td: transmit data data to be transmitted by the spi interface is stored in this register. information to be transmitted must be written to the transmit data register in a right-justified format. pcs: peripheral chip select this field is only used if variable peripheral select is active (ps = 1). if pcsdec = 0: pcs = xxx0 npcs[3:0] = 1110 pcs = xx01 npcs[3:0] = 1101 pcs = x011 npcs[3:0] = 1011 pcs = 0111 npcs[3:0] = 0111 pcs = 1111 forbidden (no peripheral is selected) (x = don?t care) if pcsdec = 1: npcs[3:0] output signals = pcs ? lastxfer: last transfer 0 = no effect. 1 = the current npcs will be deasserted afte r the character written in td has been tr ansferred. when c saat is set, this allows to close the communication with the current serial periph eral by raising the correspondi ng npcs line as soon as td transfer has completed. this field is only used if variable peripheral select is active (ps = 1). 31 30 29 28 27 26 25 24 ???????lastxfer 23 22 21 20 19 18 17 16 ???? pcs 15 14 13 12 11 10 9 8 td 76543210 td
341 6222f?atarm?14-jan-11 sam7se512/256/32 31.7.5 spi status register name: spi_sr access: read-only ? rdrf: receive data register full 0 = no data has been received since the last read of spi_rdr 1 = data has been received and the received data has been transferred from the serializer to spi_rdr since the last read of spi_rdr. ? tdre: transmit data register empty 0 = data has been written to spi_tdr and not yet transferred to the serializer. 1 = the last data written in the transmit data register has been transferred to the serializer. tdre equals zero when the spi is disabled or at reset. the spi enable command sets this bit to one. ? modf: mode fault error 0 = no mode fault has been detected since the last read of spi_sr. 1 = a mode fault occurred since the last read of the spi_sr. ? ovres: overrun error status 0 = no overrun has been detected since the last read of spi_sr. 1 = an overrun has occurred since the last read of spi_sr. an overrun occurs when spi_r dr is loaded at least twice from the serializer since the last read of the spi_rdr. ? endrx: end of rx buffer 0 = the receive counter register has not reached 0 since the last write in spi_rcr (1) or spi_rncr (1) . 1 = the receive counter register has reached 0 since the last write in spi_rcr (1) or spi_rncr (1) . ? endtx: end of tx buffer 0 = the transmit counter register has not reached 0 since the last write in spi_tcr (1) or spi_tncr (1) . 1 = the transmit counter register has reached 0 since the last write in spi_tcr (1) or spi_tncr (1) . ? rxbuff: rx buffer full 0 = spi_rcr (1) or spi_rncr (1) has a value other than 0. 1 = both spi_rcr (1) and spi_rncr (1) have a value of 0. 31 30 29 28 27 26 25 24 ???????? 23 22 21 20 19 18 17 16 ???????spiens 15 14 13 12 11 10 9 8 ??????txemptynssr 76543210 txbufe rxbuff endtx endrx ovres modf tdre rdrf
342 6222f?atarm?14-jan-11 sam7se512/256/32 ? txbufe: tx buffer empty 0 = spi_tcr (1) or spi_tncr (1) has a value other than 0. 1 = both spi_tcr (1) and spi_tncr (1) have a value of 0. ? nssr: nss rising 0 = no rising edge detected on nss pin since last read. 1 = a rising edge occurred on nss pin since last read. ? txempty: transmission registers empty 0 = as soon as data is written in spi_tdr. 1 = spi_tdr and internal shifter are empty. if a transfer delay has been defined, txempty is set after the completion of such delay. ? spiens: spi enable status 0 = spi is disabled. 1 = spi is enabled. note: 1. spi_rcr, spi_rncr, spi_tcr, spi_tncr are physically located in the pdc.
343 6222f?atarm?14-jan-11 sam7se512/256/32 31.7.6 spi interrupt enable register name: spi_ier access: write-only ? rdrf: receive data register full interrupt enable ? tdre: spi transmit data regi ster empty interrupt enable ? modf: mode fault error interrupt enable ? ovres: overrun error interrupt enable ? endrx: end of receive buffer interrupt enable ? endtx: end of transmit buffer interrupt enable ? rxbuff: receive buffer full interrupt enable ? txbufe: transmit buffer empty interrupt enable ? txempty: transmission registers empty enable ? nssr: nss rising interrupt enable 0 = no effect. 1 = enables the corresponding interrupt. 31 30 29 28 27 26 25 24 ???????? 23 22 21 20 19 18 17 16 ???????? 15 14 13 12 11 10 9 8 ??????txemptynssr 76543210 txbufe rxbuff endtx endrx ovres modf tdre rdrf
344 6222f?atarm?14-jan-11 sam7se512/256/32 31.7.7 spi interrupt disable register name: spi_idr access: write-only ? rdrf: receive data register full interrupt disable ? tdre: spi transmit data register empty interrupt disable ? modf: mode fault error interrupt disable ? ovres: overrun error interrupt disable ? endrx: end of receive buffer interrupt disable ? endtx: end of transmit buffer interrupt disable ? rxbuff: receive buffer full interrupt disable ? txbufe: transmit buffer empty interrupt disable ? txempty: transmission registers empty disable ? nssr: nss rising interrupt disable 0 = no effect. 1 = disables the corresponding interrupt. 31 30 29 28 27 26 25 24 ???????? 23 22 21 20 19 18 17 16 ???????? 15 14 13 12 11 10 9 8 ??????txemptynssr 76543210 txbufe rxbuff endtx endrx ovres modf tdre rdrf
345 6222f?atarm?14-jan-11 sam7se512/256/32 31.7.8 spi interrupt mask register name: spi_imr access: read-only ? rdrf: receive data register full interrupt mask ? tdre: spi transmit data register empty interrupt mask ? modf: mode fault error interrupt mask ? ovres: overrun error interrupt mask ? endrx: end of receive buffer interrupt mask ? endtx: end of transmit buffer interrupt mask ? rxbuff: receive buffer full interrupt mask ? txbufe: transmit buffer empty interrupt mask ? txempty: transmission registers empty mask ? nssr: nss rising interrupt mask 0 = the corresponding interrupt is not enabled. 1 = the corresponding interrupt is enabled. 31 30 29 28 27 26 25 24 ???????? 23 22 21 20 19 18 17 16 ???????? 15 14 13 12 11 10 9 8 ??????txemptynssr 76543210 txbufe rxbuff endtx endrx ovres modf tdre rdrf
346 6222f?atarm?14-jan-11 sam7se512/256/32 31.7.9 spi chip select register name: spi_csr0... spi_csr3 access: read/write ? cpol: clock polarity 0 = the inactive state value of spck is logic level zero. 1 = the inactive state value of spck is logic level one. cpol is used to determine the inactive state value of the serial clock (spck). it is used with ncpha to produce the required clock/data relationship between master and slave devices. ? ncpha: clock phase 0 = data is changed on the leading edge of spck and captured on the following edge of spck. 1 = data is captured on the leading edge of spck and changed on the following edge of spck. ncpha determines which edge of spck causes data to c hange and which edge causes data to be captured. ncpha is used with cpol to produce the required clock/da ta relationship between master and slave devices. ? csaat: chip select active after transfer 0 = the peripheral chip select line rises as soon as the last transfer is achieved. 1 = the peripheral chip select does not rise after the last tr ansfer is achieved. it remains active until a new transfer is requested on a different chip select. ? bits: bits per transfer the bits field determines the number of data bits transferred. reserved values should not be used. 31 30 29 28 27 26 25 24 dlybct 23 22 21 20 19 18 17 16 dlybs 15 14 13 12 11 10 9 8 scbr 76543210 bits csaat ? ncpha cpol bits bits per transfer 0000 8 0001 9 0010 10 0011 11 0100 12 0101 13 0110 14 0111 15 1000 16
347 6222f?atarm?14-jan-11 sam7se512/256/32 ? scbr: serial clock baud rate in master mode, the spi interface uses a modulus counter to derive the spck baud rate from the master clock mck. the baud rate is selected by writing a value from 1 to 255 in the scbr field. the following equations determine the spck baud rate: programming the scbr field at 0 is forbidden. triggering a trans fer while scbr is at 0 can le ad to unpredictable results. at reset, scbr is 0 and the user has to program it at a valid value before performing the first transfer. ? dlybs: delay before spck this field defines the delay from npcs valid to the first valid spck transition. when dlybs equals zero, the npcs valid to spck transition is 1/2 the spck clock period. otherwise, the following equations determine the delay: ? dlybct: delay between consecutive transfers this field defines the delay between two consecutive transfers with the same perip heral without removing the chip select. the delay is always inserted after each transfer and before removing the chip select if needed. when dlybct equals zero, no delay between consecutive transf ers is inserted and the clock keeps its duty cycle over the character transfers. otherwise, the following equat ion determines the delay: 1001 reserved 1010 reserved 1011 reserved 1100 reserved 1101 reserved 1110 reserved 1111 reserved bits bits per transfer spck baudrate mck scbr -------------- - = delay before spck dlybs mck ------------------ - = delay between consecutive transfers 32 dlybct mck ------------------------------------- =
348 6222f?atarm?14-jan-11 sam7se512/256/32
349 6222f?atarm?14-jan-11 sam7se512/256/32 32. two wire interface (twi) 32.1 overview the atmel two-wire interface (twi) interconnects components on a unique two-wire bus, made up of one clock line and one data line with speeds of up to 400 kbits per second, based on a byte-oriented transfer format. it can be used with any atmel two-wire interface bus serial eeprom and i2c compatible device such as real time clock (rtc), dot matrix/graphic lcd controllers and temperature sensor, to name but a few. the twi is programmable as a master or a slave with sequential or single-byte access. mu ltiple master capability is supported. arbitra- tion of the bus is performed internally and puts the twi in slave mode automatically if the bus arbitration is lost. a configurable baud rate generator permits the output data rate to be adapted to a wide range of core clock frequencies. below, table 32-1 lists the compatibility level of the atme l two-wire interface in master mode and a full i2c compatible device. note: 1. start + b000000001 + ack + sr 32.2 list of abbreviations table 32-1. atmel twi compatibilit y with i2c standard i2c standard atmel twi standard mode speed (100 khz) supported fast mode speed (400 khz) supported 7 or 10 bits slave addressing supported start byte (1) not supported repeated start (sr) condition supported ack and nack management supported slope control and input filtering (fast mode) not supported clock stretching supported table 32-2. abbreviations abbreviation description twi two-wire interface a acknowledge na non acknowledge pstop sstart sr repeated start sadr slave address adr any address except sadr rread wwrite
350 6222f?atarm?14-jan-11 sam7se512/256/32 32.3 block diagram figure 32-1. block diagram 32.4 application block diagram figure 32-2. application block diagram 32.4.1 i/o lines description apb bridge pmc mck two-wire interface pio aic twi interrupt twck twd host with twi interface twd twck atmel twi serial eeprom i2c rtc i2c lcd controller slave 1 slave 2 slave 3 vdd i2c temp. sensor slave 4 rp: pull up value as given by the i2c standard rp rp table 32-3. i/o lines description pin name pin description type twd two-wire serial data input/output twck two-wire serial clock input/output
351 6222f?atarm?14-jan-11 sam7se512/256/32 32.5 product dependencies 32.5.1 i/o lines both twd and twck are bidirectional lines, connect ed to a positive supply voltage via a current source or pull-up resistor (see figure 32-2 on page 350 ). when the bus is free, both lines are high. the output stages of devices connected to the bus must have an open-drain or open-col- lector to perform the wired-and function. twd and twck pins may be multiplexed with pi o lines. to enable the twi, the programmer must perform the following steps: ? program the pio controller to: ? dedicate twd and twck as peripheral lines. ? define twd and twck as open-drain. 32.5.2 power management ? enable the peripheral clock. the twi interface may be clocked through the power management controller (pmc), thus the programmer must first configure the pmc to enable the twi clock. 32.5.3 interrupt the twi interface has an interrupt line connected to the advanced interrupt controller (aic). in order to handle interrupts, the aic must be programmed before configuring the twi.
352 6222f?atarm?14-jan-11 sam7se512/256/32 32.6 functional description 32.6.1 transfer format the data put on the twd line must be 8 bits long. data is transferred msb first; each byte must be followed by an acknowledgement. the number of bytes per transfer is unlimited (see figure 32-4 ). each transfer begins with a start condition and terminates with a stop condition (see figure 32-3 ). ? a high-to-low transition on the twd line while twck is high defines the start condition. ? a low-to-high transition on the twd line while twck is high defines a stop condition. figure 32-3. start and stop conditions figure 32-4. transfer format 32.6.2 modes of operation the twi has six modes of operations: ? master transmitter mode ? master receiver mode ? multi-master transmitter mode ? multi-master receiver mode ? slave transmitter mode ? slave receiver mode these modes are described in the following chapters. twd twck start stop twd twck start address r/w ack data ack data ack stop
353 6222f?atarm?14-jan-11 sam7se512/256/32 32.7 master mode 32.7.1 definition the master is the device which starts a transfer, generates a clock and stops it. 32.7.2 application block diagram figure 32-5. master mode typical application block diagram 32.7.3 programming master mode the following registers have to be programmed before entering master mode: 1. dadr (+ iadrsz + iadr if a 10 bit device is addressed): the device address is used to access slave devices in read or write mode. 2. ckdiv + chdiv + cldiv: clock waveform. 3. svdis: disable the slave mode. 4. msen: enable the master mode. 32.7.4 master transmitter mode after the master initiates a start condition when writing into the tran smit holding register, twi_thr, it sends a 7-bit slave address, configured in the master mode register (dadr in twi_mmr), to notify the slave device. the bit following the slave address indicates the transfer direction, 0 in this case (mread = 0 in twi_mmr). the twi transfers require the slave to acknowledge each received byte. during the acknowl- edge clock pulse (9th pulse), the master releases the data line (high), enabling the slave to pull it down in order to generate the acknowledge. t he master polls the data line during this clock pulse and sets the not acknowledge bit ( nack) in the status register if the slave does not acknowledge the byte. as with the other status bi ts, an interrupt can be generated if enabled in the interrupt enable register (twi_ier). if the slave acknowledges the byte, the data written in the twi_thr, is then shifted in the internal shifter and transferred. when an acknowledge is detected, the txrdy bit is set un til a new write in the twi_thr. when no more data is written into the twi_thr, the master generates a stop condition to end the transfer. the end of the complete transfer is marked by the twi_txcomp bit set to one. see figure 32-6 , figure 32-7 , and figure 32-8 . host with twi interface twd twck atmel twi serial eeprom i2c rtc i2c lcd controller slave 1 slave 2 slave 3 vdd i2c temp. sensor slave 4 rp: pull up value as given by the i2c standard rp rp
354 6222f?atarm?14-jan-11 sam7se512/256/32 figure 32-6. master write with one data byte figure 32-7. master write with multiple data byte figure 32-8. master write with one byte internal address and multiple data bytes 32.7.5 master receiver mode the read sequence begins by setting the start bit. after the start condition has been sent, the master sends a 7-bit slave address to notify th e slave device. the bit following the slave address indicates the transfer direction, 1 in this ca se (mread = 1 in twi_mmr). during the acknowl- edge clock pulse (9th pulse), the master releases the data line (high), enabling the slave to pull it down in order to generate the acknowledge. t he master polls the data line during this clock pulse and sets the nack bit in the status register if the slave does not acknowledge the byte. if an acknowledge is received, the master is then ready to receive data from the slave. after data has been received, the master sends an acknowledg e condition to notify the slave that the data has been received except for the last data, after the stop condition. see figure 32-9 . when the rxrdy bit is set in the status register, a character has been received in the receive-holding reg- ister (twi_rhr). the rxrdy bit is reset when reading the twi_rhr. txcomp txrdy write thr (data) stop sent automaticaly (ack received and txrdy = 1) twd a data a s dadr w p a data n a s dadr w data n+5 a p data n+x a txcomp txrdy write thr (data n) write thr (data n+1) write thr (data n+x) last data sent stop sent automaticaly (ack received and txrdy = 1) twd a iadr(7:0) a data n a s dadr w data n+5 a p data n+x a txcomp txrdy twd write thr (data n) write thr (data n+1) write thr (data n+x) last data sent stop sent automaticaly (ack received and txrdy = 1)
355 6222f?atarm?14-jan-11 sam7se512/256/32 when a single data byte read is performed, with or without internal address (iadr ), the start and stop bits must be set at the same time. see figure 32-9 . when a multiple data byte read is performed, with or without internal address (iadr ), the stop bit must be set after the next-to- last data received. see figure 32-10 . for internal address usage see section 32.7.6 . figure 32-9. master read with one data byte figure 32-10. master read with mu ltiple data bytes 32.7.6 internal address the twi interface can perform various transfer formats: transfers with 7-bit slave address devices and 10-bit slave address devices. 32.7.6.1 7-bit slave addressing when addressing 7-bit slave devices, the internal address bytes are used to perform random address (read or write) accesses to reach one or more data bytes, within a memory page loca- tion in a serial memory, for example. when performing read operations with an internal address, the twi performs a write operation to set the internal address into the slave device, and then switch to master receiver mode. note that the second start condition (after sending the iadr) is sometimes called ?repeated start? (sr) in i2c fully-compatible devices. see figure 32-12 . see figure 32-11 and figure 32-13 for master write operation with internal address. the three internal address bytes are configurable through the master mode register (twi_mmr). if the slave device supports only a 7-bit address, i.e. no internal address, iadrsz must be set to 0. a s dadr r data n p txcomp write start & stop bit rxrdy read rhr twd n a s dadr r data n a a data (n+1) a data (n+m) data (n+m)-1 p twd txcomp write start bit rxrdy write stop bit after next-to-last data read read rhr data n read rhr data (n+1) read rhr data (n+m)-1 read rhr data (n+m)
356 6222f?atarm?14-jan-11 sam7se512/256/32 in the figures below the following abbreviations are used: figure 32-11. master write with one, two or three bytes internal address and one data byte figure 32-12. master read with one, two or three bytes internal address and one data byte 32.7.6.2 10-bit slave addressing for a slave address higher than 7 bits, the user must configure the address size (iadrsz ) and set the other slave address bits in the internal address register (twi_iadr). the two remaining internal address bytes, iadr[15:8] and iadr[23:16] can be used the same as in 7-bit slave addressing. example: address a 10-bit device (10-bit device address is b1 b2 b3 b4 b5 b6 b7 b8 b9 b10) 1. program iadrsz = 1, 2. program dadr with 1 1 1 1 0 b1 b2 (b1 is the msb of the 10-bit address, b2, etc.) 3. program twi_iadr with b3 b4 b5 b6 b7 b8 b9 b10 (b10 is the lsb of the 10-bit address) ?s start ?sr repeated start ?p stop ?w write ?r read ?a acknowledge ?n not acknowledge ?dadr device address ?iadr internal address s dadr w a iadr(23:16) a iadr(15:8) a iadr(7:0) a data a p s dadr w a iadr(15:8) a iadr(7:0) a p data a a iadr(7:0) a p data a s dadr w twd three bytes internal address two bytes internal address one byte internal address twd twd s dadr w a iadr(23:16) a iadr(15:8) a iadr(7:0) a s dadr w a iadr(15:8) a iadr(7:0) a a iadr(7:0) a s dadr w data n p sr dadr r a sr dadr r a data n p sr dadr ra data np twd twd twd three bytes internal address two bytes internal address one byte internal address
357 6222f?atarm?14-jan-11 sam7se512/256/32 figure 32-13 below shows a byte write to an atmel at24lc512 eeprom. this demonstrates the use of internal addresses to access the device. figure 32-13. internal address usage s t a r t m s b device address 0 l s b r / w a c k m s b w r i t e a c k a c k l s b a c k first word address second word address data s t o p
358 6222f?atarm?14-jan-11 sam7se512/256/32 32.7.7 read-write flowcharts the following flowcharts shown in figure 32-14 , figure 32-15 on page 359 , figure 32-16 on page 360 , figure 32-17 on page 361 , figure 32-18 on page 362 and figure 32-19 on page 363 give examples for read and writ e operations. a polling or interr upt method can be used to check the status bits. the interrupt method requires that the interrupt enable register (twi_ier) be configured first. figure 32-14. twi write operation with single data byte without internal address set twi clock (cldiv, chdiv, ckdiv) in twi_cwgr (needed only once) set the control register: - master enable twi_cr = msen + svdis set the master mode register: - device slave address (dadr) - transfer direction bit write ==> bit mread = 0 load transmit register twi_thr = data to send read status register txrdy = 1? read status register txcomp = 1? transfer finished ye s ye s begin no no
359 6222f?atarm?14-jan-11 sam7se512/256/32 figure 32-15. twi write operation with single data byte and internal address begin set twi clock (cldiv, chdiv, ckdiv) in twi_cwgr (needed only once) set the control register: - master enable twi_cr = msen + svdis set the master mode register: - device slave address (dadr) - internal address size (iadrsz) - transfer direction bit write ==> bit mread = 0 load transmit register twi_thr = data to send read status register txrdy = 1? read status register txcomp = 1? transfer finished set the internal address twi_iadr = address ye s ye s no no
360 6222f?atarm?14-jan-11 sam7se512/256/32 figure 32-16. twi write operation with multiple data bytes with or without internal address set the control register: - master enable twi_cr = msen + svdis set the master mode register: - device slave address - internal address size (if iadr used) - transfer direction bit write ==> bit mread = 0 internal address size = 0? load transmit register twi_thr = data to send read status register txrdy = 1? data to send? read status register txcomp = 1? end begin set the internal address twi_iadr = address ye s twi_thr = data to send ye s ye s ye s no no no set twi clock (cldiv, chdiv, ckdiv) in twi_cwgr (needed only once)
361 6222f?atarm?14-jan-11 sam7se512/256/32 figure 32-17. twi read operation with single data byte without internal address set the control register: - master enable twi_cr = msen + svdis set the master mode register: - device slave address - internal address size (iadrsz) - transfer direction bit read ==> bit mread = 1 read status register txcomp = 1? end begin ye s set twi clock (cldiv, chdiv, ckdiv) in twi_cwgr (needed only once) ye s set the internal address twi_iadr = address start the transfer twi_cr = start | stop read status register rxrdy = 1? read receive holding register no no
362 6222f?atarm?14-jan-11 sam7se512/256/32 figure 32-18. twi read operation with single data byte and internal address set the control register: - master enable twi_cr = msen + svdis set the master mode register: - device slave address - internal address size (iadrsz) - transfer direction bit read ==> bit mread = 1 read status register txcomp = 1? end begin ye s set twi clock (cldiv, chdiv, ckdiv) in twi_cwgr (needed only once) ye s set the internal address twi_iadr = address start the transfer twi_cr = start | stop read status register rxrdy = 1? read receive holding register no no
363 6222f?atarm?14-jan-11 sam7se512/256/32 figure 32-19. twi read operation with multiple data bytes with or without internal address internal address size = 0? start the transfer twi_cr = start stop the transfer twi_cr = stop read status register rxrdy = 1? last data to read but one? read status register txcomp = 1? end set the internal address twi_iadr = address ye s ye s ye s no ye s read receive holding register (twi_rhr) no set the control register: - master enable twi_cr = msen + svdis set the master mode register: - device slave address - internal address size (if iadr used) - transfer direction bit read ==> bit mread = 1 begin set twi clock (cldiv, chdiv, ckdiv) in twi_cwgr (needed only once) no read status register rxrdy = 1? ye s read receive holding register (twi_rhr) no
364 6222f?atarm?14-jan-11 sam7se512/256/32 32.8 multi-master mode 32.8.1 definition more than one master may handle the bus at the same time without data corruption by using arbitration. arbitration starts as soon as two or more masters place information on the bus at the same time, and stops (arbitration is lost) for the master that intends to send a logical one while the other master sends a logical zero. as soon as arbitration is lost by a master, it stop s sending data and listens to the bus in order to detect a stop. when the stop is detected, the master who has lost arbitration may put its data on the bus by respecting arbitration. arbitration is illustrated in figure 32-21 on page 365 . 32.8.2 different multi-master modes two multi-master modes may be distinguished: 1. twi is considered as a master only and will never be addressed. 2. twi may be either a master or a slave and may be addressed. note: in both multi-master modes arbitration is supported. 32.8.2.1 twi as master only in this mode, twi is considered as a master only (msen is always at one) and must be driven like a master with the arblst (arbitration lost) flag in addition. if arbitration is lost (arblst = 1), the programmer must reinitiate the data transfer. if the user starts a transfer (ex.: dadr + start + w + write in thr) and if the bus is busy, the twi automatically waits for a stop conditi on on the bus to initiate the transfer (see figure 32- 20 on page 365 ). note: the state of the bus (busy or free) is not indicated in the user interface. 32.8.2.2 twi as master or slave the automatic reversal from master to slave is not supported in case of a lost arbitration. then, in the case where twi may be either a master or a slave, the programmer must manage the pseudo multi-master mode described in the steps below. 1. program twi in slave mode (sadr + ms dis + sven) and perform slave access (if twi is addressed). 2. if twi has to be set in master mode, wait until txcomp flag is at 1. 3. program master mode (dadr + svdis + msen ) and start the transfer (ex: start + write in thr). 4. as soon as the master mode is enabled, twi scans the bus in order to detect if it is busy or free. when the bus is considered as free, twi initiates the transfer. 5. as soon as the transfer is initiated and until a stop condition is sent, the arbitration becomes relevant and the user must monitor the arblst flag. 6. if the arbitration is lost (arblst is set to 1), the user must program the twi in slave mode in the case where the master that won the arbitration wanted to access the twi. 7. if twi has to be set in slave mode, wait until txcomp flag is at 1 and then program the slave mode.
365 6222f?atarm?14-jan-11 sam7se512/256/32 note: in the case where the arbitration is lost and tw i is addressed, twi will not acknowledge even if it is programmed in slave mode as soon as arblst is set to 1. then, the master must repeat sadr. figure 32-20. programmer sends data while the bus is busy figure 32-21. arbitration cases the flowchart shown in figure 32-22 on page 366 gives an example of read and write operations in multi-master mode. twck twd data sent by a master stop sent by the master start sent by the twi data sent by the twi bus is busy bus is free a transfer is programmed (dadr + w + start + write thr) transfer is initiated twi data transfer transfer is kept bus is considered as free twck bus is busy bus is free a transfer is programmed (dadr + w + start + write thr) transfer is initiated twi data transfer transfer is kept bus is considered as free data from a master data from twi s 0 s 0 0 1 1 1 arblst s 0 s 0 0 1 1 1 twd s 0 0 1 1 1 1 1 arbitration is lost twi stops sending data p s 0 1 p 0 1 1 1 1 data from the master data from the twi arbitration is lost the master stops sending data transfer is stopped transfer is programmed again (dadr + w + start + write thr) twck twd
366 6222f?atarm?14-jan-11 sam7se512/256/32 figure 32-22. multi-master flowchart programm the slave mode: sadr + msdis + sven svacc = 1 ? txcomp = 1 ? gacc = 1 ? decoding of the programming sequence prog seq ok ? change sadr svread = 0 ? read status register rxrdy= 0 ? read twi_rhr txrdy= 1 ? eosacc = 1 ? write in twi_thr need to perform a master access ? program the master mode dadr + svdis + msen + clk + r / w read status register arblst = 1 ? mread = 1 ? txrdy= 0 ? write in twi_thr data to send ? rxrdy= 0 ? read twi_rhr data to read? stop transfer read status register txcomp = 0 ? general call treatment ye s ye s ye s ye s ye s ye s ye s ye s ye s ye s ye s ye s ye s ye s start
367 6222f?atarm?14-jan-11 sam7se512/256/32 32.9 slave mode 32.9.1 definition the slave mode is defined as a mode where the device receives the clock and the address from another device called the master. in this mode, the device never initiates and never completes the transmission (start, repeated_start and stop conditions are always provided by the master). 32.9.2 application block diagram figure 32-23. slave mode typical application block diagram 32.9.3 programming slave mode the following fields must be programmed before entering slave mode: 1. sadr (twi_smr): the slave device address is used in order to be accessed by mas- ter devices in read or write mode. 2. msdis (twi_cr): disable the master mode. 3. sven (twi_cr): enable the slave mode. as the device receives the clock, values written in twi_cwgr are not taken into account. 32.9.4 receiving data after a start or repeated start condition is detected and if the address sent by the master matches with the slave addre ss programmed in the sadr (slave address) field, svacc (slave access) flag is set and svread (slave read) indicates the direction of the transfer. svacc remains high until a stop condition or a repeated start is detected. when such a condition is detected, eosacc (end of slave access) flag is set. 32.9.4.1 read sequence in the case of a read sequence (svread is high), twi transfers data written in the twi_thr (twi transmit holding register) until a stop condition or a repeated _start + an address different from sadr is detected. note that at the end of the read sequence txcomp (transmis- sion complete) flag is set and svacc reset. as soon as data is written in the twi_t hr, txrdy (transmit holding register ready) flag is reset, and it is set when the shift register is empty and the sent data acknowledged or not. if the data is not acknowledged, the nack flag is set. host with twi interface twd twck lcd controller slave 1 slave 2 slave 3 rr vdd host with twi interface host with twi interface master
368 6222f?atarm?14-jan-11 sam7se512/256/32 note that a stop or a repeated start always follows a nack. see figure 32-24 on page 369 . 32.9.4.2 write sequence in the case of a write sequence (svread is low), the rxrdy (receive holding register ready) flag is set as soon as a character has been received in the twi_rhr (twi receive holding register). rxrdy is re set when reading the twi_rhr. twi continues receiving data until a stop co ndition or a repeated_start + an address dif- ferent from sadr is detected. note that at the end of the write sequence txcomp flag is set and svacc reset. see figure 32-25 on page 369 . 32.9.4.3 clock synchronization sequence in the case where twi_thr or twi_rhr is not written/read in time, twi performs a clock synchronization. clock stretching information is given by the sclws (clock wait state) bit. see figure 32-27 on page 371 and figure 32-28 on page 372 . 32.9.4.4 general call in the case where a general call is perfor med, gacc (general call access) flag is set. after gacc is set, it is up to the programmer to interpret the meaning of the general call and to decode the new address programming sequence. see figure 32-26 on page 370 . 32.9.5 data transfer 32.9.5.1 read operation the read mode is defined as a data requirement from the master. after a start or a repeated start condition is detected, the deco ding of the address starts. if the slave address (sadr) is decoded, svacc is set and svread indicates the direc- tion of the transfer. until a stop or repeated start condition is detected, twi continues sending data loaded in the twi_thr register. if a stop condition or a repeated start + an address different from sadr is detected, svacc is reset. figure 32-24 on page 369 describes the write operation.
369 6222f?atarm?14-jan-11 sam7se512/256/32 figure 32-24. read access ordered by a master notes: 1. when svacc is low, the state of svread becomes irrelevant. 2. txrdy is reset when data has been transmitted from twi_thr to the shift register and set when this data has been acknowledged or non acknowledged. 32.9.5.2 write operation the write mode is defined as a data transmission from the master. after a start or a repeated start, the decodi ng of the address starts . if the slave address is decoded, svacc is set and svread indicates the direction of the transfer (svread is low in this case). until a stop or repeated start condition is detected, twi stores the received data in the twi_rhr register. if a stop condition or a repeated start + an address different from sadr is detected, svacc is reset. figure 32-25 on page 369 describes the write operation. figure 32-25. write access ordered by a master notes: 1. when svacc is low, the state of svread becomes irrelevant. 2. rxrdy is set when data has been transmitted from the shift register to the twi_rhr and reset when this data is read. write thr read rhr svread has to be taken into account only while svacc is active twd txrdy nack svacc svread eosvacc sadr s adr r na r a data a a data na s/sr data na p/s/sr sadr matches, twi answers with an ack sadr does not match, twi answers with a nack ack/nack from the master rxrdy read rhr svread has to be taken into account only while svacc is active twd svacc svread eosvacc sadr does not match, twi answers with a nack sadr s adr w na w a data a a data na s/sr data na p/s/sr sadr matches, twi answers with an ack
370 6222f?atarm?14-jan-11 sam7se512/256/32 32.9.5.3 general call the general call is performed in order to change the address of the slave. if a general call is detected, gacc is set. after the detection of general call, it is up to the programmer to decode the commands which come afterwards. in case of a write command, the programmer has to decode the programming sequence and program a new sadr if the programming sequence matches. figure 32-26 on page 370 describes the general call access. figure 32-26. master performs a general call note: this method allows the user to create an own programming sequence by choosing the program- ming bytes and the number of them. the programming sequence has to be provided to the master. 0000000 + w general call p s a general call reset or write dadd a new sadr data 1 a data 2 a a new sadr programming sequence txd gcacc svacc reset command = 00000110x write command = 00000100x reset after read
371 6222f?atarm?14-jan-11 sam7se512/256/32 32.9.5.4 clock synchronization in both read and write modes, it may happen that twi_thr/tw i_rhr buffer is not filled /emp- tied before the emission/reception of a new charac ter. in this case, to avoid sending/receiving undesired data, a clock stretching mechanism is implemented. clock synchronization in read mode the clock is tied low if the shif t register is empty and if a stop or repeated start condition was not detected. it is tied low until the shift register is loaded. figure 32-27 on page 371 describes the clock synchronization in read mode. figure 32-27. clock synchronization in read mode notes: 1. txrdy is reset when data has been written in the twi_ th to the shift register and set when this data has been acknowl- edged or non acknowledged. 2. at the end of the read sequence, txcomp is set after a stop or after a repeated_start + an address different from sadr. 3. sclws is automatically set when the cl ock synchronization mechanism is started. data 1 the clock is stretched after the ack, the state of twd is undefined during clock stretching sclws svacc svread txrdy twck twi_thr txcomp the data is memorized in twi_thr until a new value is written twi_thr is transmitted to the shift register ack or nack from the master data 0 data 0 data 2 1 2 1 clock is tied low by the twi as long as thr is empty s sadr s r data 0 a a data 1 a data 2 na s xxxxxxx 2 write thr as soon as a start is detected
372 6222f?atarm?14-jan-11 sam7se512/256/32 clock synchronization in write mode the clock is tied low if the shift regist er and the twi_rhr is full. if a stop or repeated_start condition was not detected , it is tied low until twi_rhr is read. figure 32-28 on page 372 describes the clock synchronization in read mode. figure 32-28. clock synchronization in write mode notes: 1. at the end of the read sequence, txcomp is set after a stop or after a repeated_start + an address different from sadr. 2. sclws is automatically set when the cl ock synchronization mechanism is started and automatically reset when the mecha- nism is finished. rd data0 rd data1 rd data2 svacc svread rxrdy sclws txcomp data 1 data 2 scl is stretched on the last bit of data1 as soon as a start is detected twck twd twi_rhr clock is tied low by the twi as long as rhr is full data0 is not read in the rhr adr s sadr w a data 0 a a data 2 data 1 s na
373 6222f?atarm?14-jan-11 sam7se512/256/32 32.9.5.5 reversal after a repeated start reversal of read to write the master initiates the communication by a read command and finishes it by a write command. figure 32-29 on page 373 describes the repeated start + reversal from read to write mode. figure 32-29. repeated start + reversal from read to write mode 1. txcomp is only set at the end of the transmission because after the repeated start, sadr is detected again. reversal of write to read the master initiates the communication by a write command and finishes it by a read com- mand. figure 32-30 on page 373 describes the repeated start + reversal from write to read mode. figure 32-30. repeated start + reversal from write to read mode notes: 1. in this case, if twi_thr has not bee n written at the end of the read command, the clock is automatically stretched befo re the ack. 2. txcomp is only set at the end of the transmission because after the repeated st art, sadr is detected again. s sadr r a data 0 a data 1 sadr sr na w a data 2 a data 3 a p cleared after read data 0 data 1 data 2 data 3 svacc svread twd twi_thr twi_rhr eosacc txrdy rxrdy txcomp as soon as a start is detected s sadr w a data 0 a data 1 sadr sr a r a data 2 a data 3 n a p cleared after read data 0 data 2 data 3 data 1 txcomp txrdy rxrdy as soon as a start is detected read twi_rhr svacc svread twd twi_rhr twi_thr eosacc
374 6222f?atarm?14-jan-11 sam7se512/256/32 32.9.6 read write flowcharts the flowchart shown in figure 32-31 on page 374 gives an example of read and write operations in slave mode. a polling or interr upt method can be used to check the status bits. the interrupt method requires that the interrupt enable register (twi_ier) be configured first. figure 32-31. read write flowchart in slave mode set the slave mode: sadr + msdis + sven svacc = 1 ? txcomp = 1 ? gacc = 1 ? decoding of the programming sequence prog seq ok ? change sadr svread = 0 ? read status register rxrdy= 0 ? read twi_rhr txrdy= 1 ? eosacc = 1 ? write in twi_thr end general call treatment
375 6222f?atarm?14-jan-11 sam7se512/256/32 32.10 two-wire interface (twi) user interface table 32-4. register mapping offset register name access reset 0x00 control register twi_cr write-only n / a 0x04 master mode register twi_mmr read-write 0x00000000 0x08 slave mode register twi_smr read-write 0x00000000 0x0c internal address register twi_iadr read-write 0x00000000 0x10 clock waveform generator register twi_cwgr read-write 0x00000000 0x20 status register twi_sr read-only 0x0000f009 0x24 interrupt enable register twi_ier write-only n / a 0x28 interrupt disable register twi_idr write-only n / a 0x2c interrupt mask register twi_imr read-only 0x00000000 0x30 receive holding register twi_rhr read-only 0x00000000 0x34 transmit holding register twi_thr write-only 0x00000000 0x38 - 0xfc reserved ? ? ?
376 6222f?atarm?14-jan-11 sam7se512/256/32 32.10.1 twi control register name: twi_cr access: write-only reset value: 0x00000000 ? start: send a start condition 0 = no effect. 1 = a frame beginning with a start bit is transmitted according to the features defined in the mode register. this action is necessary when the twi peripheral wants to read data from a slave. when configured in master mode with a write operation, a frame is sent as soon as the user writes a character in the transmit holding register (twi_thr). ? stop: send a stop condition 0 = no effect. 1 = stop condition is sent just after completing the current byte transmission in master read mode. ? in single data byte master read, the start and stop must both be set. ? in multiple data bytes master read, the stop must be set after the last data received but one. ? in master read mode, if a nack bit is received, the stop is automatically performed. ? in multiple data write operation, when both thr and shift register are empty, a stop condition is automatically sent. ? msen: twi master mode enabled 0 = no effect. 1 = if msdis = 0, the master mode is enabled. note: switching from slave to master mo de is only permitted when txcomp = 1. ? msdis: twi master mode disabled 0 = no effect. 1 = the master mode is disabled, all pending data is transmitted. the shifter and holding characters (if it contains data) are transmitted in case of write operation. in read operation, the character being transferred must be completely received before disabling. 31 30 29 28 27 26 25 24 ???????? 23 22 21 20 19 18 17 16 ???????? 15 14 13 12 11 10 9 8 ???????? 76543210 swrst ? svdis sven msdis msen stop start
377 6222f?atarm?14-jan-11 sam7se512/256/32 ? sven: twi slave mode enabled 0 = no effect. 1 = if svdis = 0, the slave mode is enabled. note: switching from master to slave mode is only permitted when txcomp = 1. ? svdis: twi slave mode disabled 0 = no effect. 1 = the slave mode is disabled. the shifter and holding characte rs (if it contains data) are transmitted in case of read oper- ation. in write operation, the character being transferred must be completely received before disabling. ? swrst: software reset 0 = no effect. 1 = equivalent to a system reset.
378 6222f?atarm?14-jan-11 sam7se512/256/32 32.10.2 twi master mode register name: twi_mmr access: read-write reset value: 0x00000000 ? iadrsz: internal device address size ? mread: master read direction 0 = master write direction. 1 = master read direction. ? dadr: device address the device address is used to access slave devices in read or write mode. those bits are only used in master mode. 31 30 29 28 27 26 25 24 ???????? 23 22 21 20 19 18 17 16 ?dadr 15 14 13 12 11 10 9 8 ???mread?? iadrsz 76543210 ???????? iadrsz[9:8] 0 0 no internal device address 0 1 one-byte internal device address 1 0 two-byte internal device address 1 1 three-byte internal device address
379 6222f?atarm?14-jan-11 sam7se512/256/32 32.10.3 twi slave mode register name: twi_smr access: read-write reset value: 0x00000000 ? sadr: slave address the slave device address is used in slav e mode in order to be accessed by master devices in read or write mode. sadr must be programmed before enabling the slave mode or after a general call. writes at other times have no effect. 31 30 29 28 27 26 25 24 ???????? 23 22 21 20 19 18 17 16 ?sadr 15 14 13 12 11 10 9 8 ?????? 76543210 ????????
380 6222f?atarm?14-jan-11 sam7se512/256/32 32.10.4 twi internal address register name: twi_iadr access: read-write reset value: 0x00000000 ? iadr: internal address 0, 1, 2 or 3 bytes depending on iadrsz. 31 30 29 28 27 26 25 24 ???????? 23 22 21 20 19 18 17 16 iadr 15 14 13 12 11 10 9 8 iadr 76543210 iadr
381 6222f?atarm?14-jan-11 sam7se512/256/32 32.10.5 twi clock waveform generator register name: twi_cwgr access: read-write reset value: 0x00000000 twi_cwgr is only used in master mode. ? cldiv: clock low divider the scl low period is defined as follows: ? chdiv: clock high divider the scl high period is defined as follows: ? ckdiv: clock divider the ckdiv is used to increase both scl high and low periods. 31 30 29 28 27 26 25 24 ???????? 23 22 21 20 19 18 17 16 ckdiv 15 14 13 12 11 10 9 8 chdiv 76543210 cldiv t low cldiv ( 2 ckdiv () 4 ) + t mck = t high chdiv ( 2 ckdiv () 4 ) + t mck =
382 6222f?atarm?14-jan-11 sam7se512/256/32 32.10.6 twi status register name: twi_sr access: read-only reset value: 0x0000f009 ? txcomp: transmission completed (automatically set / reset) txcomp used in master mode : 0 = during the length of the current frame. 1 = when both holding and shifter registers are empty and stop condition has been sent. txcomp behavior in master mode can be seen in figure 32-8 on page 354 and in figure 32-10 on page 355 . txcomp used in slave mode : 0 = as soon as a start is detected. 1 = after a stop or a repeated start + an address different from sadr is detected. txcomp behavior in slave mode can be seen in figure 32-27 on page 371 , figure 32-28 on page 372 , figure 32-29 on page 373 and figure 32-30 on page 373 . ? rxrdy: receive holding register ready (automatically set / reset) 0 = no character has been received since the last twi_rhr read operation. 1 = a byte has been received in the twi_rhr since the last read. rxrdy behavior in master mode can be seen in figure 32-10 on page 355 . rxrdy behavior in slave mode can be seen in figure 32-25 on page 369 , figure 32-28 on page 372 , figure 32-29 on page 373 and figure 32-30 on page 373 . ? txrdy: transmit holding register ready (automatically set / reset) txrdy used in master mode : 0 = the transmit holding register has not been transferred into shift register. set to 0 when writing into twi_thr register. 1 = as soon as a data byte is transferred from twi_thr to inte rnal shifter or if a nack erro r is detected, txrdy is set at the same time as txcomp and nack. txrdy is also set when msen is set (enable twi). txrdy behavior in master mode can be seen in figure 32-8 on page 354 . 31 30 29 28 27 26 25 24 ???????? 23 22 21 20 19 18 17 16 ???????? 15 14 13 12 11 10 9 8 eosacc sclws arblst nack 76543210 ? ovre gacc svacc svread txrdy rxrdy txcomp
383 6222f?atarm?14-jan-11 sam7se512/256/32 txrdy used in slave mode : 0 = as soon as data is written in the twi_thr, until this data has been transmitted and acknowledged (ack or nack). 1 = it indicates that the twi_thr is empty and that data has been transmitted and acknowledged. if txrdy is high and if a nack has been detected, the tr ansmission will be stopped. thus when trdy = nack = 1, the programmer must not fill tw i_thr to avoid losing it. txrdy behavior in slave mode can be seen in figure 32-24 on page 369 , figure 32-27 on page 371 , figure 32-29 on page 373 and figure 32-30 on page 373 . ? svread: slave read (automatically set / reset) this bit is only used in slave mode. when svacc is low (no slave access has been detected) svread is irrelevant. 0 = indicates that a write access is performed by a master. 1 = indicates that a read access is performed by a master. svread behavior can be seen in figure 32-24 on page 369 , figure 32-25 on page 369 , figure 32-29 on page 373 and figure 32-30 on page 373 . ? svacc: slave access (automatically set / reset) this bit is only used in slave mode. 0 = twi is not addressed. svacc is automatically cleared af ter a nack or a stop condition is detected. 1 = indicates that the address decoding sequence has matched (a master has sent sadr). svacc remains high until a nack or a stop condition is detected. svacc behavior can be seen in figure 32-24 on page 369 , figure 32-25 on page 369 , figure 32-29 on page 373 and fig- ure 32-30 on page 373 . ? gacc: general call access (clear on read) this bit is only used in slave mode. 0 = no general call has been detected. 1 = a general call has been detected. after the detection of general call, the programmer decoded the commands that fol- low and the programming sequence. gacc behavior can be seen in figure 32-26 on page 370 . ? ovre: overrun error (clear on read) this bit is only used in master mode. 0 = twi_rhr has not been loaded while rxrdy was set 1 = twi_rhr has been loaded while rxrdy was set. reset by read in twi_sr when txcomp is set. ? nack: not acknowledged (clear on read) nack used in master mode : 0 = each data byte has been correctly received by the far-end side twi slave component. 1 = a data byte has not been acknowledged by the sl ave component. set at the same time as txcomp.
384 6222f?atarm?14-jan-11 sam7se512/256/32 nack used in slave read mode : 0 = each data byte has been correctly received by the master. 1 = in read mode, a data byte has not be en acknowledged by the master. when na ck is set the programmer must not fill twi_thr even if txrdy is set, because it means that the master will stop the data transfer or re initiate it. note that in slave write mode all data is acknowledged by the twi. ? arblst: arbitration lost (clear on read) this bit is only used in master mode. 0: arbitration won. 1: arbitration lost. another master of the twi bus has won the multi-master arbitration. txcomp is set at the same time. ? sclws: clock wait state (automatically set / reset) this bit is only used in slave mode. 0 = the clock is not stretched. 1 = the clock is stretched. twi_thr / tw i_rhr buffer is not filled / emptied bef ore the emission / reception of a new character. sclws behavior can be seen in figure 32-27 on page 371 and figure 32-28 on page 372 . ? eosacc: end of slave access (clear on read) this bit is only used in slave mode. 0 = a slave access is being performing. 1 = the slave access is finished. end of slave access is automatically set as soon as svacc is reset. eosacc behavior can be seen in figure 32-29 on page 373 and figure 32-30 on page 373
385 6222f?atarm?14-jan-11 sam7se512/256/32 32.10.7 twi interrupt enable register name: twi_ier access: write-only reset value: 0x00000000 ? txcomp: transmission completed interrupt enable ? rxrdy: receive holding register ready interrupt enable ? txrdy: transmit holding register ready interrupt enable ? svacc: slave access interrupt enable ? gacc: general call access interrupt enable ? ovre: overrun error interrupt enable ? nack: not acknowledge interrupt enable ? arblst: arbitration lost interrupt enable ? scl_ws: clock wait state interrupt enable ? eosacc: end of slave access interrupt enable 0 = no effect. 1 = enables the corresponding interrupt. 31 30 29 28 27 26 25 24 ???????? 23 22 21 20 19 18 17 16 ???????? 15 14 13 12 11 10 9 8 eosacc scl_ws arblst nack 76543210 ? ovre gacc svacc ? txrdy rxrdy txcomp
386 6222f?atarm?14-jan-11 sam7se512/256/32 32.10.8 twi interrupt disable register name: twi_idr access: write-only reset value: 0x00000000 ? txcomp: transmission completed interrupt disable ? rxrdy: receive holding regi ster ready interrupt disable ? txrdy: transmit holding register ready interrupt disable ? svacc: slave access interrupt disable ? gacc: general call access interrupt disable ? ovre: overrun error interrupt disable ? nack: not acknowledge interrupt disable ? arblst: arbitration lost interrupt disable ? scl_ws: clock wait state interrupt disable ? eosacc: end of slave access interrupt disable 0 = no effect. 1 = disables the corresponding interrupt. 31 30 29 28 27 26 25 24 ???????? 23 22 21 20 19 18 17 16 ???????? 15 14 13 12 11 10 9 8 eosacc scl_ws arblst nack 76543210 ? ovre gacc svacc ? txrdy rxrdy txcomp
387 6222f?atarm?14-jan-11 sam7se512/256/32 32.10.9 twi interrupt mask register name: twi_imr access: read-only reset value: 0x00000000 ? txcomp: transmission completed interrupt mask ? rxrdy: receive holding regi ster ready interrupt mask ? txrdy: transmit holding register ready interrupt mask ? svacc: slave access interrupt mask ? gacc: general call access interrupt mask ? ovre: overrun error interrupt mask ? nack: not acknowledge interrupt mask ? arblst: arbitration lost interrupt mask ? scl_ws: clock wait state interrupt mask ? eosacc: end of slave access interrupt mask 0 = the corresponding interrupt is disabled. 1 = the corresponding interrupt is enabled. 31 30 29 28 27 26 25 24 ???????? 23 22 21 20 19 18 17 16 ???????? 15 14 13 12 11 10 9 8 eosacc scl_ws arblst nack 76543210 ? ovre gacc svacc ? txrdy rxrdy txcomp
388 6222f?atarm?14-jan-11 sam7se512/256/32 32.10.10 twi receive holding register name: twi_rhr access: read-only reset value: 0x00000000 ? rxdata: master or slave receive holding data 32.10.11 twi transmit holding register name: twi_thr access: read-write reset value: 0x00000000 ? txdata: master or slave transmit holding data 31 30 29 28 27 26 25 24 ???????? 23 22 21 20 19 18 17 16 ???????? 15 14 13 12 11 10 9 8 ???????? 76543210 rxdata 31 30 29 28 27 26 25 24 ???????? 23 22 21 20 19 18 17 16 ???????? 15 14 13 12 11 10 9 8 ???????? 76543210 txdata
389 6222f?atarm?14-jan-11 sam7se512/256/32 33. universal synchronous asynchrono us receiver transceiver (usart) 33.1 overview the universal synchronous asynchronous rece iver transceiver (usart) provides one full duplex universal synchronous asynchronous serial link. data frame format is widely programma- ble (data length, parity, number of stop bits) to support a maximum of standards. the receiver implements parity error, framing error and overrun error detection. the receiver time-out enables handling variable-length frames and the transmitter timeguard facilitates communications with slow remote devices. multidrop communications are also supported through address bit han- dling in reception and transmission. the usart features three test modes: remote loopback, local loopback and automatic echo. the usart supports specific operating modes providing interfaces on rs485 buses, with iso7816 t = 0 or t = 1 smart card slots, infrared transceivers and connection to modem ports. the hardware handshaking feature enables an out-of-band flow control by automatic manage- ment of the pins rts and cts. the usart supports the connection to the peripheral dma controller, which enables data transfers to the transmitter and from the receiver. the pdc provides chained buffer manage- ment without any intervention of the processor.
390 6222f?atarm?14-jan-11 sam7se512/256/32 33.2 block diagram figure 33-1. usart block diagram peripheral dma controller channel channel aic receiver usart interrupt rxd txd sck usart pio controller cts rts dtr dsr dcd ri transmitter modem signals control baud rate generator user interface pmc mck slck div mck/div apb
391 6222f?atarm?14-jan-11 sam7se512/256/32 33.3 application block diagram figure 33-2. application block diagram 33.4 i/o lines description table 33-1. i/o line description name description type active level sck serial clock i/o txd transmit serial data i/o rxd receive serial data input ri ring indicator input low dsr data set ready input low dcd data carrier detect input low dtr data terminal ready output low cts clear to send input low rts request to send output low smart card slot usart rs232 drivers modem rs485 drivers differential bus irda transceivers modem driver field bus driver emv driver irda driver irlap rs232 drivers serial port serial driver ppp pstn
392 6222f?atarm?14-jan-11 sam7se512/256/32 33.5 product dependencies 33.5.1 i/o lines the pins used for interfacing the usart may be multiplexed with the pio lines. the program- mer must first program the pio controller to assign the desired usart pins to their peripheral function. if i/o lines of the usart are not used by the application, they can be used for other purposes by the pio controller. to prevent the txd line from falling when the usart is disa bled, the use of an internal pull up is mandatory. all the pins of the modems may or may not be implemented on the usart. only usart1 is fully equipped with all the modem signals. on usarts not equipped with the corresponding pin, the associated control bits and statuses have no effect on the behavior of the usart. 33.5.2 power management the usart is not continuously clocked. the prog rammer must first enable the usart clock in the power management controller (pmc) before usin g the usart. however, if the application does not require usart operations, the usart clock can be stopped when not needed and be restarted later. in this case, the usart will resume its operations where it left off. configuring the usart does not require the usart clock to be enabled. 33.5.3 interrupt the usart interrupt line is connected on one of the internal sources of the advanced interrupt controller. using the usart interrup t requires the aic to be programmed first. note that it is not recommended to use the usart interrupt line in edge sensitive mode.
393 6222f?atarm?14-jan-11 sam7se512/256/32 33.6 functional description the usart is capable of managing several ty pes of serial synchronous or asynchronous communications. it supports the following communication modes: ? 5- to 9-bit full-duplex asynchronous serial communication ? msb- or lsb-first ? 1, 1.5 or 2 stop bits ? parity even, odd, marked, space or none ? by 8 or by 16 over-sampling receiver frequency ? optional hardware handshaking ? optional modem signals management ? optional break management ? optional multidrop serial communication ? high-speed 5- to 9-bit full-duplex synchronous serial communication ? msb- or lsb-first ? 1 or 2 stop bits ? parity even, odd, marked, space or none ? by 8 or by 16 over-sampling frequency ? optional hardware handshaking ? optional modem signals management ? optional break management ? optional multidrop serial communication ? rs485 with driver control signal ? iso7816, t0 or t1 protocols for interfacing with smart cards ? nack handling, error counter with repetition and iteration limit ? infrared irda modulation and demodulation ? test modes ? remote loopback, local loopback, automatic echo 33.6.1 baud rate generator the baud rate generator provides the bit period clock named the baud rate clock to both the receiver and the transmitter. the baud rate generator clock source can be selected by setting the usclks field in the mode register (us_mr) between: ? the master clock mck ? a division of the master clock, the divider being product dependent, but generally set to 8 ? the external clock, available on the sck pin the baud rate generator is based upon a 16-bit divider, which is programmed with the cd field of the baud rate generator register (us_brgr). if cd is programmed at 0, the baud rate generator does not generate any clock. if cd is programmed at 1, the divider is bypassed and becomes inactive.
394 6222f?atarm?14-jan-11 sam7se512/256/32 if the external sck clock is selected, the duration of the low and high levels of the signal pro- vided on the sck pin must be longer than a master clock (mck) period. the frequency of the signal provided on sck must be at least 4.5 times lower than mck. figure 33-3. baud rate generator 33.6.1.1 baud rate in asynchronous mode if the usart is programmed to operate in as ynchronous mode, the selected clock is first divided by cd, which is field programmed in th e baud rate generator register (us_brgr). the resulting clock is provided to the receiver as a sampling clock and then divided by 16 or 8, depending on the programming of the over bit in us_mr. if over is set to 1, the receiver sampling is 8 times higher than the baud rate clock. if over is cleared, the sampling is performed at 16 times the baud rate clock. the following formula performs the calculation of the baud rate. this gives a maximum baud rate of mck divided by 8, assuming that mck is the highest possi- ble clock and that over is programmed at 1. mck/div 16-bit counter 0 baud rate clock cd cd sampling divider 0 1 >1 sampling clock reserved mck sck usclks over sck sync sync usclks = 3 1 0 2 3 0 1 0 1 fidi baudrate selectedclock 82 over ? () cd () -------------------------------------------- =
395 6222f?atarm?14-jan-11 sam7se512/256/32 33.6.1.2 baud rate calculation example table 33-2 shows calculations of cd to obtain a baud rate at 38400 bauds for different source clock frequencies. this table also shows the actual resulting baud rate and the error. the baud rate is calculated with the following formula: the baud rate error is calculated with the following formula. it is not recommended to work with an error higher than 5%. 33.6.1.3 fractional baud rate in asynchronous mode the baud rate generator previously defined is su bject to the following limitation: the output fre- quency changes by only integer multiples of the reference frequency. an approach to this problem is to integrate a fractional n clock generator that has a high resolution. the generator architecture is modified to obtain baud rate chan ges by a fraction of the reference source clock. this fractional part is programmed with the fp field in the baud rate generator register table 33-2. baud rate example (over = 0) source clock expected baud rate calculation result cd actual baud rate error mhz bit/s bit/s 3 686 400 38 400 6.00 6 38 400.00 0.00% 4 915 200 38 400 8.00 8 38 400.00 0.00% 5 000 000 38 400 8.14 8 39 062.50 1.70% 7 372 800 38 400 12.00 12 38 400.00 0.00% 8 000 000 38 400 13.02 13 38 461.54 0.16% 12 000 000 38 400 19.53 20 37 500.00 2.40% 12 288 000 38 400 20.00 20 38 400.00 0.00% 14 318 180 38 400 23.30 23 38 908.10 1.31% 14 745 600 38 400 24.00 24 38 400.00 0.00% 18 432 000 38 400 30.00 30 38 400.00 0.00% 24 000 000 38 400 39.06 39 38 461.54 0.16% 24 576 000 38 400 40.00 40 38 400.00 0.00% 25 000 000 38 400 40.69 40 38 109.76 0.76% 32 000 000 38 400 52.08 52 38 461.54 0.16% 32 768 000 38 400 53.33 53 38 641.51 0.63% 33 000 000 38 400 53.71 54 38 194.44 0.54% 40 000 000 38 400 65.10 65 38 461.54 0.16% 50 000 000 38 400 81.38 81 38 580.25 0.47% 60 000 000 38 400 97.66 98 38 265.31 0.35% 70 000 000 38 400 113.93 114 38 377.19 0.06% baudrate mck cd 16 ? = error 1 expectedbaudrate actualbaudrate -------------------------------------------------- - ?? ?? ? =
396 6222f?atarm?14-jan-11 sam7se512/256/32 (us_brgr). if fp is not 0, the fractional part is activated. the resolution is one eighth of the clock divider. this feature is only available when using usart normal mode. the fractional baud rate is calculated using the following formula: the modified architecture is presented below: figure 33-4. fractional baud rate generator 33.6.1.4 baud rate in synchronous mode if the usart is programmed to operate in synchronous mode, the selected clock is simply divided by the field cd in us_brgr. in synchronous mode, if the external clock is selected (usclks = 3), the clock is provided directly by the signal on the usart sck pin. no division is active. the value written in us_brgr has no effect. the external clock frequency must be at least 4.5 times lower than the system clock. when either the external clock sck or the inte rnal clock divided (mck/div) is selected, the value programmed in cd must be even if the user has to ensure a 50:50 mark/space ratio on the sck pin. if the internal clock mck is selected, the baud rate generator ensures a 50:50 duty cycle on the sck pin, even if the value programmed in cd is odd. 33.6.1.5 baud rate in iso 7816 mode the iso7816 specification defines the bit rate with the following formula: baudrate selectedclock 82 over ? () cd fp 8 ------- + ?? ?? ?? ?? ---------------------------------------------------------------- - = mck/div 16-bit counter 0 baud rate clock cd cd sampling divider 0 1 >1 sampling clock reserved mck sck usclks over sck sync sync usclks = 3 1 0 2 3 0 1 0 1 fidi glitch-free logic modulus control fp fp baudrate selectedclock cd ------------------------------------- - =
397 6222f?atarm?14-jan-11 sam7se512/256/32 where: ? b is the bit rate ? di is the bit-rate adjustment factor ? fi is the clock frequency division factor ? f is the iso7816 clock frequency (hz) di is a binary value encoded on a 4-bit field, named di, as represented in table 33-3 . fi is a binary value encoded on a 4-bi t field, named fi, as represented in table 33-4 . table 33-5 shows the resulting fi/di ratio, which is the ratio between the iso7816 clock and the baud rate clock. if the usart is configured in iso7816 mode, th e clock selected by the usclks field in the mode register (us_mr) is first divided by the va lue programmed in the field cd in the baud rate generator register (us_brgr). the resulting clock can be provided to the sck pin to feed the smart card clock inputs. this means that the clko bit can be set in us_mr. this clock is then divided by the value progra mmed in the fi_di_ratio field in the fi_di_ratio register (us_fidi). this is performed by the sampling divider, which performs a division by up to 2047 in iso7816 mode. the non-integer values of the fi/di ratio are not supported and the user must program the fi_di_ratio field to a va lue as close as possible to the expected value. the fi_di_ratio field resets to the value 0x174 (372 in decimal) and is the most common divider between the iso7816 clock and the bit rate (fi = 372, di = 1). figure 33-5 shows the relation between the elementary time unit, corresponding to a bit time, and the iso 7816 clock. b di fi ----- - f = table 33-3. binary and decimal values for di di field 0001 0010 0011 0100 0101 0110 1000 1001 di (decimal)1 2 4 8 163212 20 table 33-4. binary and decimal values for fi fi field 0000 0001 0010 0011 0100 0101 0110 1001 1010 1011 1100 1101 fi (decimal 372 372 558 744 1116 1488 1860 512 768 1024 1536 2048 table 33-5. possible values for the fi/di ratio fi/di 372 558 774 1116 1488 1806 512 768 1024 1536 2048 1 372 558 744 1116 1488 1860 512 768 1024 1536 2048 2 186 279 372 558 744 930 256 384 512 768 1024 4 93 139.5 186 279 372 465 128 192 256 384 512 8 46.5 69.75 93 139.5 186 232.5 64 96 128 192 256 16 23.25 34.87 46.5 69.75 93 116.2 32 48 64 96 128 32 11.62 17.43 23.25 34.87 46.5 58.13 16 24 32 48 64 12 31 46.5 62 93 124 155 42.66 64 85.33 128 170.6 20 18.6 27.9 37.2 55.8 74.4 93 25.6 38.4 51.2 76.8 102.4
398 6222f?atarm?14-jan-11 sam7se512/256/32 figure 33-5. elementary time unit (etu) 33.6.2 receiver and transmitter control after reset, the receiver is disabled. the user must enable the receiver by setting the rxen bit in the control register (us_cr). however, the receiver registers can be programmed before the receiver clock is enabled. after reset, the transmitter is disabled. the user must enable it by setting the txen bit in the control register (us_cr). however, the transmitter registers can be programmed before being enabled. the receiver and the transmitter can be enabled together or independently. at any time, the software can perform a reset on the receiver or the transmitter of the usart by setting the corresponding bit, rstrx and rsttx respectively, in the control register (us_cr). the reset commands have the same effect as a hardware reset on the corresponding logic. regardless of what the receiver or t he transmitter is performing, the communication is immediately stopped. the user can also independently disable the receiv er or the transmitter by setting rxdis and txdis respectively in us_cr. if the receiver is disabled during a character reception, the usart waits until the end of reception of the current character, then the reception is stopped. if the transmitter is disabled while it is operating, the usart waits the end of transmission of both the current character and character being stored in the transmit holding register (us_thr). if a timeguard is programmed, it is handled normally. 33.6.3 synchronous and asynchronous modes 33.6.3.1 transmitter operations the transmitter performs the same in both synchronous and asynchronous operating modes (sync = 0 or sync = 1). one start bit, up to 9 da ta bits, one optional parity bit and up to two stop bits are successively shifte d out on the txd pin at each falling edge of the programmed serial clock. the number of data bits is selected by the chrl field and the mode 9 bit in the mode register (us_mr). nine bits are selected by setting the mode 9 bit regardless of the chrl field. the parity bit is set according to the par field in us_mr. the even, odd, space, marked or none parity bit can be configured. the msbf field in us _mr configures which data bit is sent first. if written at 1, the most significant bit is sent first. at 0, the less significant bit is sent first. the num- ber of stop bits is selected by the nbstop fiel d in us_mr. the 1.5 stop bit is supported in asynchronous mode only. 1 etu iso7816 clock on sck iso7816 i/o line on txd fi_di_ratio iso7816 clock cycles
399 6222f?atarm?14-jan-11 sam7se512/256/32 figure 33-6. character transmit the characters are sent by writing in the tran smit holding register (us_thr). the transmitter reports two status bits in the channel status register (us_csr): txrdy (transmitter ready), which indicates that us_thr is empty and txempty, which indicates that all the characters written in us_thr have been processed. when the current character processing is completed, the last character written in us_thr is transferred into the shift register of the transmitter and us_thr becomes empty, thus txrdy raises. both txrdy and txempty bits are low since the transmitter is disabled. writing a character in us_thr while txrdy is active has no effect and the written character is lost. figure 33-7. transmitter status 33.6.3.2 asynchronous receiver if the usart is programmed in asynchronous operating mode (sync = 0), the receiver over- samples the rxd input line. the oversampling is either 16 or 8 times the baud rate clock, depending on the over bit in the mode register (us_mr). the receiver samples the rxd line. if the line is sampled during one half of a bit time at 0, a start bit is detected and data, parity and stop bits are successively sampled on the bit rate clock. if the oversampling is 16, (over at 0), a start is detected at the eighth sample at 0. then, data bits, parity bit and stop bit are sampled on each 16 sampling clock cycle. if the oversampling is 8 (over at 1), a start bit is detected at the fourth sample at 0. then, data bits, parity bit and stop bit are sampled on each 8 sampling clock cycle. the number of data bits, first bit sent and parity mode are selected by the same fields and bits as the transmitter, i.e. respectively chrl , mode9, msbf and par. for the synchronization mechanism only , the number of stop bits has no effect on the receiver as it considers only one stop bit, regardless of the field nbstop, so that resynchronization between the receiver and the d0 d1 d2 d3 d4 d5 d6 d7 txd start bit parity bit stop bit example: 8-bit, parity enabled one stop baud rate clock d0 d1 d2 d3 d4 d5 d6 d7 txd start bit parity bit stop bit baud rate clock start bit write us_thr d0 d1 d2 d3 d4 d5 d6 d7 parity bit stop bit txrdy txempty
400 6222f?atarm?14-jan-11 sam7se512/256/32 transmitter can occur. moreover, as soon as the st op bit is sampled, the receiver starts looking for a new start bit so that resynchronization can also be accomplished when the transmitter is operating with one stop bit. figure 33-8 and figure 33-9 illustrate start detection and character reception when usart operates in asynchronous mode. figure 33-8. asynchronous start detection figure 33-9. asynchronous character reception 33.6.3.3 synchronous receiver in synchronous mode (sync = 1), the receiver samples the rxd signal on each rising edge of the baud rate clock. if a lo w level is detected, it is considered as a start. all data bits, the parity bit and the stop bits are sampled and the receiver waits for the next start bit. synchronous mode operations provide a high speed transfer capability. configuration fields and bits are the same as in asynchronous mode. figure 33-10 illustrates a character rec eption in synchronous mode. sampling clock (x16) rxd start detection sampling baud rate clock rxd start rejection sampling 12345678 12345670 1234 12345678 9 10111213141516 d0 sampling d0 d1 d2 d3 d4 d5 d6 d7 rxd parity bit stop bit example: 8-bit, parity enabled baud rate clock start detection 16 samples 16 samples 16 samples 16 samples 16 samples 16 samples 16 samples 16 samples 16 samples 16 samples
401 6222f?atarm?14-jan-11 sam7se512/256/32 figure 33-10. synchronous mode character reception 33.6.3.4 receiver operations when a character reception is completed, it is transferred to the receive holding register (us_rhr) and the rxrdy bit in the status regist er (us_csr) rises. if a character is com- pleted while the rxrdy is set, the ovre (ove rrun error) bit is set. the last character is transferred into us_rhr and overwrites the previous one. the ovre bit is cleared by writing the control register (us_cr) with the rststa (reset status) bit at 1. figure 33-11. receiver status d0 d1 d2 d3 d4 d5 d6 d7 rxd start sampling parity bit stop bit example: 8-bit, parity enabled 1 stop baud rate clock d0 d1 d2 d3 d4 d5 d6 d7 rxd start bit parity bit stop bit baud rate clock write us_cr rxrdy ovre d0 d1 d2 d3 d4 d5 d6 d7 start bit parity bit stop bit rststa = 1 read us_rhr
402 6222f?atarm?14-jan-11 sam7se512/256/32 33.6.3.5 parity the usart supports five parity modes selected by programming the par field in the mode register (us_mr). the par field also enables the multidrop mode, see ?multidrop mode? on page 403 . even and odd parity bit generation and error detection are supported. if even parity is selected, the parity generator of the transmitter drives the parity bit at 0 if a num- ber of 1s in the character data bit is even, and at 1 if the number of 1s is odd. accordingly, the receiver parity checker counts the number of received 1s and reports a parity error if the sam- pled parity bit does not correspond. if odd parity is selected, the parity generator of the transmitter drives the parity bit at 1 if a number of 1s in the character data bit is even, and at 0 if the number of 1s is odd. accordingly, the receiver parity checker counts the number of received 1s and reports a parity error if the sampled parity bit does not correspond. if the mark parity is used, the parity generator of the transmitter drives the parity bit at 1 for all characters. the receiver parity checker reports an error if the parity bit is sampled at 0. if the space parity is used, the parity generator of the transmitter drives the parity bit at 0 for all characters. the receiver parity checker reports an error if the parity bit is sampled at 1. if parity is disabled, the transmitter does not generate any parity bit and the receiver does not report any parity error. table 33-6 shows an example of the parity bit for the character 0x41 (character ascii ?a?) depending on the configuration of the usart. because there are two bits at 1, 1 bit is added when a parity is odd, or 0 is added when a parity is even. when the receiver detects a parity error, it sets the pare (parity error) bit in the channel status register (us_csr). the pare bit can be cleared by writing the control register (us_cr) with the rststa bit at 1. figure 33-12 illustrates the parity bit status setting and clearing. table 33-6. parity bit examples character hexa binary parity bit parity mode a 0x41 0100 0001 1 odd a 0x41 0100 0001 0 even a 0x41 0100 0001 1 mark a 0x41 0100 0001 0 space a 0x41 0100 0001 none none
403 6222f?atarm?14-jan-11 sam7se512/256/32 figure 33-12. parity error 33.6.3.6 multidrop mode if the par field in the mode register (us_mr) is programmed to the value 0x6 or 0x07, the usart runs in multidrop mode. this mode differentiates the data characters and the address characters. data is transmitted with the parity bit at 0 and addresses are transmitted with the parity bit at 1. if the usart is configured in multidrop mode, the receiver sets the pare parity error bit when the parity bit is high and the transmitter is able to send a character with the parity bit high when the control register is written with the senda bit at 1. to handle parity error, the pare bit is cleared when the control register is written with the bit rststa at 1. the transmitter sends an address byte (parity bit set) when senda is written to us_cr. in this case, the next byte written to us_thr is transmi tted as an address. any character written in us_thr without having written t he command senda is transmitted normally with the parity at 0. 33.6.3.7 transmitter timeguard the timeguard feature enables the usar t interface with slow remote devices. the timeguard function enables the transmitter to insert an idle state on the txd line between two characters. this idle state actually acts as a long stop bit. the duration of the idle state is programmed in the tg field of the transmitter timeguard regis- ter (us_ttgr). when this field is programmed at zero no timeguard is generated. otherwise, the transmitter holds a high level on txd after each transmitted byte during the number of bit periods programmed in tg in addition to the number of stop bits. as illustrated in figure 33-13 , the behavior of txrdy and txempty status bits is modified by the programming of a timeguard. txrdy rises only when the start bit of the next character is sent, and thus remains at 0 during the timeguard transmission if a character has been written in us_thr. txempty remains low until the timeguard transmission is completed as the time- guard is part of the current character being transmitted. d0 d1 d2 d3 d4 d5 d6 d7 rxd start bit bad parity bit stop bit baud rate clock write us_cr pare rxrdy rststa = 1
404 6222f?atarm?14-jan-11 sam7se512/256/32 figure 33-13. timeguard operations table 33-7 indicates the maximum length of a timeguard period that the transmitter can handle in relation to the function of the baud rate. 33.6.3.8 receiver time-out the receiver time-out provides support in handling variable-length frames. this feature detects an idle condition on the rxd line. when a time-out is detected, the bit timeout in the channel status register (us_csr) rises and can generate an interrupt, thus indicating to the driver an end of frame. the time-out delay period (during which the receiver waits for a new character) is programmed in the to field of the receiver time-out regist er (us_rtor). if the to field is programmed at 0, the receiver time-out is disabled and no time-out is detected. the timeout bit in us_csr remains at 0. otherwise, the receiver loads a 16-bit counter with the value programmed in to. this counter is decremented at each bit per iod and reloaded each time a new character is received. if the counter reaches 0, the timeout bit in the status register rises. then, the user can either: ? stop the counter clock until a new character is received. this is performed by writing the control register (us_cr) with the sttto (start time-out) bit at 1. in this case, the idle state d0 d1 d2 d3 d4 d5 d6 d7 txd start bit parity bit stop bit baud rate clock start bit tg = 4 write us_thr d0 d1 d2 d3 d4 d5 d6 d7 parity bit stop bit txrdy txempty tg = 4 table 33-7. maximum timeguard length depending on baud rate baud rate bit time timeguard bit/sec s ms 1 200 833 212.50 9 600 104 26.56 14400 69.4 17.71 19200 52.1 13.28 28800 34.7 8.85 33400 29.9 7.63 56000 17.9 4.55 57600 17.4 4.43 115200 8.7 2.21
405 6222f?atarm?14-jan-11 sam7se512/256/32 on rxd before a new character is received will not provide a time-out. this prevents having to handle an interrupt before a character is received and allows waiting for the next idle state on rxd after a frame is received. ? obtain an interrupt while no character is rece ived. this is performed by writing us_cr with the retto (reload and start time-out) bit at 1. if retto is performed, the counter starts counting down immediately from the value to. this enables generation of a periodic interrupt so that a user time-out can be handled, for example when no key is pressed on a keyboard. if sttto is performed, the counter clock is stopped until a first character is received. the idle state on rxd before the start of the frame does not provide a time-out. this prevents having to obtain a periodic interrupt and enables a wait of the end of frame when the idle state on rxd is detected. if retto is performed, the counter starts counting down immediately from the value to. this enables generation of a periodic interrupt so t hat a user time-out can be handled, for example when no key is pressed on a keyboard. figure 33-14 shows the block diagram of the receiver time-out feature. figure 33-14. receiver time-out block diagram table 33-8 gives the maximum time-out period for some standard baud rates. table 33-8. maximum time-out period baud rate bit time time-out bit/sec s ms 600 1 667 109 225 1 200 833 54 613 2 400 417 27 306 4 800 208 13 653 9 600 104 6 827 14400 69 4 551 19200 52 3 413 28800 35 2 276 33400 30 1 962 16-bit time-out counter 0 to timeout baud rate clock = character received retto load clock 16-bit value sttto dq 1 clear
406 6222f?atarm?14-jan-11 sam7se512/256/32 33.6.3.9 framing error the receiver is capable of detecting framing errors. a framing error happens when the stop bit of a received character is detected at level 0. this can occur if the receiver and the transmitter are fully desynchronized. a framing error is reported on the frame bit of the channel status register (us_csr). the frame bit is asserted in the middle of the stop bi t as soon as the framing error is detected. it is cleared by writing the control register (us_cr) with the rststa bit at 1. figure 33-15. framing error status 33.6.3.10 transmit break the user can request the transmitter to generate a break condition on the txd line. a break con- dition drives the txd line low during at least one complete character. it appears the same as a 0x00 character sent with the parity and the stop bits at 0. however, the transmitter holds the txd line at least during one character until the user requests the break condition to be removed. a break is transmitted by writing the control register (us_cr) with the sttbrk bit at 1. this can be performed at any time, either while the transmitter is empty (no character in either the shift register or in us_thr) or when a character is being transmitted. if a break is requested while a character is being shifted out, the charac ter is first completed before the txd line is held low. once sttbrk command is requested further sttbrk commands are ignored until the end of the break is completed. the break condition is removed by writing us_cr with the stpbrk bit at 1. if the stpbrk is requested before the end of the minimum break duration (one character, including start, data, parity and stop bits), the transmitter ensures that the break condition completes. 56000 18 1 170 57600 17 1 138 200000 5 328 table 33-8. maximum time-out period (continued) baud rate bit time time-out d0 d1 d2 d3 d4 d5 d6 d7 rxd start bit parity bit stop bit baud rate clock write us_cr frame rxrdy rststa = 1
407 6222f?atarm?14-jan-11 sam7se512/256/32 the transmitter considers the break as though it is a character, i.e. the sttbrk and stpbrk commands are taken into account only if the txrdy bit in us_csr is at 1 and the start of the break condition clears the txrdy and txempty bits as if a character is processed. writing us_cr with the both sttbrk and stpb rk bits at 1 can lead to an unpredictable result. all stpbrk commands requested without a previous sttbrk command are ignored. a byte written into the transmit holding register while a break is pending, but not started, is ignored. after the break condition, the transmitter returns the txd line to 1 for a minimum of 12 bit times. thus, the transmitter ensures that the remote receiver detects correctly the end of break and the start of the next character. if the timeguard is programmed with a value higher than 12, the txd line is held high for the timeguard period. after holding the txd line for this period, the transmitter resumes normal operations. figure 33-16 illustrates the effect of both the start break (sttbrk ) and stop break (stpbrk) commands on the txd line. figure 33-16. break transmission 33.6.3.11 receive break the receiver detects a break condition when all data, parity and stop bits are low. this corre- sponds to detecting a framing error with data at 0x00, but frame remains low. when the low stop bit is detected, the receiver asserts the rxbrk bit in us_csr. this bit may be cleared by writing the control regi ster (us_cr) with the bit rststa at 1. an end of receive break is detected by a high leve l for at least 2/16 of a bit period in asynchro- nous operating mode or one sample at high level in synchronous operating mode. the end of break detection also asserts the rxbrk bit. 33.6.3.12 hardware handshaking the usart features a hardware handshaking out-of-band flow control. the rts and cts pins are used to connect with the remote device, as shown in figure 33-17 . d0 d1 d2 d3 d4 d5 d6 d7 txd start bit parity bit stop bit baud rate clock write us_cr txrdy txempty stpbrk = 1 sttbrk = 1 break transmission end of break
408 6222f?atarm?14-jan-11 sam7se512/256/32 figure 33-17. connection with a remote device for hardware handshaking setting the usart to operate with hardware handshaking is performed by writing the usart_mode field in the mode register (us_mr) to the value 0x2. the usart behavior when hardware handshaking is enabled is the same as the behavior in standard synchronous or asynchronous mode, except that the receiver drives the rts pin as described below and the level on the cts pin modifies the behavior of the transmitter as described below. using this mode requires usin g the pdc channel for reception. the transmitter can handle hardware handshaking in any case. figure 33-18 shows how the receiver operates if hardware handshaking is enabled. the rts pin is driven high if the receiver is disabled and if the status rxbuff (receive buffer full) com- ing from the pdc channel is high. normally, the remote device does not start transmitting while its cts pin (driven by rts) is high. as soon as the receiver is enabled, the rts falls, indicating to the remote device that it can start transmitt ing. defining a new buffer to the pdc clears the status bit rxbuff and, as a result, asserts the pin rts low. figure 33-18. receiver behavior when operating with hardware handshaking figure 33-19 shows how the transmitter operates if hardware handshaking is enabled. the cts pin disables the transmitt er. if a character is being processi ng, the transmitter is disabled only after the completion of the current character and transmission of the next character happens as soon as the pin cts falls. figure 33-19. transmitter behavior when operating with hardware handshaking usart txd cts remote device rxd txd rxd rts rts cts rts rxbuff write us_cr rxen = 1 rxd rxdis = 1 cts txd
409 6222f?atarm?14-jan-11 sam7se512/256/32 33.6.4 iso7816 mode the usart features an iso7816-compatible operating mode. this mode permits interfacing with smart cards and security access modules (sam) communicating through an iso7816 link. both t = 0 and t = 1 protocols defined by the iso7816 specification are supported. setting the usart in iso7816 mode is performed by writing the usart_mode field in the mode register (us_mr) to the value 0x4 for protoc ol t = 0 and to the value 0x5 for protocol t = 1. 33.6.4.1 iso7816 mode overview the iso7816 is a half duplex communication on only one bidirectional line. the baud rate is determined by a division of the clo ck provided to the remote device (see ?baud rate generator? on page 393 ). the usart connects to a smart card as shown in figure 33-20 . the txd line becomes bidirec- tional and the baud rate generator feeds the iso7816 clock on the sck pin. as the txd pin becomes bidirectional, its output remains driven by the output of the transmitter but only when the transmitter is active while its input is direct ed to the input of the receiver. the usart is con- sidered as the master of the communication as it generates the clock. figure 33-20. connection of a smart card to the usart when operating in iso7816, either in t = 0 or t = 1 modes, the character format is fixed. the configuration is 8 data bits, ev en parity and 1 or 2 stop bits, regardless of the values pro- grammed in the chrl, mode9, par and chmode fields. msbf can be used to transmit lsb or msb first. parity bit (par) can be used to transmit in normal or inverse mode. refer to ?usart mode register? on page 421 and ?par: parity type? on page 422 . the usart cannot operate concurrently in both receiver and transmitter modes as the commu- nication is unidirectional at a time. it has to be configured according to the required mode by enabling or disabling either the receiver or the transmitter as desired. enabling both the receiver and the transmitter at the same time in iso7816 mode may lead to unpredictable results. the iso7816 specification defines an inverse transmission format. data bits of the character must be transmitted on the i/o line at their negative value. the usart does not support this for- mat and the user has to perform an exclusive or on the data before writing it in the transmit holding register (us_thr) or after reading it in the receive holding register (us_rhr). 33.6.4.2 protocol t = 0 in t = 0 protocol, a character is made up of one start bit, eight data bits, one parity bit and one guard time, which lasts two bit times. the transmitter shifts out the bits and does not drive the i/o line during the guard time. if no parity error is detected, the i/o line remains at 1 during the guard time and the transmitter can continue with the transmission of the next character, as shown in figure 33-21 . smart card sck clk txd i/o usart
410 6222f?atarm?14-jan-11 sam7se512/256/32 if a parity error is detected by the receiver, it drives the i/o line at 0 during the guard time, as shown in figure 33-22 . this error bit is also named nack, for non acknowledge. in this case, the character lasts 1 bit time more, as the guard time length is the same and is added to the error bit time which lasts 1 bit time. when the usart is the receiver and it detects an error, it does not load the erroneous character in the receive holding register (us_rhr). it appropriately sets the pare bit in the status reg- ister (us_sr) so that the software can handle the error. figure 33-21. t = 0 protocol without parity error figure 33-22. t = 0 protocol with parity error 33.6.4.3 receive error counter the usart receiver also records the total number of errors. this can be read in the number of error (us_ner) register. the nb _errors field can record up to 255 errors. reading us_ner automatically clears the nb_errors field. 33.6.4.4 receive nack inhibit the usart can also be configured to inhibit an error. this can be achieved by setting the inack bit in the mode register (us_mr). if inack is at 1, no error signal is driven on the i/o line even if a parity bit is detected, but the inac k bit is set in the status register (us_sr). the inack bit can be cleared by writing the control register (us_cr) with the rstnack bit at 1. moreover, if inack is set, the erroneous receiv ed character is stored in the receive holding register, as if no error occurred. however, the rxrdy bit does not raise. 33.6.4.5 transmit character repetition when the usart is transmitting a character and gets a nack, it can automatically repeat the character before moving on to the next one. repetition is enabled by writing the max_iteration field in the mode register (us_mr) at a value higher than 0. each character can be transmitted up to eight times; the first transmission plus seven repetitions. if max_iteration does not equal zero, the usar t repeats the character as many times as the value loaded in max_iteration. d0 d1 d2 d3 d4 d5 d6 d7 rxd parity bit baud rate clock start bit guard time 1 next start bit guard time 2 d0 d1 d2 d3 d4 d5 d6 d7 i/o parity bit baud rate clock start bit guard time 1 start bit guard time 2 d0 d1 error repetition
411 6222f?atarm?14-jan-11 sam7se512/256/32 when the usart repetition number reaches max_iteration, the iteration bit is set in the channel status register (us_csr). if the repetition of the character is acknowledged by the receiver, the repetitions are stopped and the iteration counter is cleared. the iteration bit in us_csr can be cleared by writing the control register with the rsit bit at 1. 33.6.4.6 disable successive receive nack the receiver can limit the number of successive nacks sent back to the remote transmitter. this is programmed by setting the bit dsnack in the mode register (us_mr). the maximum number of nack transmitted is programmed in the max_iteration field. as soon as max_iteration is reached, the character is cons idered as correct, an acknowledge is sent on the line and the iteration bit in the channel status register is set. 33.6.4.7 protocol t = 1 when operating in iso7816 protocol t = 1, the transmission is similar to an asynchronous for- mat with only one stop bit. the parity is generated when transmitting and checked when receiving. parity error detection sets the pare bit in the channel status register (us_csr). 33.6.5 irda mode the usart features an irda mode supplying half-duplex point-to-point wireless communica- tion. it embeds the modulator and demodulator which allows a glueless connection to the infrared transceivers, as shown in figure 33-23 . the modulator and demodulator are compliant with the irda specification version 1.1 and support data transfer speeds ranging from 2.4 kb/s to 115.2 kb/s. the usart irda mode is enabled by setting t he usart_mode field in the mode register (us_mr) to the value 0x8. the irda filter register (us_if) allows configuring the demodulator filter. the usart transmitter and receiver operate in a normal asynchronous mode and all parameters are accessible. note that the modulator and the demodulator are activated. figure 33-23. connection to irda transceivers the receiver and the transmitter must be enabled or disabled according to the direction of the transmission to be managed. irda transceivers rxd rx txd tx usart demodulator modulator receiver transmitter
412 6222f?atarm?14-jan-11 sam7se512/256/32 33.6.5.1 irda modulation for baud rates up to and including 115.2 kbits/sec, the rzi modulation scheme is used. ?0? is represented by a light pulse of 3/16th of a bit time. some examples of signal pulse duration are shown in table 33-9 . figure 33-24 shows an example of character transmission. figure 33-24. irda modulation 33.6.5.2 irda baud rate table 33-10 gives some examples of cd values, baud rate error and pulse duration. note that the requirement on the maximum acceptable error of 1.87% must be met. table 33-9. irda pulse duration baud rate pulse duration (3/16) 2.4 kb/s 78.13 s 9.6 kb/s 19.53 s 19.2 kb/s 9.77 s 38.4 kb/s 4.88 s 57.6 kb/s 3.26 s 115.2 kb/s 1.63 s bit period bit period 3 16 start bit data bits stop bit 0 0 0 0 0 1 1 1 1 1 transmitter output txd table 33-10. irda baud rate error peripheral clock baud rate cd baud rate error pulse time 3 686 400 115 200 2 0.00% 1.63 20 000 000 115 200 11 1.38% 1.63 32 768 000 115 200 18 1.25% 1.63 40 000 000 115 200 22 1.38% 1.63 3 686 400 57 600 4 0.00% 3.26 20 000 000 57 600 22 1.38% 3.26 32 768 000 57 600 36 1.25% 3.26 40 000 000 57 600 43 0.93% 3.26 3 686 400 38 400 6 0.00% 4.88 20 000 000 38 400 33 1.38% 4.88
413 6222f?atarm?14-jan-11 sam7se512/256/32 33.6.5.3 irda demodulator the demodulator is based on the ir da receive filter comprised of an 8-bit down counter which is loaded with the value programmed in us_if. when a falling edge is detected on the rxd pin, the filter counter starts counting down at the master clock (mck) speed. if a rising edge is detected on the rxd pin, the counter stops and is reloaded with us_if. if no rising edge is detected when the counter reaches 0, the input of the receiver is driven low during one bit time. figure 33-25 illustrates the operations of the irda demodulator. figure 33-25. irda demodulator operations as the irda mode uses the same logic as the iso7816, note that the fi_di_ratio field in us_fidi must be set to a value higher than 0 in order to assure irda communications operate correctly. 32 768 000 38 400 53 0.63% 4.88 40 000 000 38 400 65 0.16% 4.88 3 686 400 19 200 12 0.00% 9.77 20 000 000 19 200 65 0.16% 9.77 32 768 000 19 200 107 0.31% 9.77 40 000 000 19 200 130 0.16% 9.77 3 686 400 9 600 24 0.00% 19.53 20 000 000 9 600 130 0.16% 19.53 32 768 000 9 600 213 0.16% 19.53 40 000 000 9 600 260 0.16% 19.53 3 686 400 2 400 96 0.00% 78.13 20 000 000 2 400 521 0.03% 78.13 32 768 000 2 400 853 0.04% 78.13 table 33-10. irda baud rate error (continued) peripheral clock baud rate cd baud rate error pulse time mck rxd receiver input pulse rejected 65432 6 1 65432 0 pulse accepted counter value
414 6222f?atarm?14-jan-11 sam7se512/256/32 33.6.6 rs485 mode the usart features the rs485 mode to enable li ne driver control. while operating in rs485 mode, the usart behaves as though in asynch ronous or synchronous mode and configuration of all the parameters is possible. the differenc e is that the rts pin is driven high when the transmitter is operating. the behavior of the rts pin is controlled by the txempty bit. a typical connection of the usart to a rs485 bus is shown in figure 33-26 . figure 33-26. typical connection to a rs485 bus the usart is set in rs485 mode by programming the usart_mode field in the mode regis- ter (us_mr) to the value 0x1. the rts pin is at a level inverse to the txempt y bit. significantly, the rts pin remains high when a timeguard is programmed so that the line can remain driven after the last character com- pletion. figure 33-27 gives an example of the rts waveform during a character transmission when the timeguard is enabled. figure 33-27. example of rts drive with timeguard usart rts txd rxd differential bus d0 d1 d2 d3 d4 d5 d6 d7 txd start bit parity bit stop bit baud rate clock tg = 4 write us_thr txrdy txempty rts
415 6222f?atarm?14-jan-11 sam7se512/256/32 33.6.7 modem mode the usart features modem mode, which enables control of the signals: dtr (data terminal ready), dsr (data set ready), rts (request to send), cts (clear to send), dcd (data car- rier detect) and ri (ring indicator). while operating in modem mode, the usart behaves as a dte (data terminal equipment) as it drives dtr and rts and can detect level change on dsr, dcd, cts and ri. setting the usart in modem mode is performed by writing the usart_mode field in the mode register (us_mr) to the value 0x3. while operating in modem mode the usart behaves as though in asynchronous mode and all the parameter configurations are available. table 33-11 gives the correspondence of the usart signals with modem connection standards. the control of the dtr output pin is performed by writing the control register (us_cr) with the dtrdis and dtren bits respectively at 1. th e disable command forces the corresponding pin to its inactive level, i.e. high. the enable co mmand forces the corresponding pin to its active level, i.e. low. rts ou tput pin is automatically controlled in this mode the level changes are detected on the ri, dsr, dcd and cts pins. if an input change is detected, the riic, dsric, dcdic and ctsic bits in the channel status register (us_csr) are set respectively and can trigger an interrupt. the status is automatically cleared when us_csr is read. furthermore, the cts automatically disables the transmitter when it is detected at its inactive state. if a character is being transmitted when the cts rises, the charac- ter transmission is completed before the transmitter is actually disabled. 33.6.8 test modes the usart can be programmed to operate in three different test modes. the internal loopback capability allows on-boar d diagnostics. in the loopback mode the usart interface pins are dis- connected or not and reconfigured for loopback internally or externally. 33.6.8.1 normal mode normal mode connects the rxd pin on the receiver input and the transmitter output on the txd pin. table 33-11. circuit references usart pin v24 ccitt direction txd 2 103 from terminal to modem rts 4 105 from terminal to modem dtr 20 108.2 from terminal to modem rxd 3 104 from modem to terminal cts 5 106 from terminal to modem dsr 6 107 from terminal to modem dcd 8 109 from terminal to modem ri 22 125 from terminal to modem
416 6222f?atarm?14-jan-11 sam7se512/256/32 figure 33-28. normal mode configuration 33.6.8.2 automatic echo mode automatic echo mode allows bit-by-bit retransmission. when a bit is received on the rxd pin, it is sent to the txd pin, as shown in figure 33-29 . programming the transmitter has no effect on the txd pin. the rxd pin is still connected to the receiver input, thus the receiver remains active. figure 33-29. automatic echo mode configuration 33.6.8.3 local loopback mode local loopback mode c onnects the output of the transmitter directly to the input of the receiver, as shown in figure 33-30 . the txd and rxd pins are not used. the rxd pin has no effect on the receiver and the txd pin is continuously driven high, as in idle state. figure 33-30. local loopback mode configuration 33.6.8.4 remote loopback mode remote loopback mode directly connects the rxd pin to the txd pin, as shown in figure 33-31 . the transmitter and the receiver are disabled and have no effect. this mode allows bit-by-bit retransmission. receiver transmitter rxd txd receiver transmitter rxd txd receiver transmitter rxd txd 1
417 6222f?atarm?14-jan-11 sam7se512/256/32 figure 33-31. remote loopback mode configuration receiver transmitter rxd txd 1
418 6222f?atarm?14-jan-11 sam7se512/256/32 33.7 usart user interface table 33-12. usart memory map offset register name access reset state 0x0000 control register us_cr write-only ? 0x0004 mode register us_mr read/write ? 0x0008 interrupt enable register us_ier write-only ? 0x000c interrupt disable register us_idr write-only ? 0x0010 interrupt mask register us_imr read-only 0x0 0x0014 channel status register us_csr read-only ? 0x0018 receiver holding register us_rhr read-only 0x0 0x001c transmitter holding register us_thr write-only ? 0x0020 baud rate generator register us_brgr read/write 0x0 0x0024 receiver time-out register us_rtor read/write 0x0 0x0028 transmitter timeguard register us_ttgr read/write 0x0 0x2c - 0x3c reserved ? ? ? 0x0040 fi di ratio register us_fidi read/write 0x174 0x0044 number of errors register us_ner read-only ? 0x0048 reserved ? ? ? 0x004c irda filter register us_if read/write 0x0 0x5c - 0xfc reserved ? ? ? 0x100 - 0x128 reserved for pdc registers ? ? ?
419 6222f?atarm?14-jan-11 sam7se512/256/32 33.7.1 usart control register name: us_cr access: write-only ? rstrx: reset receiver 0: no effect. 1: resets the receiver. ? rsttx: reset transmitter 0: no effect. 1: resets the transmitter. ? rxen: receiver enable 0: no effect. 1: enables the receiver, if rxdis is 0. ? rxdis: receiver disable 0: no effect. 1: disables the receiver. ? txen: transmitter enable 0: no effect. 1: enables the transmitter if txdis is 0. ? txdis: transmitter disable 0: no effect. 1: disables the transmitter. ? rststa: reset status bits 0: no effect. 1: resets the status bits pare, frame, ovre, and rxbrk in us_csr. ? sttbrk: start break 0: no effect. 31 30 29 28 27 26 25 24 ???????? 23 22 21 20 19 18 17 16 ????rtsdisrtsendtrdisdtren 15 14 13 12 11 10 9 8 retto rstnack rstit senda sttto stpbrk sttbrk rststa 76543210 txdis txen rxdis rxen rsttx rstrx ? ?
420 6222f?atarm?14-jan-11 sam7se512/256/32 1: starts transmission of a break after the characters present in us_thr and the transmit shi ft register have been trans- mitted. no effect if a break is already being transmitted. ? stpbrk: stop break 0: no effect. 1: stops transmission of the break after a minimum of one char acter length and transmits a high level during 12-bit periods. no effect if no break is being transmitted. ? sttto: start time-out 0: no effect. 1: starts waiting for a character before clocking the time-out counter. resets the status bit timeout in us_csr. ? senda: send address 0: no effect. 1: in multidrop mode only, the next character written to the us_thr is sent with the address bit set. ? rstit: reset iterations 0: no effect. 1: resets iteration in us_csr. no e ffect if the iso7816 is not enabled. ? rstnack: reset non acknowledge 0: no effect 1: resets nack in us_csr. ? retto: rearm time-out 0: no effect 1: restart time-out ? dtren: data terminal ready enable 0: no effect. 1: drives the pin dtr at 0. ? dtrdis: data terminal ready disable 0: no effect. 1: drives the pin dtr to 1. ? rtsen: request to send enable 0: no effect. 1: drives the pin rts to 0. ? rtsdis: request to send disable 0: no effect. 1: drives the pin rts to 1.
421 6222f?atarm?14-jan-11 sam7se512/256/32 33.7.2 usart mode register name: us_mr access: read/write ? usart_mode ? usclks: clock selection ? chrl: character length. 31 30 29 28 27 26 25 24 ? ? ? filter ? max_iteration 23 22 21 20 19 18 17 16 ? ? dsnack inack over clko mode9 msbf 15 14 13 12 11 10 9 8 chmode nbstop par sync 76543210 chrl usclks usart_mode usart_mode mode of the usart 0000normal 0001rs485 0 0 1 0 hardware handshaking 0011modem 0 1 0 0 is07816 protocol: t = 0 0101reserved 0 1 1 0 is07816 protocol: t = 1 0111reserved 1000irda 11xxreserved usclks selected clock 00mck 0 1 mck/div (div = 8) 10reserved 11sck chrl character length 0 0 5 bits 0 1 6 bits 1 0 7 bits 1 1 8 bits
422 6222f?atarm?14-jan-11 sam7se512/256/32 ? sync: synchronous mode select 0: usart operates in asynchronous mode. 1: usart operates in synchronous mode. ? par: parity type ? nbstop: number of stop bits ? chmode: channel mode ? msbf: bit order 0: least significant bit is sent/received first. 1: most significant bit is sent/received first. ? mode9: 9-bit character length 0: chrl defines character length. 1: 9-bit character length. ? clko: clock output select 0: the usart does not drive the sck pin. 1: the usart drives the sck pin if usclks does not select the external clock sck. ? over: oversampling mode 0: 16x oversampling. par parity type 0 0 0 even parity 001odd parity 0 1 0 parity forced to 0 (space) 0 1 1 parity forced to 1 (mark) 1 0 x no parity 1 1 x multidrop mode nbstop asynchronous (sync = 0) synchronous (sync = 1) 0 0 1 stop bit 1 stop bit 0 1 1.5 stop bits reserved 1 0 2 stop bits 2 stop bits 1 1 reserved reserved chmode mode description 0 0 normal mode 0 1 automatic echo. receiver input is connected to the txd pin. 1 0 local loopback. transmitter output is connected to the receiver input.. 1 1 remote loopback. rxd pin is internally connected to the txd pin.
423 6222f?atarm?14-jan-11 sam7se512/256/32 1: 8x oversampling. ? inack: inhibit non acknowledge 0: the nack is generated. 1: the nack is not generated. ? dsnack: disable successive nack 0: nack is sent on the iso line as soon as a parity erro r occurs in the received character (unless inack is set). 1: successive parity errors are counted up to the value spec ified in the max_iteration field. these parity errors gener- ate a nack on the iso line. as soon as this value is reac hed, no additional nack is sent on the iso line. the flag iteration is asserted. ? max_iteration defines the maximum number of iterations in mode iso7816, protocol t= 0. ? filter: infrared receive line filter 0: the usart does not filter the receive line. 1: the usart filters the receive line using a three-sample filter (1/16-bit clock) (2 over 3 majority).
424 6222f?atarm?14-jan-11 sam7se512/256/32 33.7.3 usart interrupt enable register name: us_ier access: write-only ? rxrdy: rxrdy interrupt enable ? txrdy: txrdy interrupt enable ? rxbrk: receiver break interrupt enable ? endrx: end of receive transfer interrupt enable ? endtx: end of transmit interrupt enable ? ovre: overrun error interrupt enable ? frame: framing error interrupt enable ? pare: parity error interrupt enable ? timeout: time-out interrupt enable ? txempty: txempty interrupt enable ? iteration: iteration interrupt enable ? txbufe: buffer empty interrupt enable ? rxbuff: buffer full interrupt enable ? nack: non acknowledge interrupt enable ? riic: ring indicator input change enable ? dsric: data set ready input change enable ? dcdic: data carrier detect input change interrupt enable ? ctsic: clear to send input change interrupt enable 31 30 29 28 27 26 25 24 ???????? 23 22 21 20 19 18 17 16 ????ctsic dcdic dsric riic 15 14 13 12 11 10 9 8 ? ? nack rxbuff txbufe iteration txempty timeout 76543210 pare frame ovre endtx endrx rxbrk txrdy rxrdy
425 6222f?atarm?14-jan-11 sam7se512/256/32 33.7.4 usart interrupt disable register name: us_idr access: write-only ? rxrdy: rxrdy interrupt disable ? txrdy: txrdy interrupt disable ? rxbrk: receiver bre ak interrupt disable ? endrx: end of receive transfer interrupt disable ? endtx: end of transmit interrupt disable ? ovre: overrun error interrupt disable ? frame: framing error interrupt disable ? pare: parity error interrupt disable ? timeout: time-out interrupt disable ? txempty: txempty interrupt disable ? iteration: iteration interrupt disable ? txbufe: buffer empty interrupt disable ? rxbuff: buffer full interrupt disable ? nack: non acknowledge interrupt disable ? riic: ring indicator input change disable ? dsric: data set ready input change disable ? dcdic: data carrier detect input change interrupt disable ? ctsic: clear to send input change interrupt disable 31 30 29 28 27 26 25 24 ???????? 23 22 21 20 19 18 17 16 ????ctsic dcdic dsric riic 15 14 13 12 11 10 9 8 ? ? nack rxbuff txbufe iteration txempty timeout 76543210 pare frame ovre endtx endrx rxbrk txrdy rxrdy
426 6222f?atarm?14-jan-11 sam7se512/256/32 33.7.5 usart interrupt mask register name: us_imr access: read-only ? rxrdy: rxrdy interrupt mask ? txrdy: txrdy interrupt mask ? rxbrk: receiver break interrupt mask ? endrx: end of receive transfer interrupt mask ? endtx: end of transmit interrupt mask ? ovre: overrun error interrupt mask ? frame: framing error interrupt mask ? pare: parity error interrupt mask ? timeout: time-out interrupt mask ? txempty: txempty interrupt mask ? iteration: iteration interrupt mask ? txbufe: buffer empty interrupt mask ? rxbuff: buffer full interrupt mask ? nack: non acknowledge interrupt mask ? riic: ring indicator input change mask ? dsric: data set ready input change mask ? dcdic: data carrier detect input change interrupt mask ? ctsic: clear to send input change interrupt mask 31 30 29 28 27 26 25 24 ???????? 23 22 21 20 19 18 17 16 ????ctsic dcdic dsric riic 15 14 13 12 11 10 9 8 ? ? nack rxbuff txbufe iteration txempty timeout 76543210 pare frame ovre endtx endrx rxbrk txrdy rxrdy
427 6222f?atarm?14-jan-11 sam7se512/256/32 33.7.6 usart channel status register name: us_csr access: read-only ? rxrdy: receiver ready 0: no complete character has been received since the last read of us_rhr or the receiver is disabled. if characters were being received when the receiver was disabled, rx rdy changes to 1 when the receiver is enabled. 1: at least one complete char acter has been rece ived and us_rhr has not yet been read. ? txrdy: transmitter ready 0: a character is in the us_thr waiting to be transferred to the transmit shift register, or an sttbrk command has been requested, or the transmitter is disabled. as soon as the transmitter is enabled, txrdy becomes 1. 1: there is no char acter in the us_thr. ? rxbrk: break received/end of break 0: no break received or end of break detected since the last rststa. 1: break received or end of break detected since the last rststa. ? endrx: end of receiver transfer 0: the end of transfer signal from the receive pdc channel is inactive. 1: the end of transfer signal from the receive pdc channel is active. ? endtx: end of transmitter transfer 0: the end of transfer signal from the transmit pdc channel is inactive. 1: the end of transfer signal from the transmit pdc channel is active. ? ovre: overrun error 0: no overrun error has occurred since the last rststa. 1: at least one overrun error has occurred since the last rststa. ? frame: framing error 0: no stop bit has been detected low since the last rststa. 1: at least one stop bit has been detected low since the last rststa. 31 30 29 28 27 26 25 24 ???????? 23 22 21 20 19 18 17 16 cts dcd dsr ri ctsic dcdic dsric riic 15 14 13 12 11 10 9 8 ? ? nack rxbuff txbufe iteration txempty timeout 76543210 pare frame ovre endtx endrx rxbrk txrdy rxrdy
428 6222f?atarm?14-jan-11 sam7se512/256/32 ? pare: parity error 0: no parity error has been detected since the last rststa. 1: at least one parity error has been detected since the last rststa. ? timeout: receiver time-out 0: there has not been a time-out since t he last start time-out command (sttto in us_cr) or the time-out register is 0. 1: there has been a time-out since the last start time-out command (sttto in us_cr). ? txempty: transmitter empty 0: there are characters in either us_thr or the tr ansmit shift register, or the transmitter is disabled. 1: there are no characters in us_thr, nor in the transmit shift register. ? iteration: max number of repetitions reached 0: maximum number of repetitions has not been reached since the last rsit. 1: maximum number of repetitions has been reached since the last rsit. ? txbufe: transmission buffer empty 0: the signal buffer empty from the transmit pdc channel is inactive. 1: the signal buffer empty from the transmit pdc channel is active. ? rxbuff: reception buffer full 0: the signal buffer full from the receive pdc channel is inactive. 1: the signal buffer full from th e receive pdc channel is active. ? nack: non acknowledge 0: no non acknowledge has not been detected since the last rstnack. 1: at least one non acknowledge has been detected since the last rstnack. ? riic: ring indicator input change flag 0: no input change has been detected on the ri pin since the last read of us_csr. 1: at least one input change has been detected on the ri pin since the last read of us_csr. ? dsric: data set ready input change flag 0: no input change has been detected on the dsr pin since the last read of us_csr. 1: at least one input change has been detected on the dsr pin since the last read of us_csr. ? dcdic: data carrier detect input change flag 0: no input change has been detected on the dcd pin since the last read of us_csr. 1: at least one input change has been detected on the dcd pin since the last read of us_csr. ? ctsic: clear to send input change flag 0: no input change has been detected on the cts pin since the last read of us_csr. 1: at least one input change has been detected on the cts pin since the last read of us_csr.
429 6222f?atarm?14-jan-11 sam7se512/256/32 ? ri: image of ri input 0: ri is at 0. 1: ri is at 1. ? dsr: image of dsr input 0: dsr is at 0 1: dsr is at 1. ? dcd: image of dcd input 0: dcd is at 0. 1: dcd is at 1. ? cts: image of cts input 0: cts is at 0. 1: cts is at 1.
430 6222f?atarm?14-jan-11 sam7se512/256/32 33.7.7 usart receive holding register name: us_rhr access: read-only ? rxchr: received character last character received if rxrdy is set. ? rxsynh: received sync 0: last character received is a data. 1: last character received is a command. 31 30 29 28 27 26 25 24 ???????? 23 22 21 20 19 18 17 16 ???????? 15 14 13 12 11 10 9 8 rxsynh ??????rxchr 76543210 rxchr
431 6222f?atarm?14-jan-11 sam7se512/256/32 33.7.8 usart transmit holding register name: us_thr access: write-only ? txchr: character to be transmitted next character to be transmitted after the current character if txrdy is not set. ? txsynh: sync field to be transmitted 0: the next character sent is encoded as a data. start frame delimiter is data sync. 1: the next character sent is encoded as a command. start frame delimiter is command sync. 31 30 29 28 27 26 25 24 ???????? 23 22 21 20 19 18 17 16 ???????? 15 14 13 12 11 10 9 8 txsynh ??????txchr 76543210 txchr
432 6222f?atarm?14-jan-11 sam7se512/256/32 33.7.9 usart baud rate generator register name: us_brgr access: read/write ? cd: clock divider ? fp: fractional part 0: fractional divider is disabled. 1 - 7: baudrate resolution, defined by fp x 1/8. 31 30 29 28 27 26 25 24 ???????? 23 22 21 20 19 18 17 16 ????? fp 15 14 13 12 11 10 9 8 cd 76543210 cd cd usart_mode iso7816 usart_mode = iso7816 sync = 0 sync = 1 over = 0 over = 1 0 baud rate clock disabled 1 to 65535 baud rate = selected clock/16/cd baud rate = selected clock/8/cd baud rate = selected clock /cd baud rate = selected clock/cd/fi_di_ratio
433 6222f?atarm?14-jan-11 sam7se512/256/32 33.7.10 usart receiver time-out register name: us_rtor access: read/write ? to: time-out value 0: the receiver time-out is disabled. 1 - 65535: the receiver time-out is enabled and the time-out delay is to x bit period. 31 30 29 28 27 26 25 24 ???????? 23 22 21 20 19 18 17 16 ???????? 15 14 13 12 11 10 9 8 to 76543210 to
434 6222f?atarm?14-jan-11 sam7se512/256/32 33.7.11 usart transmitter timeguard register name: us_ttgr access: read/write ? tg: timeguard value 0: the transmitter timeguard is disabled. 1 - 255: the transmitter timeguard is enabled and the timeguard delay is tg x bit period. 31 30 29 28 27 26 25 24 ???????? 23 22 21 20 19 18 17 16 ???????? 15 14 13 12 11 10 9 8 ???????? 76543210 tg
435 6222f?atarm?14-jan-11 sam7se512/256/32 33.7.12 usart fi di ratio register name: us_fidi access: read/write reset value : 0x174 ? fi_di_ratio: fi over di ratio value 0: if iso7816 mode is selected, the baud rate generator generates no signal. 1 - 2047: if iso7816 mode is selected, the baud rate is the clock provided on sck divided by fi_di_ratio. 33.7.13 usart number of errors register name: us_ner access: read-only ? nb_errors: number of errors total number of errors that occurred during an iso7816 transfer. this register automatically clears when read. 31 30 29 28 27 26 25 24 ???????? 23 22 21 20 19 18 17 16 ???????? 15 14 13 12 11 10 9 8 ????? fi_di_ratio 76543210 fi_di_ratio 31 30 29 28 27 26 25 24 ???????? 23 22 21 20 19 18 17 16 ???????? 15 14 13 12 11 10 9 8 ???????? 76543210 nb_errors
436 6222f?atarm?14-jan-11 sam7se512/256/32 33.7.14 usart irda filter register name: us_if access: read/write ? irda_filter: irda filter sets the filter of the irda demodulator. 31 30 29 28 27 26 25 24 ???????? 23 22 21 20 19 18 17 16 ???????? 15 14 13 12 11 10 9 8 ???????? 76543210 irda_filter
437 6222f?atarm?14-jan-11 sam7se512/256/32 34. parallel input outp ut controller (pio) 34.1 overview the parallel input/output controller (pio) manages up to 32 fully programmable input/output lines. each i/o line may be dedicated as a general-purpose i/o or be assigned to a function of an embedded peripheral. this assures effective optimization of the pins of a product. each i/o line is associated with a bit number in all of the 32-bit registers of the 32-bit wide user interface. each i/o line of the pio controller features: ? an input change interrupt enabling level change detection on any i/o line. ? a glitch filter providing rejection of pulses lower than one-half of clock cycle. ? multi-drive capability similar to an open drain i/o line. ? control of the pull-up of the i/o line. ? input visibility and output control. the pio controller also features a synchronous output providing up to 32 bits of data output in a single write operation.
438 6222f?atarm?14-jan-11 sam7se512/256/32 34.2 block diagram figure 34-1. block diagram figure 34-2. application block diagram embedded peripheral embedded peripheral pio interrupt pio controller up to 32 pins pmc up to 32 peripheral ios up to 32 peripheral ios pio clock apb aic data, enable pin 31 pin 1 pin 0 data, enable on-chip peripherals pio controller on-chip peripheral drivers control & command driver keyboard driver keyboard driver general purpose i/os external devices
439 6222f?atarm?14-jan-11 sam7se512/256/32 34.3 product dependencies 34.3.1 pin multiplexing each pin is configurable, according to product definition as either a general-purpose i/o line only, or as an i/o line multiplexed with one or two peripheral i/os. as the multiplexing is hard- ware-defined and thus product-dependent, the hardware designer and programmer must carefully determine the configuration of the pio controllers required by their application. when an i/o line is general-purpose only, i.e. not multiplexed with any peripheral i/o, programming of the pio controller regarding the assignment to a peripheral has no effect and only the pio con- troller can control how the pin is driven by the product. 34.3.2 external interrupt lines the interrupt signals fiq and irq0 to irqn are most generally multiplexed through the pio controllers. however, it is not necessary to assign the i/o line to the interrupt function as the pio controller has no effect on inputs and the interrupt lines (fiq or irqs) are used only as inputs. 34.3.3 power management the power management controller controls the pio controller clock in order to save power. writing any of the registers of the user interface does not require the pio controller clock to be enabled. this means that the configuration of the i/o lines does not require the pio controller clock to be enabled. however, when the clock is disabled, not all of t he features of the pio controller are available. note that the input change interrupt and the read of the pin level require the clock to be validated. after a hardware reset, the pio clock is disabled by default. the user must configure the power management controller before any access to the input line information. 34.3.4 interrupt generation for interrupt handling, the pio controllers are considered as user peripherals. this means that the pio controller interrupt lines are connected among the interrupt sources 2 to 31. refer to the pio controller peripheral identifier in the produc t description to identify the interrupt sources dedicated to the pio controllers. the pio controller interrupt can be generated only if the pio controller clock is enabled.
440 6222f?atarm?14-jan-11 sam7se512/256/32 34.4 functional description the pio controller features up to 32 fully-programmable i/o lines. most of the control logic asso- ciated to each i/o is represented in figure 34-3 . in this description each signal shown represents but one of up to 32 possible indexes. figure 34-3. i/o line control logic 1 0 1 0 1 0 glitch filter peripheral b input peripheral a input 1 0 pio_ifdr[0] pio_ifsr[0] pio_ifer[0] edge detector pio_pdsr[0] pio_isr[0] pio_idr[0] pio_imr[0] pio_ier[0] pio interrupt (up to 32 possible inputs) pio_isr[31] pio_idr[31] pio_imr[31] pio_ier[31] pad 1 0 pio_pudr[0] pio_pusr[0] pio_puer[0] pio_mddr[0] pio_mdsr[0] pio_mder[0] pio_codr[0] pio_odsr[0] pio_sodr[0] pio_pdr[0] pio_psr[0] pio_per[0] 1 0 1 0 pio_bsr[0] pio_absr[0] pio_asr[0] peripheral b output enable peripheral a output enable peripheral b output peripheral a output pio_odr[0] pio_osr[0] pio_oer[0]
441 6222f?atarm?14-jan-11 sam7se512/256/32 34.4.1 pull-up resistor control each i/o line is designed with an embedded pull-up resistor. the pull-up resistor can be enabled or disabled by writing respectively pio_puer (pull-up enable register) and pio_pudr (pull- up disable resistor). writing in these registers re sults in setting or clearing the corresponding bit in pio_pusr (pull-up status register). readi ng a 1 in pio_pusr means the pull-up is dis- abled and reading a 0 means the pull-up is enabled. control of the pull-up resistor is possible regardless of the configuration of the i/o line. after reset, all of the pull-ups are enabled, i.e. pio_pusr resets at the value 0x0. 34.4.2 i/o line or peripheral function selection when a pin is multiplexed with one or two periph eral functions, the selection is controlled with the registers pio_per (pio enable register) and pio_pdr (pio disable register). the regis- ter pio_psr (pio status register) is the resu lt of the set and clear registers and indicates whether the pin is controlled by the corresponding peripheral or by the pio controller. a value of 0 indicates that the pin is controlled by the co rresponding on-chip peripheral selected in the pio_absr (ab select status regist er). a value of 1 indicates the pin is controlled by the pio controller. if a pin is used as a general purpose i/o line (not multiplexed with an on-chip peripheral), pio_per and pio_pdr have no effect and pio_psr returns 1 for the corresponding bit. after reset, most generally, the i/o lines are controlled by the pio controller, i.e. pio_psr resets at 1. however, in some events, it is important that pio lines are controlled by the periph- eral (as in the case of memory chip select lines that must be driven inactive after reset or for address lines that must be driven low for booting out of an external memory). thus, the reset value of pio_psr is defined at the product level, depending on the multiplexing of the device. 34.4.3 peripheral a or b selection the pio controller provides multiplexing of up to two peripheral functions on a single pin. the selection is performed by writing pio_asr (a select register) and pio_bsr (select b regis- ter). pio_absr (ab select status register) indicates which peripheral line is currently selected. for each pin, the corresponding bit at level 0 means peripheral a is selected whereas the corre- sponding bit at level 1 indicates that peripheral b is selected. note that multiplexing of peripheral lines a and b only affects the output line. the peripheral input lines are always connected to the pin input. after reset, pio_absr is 0, thus indicating that all the pio lines are configur ed on peripheral a. however, peripheral a generally does not drive the pin as the pio controller resets in i/o line mode. writing in pio_asr an d pio_bsr manages pio_absr regardless of th e configuration of the pin. however, assignment of a pin to a peripheral function requires a write in the corresponding peripheral selection register (pio_asr or pio_bsr) in addition to a write in pio_pdr. 34.4.4 output control when the i/0 line is assigned to a peripheral functi on, i.e. the corresponding bit in pio_psr is at 0, the drive of the i/o line is controlled by the peripheral. peripheral a or b, depending on the value in pio_absr, determines whet her the pin is driven or not. when the i/o line is controlled by the pio controller, the pin can be configured to be driven. this is done by writing pio_oer (output enable register) and pio_odr (output disable register).
442 6222f?atarm?14-jan-11 sam7se512/256/32 the results of these write operations are detected in pio_osr (output status register). when a bit in this register is at 0, the corresponding i/o line is used as an input only. when the bit is at 1, the corresponding i/o line is driven by the pio controller. the level driven on an i/o line can be determined by writing in pio_sodr (set output data register) and pio_codr (cle ar output data register). these write operations respectively set and clear pio_odsr (output data status register ), which represents the data driven on the i/o lines. writing in pio_oer and pio_odr manages pio_osr whether the pin is configured to be controlled by the pio controller or assigned to a peripheral function. this enables configura- tion of the i/o line prior to setting it to be managed by the pio controller. similarly, writing in pio_sodr and pio_codr effects pio_odsr. this is important as it defines the first level driven on the i/o line. 34.4.5 synchronous data output controlling all paralle l busses using several pios requires two successive write operations in the pio_sodr and pio_codr registers. this may lead to unexpected transient values. the pio controller offers a direct control of pio outputs by single write access to pio_odsr (output data status register). only bits unmasked by pio_owsr (output write status register) are written. the mask bits in the pio_owsr are se t by writing to pio_ower (output write enable register) and cleared by writing to pio_owdr (output write disable register). after reset, the synchronous data output is disabled on all the i/o lines as pio_owsr resets at 0x0. 34.4.6 multi drive control (open drain) each i/o can be independently programmed in open drain by using the multi drive feature. this feature permits several drivers to be connected on the i/o line which is driven low only by each device. an external pull-up resistor (or enabling of the internal one) is generally required to guar- antee a high level on the line. the multi drive feature is controlled by pio_mder (multi-driver enable register) and pio_mddr (multi-driver disable register). the multi drive can be selected whether the i/o line is controlled by the pio controller or assigned to a peripheral function. pio_mdsr (multi-driver status register) indicates the pins that are configured to support external drivers. after reset, the multi drive feature is disabled on all pins, i.e. pio_mdsr resets at value 0x0. 34.4.7 output line timings figure 34-4 shows how the outputs are driven either by writing pio_sodr or pio_codr, or by directly writing pio_odsr. this last case is valid only if the corresponding bit in pio_owsr is set. figure 34-4 also shows when the feedback in pio_pdsr is available.
443 6222f?atarm?14-jan-11 sam7se512/256/32 figure 34-4. output line timings 34.4.8 inputs the level on each i/o line can be read through pio_pdsr (pin data status register). this reg- ister indicates the level of the i/o lines regardless of their configuration, whether uniquely as an input or driven by the pio controller or driven by a peripheral. reading the i/o line levels requires the clock of the pio controller to be enabled, otherwise pio_pdsr reads the levels present on the i/o line at the time the clock was disabled. 34.4.9 input glitch filtering optional input glitch filters are independently programmable on each i/o line. when the glitch fil- ter is enabled, a glitch with a duration of less than 1/2 master clock (mck) cycle is automatically rejected, while a pulse with a duration of 1 mast er clock cycle or more is accepted. for pulse durations between 1/2 master clock cycle and 1 master clock cycle the pulse may or may not be taken into account, depending on the precise timing of its occurrence. thus for a pulse to be visible it must exceed 1 master clock cycle, whereas for a glitch to be reliably filtered out, its duration must not exceed 1/2 master clock cycle. the filter introduces one master clock cycle latency if the pin level change occurs before a rising edge. however, this latency does not appear if the pin level chan ge occurs before a falling ed ge. this is illustrated in figure 34-5 . the glitch filters are controlled by the register set; pio_ifer (input filter enable register), pio_ifdr (input filter disable register) and pio_if sr (input filter status register). writing pio_ifer and pio_ifdr respectively sets and cl ears bits in pio_ifsr. this last register enables the glitch filt er on the i/o lines. when the glitch filter is enabled, it does not modify the behavior of the inputs on the peripherals. it acts only on the value read in pio_pdsr and on the input change interrupt detection. the glitch filters require that the pio controller clock is enabled. 2 cycles apb access 2 cycles apb access mck write pio_sodr write pio_odsr at 1 pio_odsr pio_pdsr write pio_codr write pio_odsr at 0
444 6222f?atarm?14-jan-11 sam7se512/256/32 figure 34-5. input glitch filter timing 34.4.10 input change interrupt the pio controller can be programmed to generate an interrupt when it detects an input change on an i/o line. the input change interrupt is cont rolled by writing pio_ier (interrupt enable register) and pio_idr (interrupt disable register), which respectively enable and disable the input change interrupt by setting and clearing the corresponding bit in pio_imr (interrupt mask register). as input change detection is possible only by comparing two successive samplings of the input of the i/o line, the pio controller clock must be enabled. the input change interrupt is available, regardless of the configuration of the i/o line, i.e. configured as an input only, con- trolled by the pio controller or assigned to a peripheral function. when an input change is detected on an i/o line, the corresponding bit in pio_isr (interrupt status register) is set. if the corresponding bit in pio_imr is set, the pio controller interrupt line is asserted. the interrupt signals of the thirty-two channels are ored-wired together to gen- erate a single interrupt signal to the advanced interrupt controller. when the software reads pio_isr, all the interrupts are automatically cleared. this signifies that all the interrupts that are pending when pio_isr is read must be handled. figure 34-6. input change interrupt timings 34.5 i/o lines programming example the programing example as shown in table 34-1 below is used to define the following configuration. ? 4-bit output port on i/o lines 0 to 3, (should be written in a single write operation), open-drain, with pull-up resistor mck pin level pio_pdsr if pio_ifsr = 0 pio_pdsr if pio_ifsr = 1 1 cycle 1 cycle 1 cycle up to 1.5 cycles 2 cycles up to 2.5 cycles up to 2 cycles 1 cycle 1 cycle mck pin level read pio_isr apb access pio_isr apb access
445 6222f?atarm?14-jan-11 sam7se512/256/32 ? four output signals on i/o lines 4 to 7 (to drive leds for example), driven high and low, no pull-up resistor ? four input signals on i/o lines 8 to 11 (to read push-button states for example), with pull-up resistors, glitch filters and input change interrupts ? four input signals on i/o line 12 to 15 to read an external device status (polled, thus no input change interrupt), no pull-up resistor, no glitch filter ? i/o lines 16 to 19 assigned to peripheral a functions with pull-up resistor ? i/o lines 20 to 23 assigned to peripheral b functions, no pull-up resistor ? i/o line 24 to 27 assigned to peripheral a with input change interrupt and pull-up resistor table 34-1. programming example register value to be written pio_per 0x0000 ffff pio_pdr 0x0fff 0000 pio_oer 0x0000 00ff pio_odr 0x0fff ff00 pio_ifer 0x0000 0f00 pio_ifdr 0x0fff f0ff pio_sodr 0x0000 0000 pio_codr 0x0fff ffff pio_ier 0x0f00 0f00 pio_idr 0x00ff f0ff pio_mder 0x0000 000f pio_mddr 0x0fff fff0 pio_pudr 0x00f0 00f0 pio_puer 0x0f0f ff0f pio_asr 0x0f0f 0000 pio_bsr 0x00f0 0000 pio_ower 0x0000 000f pio_owdr 0x0fff fff0
446 6222f?atarm?14-jan-11 sam7se512/256/32 34.6 pio user interface each i/o line controlled by the pio controller is associated with a bit in each of the pio control- ler user interface registers. each register is 32 bits wide. if a parallel i/o line is not defined, writing to the corresponding bits has no effect. undefined bits read zero. if the i/o line is not mul- tiplexed with any peripheral, the i/o line is controlled by the pio controller and pio_psr returns 1 systematically. table 34-2. pio register mapping offset register name access reset value 0x0000 pio enable register pio_per write-only ? 0x0004 pio disable register pio_pdr write-only ? 0x0008 pio status register pio_psr read-only (1) 0x000c reserved 0x0010 output enable register pio_oer write-only ? 0x0014 output disable register pio_odr write-only ? 0x0018 output status regist er pio_osr read-only 0x0000 0000 0x001c reserved 0x0020 glitch input filter enab le register pio_ifer write-only ? 0x0024 glitch input filter disab le register pio_ifdr write-only ? 0x0028 glitch input filter status register pio_ifsr read-only 0x0000 0000 0x002c reserved 0x0030 set output data register pio_sodr write-only ? 0x0034 clear output data register pio_codr write-only 0x0038 output data status register pio_odsr read-only or (2) read/write ? 0x003c pin data status register pio_pdsr read-only (3) 0x0040 interrupt enable register pio_ier write-only ? 0x0044 interrupt disable register pio_idr write-only ? 0x0048 interrupt mask register pio_imr read-only 0x00000000 0x004c interrupt status register (4) pio_isr read-only 0x00000000 0x0050 multi-driver enable register pio_mder write-only ? 0x0054 multi-driver disable register pio_mddr write-only ? 0x0058 multi-driver status re gister pio_mdsr read-only 0x00000000 0x005c reserved 0x0060 pull-up disable register pio_pudr write-only ? 0x0064 pull-up enable register pio_puer write-only ? 0x0068 pad pull-up status regi ster pio_pusr read-only 0x00000000 0x006c reserved
447 6222f?atarm?14-jan-11 sam7se512/256/32 notes: 1. reset value of pio_psr depends on the product implementation. 2. pio_odsr is read-only or read/write depending on pio_owsr i/o lines. 3. reset value of pio_pdsr depends on the level of the i/o line s. reading the i/o line levels requires the clock of the pio controller to be enabled, ot herwise pio_pdsr reads the levels present on the i/o line at the time the clock was disabled. 4. pio_isr is reset at 0x0. however, the first read of the register may read a different value as input changes may have occurred. 5. only this set of registers clears the stat us by writing 1 in the first register and sets the status by writing 1 in the secon d register. 0x0070 peripheral a select register (5) pio_asr write-only ? 0x0074 peripheral b select register (5) pio_bsr write-only ? 0x0078 ab status register (5) pio_absr read-only 0x00000000 0x007c to 0x009c reserved 0x00a0 output write enab le pio_ower write-only ? 0x00a4 output write disab le pio_owdr write-only ? 0x00a8 output write status re gister pio_owsr read-only 0x00000000 0x00ac reserved table 34-2. pio register mapping (continued) offset register name access reset value
448 6222f?atarm?14-jan-11 sam7se512/256/32 34.6.1 pio controller pio enable register name: pio_per access: write-only ? p0-p31: pio enable 0 = no effect. 1 = enables the pio to control the corresponding pin (disables peripheral control of the pin). 34.6.2 pio controller pio disable register name: pio_pdr access: write-only ? p0-p31: pio disable 0 = no effect. 1 = disables the pio from controllin g the corresponding pin (enables peripheral contro l of the pin). 31 30 29 28 27 26 25 24 p31 p30 p29 p28 p27 p26 p25 p24 23 22 21 20 19 18 17 16 p23 p22 p21 p20 p19 p18 p17 p16 15 14 13 12 11 10 9 8 p15 p14 p13 p12 p11 p10 p9 p8 76543210 p7 p6 p5 p4 p3 p2 p1 p0 31 30 29 28 27 26 25 24 p31 p30 p29 p28 p27 p26 p25 p24 23 22 21 20 19 18 17 16 p23 p22 p21 p20 p19 p18 p17 p16 15 14 13 12 11 10 9 8 p15 p14 p13 p12 p11 p10 p9 p8 76543210 p7 p6 p5 p4 p3 p2 p1 p0
449 6222f?atarm?14-jan-11 sam7se512/256/32 34.6.3 pio controller pio status register name: pio_psr access: read-only ? p0-p31: pio status 0 = pio is inactive on the corresponding i/o line (peripheral is active). 1 = pio is active on the corresponding i/o line (peripheral is inactive). 34.6.4 pio controller output enable register name: pio_oer access: write-only ? p0-p31: output enable 0 = no effect. 1 = enables the output on the i/o line. 31 30 29 28 27 26 25 24 p31 p30 p29 p28 p27 p26 p25 p24 23 22 21 20 19 18 17 16 p23 p22 p21 p20 p19 p18 p17 p16 15 14 13 12 11 10 9 8 p15 p14 p13 p12 p11 p10 p9 p8 76543210 p7 p6 p5 p4 p3 p2 p1 p0 31 30 29 28 27 26 25 24 p31 p30 p29 p28 p27 p26 p25 p24 23 22 21 20 19 18 17 16 p23 p22 p21 p20 p19 p18 p17 p16 15 14 13 12 11 10 9 8 p15 p14 p13 p12 p11 p10 p9 p8 76543210 p7 p6 p5 p4 p3 p2 p1 p0
450 6222f?atarm?14-jan-11 sam7se512/256/32 34.6.5 pio controller output disable register name: pio_odr access: write-only ? p0-p31: output disable 0 = no effect. 1 = disables the output on the i/o line. 34.6.6 pio controller output status register name: pio_osr access: read-only ? p0-p31: output status 0 = the i/o line is a pure input. 1 = the i/o line is enabled in output. 31 30 29 28 27 26 25 24 p31 p30 p29 p28 p27 p26 p25 p24 23 22 21 20 19 18 17 16 p23 p22 p21 p20 p19 p18 p17 p16 15 14 13 12 11 10 9 8 p15 p14 p13 p12 p11 p10 p9 p8 76543210 p7 p6 p5 p4 p3 p2 p1 p0 31 30 29 28 27 26 25 24 p31 p30 p29 p28 p27 p26 p25 p24 23 22 21 20 19 18 17 16 p23 p22 p21 p20 p19 p18 p17 p16 15 14 13 12 11 10 9 8 p15 p14 p13 p12 p11 p10 p9 p8 76543210 p7 p6 p5 p4 p3 p2 p1 p0
451 6222f?atarm?14-jan-11 sam7se512/256/32 34.6.7 pio controller input filter enable register name: pio_ifer access: write-only ? p0-p31: input filter enable 0 = no effect. 1 = enables the input glitch filter on the i/o line. 34.6.8 pio controller input filter disable register name: pio_ifdr access: write-only ? p0-p31: input filter disable 0 = no effect. 1 = disables the input glitch filter on the i/o line. 31 30 29 28 27 26 25 24 p31 p30 p29 p28 p27 p26 p25 p24 23 22 21 20 19 18 17 16 p23 p22 p21 p20 p19 p18 p17 p16 15 14 13 12 11 10 9 8 p15 p14 p13 p12 p11 p10 p9 p8 76543210 p7 p6 p5 p4 p3 p2 p1 p0 31 30 29 28 27 26 25 24 p31 p30 p29 p28 p27 p26 p25 p24 23 22 21 20 19 18 17 16 p23 p22 p21 p20 p19 p18 p17 p16 15 14 13 12 11 10 9 8 p15 p14 p13 p12 p11 p10 p9 p8 76543210 p7 p6 p5 p4 p3 p2 p1 p0
452 6222f?atarm?14-jan-11 sam7se512/256/32 34.6.9 pio controller input filter status register name: pio_ifsr access: read-only ? p0-p31: input filer status 0 = the input glitch filter is disabled on the i/o line. 1 = the input glitch filter is enabled on the i/o line. 34.6.10 pio controller set output data register name: pio_sodr access: write-only ? p0-p31: set output data 0 = no effect. 1 = sets the data to be driven on the i/o line. 31 30 29 28 27 26 25 24 p31 p30 p29 p28 p27 p26 p25 p24 23 22 21 20 19 18 17 16 p23 p22 p21 p20 p19 p18 p17 p16 15 14 13 12 11 10 9 8 p15 p14 p13 p12 p11 p10 p9 p8 76543210 p7 p6 p5 p4 p3 p2 p1 p0 31 30 29 28 27 26 25 24 p31 p30 p29 p28 p27 p26 p25 p24 23 22 21 20 19 18 17 16 p23 p22 p21 p20 p19 p18 p17 p16 15 14 13 12 11 10 9 8 p15 p14 p13 p12 p11 p10 p9 p8 76543210 p7 p6 p5 p4 p3 p2 p1 p0
453 6222f?atarm?14-jan-11 sam7se512/256/32 34.6.11 pio controller clear output data register name: pio_codr access: write-only ? p0-p31: set output data 0 = no effect. 1 = clears the data to be driven on the i/o line. 34.6.12 pio controller output data status register name: pio_odsr access: read-only or read/write ? p0-p31: output data status 0 = the data to be driven on the i/o line is 0. 1 = the data to be driven on the i/o line is 1. 31 30 29 28 27 26 25 24 p31 p30 p29 p28 p27 p26 p25 p24 23 22 21 20 19 18 17 16 p23 p22 p21 p20 p19 p18 p17 p16 15 14 13 12 11 10 9 8 p15 p14 p13 p12 p11 p10 p9 p8 76543210 p7 p6 p5 p4 p3 p2 p1 p0 31 30 29 28 27 26 25 24 p31 p30 p29 p28 p27 p26 p25 p24 23 22 21 20 19 18 17 16 p23 p22 p21 p20 p19 p18 p17 p16 15 14 13 12 11 10 9 8 p15 p14 p13 p12 p11 p10 p9 p8 76543210 p7 p6 p5 p4 p3 p2 p1 p0
454 6222f?atarm?14-jan-11 sam7se512/256/32 34.6.13 pio controller pin data status register name: pio_pdsr access: read-only ? p0-p31: output data status 0 = the i/o line is at level 0. 1 = the i/o line is at level 1. 34.6.14 pio controller interrupt enable register name: pio_ier access: write-only ? p0-p31: input change interrupt enable 0 = no effect. 1 = enables the input change interrupt on the i/o line. 31 30 29 28 27 26 25 24 p31 p30 p29 p28 p27 p26 p25 p24 23 22 21 20 19 18 17 16 p23 p22 p21 p20 p19 p18 p17 p16 15 14 13 12 11 10 9 8 p15 p14 p13 p12 p11 p10 p9 p8 76543210 p7 p6 p5 p4 p3 p2 p1 p0 31 30 29 28 27 26 25 24 p31 p30 p29 p28 p27 p26 p25 p24 23 22 21 20 19 18 17 16 p23 p22 p21 p20 p19 p18 p17 p16 15 14 13 12 11 10 9 8 p15 p14 p13 p12 p11 p10 p9 p8 76543210 p7 p6 p5 p4 p3 p2 p1 p0
455 6222f?atarm?14-jan-11 sam7se512/256/32 34.6.15 pio controller interrupt disable register name: pio_idr access: write-only ? p0-p31: input change interrupt disable 0 = no effect. 1 = disables the input change interrupt on the i/o line. 34.6.16 pio controller interrupt mask register name: pio_imr access: read-only ? p0-p31: input change interrupt mask 0 = input change interrupt is disabled on the i/o line. 1 = input change interrupt is enabled on the i/o line. 31 30 29 28 27 26 25 24 p31 p30 p29 p28 p27 p26 p25 p24 23 22 21 20 19 18 17 16 p23 p22 p21 p20 p19 p18 p17 p16 15 14 13 12 11 10 9 8 p15 p14 p13 p12 p11 p10 p9 p8 76543210 p7 p6 p5 p4 p3 p2 p1 p0 31 30 29 28 27 26 25 24 p31 p30 p29 p28 p27 p26 p25 p24 23 22 21 20 19 18 17 16 p23 p22 p21 p20 p19 p18 p17 p16 15 14 13 12 11 10 9 8 p15 p14 p13 p12 p11 p10 p9 p8 76543210 p7 p6 p5 p4 p3 p2 p1 p0
456 6222f?atarm?14-jan-11 sam7se512/256/32 34.6.17 pio controller interrupt status register name: pio_isr access: read-only ? p0-p31: input change interrupt status 0 = no input change has been detected on the i/o line since pio_isr was last read or since reset. 1 = at least one input change has been detected on the i/o line since pio_isr was last read or since reset. 34.6.18 pio multi-driver enable register name: pio_mder access: write-only ? p0-p31: multi drive enable. 0 = no effect. 1 = enables multi drive on the i/o line. 31 30 29 28 27 26 25 24 p31 p30 p29 p28 p27 p26 p25 p24 23 22 21 20 19 18 17 16 p23 p22 p21 p20 p19 p18 p17 p16 15 14 13 12 11 10 9 8 p15 p14 p13 p12 p11 p10 p9 p8 76543210 p7 p6 p5 p4 p3 p2 p1 p0 31 30 29 28 27 26 25 24 p31 p30 p29 p28 p27 p26 p25 p24 23 22 21 20 19 18 17 16 p23 p22 p21 p20 p19 p18 p17 p16 15 14 13 12 11 10 9 8 p15 p14 p13 p12 p11 p10 p9 p8 76543210 p7 p6 p5 p4 p3 p2 p1 p0
457 6222f?atarm?14-jan-11 sam7se512/256/32 34.6.19 pio multi-driver disable register name: pio_mddr access: write-only ? p0-p31: multi drive disable. 0 = no effect. 1 = disables multi drive on the i/o line. 34.6.20 pio multi-driver status register name: pio_mdsr access: read-only ? p0-p31: multi drive status. 0 = the multi drive is disabled on the i/o line. the pin is driven at high and low level. 1 = the multi drive is enabled on the i/o lin e. the pin is driven at low level only. 31 30 29 28 27 26 25 24 p31 p30 p29 p28 p27 p26 p25 p24 23 22 21 20 19 18 17 16 p23 p22 p21 p20 p19 p18 p17 p16 15 14 13 12 11 10 9 8 p15 p14 p13 p12 p11 p10 p9 p8 76543210 p7 p6 p5 p4 p3 p2 p1 p0 31 30 29 28 27 26 25 24 p31 p30 p29 p28 p27 p26 p25 p24 23 22 21 20 19 18 17 16 p23 p22 p21 p20 p19 p18 p17 p16 15 14 13 12 11 10 9 8 p15 p14 p13 p12 p11 p10 p9 p8 76543210 p7 p6 p5 p4 p3 p2 p1 p0
458 6222f?atarm?14-jan-11 sam7se512/256/32 34.6.21 pio pull up disable register name: pio_pudr access: write-only ? p0-p31: pull up disable. 0 = no effect. 1 = disables the pull up resistor on the i/o line. 34.6.22 pio pull up enable register name: pio_puer access: write-only ? p0-p31: pull up enable. 0 = no effect. 1 = enables the pull up resistor on the i/o line. 31 30 29 28 27 26 25 24 p31 p30 p29 p28 p27 p26 p25 p24 23 22 21 20 19 18 17 16 p23 p22 p21 p20 p19 p18 p17 p16 15 14 13 12 11 10 9 8 p15 p14 p13 p12 p11 p10 p9 p8 76543210 p7 p6 p5 p4 p3 p2 p1 p0 31 30 29 28 27 26 25 24 p31 p30 p29 p28 p27 p26 p25 p24 23 22 21 20 19 18 17 16 p23 p22 p21 p20 p19 p18 p17 p16 15 14 13 12 11 10 9 8 p15 p14 p13 p12 p11 p10 p9 p8 76543210 p7 p6 p5 p4 p3 p2 p1 p0
459 6222f?atarm?14-jan-11 sam7se512/256/32 34.6.23 pio pull up status register name: pio_pusr access: read-only ? p0-p31: pull up status. 0 = pull up resistor is enabled on the i/o line. 1 = pull up resistor is disabled on the i/o line. 34.6.24 pio peripheral a select register name: pio_asr access: write-only ? p0-p31: peripheral a select. 0 = no effect. 1 = assigns the i/o line to the peripheral a function. 31 30 29 28 27 26 25 24 p31 p30 p29 p28 p27 p26 p25 p24 23 22 21 20 19 18 17 16 p23 p22 p21 p20 p19 p18 p17 p16 15 14 13 12 11 10 9 8 p15 p14 p13 p12 p11 p10 p9 p8 76543210 p7 p6 p5 p4 p3 p2 p1 p0 31 30 29 28 27 26 25 24 p31 p30 p29 p28 p27 p26 p25 p24 23 22 21 20 19 18 17 16 p23 p22 p21 p20 p19 p18 p17 p16 15 14 13 12 11 10 9 8 p15 p14 p13 p12 p11 p10 p9 p8 76543210 p7 p6 p5 p4 p3 p2 p1 p0
460 6222f?atarm?14-jan-11 sam7se512/256/32 34.6.25 pio peripheral b select register name: pio_bsr access: write-only ? p0-p31: peripheral b select. 0 = no effect. 1 = assigns the i/o line to the peripheral b function. 34.6.26 pio peripheral a b status register name: pio_absr access: read-only ? p0-p31: peripheral a b status. 0 = the i/o line is assigned to the peripheral a. 1 = the i/o line is assigned to the peripheral b. 31 30 29 28 27 26 25 24 p31 p30 p29 p28 p27 p26 p25 p24 23 22 21 20 19 18 17 16 p23 p22 p21 p20 p19 p18 p17 p16 15 14 13 12 11 10 9 8 p15 p14 p13 p12 p11 p10 p9 p8 76543210 p7 p6 p5 p4 p3 p2 p1 p0 31 30 29 28 27 26 25 24 p31 p30 p29 p28 p27 p26 p25 p24 23 22 21 20 19 18 17 16 p23 p22 p21 p20 p19 p18 p17 p16 15 14 13 12 11 10 9 8 p15 p14 p13 p12 p11 p10 p9 p8 76543210 p7 p6 p5 p4 p3 p2 p1 p0
461 6222f?atarm?14-jan-11 sam7se512/256/32 34.6.27 pio output write enable register name: pio_ower access: write-only ? p0-p31: output write enable. 0 = no effect. 1 = enables writing pio_odsr for the i/o line. 34.6.28 pio output write disable register name: pio_owdr access: write-only ? p0-p31: output write disable. 0 = no effect. 1 = disables writing pio_odsr for the i/o line. 31 30 29 28 27 26 25 24 p31 p30 p29 p28 p27 p26 p25 p24 23 22 21 20 19 18 17 16 p23 p22 p21 p20 p19 p18 p17 p16 15 14 13 12 11 10 9 8 p15 p14 p13 p12 p11 p10 p9 p8 76543210 p7 p6 p5 p4 p3 p2 p1 p0 31 30 29 28 27 26 25 24 p31 p30 p29 p28 p27 p26 p25 p24 23 22 21 20 19 18 17 16 p23 p22 p21 p20 p19 p18 p17 p16 15 14 13 12 11 10 9 8 p15 p14 p13 p12 p11 p10 p9 p8 76543210 p7 p6 p5 p4 p3 p2 p1 p0
462 6222f?atarm?14-jan-11 sam7se512/256/32 34.6.29 pio output write status register name: pio_owsr access: read-only ? p0-p31: output write status. 0 = writing pio_odsr does not affect the i/o line. 1 = writing pio_odsr affects the i/o line. 31 30 29 28 27 26 25 24 p31 p30 p29 p28 p27 p26 p25 p24 23 22 21 20 19 18 17 16 p23 p22 p21 p20 p19 p18 p17 p16 15 14 13 12 11 10 9 8 p15 p14 p13 p12 p11 p10 p9 p8 76543210 p7 p6 p5 p4 p3 p2 p1 p0
463 6222f?atarm?14-jan-11 sam7se512/256/32 35. synchronous serial controller (ssc) 35.1 description the atmel synchronous serial controller (ssc ) provides a synchronous communication link with external devices. it supports many serial synchronous communication protocols generally used in audio and telecom applications such as i2s, short frame sync, long frame sync, etc. the ssc contains an independent receiver and transmitter and a common clock divider. the receiver and the transmitter each interface with three signals: the td/rd signal for data, the tk/rk signal for the clock and the tf/rf signal for the frame sync. the transfers can be pro- grammed to start automatically or on different events detected on the frame sync signal. the ssc?s high-level of programmability and its two dedicated pdc channels of up to 32 bits permit a continuous high bit rate data transfer without processor intervention. featuring connection to two pdc channels, the ssc permits interfacing with low processor overhead to the following: ? codec?s in master or slave mode ? dac through dedicated serial interface, particularly i2s ? magnetic card reader
464 6222f?atarm?14-jan-11 sam7se512/256/32 35.2 block diagram figure 35-1. block diagram 35.3 application block diagram figure 35-2. application block diagram ssc interface pio pdc apb bridge mck system bus peripheral bus tf tk td rf rk rd interrupt control ssc interrupt pmc interrupt management power management test management ssc serial audio os or rtos driver codec frame management line interface time slot management
465 6222f?atarm?14-jan-11 sam7se512/256/32 35.4 pin name list 35.5 product dependencies 35.5.1 i/o lines the pins used for interfacing the compliant external devices may be multiplexed with pio lines. before using the ssc receiver, the pio contro ller must be configured to dedicate the ssc receiver i/o lines to the ssc peripheral mode. before using the ssc transmitter, the pio controller must be configured to dedicate the ssc transmitter i/o lines to the ssc peripheral mode. 35.5.2 power management the ssc is not continuously clocked. the ssc interface may be clocked through the power management controller (pmc), therefore the programmer must first configure the pmc to enable the ssc clock. 35.5.3 interrupt the ssc interface has an interrupt line connected to the advanced interrupt controller (aic). handling interrupts requires programming the aic before configuring the ssc. all ssc interrupts can be enabled/disabled configur ing the ssc interrupt mask register. each pending and unmasked ssc interrupt will assert the ssc interrupt line. the ssc interrupt ser- vice routine can get the interrupt origin by reading the ssc interrupt status register. 35.6 functional description this chapter contains the functional description of the following: ssc functional block, clock management, data format, start, transmitter, receiver and frame sync. the receiver and transmitter operate separately. however, they can work synchronously by pro- gramming the receiver to use the transmit clock and/or to start a data transfer when transmission starts. alternatively, this can be done by programming the transmitter to use the receive clock and/or to start a data transfer when reception starts. the transmitter and the receiver can be pro- grammed to operate with the clock signals provided on either the tk or rk pins. this allows the ssc to support many slave-mode data transfer s. the maximum clock speed allowed on the tk and rk pins is the master clock divided by 2. table 35-1. i/o lines description pin name pin description type rf receiver frame synchro input/output rk receiver clock input/output rd receiver data input tf transmitter frame synchro input/output tk transmitter clock input/output td transmitter data output
466 6222f?atarm?14-jan-11 sam7se512/256/32 figure 35-3. ssc functional block diagram 35.6.1 clock management the transmitter clock can be generated by: ? an external clock received on the tk i/o pad ? the receiver clock ? the internal clock divider the receiver clock can be generated by: ? an external clock received on the rk i/o pad ? the transmitter clock ? the internal clock divider furthermore, the transmitter block can generate an external clock on the tk i/o pad, and the receiver block can generate an external clock on the rk i/o pad. this allows the ssc to support many master and slave mode data transfers. interrupt control aic user interface apb mck receive clock controller start selector tx clock rk input rf tf clock output controller frame sync controller transmit clock controller transmit shift register start selector transmit sync holding register transmit holding register load shift rx clock tx clock tk input tf tx pdc rf rd rf rk clock output controller frame sync controller receive shift register receive sync holding register receive holding register load shift td tf tk rx clock rx pdc receiver pdc transmitter clock divider
467 6222f?atarm?14-jan-11 sam7se512/256/32 35.6.1.1 clock divider figure 35-4. divided clock block diagram the master clock divider is determined by the 12-bit field div counter and comparator (so its maximal value is 4095) in the clock mode register ssc_cmr, a llowing a master clock division by up to 8190. the divided clock is provided to both the receiver and transmitter. when this field is programmed to 0, the clock divider is not used and remains inactive. when div is set to a value equal to or greater than 1, the divided clock has a frequency of mas- ter clock divided by 2 times div. each level of the divided clock has a duration of the master clock multiplied by div. this ensures a 50% duty cycle for the divided clock regardless of whether the div value is even or odd. figure 35-5. divided clock generation 35.6.1.2 transmitter clock management the transmitter clock is generated from the receiver clock or the divider clock or an external clock scanned on the tk i/o pad. the transm itter clock is selected by the cks field in ssc_tcmr (transmit clock mode register). transmit clock can be inverted independently by the cki bits in ssc_tcmr. table 35-2. maximum minimum mck / 2 mck / 8190 mck divided clock clock divider / 2 12-bit counter ssc_cmr master clock divided clock div = 1 master clock divided clock div = 3 divided clock frequency = mck/2 divided clock frequency = mck/6
468 6222f?atarm?14-jan-11 sam7se512/256/32 the transmitter can also drive the tk i/o pad cont inuously or be limited to the actual data trans- fer. the clock output is configured by the ssc_tcmr register. the transmit clock inversion (cki) bits have no effect on the clock outputs. programming the tcmr register to select tk pin (cks field) and at the same time continuous transmit clock (cko field) might lead to unpredict- able results. figure 35-6. transmitter clock management 35.6.1.3 receiver clock management the receiver clock is generated from the transmitter clock or the divider clock or an external clock scanned on the rk i/o pad. the receive clock is selected by the cks field in ssc_rcmr (receive clock mode register). receive clocks can be inverted independently by the cki bits in ssc_rcmr. the receiver can also drive the rk i/o pad continuo usly or be limited to the actual data transfer. the clock output is configured by the ssc_rcmr register. the receive clock inversion (cki) bits have no effect on the clock outputs. programming the rcmr register to select rk pin (cks field) and at the same time continuous receive clock (cko field) can lead to unpredictable results. tk (pin) receiver clock divider clock cks cko data transfer cki ckg transmitter clock clock output mux tri_state controller tri-state controller inv mux
469 6222f?atarm?14-jan-11 sam7se512/256/32 figure 35-7. receiver clock management 35.6.1.4 serial clock ratio considerations the transmitter and the receiver can be programmed to operate with the clock signals provided on either the tk or rk pins. this allows the ssc to support many slave-mode data transfers. in this case, the maximum clock speed allowed on the rk pin is: ? master clock divided by 2 if receiver frame synchro is input ? master clock divided by 3 if receiver frame synchro is output in addition, the maximum clock speed allowed on the tk pin is: ? master clock divided by 6 if transmit frame synchro is input ? master clock divided by 2 if transmit frame synchro is output 35.6.2 transmitter operations a transmitted frame is triggered by a start event and can be followed by synchronization data before data transmission. the start event is configured by setting the transmit clock mode register (ssc_tcmr). see ?start? on page 471. the frame synchronization is configured se tting the transmit frame mode register (ssc_tfmr). see ?frame sync? on page 473. to transmit data, the transmitter uses a shift regi ster clocked by the transmitter clock signal and the start mode selected in the ssc_tcmr. data is written by the application to the ssc_thr register then transferred to the shift register according to the data format selected. when both the ssc_thr and the transmit shift register are empty, the status flag txempty is set in ssc_sr. when the transmit holding register is transferred in the transmit shift register, the status flag txrdy is set in ssc_sr and additional data can be loaded in the holding register. rk (pin) transmitter clock divider clock cks cko data transfer cki ckg receiver clock clock output mux tri-state controller tri-state controller inv mux
470 6222f?atarm?14-jan-11 sam7se512/256/32 figure 35-8. transmitter block diagram 35.6.3 receiver operations a received frame is triggered by a start event and can be followed by synchronization data before data transmission. the start event is configured setting the receive clock mode register (ssc_rcmr). see ?start? on page 471. the frame synchronization is configured setting the receive frame mode register (ssc_rfmr). see ?frame sync? on page 473. the receiver uses a shift register clocked by the receiver clock signal and the start mode selected in the ssc_rcmr. the data is transferred from the shift register depending on the data format selected. when the receiver shift register is full, the ssc transfers this data in the holding register, the sta- tus flag rxrdy is set in ssc_sr and the data c an be read in the receiver holding register. if another transfer occurs before read of the rhr re gister, the status flag overun is set in ssc_sr and the receiver shift register is transferred in the rhr register. transmit shift register start selector ssc_tshr ssc_thr transmitter clock td ssc_tfmr.fslen ssc_tfmr.datlen ssc_cr.txen ssc_cr.txdis ssc_tcmr.sttdly ssc_tfmr.fsden ssc_tfmr.datnb ssc_sr.txen ssc_tfmr.datdef ssc_tfmr.msbf ssc_tcmr.sttdly ssc_tfmr.fsden 0 1 1 0 rf tf
471 6222f?atarm?14-jan-11 sam7se512/256/32 figure 35-9. receiver block diagram 35.6.4 start the transmitter and receiver can both be programmed to start their operations when an event occurs, respectively in the transmit start sele ction (start) field of ssc_tcmr and in the receive start selection (start) field of ssc_rcmr. under the following conditions the start event is independently programmable: ? continuous. in this case, the transmission st arts as soon as a word is written in ssc_thr and the reception starts as soon as the receiver is enabled. ? synchronously with the transmitter/receiver ? on detection of a falling/rising edge on tf/rf ? on detection of a low level/high level on tf/rf ? on detection of a level change or an edge on tf/rf a start can be programmed in the same manner on either side of the transmit/receive clock register (rcmr/tcmr). thus, the start coul d be on tf (transmit) or rf (receive). moreover, the receiver can start when data is detected in the bit stream with the compare functions. detection on tf/rf input/output is done by the field fsos of the transmit/receive frame mode register (tfmr/rfmr). receive shift register start selector ssc_rhr ssc_rshr receiver clock rd ssc_rfmr.fslen ssc_rfmr.datlen rf ssc_cr.rxen ssc_cr.rxdis ssc_sr.rxen ssc_rfmr.msbf ssc_rcmr.sttdly ssc_rfmr.datnb tf
472 6222f?atarm?14-jan-11 sam7se512/256/32 figure 35-10. transmit start mode figure 35-11. receive pulse/ed ge start modes x tk tf (input) td (output) td (output) td (output) td (output) td (output) td (output) xbob1 x bo b1 bo b1 bo b1 bo b1 bo b1 bo b1 b1 bo x x x sttdly sttdly sttdly sttdly sttdly sttdly start = falling edge on tf start = rising edge on tf start = low level on tf start = high level on tf start = any edge on tf start = level change on tf x rk rf (input) rd (input) rd (input) rd (input) rd (input) rd (input) rd (input) xbob1 x bo b1 bo b1 bo b1 bo b1 bo b1 bo b1 b1 bo x x x sttdly sttdly sttdly sttdly sttdly sttdly start = falling edge on rf start = rising edge on rf start = low level on rf start = high level on rf start = any edge on rf start = level change on rf
473 6222f?atarm?14-jan-11 sam7se512/256/32 35.6.5 frame sync the transmitter and receiver frame sync pins, tf and rf, can be programmed to generate different kinds of frame synchron ization signals. the frame sync output selection (fsos) field in the receive frame mode register (ssc_rfmr) and in the transmit frame mode register (ssc_tfmr) are used to select the required waveform. ? programmable low or high levels during data transfer are supported. ? programmable high levels before the start of data transfers or toggling are also supported. if a pulse waveform is selected, the frame sync length (fslen) field in ssc_rfmr and ssc_tfmr programs the length of the pulse, from 1 bit time up to 16 bit time. the periodicity of the receive and transmit frame sync pulse output can be programmed through the period divider selection ( period) field in ssc_rcmr and ssc_tcmr. 35.6.5.1 frame sync data frame sync data transmits or receives a specific tag during the frame sync signal. during the frame sync signal, the receiver can sample the rd line and store the data in the receive sync holding register a nd the transmitter can transfer transmit sync holding register in the shifter register. the data length to be sampled/shifted out during the frame sync signal is programmed by the fslen field in ssc_rfmr/ssc_tfmr and has a maximum value of 16. concerning the receive frame sync data operation, if the frame sync length is equal to or lower than the delay between the start event and the actual data reception, the data sampling operation is performed in the re ceive sync holding register thr ough the receive shift register. the transmit frame sync operation is performed by the transmitter only if the bit frame sync data enable (fsden) in ssc_tfmr is set. if the frame sync length is equal to or lower than the delay between the start event and the actual data transmission, the normal transmission has priority and the data contained in the transmit sync holding register is transferred in the trans- mit register, then shifted out. 35.6.5.2 frame sync edge detection the frame sync edge detection is programmed by the fsedge field in ssc_rfmr/ssc_tfmr. this sets the corres ponding flags rxsyn/txsyn in the ssc status register (ssc_sr) on frame synchro edge detection (signals rf/tf). 35.6.6 receive compare modes figure 35-12. receive compare modes cmp0 cmp3 cmp2 cmp1 ignored b0 b2 b1 start rk rd (input) fslen up to 16 bits (4 in this example) stdly datlen
474 6222f?atarm?14-jan-11 sam7se512/256/32 35.6.6.1 compare functions length of the comparison patterns (compare 0, compare 1) and thus the number of bits they are compared to is defined by fslen, but with a maximum value of 16 bits. comparison is always done by comparing the last bits received with the comparison pattern. compare 0 can be one start event of the receiver. in this case, the receiver compares at each new sample the last bits received at the compare 0 pattern contained in the compare 0 register (ssc_rc0r). when this start event is selected, the user can program the receiver to start a new data transfer either by writing a new compare 0, or by receiving continuously until compare 1 occurs. this selection is done with the bit (stop) in ssc_rcmr. 35.6.7 data format the data framing format of both the transmitter and the receiver are programmable through the transmitter frame mode register (ssc_tfmr) and the receiver frame mode register (ssc_rfmr). in either case, the user can independently select: ? the event that starts the data transfer (start) ? the delay in number of bit periods between the start event and the first data bit (sttdly) ? the length of the data (datlen) ? the number of data to be transferred for each start event (datnb). ? the length of synchronization transferred for each start event (fslen) ? the bit sense: most or lowest significant bit first (msbf) additionally, the transmitter can be used to trans fer synchronization and select the level driven on the td pin while not in data transfer operation. this is done respectively by the frame sync data enable (fsden) and by the data default value (datdef) bits in ssc_tfmr.
475 6222f?atarm?14-jan-11 sam7se512/256/32 figure 35-13. transmit and receive frame format in edge/pulse start modes note: 1. example of input on falling edge of tf/rf. figure 35-14. transmit frame format in continuous mode note: 1. sttdly is set to 0. in this example, ssc_thr is loaded twice. fsden value has no effect on the transmission. syncdata cannot be output in continuous mode. table 35-3. data frame registers transmitter receiver field length comment ssc_tfmr ssc_rfmr datlen up to 32 size of word ssc_tfmr ssc_rfmr datnb up to 16 number of words transmitted in frame ssc_tfmr ssc_rfmr msbf most significant bit first ssc_tfmr ssc_rfmr fslen up to 16 size of synchro data register ssc_tfmr datdef 0 or 1 data default value ended ssc_tfmr fsden enable send ssc_tshr ssc_tcmr ssc_rcmr period up to 512 frame size ssc_tcmr ssc_rcmr sttdly up to 255 size of transmit start delay sync data default sttdly sync data ignored rd default data datlen data data data datlen data data default default ignored sync data sync data fslen tf/rf (1) start start from ssc_tshr from ssc_thr from ssc_thr from ssc_thr from ssc_thr to ssc_rhr to ssc_rhr to ssc_rshr td (if fsden = 0) td (if fsden = 1) period fromdatdef fromdatdef from datdef from datdef datnb datlen data datlen data default start from ssc_thr from ssc_thr td start: 1. txempty set to 1 2. write into the ssc_thr
476 6222f?atarm?14-jan-11 sam7se512/256/32 figure 35-15. receive frame format in continuous mode note: 1. sttdly is set to 0. 35.6.8 loop mode the receiver can be programmed to receive transmissions from the transmitter. this is done by setting the loop mode (loop) bit in ssc_rfmr. in this case, rd is connected to td, rf is connected to tf and rk is connected to tk. 35.6.9 interrupt most bits in ssc_sr have a corresponding bit in interrupt management registers. the ssc can be programmed to generate an interrupt when it detects an event. the interrupt is controlled by writing ssc_ier (interrupt enable register) and ssc_idr (interrupt disable reg- ister) these registers enable and disable, respectively, the corresponding interrupt by setting and clearing the corresponding bit in ssc_imr (interrupt mask register), which controls the generation of interrupts by asserting the ssc interrupt line connected to the aic. figure 35-16. interrupt block diagram data datlen data datlen start = enable receiver to ssc_rhr to ssc_rhr rd ssc_imr pdc interrupt control ssc interrupt set rxrdy ovrun rxsync receiver transmitter txrdy txempty txsync txbufe endtx rxbuff endrx clear ssc_ier ssc_idr
477 6222f?atarm?14-jan-11 sam7se512/256/32 35.7 ssc application examples the ssc can support several serial communicati on modes used in audio or high speed serial links. some standard applications are shown in the following figures. all seri al link applications supported by the ssc are not listed here. figure 35-17. audio application block diagram figure 35-18. codec application block diagram ssc rk rf rd td tf tk clock sck word select ws data sd i2s receiver clock sck word select ws data sd right channel left channel msb msb lsb ssc rk rf rd td tf tk serial data clock (sclk) frame sync (fsync) serial data out serial data in codec serial data clock (sclk) frame sync (fsync) serial data out serial data in first time slot dstart dend
478 6222f?atarm?14-jan-11 sam7se512/256/32 figure 35-19. time slot application block diagram ssc rk rf rd td tf tk sclk fsync data out data in codec first time slot serial data clock (sclk) frame sync (fsync) serial data out serial data in codec second time slot first time slot second time slot dstart dend
479 6222f?atarm?14-jan-11 sam7se512/256/32 35.8 synchronous serial contro ller (ssc) user interface table 35-4. register mapping offset register register name access reset 0x0 control register ssc_cr write ? 0x4 clock mode register ssc_cmr read/write 0x0 0x8 reserved ? ? ? 0xc reserved ? ? ? 0x10 receive clock mode register ssc_rcmr read/write 0x0 0x14 receive frame mode register ssc_rfmr read/write 0x0 0x18 transmit clock mode register ssc_tcmr read/write 0x0 0x1c transmit frame mode register ssc_tfmr read/write 0x0 0x20 receive holding register ssc_rhr read 0x0 0x24 transmit holding register ssc_thr write ? 0x28 reserved ? ? ? 0x2c reserved ? ? ? 0x30 receive sync. holding register ssc_rshr read 0x0 0x34 transmit sync. holding register ssc_tshr read/write 0x0 0x38 receive compare 0 register ssc_rc0r read/write 0x0 0x3c receive compare 1 register ssc_rc1r read/write 0x0 0x40 status register ssc_sr read 0x000000cc 0x44 interrupt enable register ssc_ier write ? 0x48 interrupt disable register ssc_idr write ? 0x4c interrupt mask register ssc_imr read 0x0 0x50-0xfc reserved ? ? ? 0x100- 0x124 reserved for peripheral data controller (pdc) ? ? ?
480 6222f?atarm?14-jan-11 sam7se512/256/32 35.8.1 ssc control register name: ssc_cr access: write-only ? rxen: receive enable 0: no effect. 1: enables receive if rxdis is not set. ? rxdis: receive disable 0: no effect. 1: disables receive. if a character is currently being re ceived, disables at end of current character reception. ? txen: transmit enable 0: no effect. 1: enables transmit if txdis is not set. ? txdis: transmit disable 0: no effect. 1: disables transmit. if a character is currently being transmitted, disables at end of current character transmission. ? swrst: software reset 0: no effect. 1: performs a software reset. has priority on any other bit in ssc_cr. 31 30 29 28 27 26 25 24 ???????? 23 22 21 20 19 18 17 16 ???????? 15 14 13 12 11 10 9 8 swrst?????txdistxen 76543210 ??????rxdisrxen
481 6222f?atarm?14-jan-11 sam7se512/256/32 35.8.2 ssc clock mode register name: ssc_cmr access: read/write ? div: clock divider 0: the clock divider is not active. any other value: the divided clock equals the master clock divided by 2 times div. the maximum bit rate is mck/2. the minimum bit rate is mck/2 x 4095 = mck/8190. 31 30 29 28 27 26 25 24 ???????? 23 22 21 20 19 18 17 16 ???????? 15 14 13 12 11 10 9 8 ???? div 76543210 div
482 6222f?atarm?14-jan-11 sam7se512/256/32 35.8.3 ssc receive clock mode register name: ssc_rcmr access: read/write ? cks: receive clock selection ? cko: receive clock output mode selection ? cki: receive clock inversion 0: the data inputs (data and frame sync signals) are sample d on receive clock falling edge . the frame sync signal out- put is shifted out on receive clock rising edge. 1: the data inputs (data and frame sync signals) are sample d on receive clock rising edge. the frame sync signal out- put is shifted out on receive clock falling edge. cki affects only the receive clock and not the output clock signal. 31 30 29 28 27 26 25 24 period 23 22 21 20 19 18 17 16 stddly 15 14 13 12 11 10 9 8 ? ? ? stop start 76543210 ckg cki cko cks cks selected receive clock 0x0 divided clock 0x1 tk clock signal 0x2 rk pin 0x3 reserved cko receive clock output mode rk pin 0x0 none input-only 0x1 continuous receive clock output 0x2 receive clock only during data transfers output 0x3-0x7 reserved
483 6222f?atarm?14-jan-11 sam7se512/256/32 ? ckg: receive clock gating selection ? start: receive start selection ? stop: receive stop selection 0: after completion of a data transfer when starting with a compare 0, the receiver stops the data transfer and waits for a new compare 0. 1: after starting a receive with a compare 0, the receiver operates in a continuous mode until a compare 1 is detected. ? sttdly: receive start delay if sttdly is not 0, a delay of sttdly clock cycles is inserted between the start event and the actual start of reception. when the receiver is programmed to start synchronously with the transmitter, the delay is also applied. note: it is very important that sttdly be set carefully. if sttdly must be set, it should be done in relation to tag (receive sync data) reception. ? period: receive period divider selection this field selects the divider to apply to the selected receive clock in order to generate a new frame sync signal. if 0, no period signal is generated. if not 0, a period sig nal is generated each 2 x (period+1) receive clock. ckg receive clock gating 0x0 none, continuous clock 0x1 receive clock enabled only if rf low 0x2 receive clock enabled only if rf high 0x3 reserved start receive start 0x0 continuous, as soon as the receiver is enabled, and imme diately after the end of transfer of the previous data. 0x1 transmit start 0x2 detection of a low level on rf signal 0x3 detection of a high level on rf signal 0x4 detection of a falling edge on rf signal 0x5 detection of a rising edge on rf signal 0x6 detection of any level change on rf signal 0x7 detection of any edge on rf signal 0x8 compare 0 0x9-0xf reserved
484 6222f?atarm?14-jan-11 sam7se512/256/32 35.8.4 ssc receive frame mode register name: ssc_rfmr access: read/write ? datlen: data length 0: forbidden value (1-bit data length not supported). any other value: the bit stream contains datlen + 1 data bits. moreover, it defines the transfer size performed by the pdc2 assigned to the receiver. if datlen is lower or equal to 7, data transfers are in bytes. if datlen is between 8 and 15 (included), half-words are transferred, and for any other value, 32-bit words are transferred. ? loop: loop mode 0: normal operating mode. 1: rd is driven by td, rf is driven by tf and tk drives rk. ? msbf: most significant bit first 0: the lowest significant bit of the data register is sampled first in the bit stream. 1: the most significant bit of the data register is sampled first in the bit stream. ? datnb: data number per frame this field defines the number of data words to be received after each transfer start, which is equal to (datnb + 1). ? fslen: receive frame sync length this field defines the number of bits sampled and stored in th e receive sync data register. when this mode is selected by the start field in the receive clock mode register, it also determines the length of the sampled data to be compared to the compare 0 or compare 1 register. this field is used with fslen_ext to determine the pulse length of the receive frame sync signal. pulse length is equal to fslen + 1 receive clock periods. 31 30 29 28 27 26 25 24 ??? ? ???fsedge 23 22 21 20 19 18 17 16 ? fsos fslen 15 14 13 12 11 10 9 8 ??? ? datnb 765 4 3210 msbf ? loop datlen
485 6222f?atarm?14-jan-11 sam7se512/256/32 ? fsos: receive frame sync output selection ? fsedge: frame sync edge detection determines which edge on frame sy nc will generate the in terrupt rxsyn in the ssc status register. fsos selected receive frame sync signal rf pin 0x0 none input-only 0x1 negative pulse output 0x2 positive pulse output 0x3 driven low during data transfer output 0x4 driven high during data transfer output 0x5 toggling at each start of data transfer output 0x6-0x7 reserved undefined fsedge frame sync edge detection 0x0 positive edge detection 0x1 negative edge detection
486 6222f?atarm?14-jan-11 sam7se512/256/32 35.8.5 ssc transmit clock mode register name: ssc_tcmr access: read/write ? cks: transmit clock selection ? cko: transmit clock output mode selection ? cki: transmit clock inversion 0: the data outpu ts (data and frame sync signals) are shifted out on tr ansmit clock falling edge . the frame sync signal input is sampled on transmit clock rising edge. 1: the data outputs (data and frame sync signals) are shifted out on transmit clock rising edge. the frame sync signal input is sampled on tran smit clock falling edge. cki affects only the transmit clock and not the output clock signal. 31 30 29 28 27 26 25 24 period 23 22 21 20 19 18 17 16 sttdly 15 14 13 12 11 10 9 8 ???? start 76543210 ckg cki cko cks cks selected transmit clock 0x0 divided clock 0x1 rk clock signal 0x2 tk pin 0x3 reserved cko transmit clock output mode tk pin 0x0 none input-only 0x1 continuous transmit clock output 0x2 transmit clock only during data transfers output 0x3-0x7 reserved
487 6222f?atarm?14-jan-11 sam7se512/256/32 ? ckg: transmit clock gating selection ? start: transmit start selection ? sttdly: transmit start delay if sttdly is not 0, a delay of sttdly clock cycles is insert ed between the start event and the actual start of transmission of data. when the transmitter is programmed to start sync hronously with the receiver, the delay is also applied. note: sttdly must be set carefully. if sttdly is too short in respect to tag (transmit sync data) emission, data is emit- ted instead of the end of tag. ? period: transmit period divider selection this field selects the divider to apply to the selected transmi t clock to generate a new frame sync signal. if 0, no period signal is generated. if not 0, a period signal is generated at each 2 x (period+1) transmit clock. ckg transmit clock gating 0x0 none, continuous clock 0x1 transmit clock enabled only if tf low 0x2 transmit clock enabled only if tf high 0x3 reserved start transmit start 0x0 continuous, as soon as a word is written in the ssc_thr register (if transmit is enabled), and immediately after the end of transfer of the previous data. 0x1 receive start 0x2 detection of a low level on tf signal 0x3 detection of a high level on tf signal 0x4 detection of a falling edge on tf signal 0x5 detection of a rising edge on tf signal 0x6 detection of any level change on tf signal 0x7 detection of any edge on tf signal 0x8 - 0xf reserved
488 6222f?atarm?14-jan-11 sam7se512/256/32 35.8.6 ssc transmit frame mode register name: ssc_tfmr access: read/write ? datlen: data length 0: forbidden value (1-bit data length not supported). any other value: the bit stream contains datlen + 1 data bits. moreover, it defines the transfer size performed by the pdc2 assigned to the transmit. if datlen is lower or equal to 7, data transfers are bytes, if datlen is between 8 and 15 (included), half-words are transferred, and for any other value, 32-bit words are transferred. ? datdef: data default value this bit defines the level driven on the td pin while out of tran smission. note that if the pin is defined as multi-drive by th e pio controller, the pin is enabled only if the scc td output is 1. ? msbf: most significant bit first 0: the lowest significant bit of the data register is shifted out first in the bit stream. 1: the most significant bit of the data register is shifted out first in the bit stream. ? datnb: data number per frame this field defines the number of data words to be transferred after each transfer start, which is equal to (datnb +1). ? fslen: transmit frame sync length this field defines the length of the transmit frame sync signal and the number of bits shifted out from the transmit sync data register if fsden is 1. this field is used with fslen_ext to determine the pulse length of the transmit frame sync signal. pulse length is equal to fslen + 1 transmit clock periods. 31 30 29 28 27 26 25 24 ??? ? ???fsedge 23 22 21 20 19 18 17 16 fsden fsos fslen 15 14 13 12 11 10 9 8 ??? ? datnb 765 4 3210 m s b f ? dat d e f dat l e n
489 6222f?atarm?14-jan-11 sam7se512/256/32 ? fsos: transmit frame sync output selection ? fsden: frame sync data enable 0: the td line is driven with the default va lue during the transmi t frame sync signal. 1: ssc_tshr value is shifted out during the tran smission of the transmit frame sync signal. ? fsedge: frame sync edge detection determines which edge on frame sync will gene rate the interrupt tx syn (status register). fsos selected transmit frame sync signal tf pin 0x0 none input-only 0x1 negative pulse output 0x2 positive pulse output 0x3 driven low during data transfer output 0x4 driven high during data transfer output 0x5 toggling at each start of data transfer output 0x6-0x7 reserved undefined fsedge frame sync edge detection 0x0 positive edge detection 0x1 negative edge detection
490 6222f?atarm?14-jan-11 sam7se512/256/32 35.8.7 ssc receive holding register name: ssc_rhr access: read-only ? rdat: receive data right aligned regardless of the number of data bits defined by datlen in ssc_rfmr. 35.8.8 ssc transmit holding register name: ssc_thr access: write-only ? tdat: transmit data right aligned regardless of the number of data bits defined by datlen in ssc_tfmr. 31 30 29 28 27 26 25 24 rdat 23 22 21 20 19 18 17 16 rdat 15 14 13 12 11 10 9 8 rdat 76543210 rdat 31 30 29 28 27 26 25 24 tdat 23 22 21 20 19 18 17 16 tdat 15 14 13 12 11 10 9 8 tdat 76543210 tdat
491 6222f?atarm?14-jan-11 sam7se512/256/32 35.8.9 ssc receive synchronization holding register name: ssc_rshr access: read-only ? rsdat: receive synchronization data 35.8.10 ssc transmit synchronization holding register name: ssc_tshr access: read/write ? tsdat: transmit synchronization data 31 30 29 28 27 26 25 24 ???????? 23 22 21 20 19 18 17 16 ???????? 15 14 13 12 11 10 9 8 rsdat 76543210 rsdat 31 30 29 28 27 26 25 24 ???????? 23 22 21 20 19 18 17 16 ???????? 15 14 13 12 11 10 9 8 tsdat 76543210 tsdat
492 6222f?atarm?14-jan-11 sam7se512/256/32 35.8.11 ssc receive compare 0 register name: ssc_rc0r access: read/write ? cp0: receive compare data 0 35.8.12 ssc receive compare 1 register name: ssc_rc1r access: read/write ? cp1: receive compare data 1 31 30 29 28 27 26 25 24 ???????? 23 22 21 20 19 18 17 16 ???????? 15 14 13 12 11 10 9 8 cp0 76543210 cp0 31 30 29 28 27 26 25 24 ???????? 23 22 21 20 19 18 17 16 ???????? 15 14 13 12 11 10 9 8 cp1 76543210 cp1
493 6222f?atarm?14-jan-11 sam7se512/256/32 35.8.13 ssc status register name: ssc_sr access: read-only ? txrdy: transmit ready 0: data has been loaded in ssc_thr and is waiting to be loaded in the transmit shift register (tsr). 1: ssc_thr is empty. ? txempty: transmit empty 0: data remains in ssc_thr or is currently transmitted from tsr. 1: last data written in ssc_thr has been loaded in tsr and last data loaded in tsr has been transmitted. ? endtx: end of transmission 0: the register ssc_tcr has not reached 0 since the last write in ssc_tcr or ssc_tncr. 1: the register ssc_tcr has reached 0 sinc e the last write in ssc_tcr or ssc_tncr. ? txbufe: transmit buffer empty 0: ssc_tcr or ssc_tncr have a value other than 0. 1: both ssc_tcr and ssc_tncr have a value of 0. ? rxrdy: receive ready 0: ssc_rhr is empty. 1: data has been received and loaded in ssc_rhr. ? ovrun: receive overrun 0: no data has been loaded in ssc_rhr wh ile previous data has not been read since the last read of the status register. 1: data has been loaded in ssc_rhr while previous data has not yet been read since the last read of the status register. ? endrx: end of reception 0: data is written on the receive counter register or receive ne xt counter register. 1: end of pdc transfer when receive counter register has arrived at zero. 31 30 29 28 27 26 25 24 ???????? 23 22 21 20 19 18 17 16 ??????rxentxen 15 14 13 12 11 10 9 8 ????rxsynt xsyn cp1 cp0 76543210 rxbuff endrx ovrun rxrdy txbufe endtx txempty txrdy
494 6222f?atarm?14-jan-11 sam7se512/256/32 ? rxbuff: receive buffer full 0: ssc_rcr or ssc_rncr have a value other than 0. 1: both ssc_rcr and ssc_rncr have a value of 0. ?cp0: compare 0 0: a compare 0 has not occurred since the last read of the status register. 1: a compare 0 has occurred since the last read of the status register. ?cp1: compare 1 0: a compare 1 has not occurred since the last read of the status register. 1: a compare 1 has occurred since the last read of the status register. ? txsyn: transmit sync 0: a tx sync has not occurred since the last read of the status register. 1: a tx sync has occurred since the last read of the status register. ? rxsyn: receive sync 0: an rx sync has not occurred since the last read of the status register. 1: an rx sync has occurred since the last read of the status register. ? txen: transmit enable 0: transmit is disabled. 1: transmit is enabled. ? rxen: receive enable 0: receive is disabled. 1: receive is enabled.
495 6222f?atarm?14-jan-11 sam7se512/256/32 35.8.14 ssc interrupt enable register name: ssc_ier access: write-only ? txrdy: transmit ready interrupt enable 0: no effect. 1: enables the transmit ready interrupt. ? txempty: transmit empty interrupt enable 0: no effect. 1: enables the transmit empty interrupt. ? endtx: end of transmission interrupt enable 0: no effect. 1: enables the end of transmission interrupt. ? txbufe: transmit buffer empty interrupt enable 0: no effect. 1: enables the transmit buffer empty interrupt ? rxrdy: receive ready interrupt enable 0: no effect. 1: enables the receive ready interrupt. ? ovrun: receive overrun interrupt enable 0: no effect. 1: enables the receive overrun interrupt. ? endrx: end of reception interrupt enable 0: no effect. 1: enables the end of reception interrupt. 31 30 29 28 27 26 25 24 ???????? 23 22 21 20 19 18 17 16 ???????? 15 14 13 12 11 10 9 8 ????rxsynt xsyn cp1 cp0 76543210 rxbuff endrx ovrun rxrdy txbufe endtx txempty txrdy
496 6222f?atarm?14-jan-11 sam7se512/256/32 ? rxbuff: receive buffer full interrupt enable 0: no effect. 1: enables the receive buffer full interrupt. ? cp0: compare 0 interrupt enable 0: no effect. 1: enables the compare 0 interrupt. ? cp1: compare 1 interrupt enable 0: no effect. 1: enables the compare 1 interrupt. ? txsyn: tx sync interrupt enable 0: no effect. 1: enables the tx sync interrupt. ? rxsyn: rx sync interrupt enable 0: no effect. 1: enables the rx sync interrupt.
497 6222f?atarm?14-jan-11 sam7se512/256/32 35.8.15 ssc interrupt disable register name: ssc_idr access: write-only ? txrdy: transmit ready interrupt disable 0: no effect. 1: disables the transmit ready interrupt. ? txempty: transmit empty interrupt disable 0: no effect. 1: disables the transmit empty interrupt. ? endtx: end of transmission interrupt disable 0: no effect. 1: disables the end of transmission interrupt. ? txbufe: transmit buffer empty interrupt disable 0: no effect. 1: disables the transmit buffer empty interrupt. ? rxrdy: receive ready interrupt disable 0: no effect. 1: disables the rece ive ready interrupt. ? ovrun: receive overrun interrupt disable 0: no effect. 1: disables the receive overrun interrupt. ? endrx: end of reception interrupt disable 0: no effect. 1: disables the end of reception interrupt. 31 30 29 28 27 26 25 24 ???????? 23 22 21 20 19 18 17 16 ???????? 15 14 13 12 11 10 9 8 ????rxsynt xsyn cp1 cp0 76543210 rxbuff endrx ovrun rxrdy txbufe endtx txempty txrdy
498 6222f?atarm?14-jan-11 sam7se512/256/32 ? rxbuff: receive buffer full interrupt disable 0: no effect. 1: disables the receiv e buffer full interrupt. ? cp0: compare 0 interrupt disable 0: no effect. 1: disables the compare 0 interrupt. ? cp1: compare 1 interrupt disable 0: no effect. 1: disables the compare 1 interrupt. ? txsyn: tx sync interrupt enable 0: no effect. 1: disables the tx sync interrupt. ? rxsyn: rx sync interrupt enable 0: no effect. 1: disables the rx sync interrupt.
499 6222f?atarm?14-jan-11 sam7se512/256/32 35.8.16 ssc interrupt mask register name: ssc_imr access: read-only ? txrdy: transmit ready interrupt mask 0: the transmit ready interrupt is disabled. 1: the transmit ready interrupt is enabled. ? txempty: transmit empty interrupt mask 0: the transmit empty interrupt is disabled. 1: the transmit empty interrupt is enabled. ? endtx: end of transmission interrupt mask 0: the end of transmission interrupt is disabled. 1: the end of transmission interrupt is enabled. ? txbufe: transmit buffer empty interrupt mask 0: the transmit buffer empty interrupt is disabled. 1: the transmit buffer empty interrupt is enabled. ? rxrdy: receive ready interrupt mask 0: the receive ready interrupt is disabled. 1: the receive ready interrupt is enabled. ? ovrun: receive overrun interrupt mask 0: the receive overrun interrupt is disabled. 1: the receive overrun interrupt is enabled. ? endrx: end of reception interrupt mask 0: the end of reception interrupt is disabled. 1: the end of reception interrupt is enabled. 31 30 29 28 27 26 25 24 ???????? 23 22 21 20 19 18 17 16 ???????? 15 14 13 12 11 10 9 8 ????rxsynt xsyn cp1 cp0 76543210 rxbuf endrx ovrun rxrdy txbufe endtx txempty txrdy
500 6222f?atarm?14-jan-11 sam7se512/256/32 ? rxbuff: receive buffer full interrupt mask 0: the receive buffer full interrupt is disabled. 1: the receive buffer full interrupt is enabled. ? cp0: compare 0 interrupt mask 0: the compare 0 interrupt is disabled. 1: the compare 0 interrupt is enabled. ? cp1: compare 1 interrupt mask 0: the compare 1 interrupt is disabled. 1: the compare 1 interrupt is enabled. ? txsyn: tx sync interrupt mask 0: the tx sync interrupt is disabled. 1: the tx sync interrupt is enabled. ? rxsyn: rx sync interrupt mask 0: the rx sync interrupt is disabled. 1: the rx sync interrupt is enabled.
501 6222f?atarm?14-jan-11 sam7se512/256/32 36. timer/counter (tc) 36.1 overview the timer counter (tc) includes three identical 16-bit timer counter channels. each channel can be independently programmed to perform a wide range of functions including frequency measurement, event counting, interval measurement, pulse generation, delay timing and pulse width modulation. each channel has three external clock inputs, fi ve internal clock inputs and two multi-purpose input/output signals which can be configured by the user. each channel drives an internal inter- rupt signal which can be programmed to generate processor interrupts. the timer counter block has two global registers which act upon all three tc channels. the block control register allows the three channels to be started simultaneously with the same instruction. the block mode register defines the external clock inputs for each channel, allowing them to be chained. table gives the assignment of the device timer co unter clock inputs common to timer counter 0 to 2. timer counter clock assignment name definition timer_clock1 mck/2 timer_clock2 mck/8 timer_clock3 mck/32 timer_clock4 mck/128 timer_clock5 mck/1024
502 6222f?atarm?14-jan-11 sam7se512/256/32 36.2 block diagram figure 36-1. timer/counter block diagram table 36-1. signal name description block/channel signal name description channel signal xc0, xc1, xc2 external clock inputs tioa capture mode: timer/counter input waveform mode: timer/counter output tiob capture mode: timer/counter input waveform mode: timer/counter input/output int interrupt signal output sync synchronization input signal timer/counter channel 0 timer/counter channel 1 timer/counter channel 2 sync parallel i/o controller tc1xc1s tc0xc0s tc2xc2s int0 int1 int2 tioa0 tioa1 tioa2 tiob0 tiob1 tiob2 xc0 xc1 xc2 xc0 xc1 xc2 xc0 xc1 xc2 tclk0 tclk1 tclk2 tclk0 tclk1 tclk2 tclk0 tclk1 tclk2 tioa1 tioa2 tioa0 tioa2 tioa0 tioa1 advanced interrupt controller tclk0 tclk1 tclk2 tioa0 tiob0 tioa1 tiob1 tioa2 tiob2 timer counter tioa tiob tioa tiob tioa tiob sync sync timer_clock2 timer_clock3 timer_clock4 timer_clock5 timer_clock1
503 6222f?atarm?14-jan-11 sam7se512/256/32 36.3 pin name list 36.4 product dependencies 36.4.1 i/o lines the pins used for interfacing the compliant ex ternal devices may be multiplexed with pio lines. the programmer must first program the pio controllers to assign the tc pins to their peripheral functions. 36.4.2 power management the tc is clocked through the power management controller (pmc), thus the programmer must first configure the pmc to enable the timer/counter clock. 36.4.3 interrupt the tc has an interrupt line connected to the advanced interrupt controller (aic). handling the tc interrupt requires programming the aic before configuring the tc. table 36-2. tc pin list pin name description type tclk0-tclk2 external clock input input tioa0-tioa2 i/o line a i/o tiob0-tiob2 i/o line b i/o
504 6222f?atarm?14-jan-11 sam7se512/256/32 36.5 functional description 36.5.1 tc description the three channels of the timer/counter are independent and identical in operation. the regis- ters for channel programming are listed in table 36-4 on page 517 . 36.5.1.1 16-bit counter each channel is organized around a 16-bit counter. the value of the counter is incremented at each positive edge of the selected clock. when the counter has reached the value 0xffff and passes to 0x0000, an overflow occurs and the covfs bit in tc_sr (status register) is set. the current value of the counter is accessible in real time by reading the counter value regis- ter, tc_cv. the counter can be reset by a trigger. in this case, the counter value passes to 0x0000 on the next valid edge of the selected clock. 36.5.1.2 clock selection at block level, input clock signals of each channel can either be connected to the external inputs tclk0, tclk1 or tclk2, or be connected to th e configurable i/o signals tioa0, tioa1 or tioa2 for chaining by programming the tc_bmr (block mode). see figure 36-2 on page 505 . each channel can independently select an internal or external clock source for its counter: ? internal clock signals: timer_cl ock1, timer_clock2, timer_clock3, timer_clock4, timer_clock5 ? external clock signals: xc0, xc1 or xc2 this selection is made by the tcclks bits in the tc channel mode register. the selected clock can be inverted with the clki bit in tc_cmr. this allows counting on the opposite edges of the clock. the burst function allows the clock to be validat ed when an external signal is high. the burst parameter in the mode register defines this signal (none, xc0, xc1, xc2). see figure 36-3 on page 505 . note: in all cases, if an external clock is used, the du ration of each of its leve ls must be longer than the master clock period. the external clock frequen cy must be at least 2.5 times lower than the mas- ter clock.
505 6222f?atarm?14-jan-11 sam7se512/256/32 figure 36-2. clock chaining selection figure 36-3. clock selection timer/counter channel 0 sync tc0xc0s tioa0 tiob0 xc0 xc1 = tclk1 xc2 = tclk2 tclk0 tioa1 tioa2 timer/counter channel 1 sync tc1xc1s tioa1 tiob1 xc0 = tclk2 xc1 xc2 = tclk2 tclk1 tioa0 tioa2 timer/counter channel 2 sync tc2xc2s tioa2 tiob2 xc0 = tclk0 xc1 = tclk1 xc2 tclk2 tioa0 tioa1 timer_clock1 timer_clock2 timer_clock3 timer_clock4 timer_clock5 xc0 xc1 xc2 tcclks clki burst 1 selected clock
506 6222f?atarm?14-jan-11 sam7se512/256/32 36.5.1.3 clock control the clock of each counter can be controlled in two different ways: it can be enabled/disabled and started/stopped. see figure 36-4 . ? the clock can be enabled or disabled by the user with the clken and the clkdis commands in the control register. in capture mode it can be disabled by an rb load event if ldbdis is set to 1 in tc_cmr. in waveform mode, it can be disabled by an rc compare event if cpcdis is set to 1 in tc_cmr. when disabled, the start or the stop actions have no effect: only a clken command in the control register can re-enable the clock. when the clock is enabled, the clksta bit is set in the status register. ? the clock can also be started or stopped: a trigger (software, synchro, external or compare) always starts the clock. the clock can be stopped by an rb load event in capture mode (ldbstop = 1 in tc_cmr) or a rc compare event in waveform mode (cpcstop = 1 in tc_cmr). the start and the stop commands have effect only if the clock is enabled. figure 36-4. clock control 36.5.1.4 tc operating modes each channel can independently operate in two different modes: ? capture mode provides measurement on signals. ? waveform mode provides wave generation. the tc operating mode is prog rammed with the wave bit in th e tc channel mode register. in capture mode, tioa and tiob are configured as inputs. in waveform mode, tioa is always configured to be an output and tiob is an output if it is not selected to be the external trigger. 36.5.1.5 trigger a trigger resets the counter and starts the counter clock. three types of triggers are common to both modes, and a fourth external trigger is available to each mode. the following triggers are common to both modes: qs r s r q clksta clken clkdis stop event disable event counter clock selected clock trigger
507 6222f?atarm?14-jan-11 sam7se512/256/32 ? software trigger: each channel has a software trigger, available by setting swtrg in tc_ccr. ? sync: each channel has a synchronization signal sync. when asserted, this signal has the same effect as a software trigger. the sync signals of all channels are asserted simultaneously by writing tc_bcr (block control) with sync set. ? compare rc trigger: rc is implemented in each channel and can provide a trigger when the counter value matches the rc value if cpctrg is set in tc_cmr. the channel can also be configured to have an external trigger. in capture mode, the external trigger signal can be selected between tioa and tiob. in waveform mode, an external event can be programmed on one of the following signals: tiob, xc0, xc1 or xc2. this external event can then be programmed to perform a trigger by setting enetrg in tc_cmr. if an external trigger is used, the duration of the pulses must be longer than the master clock period in order to be detected. regardless of the trigger used, it will be taken into account at the following active edge of the selected clock. this means that the counter value can be read differently from zero just after a trigger, especially when a low frequency signal is selected as the clock. 36.5.2 capture operating mode this mode is entered by clearing the wave parameter in tc_cmr (channel mode register). capture mode allows the tc channel to perform measurements such as pulse timing, fre- quency, period, duty cycle and phase on tioa and tiob sig nals which are considered as inputs. figure 36-5 shows the configuration of the tc channel when programmed in capture mode. 36.5.2.1 capture registers a and b registers a and b (ra and rb) are used as capture registers. this means that they can be loaded with the counter value when a progr ammable event occurs on the signal tioa. the ldra parameter in tc_cmr defines the tioa edge for the loading of register a, and the ldrb parameter defines the tioa edge for the loading of register b. ra is loaded only if it has not been loaded since the last trigger or if rb has been loaded since the last loading of ra. rb is loaded only if ra has been loaded sinc e the last trigger or t he last loading of rb. loading ra or rb before the read of the last value loaded sets the overrun error flag (lovrs) in tc_sr (status register). in this case, the old value is overwritten. 36.5.2.2 trigger conditions in addition to the sync signal, the software trigger and the rc compare trigger, an external trig- ger can be defined. the abetrg bit in tc_cmr selects tioa or tiob input signal as an external trigger. the etrgedg parameter defines the ed ge (rising, falling or both) detec ted to generate an external trigger. if etrgedg = 0 (none), the external trigger is disabled.
508 6222f?atarm?14-jan-11 sam7se512/256/32 figure 36-5. capture mode timer_clock1 timer_clock2 timer_clock3 timer_clock4 timer_clock5 xc0 xc1 xc2 tcclks clki qs r s r q clksta clken clkdis burst tiob register c capture register a capture register b compare rc = 16-bit counter abetrg swtrg etrgedg cpctrg tc1_imr trig ldrbs ldras etrgs tc1_sr lovrs covfs sync 1 mtiob tioa mtioa ldra ldbstop if ra is not loaded or rb is loaded if ra is loaded ldbdis cpcs int edge detector edge detector ldrb edge detector clk ovf reset timer/counter channel
509 6222f?atarm?14-jan-11 sam7se512/256/32 36.5.3 waveform operating mode waveform operating mode is entered by setting the wave parameter in tc_cmr (channel mode register). in waveform operating mode the tc channel generates 1 or 2 pwm signals with the same fre- quency and independently programmable duty cycles, or generates different types of one-shot or repetitive pulses. in this mode, tioa is configured as an output and tiob is defined as an output if it is not used as an external event ( eevt parameter in tc_cmr). figure 36-6 shows the configuration of the tc channel when programmed in waveform operat- ing mode. 36.5.3.1 waveform selection depending on the wavsel parameter in tc_c mr (channel mode register), the behavior of tc_cv varies. with any selection, ra, rb and rc can all be used as compare registers. ra compare is used to control the tioa output, rb compare is used to control the tiob output (if correctly configured) and rc compare is used to control tioa and/or tiob outputs.
510 6222f?atarm?14-jan-11 sam7se512/256/32 figure 36-6. waveform mode tcclks clki qs r s r q clksta clken clkdis cpcdis burst tiob register a register b register c compare ra = compare rb = compare rc = cpcstop 16-bit counter eevt eevtedg sync swtrg enetrg wavsel tc1_imr trig acpc acpa aeevt aswtrg bcpc bcpb beevt bswtrg tioa mtioa tiob mtiob cpas covfs etrgs tc1_sr cpcs cpbs clk ovf reset output controller output controller int 1 edge detector timer/counter channel timer_clock1 timer_clock2 timer_clock3 timer_clock4 timer_clock5 xc0 xc1 xc2 wavsel
511 6222f?atarm?14-jan-11 sam7se512/256/32 36.5.3.2 wavsel = 00 when wavsel = 00, the value of tc_cv is incr emented from 0 to 0x ffff. once 0xffff has been reached, the value of tc_cv is reset. incrementation of tc_cv starts again and the cycle continues. see figure 36-7 . an external event trigger or a software trigger can reset the value of tc_cv. it is important to note that the trigger may occur at any time. see figure 36-8 . rc compare cannot be programmed to generate a trigger in this configuration. at the same time, rc compare can stop the counter clock (cpcstop = 1 in tc_cmr) and/or disable the counter clock (cpcdis = 1 in tc_cmr). figure 36-7. wavsel= 00 without trigger time counter value r c r b r a tiob tioa counter cleared by compare match with 0xffff 0xffff waveform examples
512 6222f?atarm?14-jan-11 sam7se512/256/32 figure 36-8. wavsel= 00 with trigger 36.5.3.3 wavsel = 10 when wavsel = 10, the value of tc_cv is incremented from 0 to the value of rc, then auto- matically reset on a rc compare. once the value of tc_cv has been reset, it is then incremented and so on. see figure 36-9 . it is important to note that tc_cv can be reset at any time by an external event or a software trigger if both are programmed correctly. see figure 36-10 . in addition, rc compare can stop the counter clock (cpcstop = 1 in tc_cmr) and/or disable the counter clock (cpcdis = 1 in tc_cmr). time counter value r c r b r a tiob tioa counter cleared by compare match with 0xffff 0xffff waveform examples counter cleared by trigger
513 6222f?atarm?14-jan-11 sam7se512/256/32 figure 36-9. wavsel = 10 without trigger figure 36-10. wavsel = 10 with trigger 36.5.3.4 wavsel = 01 when wavsel = 01, the value of tc_cv is incremented from 0 to 0xffff. once 0xffff is reached, the value of tc_cv is decremented to 0, then re-incremented to 0xffff and so on. see figure 36-11 . a trigger such as an external event or a software trigger can modify tc_cv at any time. if a trig- ger occurs while tc_cv is incrementing, tc_cv then decrements. if a trigger is received while tc_cv is decrementing, tc_cv then increments. see figure 36-12 . time counter value r c r b r a tiob tioa counter cleared by compare match with rc 0xffff waveform examples time counter value r c r b r a tiob tioa counter cleared by compare match with rc 0xffff waveform examples counter cleared by trigger
514 6222f?atarm?14-jan-11 sam7se512/256/32 rc compare cannot be programmed to generate a trigger in this configuration. at the same time, rc compare can stop the counter clock (cpcstop = 1) and/or disable the counter clock (cpcdis = 1). figure 36-11. wavsel = 01 without trigger figure 36-12. wavsel = 01 with trigger 36.5.3.5 wavsel = 11 when wavsel = 11, the value of tc_cv is incremented from 0 to rc. once rc is reached, the value of tc_cv is decremented to 0, then re-incremented to rc and so on. see figure 36-13 . time counter value r c r b r a tiob tioa counter decremented by compare match with 0xffff 0xffff waveform examples time counter value tiob tioa counter decremented by compare match with 0xffff 0xffff waveform examples counter decremented by trigger counter incremented by trigger r c r b r a
515 6222f?atarm?14-jan-11 sam7se512/256/32 a trigger such as an external event or a software trigger can modify tc_cv at any time. if a trig- ger occurs while tc_cv is incrementing, tc_cv then decrements. if a trigger is received while tc_cv is decrementing, tc_cv then increments. see figure 36-14 . rc compare can stop the counter clock (cpcstop = 1) and/or disable the counter clock (cpc- dis = 1). figure 36-13. wavsel = 11 without trigger figure 36-14. wavsel = 11 with trigger 36.5.3.6 external event/trigger conditions an external event can be programmed to be detected on one of the clock sources (xc0, xc1, xc2) or tiob. the external event selected can then be used as a trigger. time counter value r c r b r a tiob tioa counter decremented by compare match with rc 0xffff waveform examples time counter value tiob tioa counter decremented by compare match with rc 0xffff waveform examples counter decremented by trigger counter incremented by trigger r c r b r a
516 6222f?atarm?14-jan-11 sam7se512/256/32 the eevt parameter in tc_cmr selects the external tr igger. the eevtedg parameter defines the trigger edge for each of the possible external triggers (risin g, falling or both). if eevtedg is cleared (none), no external event is defined. if tiob is defined as an external event signal (eevt = 0), tiob is no longer used as an output and the compare register b is not used to generate waveforms and subsequently no irqs. in this case the tc channel can only generate a waveform on tioa. when an external event is defined, it can be used as a trigger by setting bit enetrg in tc_cmr. as in capture mode, the sync signal and the softw are trigger are also available as triggers. rc compare can also be used as a trigger depending on the parameter wavsel. 36.5.3.7 output controller the output controller defines the output level changes on tioa and tiob following an event. tiob control is used only if tiob is defin ed as output (not as an external event). the following events control tioa and tiob: software trigger, external event and rc compare. ra compare controls tioa and rb compare controls tiob. each of these events can be pro- grammed to set, clear or toggle the output as defined in the corresponding parameter in tc_cmr.
517 6222f?atarm?14-jan-11 sam7se512/256/32 36.6 timer/counter (tc) user interface 36.6.1 global register mapping tc_bcr (block control register) and tc_bmr (b lock mode register) control the whole tc block. tc channels are controlled by the registers listed in table 36-4 . the offset of each of the channel registers in table 36-4 is in relation to the offset of the corresponding channel as men - tioned in table 36-4 . 36.6.2 channel memory mapping note: 1. read-only if wave = 0 table 36-3. timer/counter (tc) global register map offset channel/register name access reset value 0x00 tc channel 0 see table 36-4 0x40 tc channel 1 see table 36-4 0x80 tc channel 2 see table 36-4 0xc0 tc block control register tc_bcr write-only ? 0xc4 tc block mode register tc_bmr read/write 0 table 36-4. tc channel memory map offset register name access reset value 0x00 channel control register tc_ccr write-only ? 0x04 channel mode register tc_cmr read/write 0 0x08 reserved ? 0x0c reserved ? 0x10 counter value tc_cv read-only 0 0x14 register a tc_ra read/write (1) 0 0x18 register b tc_rb read/write (1) 0 0x1c register c tc_rc read/write 0 0x20 status register tc_sr read-only 0 0x24 interrupt enable register tc_ier write-only ? 0x28 interrupt disable register tc_idr write-only ? 0x2c interrupt mask register tc_imr read-only 0 0xfc reserved ? ? ?
518 6222f?atarm?14-jan-11 sam7se512/256/32 36.6.3 tc block control register name: tc_bcr access: write-only ? sync: synchro command 0 = no effect. 1 = asserts the sync signal which generates a software trigger simultaneously for each of the channels. 31 30 29 28 27 26 25 24 ???????? 23 22 21 20 19 18 17 16 ???????? 15 14 13 12 11 10 9 8 ???????? 76543210 ???????sync
519 6222f?atarm?14-jan-11 sam7se512/256/32 36.6.4 tc block mode register name: tc_bmr access: read/write ? tc0xc0s: external clock signal 0 selection ? tc1xc1s: external clock signal 1 selection ? tc2xc2s: external clock signal 2 selection 31 30 29 28 27 26 25 24 ???????? 23 22 21 20 19 18 17 16 ???????? 15 14 13 12 11 10 9 8 ???????? 76543210 ? ? tc2xc2s tcxc1s tc0xc0s tc0xc0s signal connected to xc0 00tclk0 0 1 none 10tioa1 11tioa2 tc1xc1s signal connected to xc1 00tclk1 0 1 none 10tioa0 11tioa2 tc2xc2s signal connected to xc2 00tclk2 0 1 none 10tioa0 11tioa1
520 6222f?atarm?14-jan-11 sam7se512/256/32 36.6.5 tc channel control register name: tc_ccr access: write-only ? clken: counter clock enable command 0 = no effect. 1 = enables the clock if clkdis is not 1. ? clkdis: counter clock disable command 0 = no effect. 1 = disables the clock. ? swtrg: software trigger command 0 = no effect. 1 = a software trigger is performed: the counter is reset and the clock is started. 31 30 29 28 27 26 25 24 ???????? 23 22 21 20 19 18 17 16 ???????? 15 14 13 12 11 10 9 8 ???????? 76543210 ?????swtrgclkdisclken
521 6222f?atarm?14-jan-11 sam7se512/256/32 36.6.6 tc channel mode register: capture mode name: tc_cmr access: read/write ? tcclks: clock selection ? clki: clock invert 0 = counter is incremented on rising edge of the clock. 1 = counter is incremented on falling edge of the clock. ? burst: burst signal selection ? ldbstop: counter clock stopped with rb loading 0 = counter clock is not stopped when rb loading occurs. 1 = counter clock is stopped when rb loading occurs. ? ldbdis: counter clock disable with rb loading 0 = counter clock is not disabl ed when rb loading occurs. 1 = counter clock is disabled when rb loading occurs. 31 30 29 28 27 26 25 24 ???????? 23 22 21 20 19 18 17 16 ? ? ? ? ldrb ldra 15 14 13 12 11 10 9 8 wave = 0 cpctrg ? ? ? abetrg etrgedg 76543210 ldbdis ldbstop burst clki tcclks tcclks clock selected 000timer_clock1 001timer_clock2 010timer_clock3 011timer_clock4 100timer_clock5 101xc0 110xc1 111xc2 burst 0 0 the clock is not gated by an external signal. 0 1 xc0 is anded with the selected clock. 1 0 xc1 is anded with the selected clock. 1 1 xc2 is anded with the selected clock.
522 6222f?atarm?14-jan-11 sam7se512/256/32 ? etrgedg: external trigger edge selection ? abetrg: tioa or tiob external trigger selection 0 = tiob is used as an external trigger. 1 = tioa is used as an external trigger. ? cpctrg: rc compare trigger enable 0 = rc compare has no effect on the counter and its clock. 1 = rc compare resets the counter and starts the counter clock. ?wave 0 = capture mode is enabled. 1 = capture mode is disabled (waveform mode is enabled). ? ldra: ra loading selection ? ldrb: rb loading selection etrgedg edge 0 0 none 0 1 rising edge 1 0 falling edge 1 1 each edge ldra edge 0 0 none 0 1 rising edge of tioa 1 0 falling edge of tioa 1 1 each edge of tioa ldrb edge 0 0 none 0 1 rising edge of tioa 1 0 falling edge of tioa 1 1 each edge of tioa
523 6222f?atarm?14-jan-11 sam7se512/256/32 36.6.7 tc channel mode register: waveform mode name: tc_cmr access: read/write ? tcclks: clock selection ? clki: clock invert 0 = counter is incremented on rising edge of the clock. 1 = counter is incremented on falling edge of the clock. ? burst: burst signal selection ? cpcstop: counter clock stopped with rc compare 0 = counter clock is not stopped when counter reaches rc. 1 = counter clock is stopped when counter reaches rc. ? cpcdis: counter clock disable with rc compare 0 = counter clock is not disabl ed when counter reaches rc. 1 = counter clock is disabled when counter reaches rc. 31 30 29 28 27 26 25 24 bswtrg beevt bcpc bcpb 23 22 21 20 19 18 17 16 aswtrg aeevt acpc acpa 15 14 13 12 11 10 9 8 wave = 1 wavsel enetrg eevt eevtedg 76543210 cpcdis cpcstop burst clki tcclks tcclks clock selected 0 0 0 timer_clock1 0 0 1 timer_clock2 0 1 0 timer_clock3 0 1 1 timer_clock4 1 0 0 timer_clock5 101xc0 110xc1 111xc2 burst 0 0 the clock is not gated by an external signal. 0 1 xc0 is anded with the selected clock. 1 0 xc1 is anded with the selected clock. 1 1 xc2 is anded with the selected clock.
524 6222f?atarm?14-jan-11 sam7se512/256/32 ? eevtedg: external ev ent edge selection ? eevt: external event selection note: 1. if tiob is chosen as the external ev ent signal, it is configured as an input and no longer generates waveforms and sub- sequently no irqs . ? enetrg: external event trigger enable 0 = the external event has no effect on the counter and its clock. in this case, the selected external event only controls the tioa output. 1 = the external event resets the counter and starts the counter clock. ? wavsel: waveform selection ? wave = 1 0 = waveform mode is disabled (capture mode is enabled). 1 = waveform mode is enabled. ? acpa: ra compare effect on tioa eevtedg edge 0 0 none 0 1 rising edge 1 0 falling edge 1 1 each edge eevt signal selected as exte rnal event tiob direction 0 0 tiob input (1) 01xc0 output 10xc1 output 11xc2 output wavsel effect 0 0 up mode without automatic trigger on rc compare 1 0 up mode with automa tic trigger on rc compare 0 1 updown mode without automatic trigger on rc compare 1 1 updown mode with automatic trigger on rc compare acpa effect 0 0 none 0 1 set 1 0 clear 1 1 toggle
525 6222f?atarm?14-jan-11 sam7se512/256/32 ? acpc: rc compare effect on tioa ? aeevt: external event effect on tioa ? aswtrg: software trigger effect on tioa ? bcpb: rb compare effect on tiob ? bcpc: rc compare effect on tiob acpc effect 0 0 none 0 1 set 1 0 clear 1 1 toggle aeevt effect 0 0 none 0 1 set 1 0 clear 1 1 toggle aswtrg effect 0 0 none 0 1 set 1 0 clear 1 1 toggle bcpb effect 0 0 none 0 1 set 1 0 clear 1 1 toggle bcpc effect 0 0 none 0 1 set 1 0 clear 1 1 toggle
526 6222f?atarm?14-jan-11 sam7se512/256/32 ? beevt: external event effect on tiob ? bswtrg: software trigger effect on tiob beevt effect 0 0 none 0 1 set 1 0 clear 1 1 toggle bswtrg effect 0 0 none 0 1 set 1 0 clear 1 1 toggle
527 6222f?atarm?14-jan-11 sam7se512/256/32 36.6.8 tc counter value register name: tc_cv access: read-only ? cv: counter value cv contains the counter value in real time. 31 30 29 28 27 26 25 24 ???????? 23 22 21 20 19 18 17 16 ???????? 15 14 13 12 11 10 9 8 cv 76543210 cv
528 6222f?atarm?14-jan-11 sam7se512/256/32 36.6.9 tc register a name: tc_ra access: read-only if wave = 0, read/write if wave = 1 ? ra: register a ra contains the register a value in real time. 31 30 29 28 27 26 25 24 ???????? 23 22 21 20 19 18 17 16 ???????? 15 14 13 12 11 10 9 8 ra 76543210 ra
529 6222f?atarm?14-jan-11 sam7se512/256/32 36.6.10 tc register b name: tc_rb access: read-only if wave = 0, read/write if wave = 1 ? rb: register b rb contains the register b value in real time. 36.6.11 tc register c name: tc_rc access: read/write ? rc: register c rc contains the register c value in real time. 31 30 29 28 27 26 25 24 ???????? 23 22 21 20 19 18 17 16 ???????? 15 14 13 12 11 10 9 8 rb 76543210 rb 31 30 29 28 27 26 25 24 ???????? 23 22 21 20 19 18 17 16 ???????? 15 14 13 12 11 10 9 8 rc 76543210 rc
530 6222f?atarm?14-jan-11 sam7se512/256/32 36.6.12 tc status register name: tc_sr access: read-only ? covfs: counter overflow status 0 = no counter overflow has occurred since the last read of the status register. 1 = a counter overflow has occurred since the last read of the status register. ? lovrs: load overrun status 0 = load overrun has not occurred since the last read of the status register or wave = 1. 1 = ra or rb have been loaded at least twice without any read of the corresponding register since the last read of the sta- tus register, if wave = 0. ? cpas: ra compare status 0 = ra compare has not occurred since the last read of the status register or wave = 0. 1 = ra compare has occurred since the last read of the status register, if wave = 1. ? cpbs: rb compare status 0 = rb compare has not occurred since the last read of the status register or wave = 0. 1 = rb compare has occurred since the last read of the status register, if wave = 1. ? cpcs: rc compare status 0 = rc compare has not occurred since the last read of the status register. 1 = rc compare has occurred since the last read of the status register. ? ldras: ra loading status 0 = ra load has not occurred si nce the last read of the status register or wave = 1. 1 = ra load has occurred since the last re ad of the status register, if wave = 0. ? ldrbs: rb loading status 0 = rb load has not occurred si nce the last read of the status register or wave = 1. 1 = rb load has occurred since the last re ad of the status register, if wave = 0. ? etrgs: external trigger status 0 = external trigger has not occurred since the last read of the status register. 1 = external trigger has occurred since the last read of the status register. 31 30 29 28 27 26 25 24 ???????? 23 22 21 20 19 18 17 16 ?????mtiobmtioaclksta 15 14 13 12 11 10 9 8 ???????? 76543210 etrgs ldrbs ldras cpcs cpbs cpas lovrs covfs
531 6222f?atarm?14-jan-11 sam7se512/256/32 ? clksta: clock enabling status 0 = clock is disabled. 1 = clock is enabled. ? mtioa: tioa mirror 0 = tioa is low. if wave = 0, this mean s that tioa pin is low. if wave = 1, this means that tioa is driven low. 1 = tioa is high. if wave = 0, this mean s that tioa pin is high. if wave = 1, this means that ti oa is driven high. ? mtiob: tiob mirror 0 = tiob is low. if wave = 0, this mean s that tiob pin is low. if wave = 1, this means that tiob is driven low. 1 = tiob is high. if wave = 0, this mean s that tiob pin is high. if wave = 1, this means that ti ob is driven high.
532 6222f?atarm?14-jan-11 sam7se512/256/32 36.6.13 tc interrupt enable register name: tc_ier access: write-only ? covfs: counter overflow 0 = no effect. 1 = enables the counter overflow interrupt. ? lovrs: load overrun 0 = no effect. 1 = enables the load overrun interrupt. ? cpas: ra compare 0 = no effect. 1 = enables the ra compare interrupt. ? cpbs: rb compare 0 = no effect. 1 = enables the rb compare interrupt. ? cpcs: rc compare 0 = no effect. 1 = enables the rc compare interrupt. ? ldras: ra loading 0 = no effect. 1 = enables the ra load interrupt. ? ldrbs: rb loading 0 = no effect. 1 = enables the rb load interrupt. ? etrgs: external trigger 0 = no effect. 1 = enables the external trigger interrupt. 31 30 29 28 27 26 25 24 ???????? 23 22 21 20 19 18 17 16 ???????? 15 14 13 12 11 10 9 8 ???????? 76543210 etrgs ldrbs ldras cpcs cpbs cpas lovrs covfs
533 6222f?atarm?14-jan-11 sam7se512/256/32 36.6.14 tc interrupt disable register name: tc_idr access: write-only ? covfs: counter overflow 0 = no effect. 1 = disables the counter overflow interrupt. ? lovrs: load overrun 0 = no effect. 1 = disables the load overru n interrupt (if wave = 0). ? cpas: ra compare 0 = no effect. 1 = disables the ra compare interrupt (if wave = 1). ? cpbs: rb compare 0 = no effect. 1 = disables the rb compare interrupt (if wave = 1). ? cpcs: rc compare 0 = no effect. 1 = disables the rc compare interrupt. ? ldras: ra loading 0 = no effect. 1 = disables the ra load interrupt (if wave = 0). ? ldrbs: rb loading 0 = no effect. 1 = disables the rb load interrupt (if wave = 0). ? etrgs: external trigger 0 = no effect. 1 = disables the external trigger interrupt. 31 30 29 28 27 26 25 24 ???????? 23 22 21 20 19 18 17 16 ???????? 15 14 13 12 11 10 9 8 ???????? 76543210 etrgs ldrbs ldras cpcs cpbs cpas lovrs covfs
534 6222f?atarm?14-jan-11 sam7se512/256/32 36.6.15 tc interrupt mask register name: tc_imr access: read-only ? covfs: counter overflow 0 = the counter overflow interrupt is disabled. 1 = the counter overflow interrupt is enabled. ? lovrs: load overrun 0 = the load overrun interrupt is disabled. 1 = the load overrun interrupt is enabled. ? cpas: ra compare 0 = the ra compare interrupt is disabled. 1 = the ra compare interrupt is enabled. ? cpbs: rb compare 0 = the rb compare interrupt is disabled. 1 = the rb compare interrupt is enabled. ? cpcs: rc compare 0 = the rc compare interrupt is disabled. 1 = the rc compare interrupt is enabled. ? ldras: ra loading 0 = the load ra interrupt is disabled. 1 = the load ra interrupt is enabled. ? ldrbs: rb loading 0 = the load rb interrupt is disabled. 1 = the load rb interrupt is enabled. ? etrgs: external trigger 0 = the external trigger interrupt is disabled. 1 = the external trigger interrupt is enabled. 31 30 29 28 27 26 25 24 ???????? 23 22 21 20 19 18 17 16 ???????? 15 14 13 12 11 10 9 8 ???????? 76543210 etrgs ldrbs ldras cpcs cpbs cpas lovrs covfs
535 6222f?atarm?14-jan-11 sam7se512/256/32 37. pulse width modulation controller (pwm) 37.1 overview the pwm macrocell controls several cha nnels independently. each channel controls one square output waveform. characteristics of the output waveform such as period, duty-cycle and polarity are configurable through the user interface. each channel selects and uses one of the clocks provided by the clock generator. the cloc k generator provides several clocks resulting from the division of the pwm macrocell master clock. all pwm macrocell accesses are made through apb mapped registers. channels can be synchronized, to generate non overlapped waveforms. all channels integrate a double buffering system in order to prevent an unexpected output waveform while modifying the period or the duty-cycle. 37.2 block diagram figure 37-1. pulse width modulation controller block diagram pwm controller apb pwmx pwmx pwmx channel update duty cycle counter pwm0 channel pio aic pmc mck clock generator apb interface interrupt generator clock selector period comparator update duty cycle counter clock selector period comparator pwm0 pwm0
536 6222f?atarm?14-jan-11 sam7se512/256/32 37.3 i/o lines description each channel outputs one waveform on one external i/o line. 37.4 product dependencies 37.4.1 i/o lines the pins used for interfacing the pwm may be multiplexed with pio lines. the programmer must first program the pio controller to assign the desire d pwm pins to their peripheral function. if i/o lines of the pwm are not used by the applicati on, they can be used for other purposes by the pio controller. all of the pwm outputs may or may not be enabled. if an application requires only four channels, then only four pio lines will be assigned to pwm outputs. 37.4.2 power management the pwm is not continuously clocked. the programmer must first enable the pwm clock in the power management controller (pmc) before using the pwm. however, if the application does not require pwm operations, the pwm clock can be stopped when not needed and be restarted later. in this case, th e pwm will resume its operat ions where it left off. configuring the pwm does not require the pwm clock to be enabled. 37.4.3 interrupt sources the pwm interrupt line is connected on one of the internal sources of the advanced interrupt controller. using the pwm interrupt requires the ai c to be programmed first. note that it is not recommended to use the pwm interrupt line in edge sensitive mode. table 37-1. i/o line description name description type pwmx pwm waveform output for channel x output
537 6222f?atarm?14-jan-11 sam7se512/256/32 37.5 functional description the pwm macrocell is primarily composed of a clock generator module and 4 channels. ? clocked by the system clock, mck, the clock generator module provides 13 clocks. ? each channel can independently choose one of the clock generator outputs. ? each channel generates an output waveform with attributes that can be defined independently for each channel through the user interface registers. 37.5.1 pwm clock generator figure 37-2. functional view of the clock generator block diagram caution: before using the pwm macrocell, the prog rammer must first enable the pwm clock in the power management controller (pmc). the pwm macrocell master clock, mck, is divide d in the clock generator module to provide dif- ferent clocks available for all channels. each channel can independently select one of the divided clocks. the clock generator is divided in three blocks: ? a modulo n counter which provides 11 clocks: f mck , f mck /2, f mck /4, f mck /8, f mck /16, f mck /32, f mck /64, f mck /128, f mck /256, f mck /512, f mck /1024 modulo n counter mck mck/2 mck/4 mck/16 mck/32 mck/64 mck/8 divider a clka diva pwm_mr mck mck/128 mck/256 mck/512 mck/1024 prea divider b clkb divb pwm_mr preb
538 6222f?atarm?14-jan-11 sam7se512/256/32 ? two linear dividers (1, 1/2, 1/3, ... 1/255) that provide two separate clocks: clka and clkb each linear divider can independently divide one of the clocks of the modulo n counter. the selection of the clock to be divided is made ac cording to the prea (preb) field of the pwm mode register (pwm_mr). the resulting clock clka (clkb) is the clock selected divided by diva (divb) field value in the pwm mode register (pwm_mr). after a reset of the pwm controller, diva (divb) and prea (preb) in the pwm mode register are set to 0. this implies that after reset clka (clkb) are turned off. at reset, all clocks provided by the modulo n counter are turned off except clock ?clk?. this situa- tion is also true when the pwm master cloc k is turned off through the power management controller. 37.5.2 pwm channel 37.5.2.1 block diagram figure 37-3. functional view of the channel block diagram each of the 4 channels is composed of three blocks: ? a clock selector which selects one of the clocks provided by the clock generator described in section 37.5.1 ?pwm clock generator? on page 537 . ? an internal counter clocked by the output of the clock selector. this internal counter is incremented or decremented according to the channel configuration and comparators events. the size of the internal counter is 16 bits. ? a comparator used to generate events according to the internal counter value. it also computes the pwmx output waveform according to the configuration. 37.5.2.2 waveform properties the different properties of output waveforms are: ? the internal clock selection . the internal channel counter is clocked by one of the clocks provided by the clock generator described in the previous section. this channel parameter is defined in the cpre field of the pwm_cmrx register. this field is reset at 0. ? the waveform period . this channel parameter is defined in the cprd field of the pwm_cprdx register. - if the waveform is left aligned, then the output waveform period depends on the counter source clock and can be calculated: by using the master clock (mck) divided by an x given prescaler value (with x being 1, 2, 4, 8, 16, 32, 64, 128, 256, 512, or 1024), the resulting period formula comparator pwmx output waveform internal counter clock selector inputs from clock generator inputs from apb bus channel
539 6222f?atarm?14-jan-11 sam7se512/256/32 will be: by using a master clock divided by one of both diva or divb divider, the formula becomes, respectively: or if the waveform is center aligned then the output waveform period depends on the counter source clock and can be calculated: by using the master clock (mck) divided by an x given prescaler value (with x being 1, 2, 4, 8, 16, 32, 64, 128, 256, 512, or 1024 ). the resulting period formula will be: by using a master clock divided by one of both diva or divb divider, the formula becomes, respectively: or ? the waveform duty cycle . this channel parameter is defined in the cdty field of the pwm_cdtyx register. if the waveform is left aligned then: if the waveform is center aligned, then: ? the waveform polarity. at the beginning of the period, the signal can be at high or low level. this property is defined in the cpol field of the pwm_cmrx register. by default the signal starts by a low level. ? the waveform alignment . the output waveform can be left or center aligned. center aligned waveforms can be used to generate non overlapped waveforms. this property is defined in the calg field of the pwm_cmrx register. the default mode is left aligned. xcprd () mck -------------------------------- crpd diva () mck ------------------------------------------- crpd divab () mck ----------------------------------------------- 2 xcprd () mck ------------------------------------------ - 2 cprd diva () mck ----------------------------------------------------- - 2 cprd divb () mck ----------------------------------------------------- - duty cycle period 1 fchannel_x_clock cdty ? ? () period ----------------------------------------------------------------------------------------------------------- - = duty cycle period 2 ? () 1 fchannel_x_clock cdty ? ? ()) period 2 ? () ------------------------------------------------------------------------------------------------------------------------------ =
540 6222f?atarm?14-jan-11 sam7se512/256/32 figure 37-4. non overlapped center aligned waveforms note: 1. see figure 37-5 on page 541 for a detailed description of center aligned waveforms. when center aligned, the internal channel count er increases up to cprd and.decreases down to 0. this ends the period. when left aligned, the internal channel counter increases up to cprd and is reset. this ends the period. thus, for the same cprd value, the period for a ce nter aligned channel is twice the period for a left aligned channel. waveforms are fixed at 0 when: ? cdty = cprd and cpol = 0 ? cdty = 0 and cpol = 1 waveforms are fixed at 1 (once the channel is enabled) when: ? cdty = 0 and cpol = 0 ? cdty = cprd and cpol = 1 the waveform polarity must be set before enabling the channel. this immediately affects the channel output level. changes on channel polari ty are not taken into account while the channel is enabled. pwm0 pwm1 period no overlap
541 6222f?atarm?14-jan-11 sam7se512/256/32 figure 37-5. waveform properties pwm_mckx chidx(pwm_sr) center aligned cprd(pwm_cprdx) cdty(pwm_cdtyx) pwm_ccntx output waveform pwmx cpol(pwm_cmrx) = 0 output waveform pwmx cpol(pwm_cmrx) = 1 chidx(pwm_isr) left aligned cprd(pwm_cprdx) cdty(pwm_cdtyx) pwm_ccntx output waveform pwmx cpol(pwm_cmrx) = 0 output waveform pwmx cpol(pwm_cmrx) = 1 chidx(pwm_isr) calg(pwm_cmrx) = 0 calg(pwm_cmrx) = 1 period period chidx(pwm_ena) chidx(pwm_dis)
542 6222f?atarm?14-jan-11 sam7se512/256/32 37.5.3 pwm controller operations 37.5.3.1 initialization before enabling the output channel, this channel must have been configured by the software application: ? configuration of the clock generator if diva and divb are required ? selection of the clock for each channel (cpre field in the pwm_cmrx register) ? configuration of the waveform alignment for each channel (calg field in the pwm_cmrx register) ? configuration of the period for each channel (cprd in the pwm_cprdx register). writing in pwm_cprdx register is possible while the channel is disabled. after validation of the channel, the user must use pwm_cupdx register to update pwm_cprdx as explained below. ? configuration of the duty cycl e for each channel (cdty in the pwm_cdtyx register). writing in pwm_cdtyx register is possible while the channel is disabled. after validation of the channel, the user must use pwm_cupdx register to update pwm_cdtyx as explained below. ? configuration of the output waveform polarity for each channel (cpol in the pwm_cmrx register) ? enable interrupts (writing chidx in the pwm_ier register) ? enable the pwm channel (writing chidx in the pwm_ena register) it is possible to synchronize different channels by enabling them at the same time by means of writing simultaneously several chidx bits in the pwm_ena register. ? in such a situation, all channels may have the same clock selector configuration and the same period specified. 37.5.3.2 source clock selection criteria the large number of source clocks can make selection difficult. the relationship between the value in the period register (pwm_cprdx) an d the duty cycle regi ster (pwm_cdtyx) can help the user in choosing. the event number written in the period register gives the pwm accu- racy. the duty cycle quantum cannot be lower than 1/pwm_cprdx value. the higher the value of pwm_cprdx, the greater the pwm accuracy. for example, if the user sets 15 (in decimal) in pwm_cprdx, the user is able to set a value between 1 up to 14 in pwm_cdtyx register. the resulting duty cycle quantum cannot be lower than 1/15 of the pwm period. 37.5.3.3 changing the duty cycle or the period it is possible to modulate the output waveform duty cycle or period. to prevent unexpected output waveform, the user must use the update register (pwm_cupdx) to change waveform parameters while the channel is still enabled. the user can write a new period value or duty cycle value in the update re gister (pwm_cupdx). this register holds the new value until the end of the current cycle and updates the value for the next cycle. depending on the cpd field in the pwm_cmrx register , pwm_cupdx either updates pwm_cprdx or pwm_cdtyx. note that even if the update register is used, the period must not be smaller than the duty cycle.
543 6222f?atarm?14-jan-11 sam7se512/256/32 figure 37-6. synchronized period or duty cycle update to prevent overwriting the pwm_cupdx by software , the user can use status events in order to synchronize his software. two methods are possibl e. in both, the user must enable the dedi- cated interrupt in pwm_ier at pwm controller level. the first method ( polling method) consists of reading the relevant status bit in pwm_isr regis- ter according to the enabled channel(s). see figure 37-7 . the second method uses an interrupt service routine associated with the pwm channel. note: reading the pwm_isr register automatically clears chidx flags. figure 37-7. polling method note: polarity and alignment can be modified only when the channel is disabled. pwm_cupdx value pwm_cprdx pwm_cdtyx end of cycle pwm_cmrx. cpd user's writing 1 0 writing in pwm_cupdx the last write has been taken into account chidx = 1 writing in cpd field update of the period or duty cycle pwm_isr read acknowledgement and clear previous register state yes
544 6222f?atarm?14-jan-11 sam7se512/256/32 37.5.3.4 interrupts depending on the interrupt mask in the pwm_imr register, an interrupt is generated at the end of the corresponding channel period. the interrupt remains active until a read operation in the pwm_isr register occurs. a channel interrupt is enabled by setting the corresponding bit in the pwm_ier register. a chan- nel interrupt is disabled by setting the corresponding bit in the pwm_idr register.
545 6222f?atarm?14-jan-11 sam7se512/256/32 37.6 pulse width modulation (pwm ) controller user interface table 37-2. pwm controller registers offset register name access peripheral reset value 0x00 pwm mode register pwm_mr read/write 0 0x04 pwm enable register pwm_ena write-only - 0x08 pwm disable register pwm_dis write-only - 0x0c pwm status register pwm_sr read-only 0 0x10 pwm interrupt enable register pwm_ier write-only - 0x14 pwm interrupt disable register pwm_idr write-only - 0x18 pwm interrupt mask register pwm_imr read-only 0 0x1c pwm interrupt status register pwm_isr read-only 0 0x4c - 0xfc reserved ? ? ? 0x100 - 0x1fc reserved 0x200 channel 0 mode register pwm_cmr0 read/write 0x0 0x204 channel 0 duty cycle register pwm_cdty0 read/write 0x0 0x208 channel 0 period register pwm_cprd0 read/write 0x0 0x20c channel 0 counter register pwm_ccnt0 read-only 0x0 0x210 channel 0 update register pwm_cupd0 write-only - ... reserved 0x220 channel 1 mode register pwm_cmr1 read/write 0x0 0x224 channel 1 duty cycle register pwm_cdty1 read/write 0x0 0x228 channel 1 period register pwm_cprd1 read/write 0x0 0x22c channel 1 counter register pwm_ccnt1 read-only 0x0 0x230 channel 1 update register pwm_cupd1 write-only - ... ... ... ... ...
546 6222f?atarm?14-jan-11 sam7se512/256/32 37.6.1 pwm mode register name: pwm_mr access: read/write ? diva, divb: clka, clkb divide factor ? prea, preb 31 30 29 28 27 26 25 24 ???? preb 23 22 21 20 19 18 17 16 divb 15 14 13 12 11 10 9 8 ???? prea 76543210 diva diva, divb clka, clkb 0 clka, clkb clock is turned off 1 clka, clkb clock is clock selected by prea, preb 2-255 clka, clkb clock is clock selected by prea, preb divided by diva, divb factor. prea, preb divider input clock 0000mck. 0001mck/2 0010mck/4 0011mck/8 0100mck/16 0101mck/32 0110mck/64 0111mck/128 1000mck/256 1001mck/512 1010mck/ 1024 other reserved
547 6222f?atarm?14-jan-11 sam7se512/256/32 37.6.2 pwm enable register name: pwm_ena access: write-only ? chidx: channel id 0 = no effect. 1 = enable pwm output for channel x. 37.6.3 pwm disable register name: pwm_dis access: write-only ? chidx: channel id 0 = no effect. 1 = disable pwm output for channel x. 31 30 29 28 27 26 25 24 ???????? 23 22 21 20 19 18 17 16 ???????? 15 14 13 12 11 10 9 8 ???????? 76543210 ????chid3chid2chid1chid0 31 30 29 28 27 26 25 24 ???????? 23 22 21 20 19 18 17 16 ???????? 15 14 13 12 11 10 9 8 ???????? 76543210 ????chid3chid2chid1chid0
548 6222f?atarm?14-jan-11 sam7se512/256/32 37.6.4 pwm status register name: pwm_sr access: read-only ? chidx: channel id 0 = pwm output for channel x is disabled. 1 = pwm output for channel x is enabled. 31 30 29 28 27 26 25 24 ???????? 23 22 21 20 19 18 17 16 ???????? 15 14 13 12 11 10 9 8 ???????? 76543210 ????chid3chid2chid1chid0
549 6222f?atarm?14-jan-11 sam7se512/256/32 37.6.5 pwm interrupt enable register name: pwm_ier access: write-only ? chidx: channel id. 0 = no effect. 1 = enable interrupt for pwm channel x. 37.6.6 pwm interrupt disable register name: pwm_idr access: write-only ? chidx: channel id. 0 = no effect. 1 = disable interrupt for pwm channel x. 31 30 29 28 27 26 25 24 ???????? 23 22 21 20 19 18 17 16 ???????? 15 14 13 12 11 10 9 8 ???????? 76543210 ????chid3chid2chid1chid0 31 30 29 28 27 26 25 24 ???????? 23 22 21 20 19 18 17 16 ???????? 15 14 13 12 11 10 9 8 ???????? 76543210 ????chid3chid2chid1chid0
550 6222f?atarm?14-jan-11 sam7se512/256/32 37.6.7 pwm interrupt mask register name: pwm_imr access: read-only ? chidx: channel id. 0 = interrupt for pwm channel x is disabled. 1 = interrupt for pwm channel x is enabled. 37.6.8 pwm interrupt status register name: pwm_isr access: read-only ? chidx: channel id 0 = no new channel period has been achieved si nce the last read of the pwm_isr register. 1 = at least one new channel period has been achiev ed since the last read of the pwm_isr register. note: reading pwm_isr automa tically clears chidx flags. 31 30 29 28 27 26 25 24 ???????? 23 22 21 20 19 18 17 16 ???????? 15 14 13 12 11 10 9 8 ???????? 76543210 ????chid3chid2chid1chid0 31 30 29 28 27 26 25 24 ???????? 23 22 21 20 19 18 17 16 ???????? 15 14 13 12 11 10 9 8 ???????? 76543210 ????chid3chid2chid1chid0
551 6222f?atarm?14-jan-11 sam7se512/256/32 37.6.9 pwm channel mode register name: pwm_cmrx access: read/write ? cpre: channel pre-scaler ? calg: channel alignment 0 = the period is left aligned. 1 = the period is center aligned. ? cpol: channel polarity 0 = the output waveform starts at a low level. 1 = the output waveform starts at a high level. ? cpd: channel update period 0 = writing to the pwm_cupdx will modify the duty cycle at the next period start event. 1 = writing to the pwm_cupdx will modify th e period at the next period start event. 31 30 29 28 27 26 25 24 ???????? 23 22 21 20 19 18 17 16 ???????? 15 14 13 12 11 10 9 8 ?????cpdcpolcalg 76543210 ???? cpre cpre channel pre-scaler 0000mck 0001mck/2 0010mck/4 0011mck/8 0100mck/16 0101mck/32 0110mck/64 0111mck/128 1000mck/256 1001mck/512 1010mck/1024 1011clka 1100clkb other reserved
552 6222f?atarm?14-jan-11 sam7se512/256/32 37.6.10 pwm channel duty cycle register name: pwm_cdtyx access: read/write only the first 16 bits (internal ch annel counter size) are significant. ? cdty: channel duty cycle defines the waveform duty cycle. this value must be defined between 0 and cprd (pwm_cprx). 31 30 29 28 27 26 25 24 cdty 23 22 21 20 19 18 17 16 cdty 15 14 13 12 11 10 9 8 cdty 76543210 cdty
553 6222f?atarm?14-jan-11 sam7se512/256/32 37.6.11 pwm channel period register name: pwm_cprdx access: read/write only the first 16 bits (internal ch annel counter size) are significant. ? cprd: channel period if the waveform is left-aligned, then the output waveform period depends on the counter source clock and can be calculated: ? by using the master clock (mck) divided by an x given prescaler value (with x being 1, 2, 4, 8, 16, 32, 64, 128, 256, 512, or 1024). the resu lting period formula will be: ? by using a master clock divided by one of both diva or divb divider, the formula becomes, respectively: or if the waveform is center-aligned, then the output waveform period depends on the counter source clock and can be calculated: ? by using the master clock (mck) divided by an x given prescaler value (with x being 1, 2, 4, 8, 16, 32, 64, 128, 256, 512, or 1024) . the resulting pe riod formula will be: ? by using a master clock divided by one of both diva or divb divider, the formula becomes, respectively: or 31 30 29 28 27 26 25 24 cprd 23 22 21 20 19 18 17 16 cprd 15 14 13 12 11 10 9 8 cprd 76543210 cprd xcprd () mck -------------------------------- crpd diva () mck ------------------------------------------- crpd divab () mck ----------------------------------------------- 2 xcprd () mck ------------------------------------------ - 2 cprd diva () mck ----------------------------------------------------- - 2 cprd divb () mck ----------------------------------------------------- -
554 6222f?atarm?14-jan-11 sam7se512/256/32 37.6.12 pwm channel counter register name: pwm_ccntx access: read-only ? cnt: channel counter register internal counter value. this register is reset when: the channel is enabled (writing chidx in the pwm_ena register). the counter reaches cprd value defined in the pwm_cp rdx register if the wave form is left aligned. 37.6.13 pwm channel update register name: pwm_cupdx access: write-only this register acts as a double buffer for the period or the duty cycle. this prevents an unexpected waveform when modify- ing the waveform period or duty-cycle. only the first 16 bits (internal ch annel counter size) are significant. 31 30 29 28 27 26 25 24 cnt 23 22 21 20 19 18 17 16 cnt 15 14 13 12 11 10 9 8 cnt 76543210 cnt 31 30 29 28 27 26 25 24 cupd 23 22 21 20 19 18 17 16 cupd 15 14 13 12 11 10 9 8 cupd 76543210 cupd cpd (pwm_cmrx register) 0 the duty-cycle (cdtc in the pwm_cdrx regist er) is updated with the cupd value at the beginning of the next period. 1 the period (cprd in the pwm_cprx register) is updated with the cupd value at the beginning of the next period.
555 6222f?atarm?14-jan-11 sam7se512/256/32 38. usb device port (udp) 38.1 overview the usb device port (udp) is compliant with the universal serial bus (usb) v2.0 full-speed device specification. each endpoint can be configured in one of several usb transfer types. it can be associated with one or two banks of a dual-port ram used to store the current data payload. if two banks are used, one dpr bank is read or written by the proc essor, while the other is read or written by the usb device peripheral. this feature is mandator y for isochronous endpoints. thus the device maintains the maximum bandwidth (1m bytes/s) by working with endpoints with two banks of dpr. note: 1. the dual-bank function provides two banks for an endpoint. this feature is used for ping-pong mode. suspend and resume are automatically detected by the usb device, which notifies the proces- sor by raising an interrupt. depending on the product, an external signal can be used to send a wake up to the usb host controller. table 38-1. usb endpoint description endpoint number mn emonic dual-bank (1) max. endpoint size endpoint type 0 ep0 no 8 control/bulk/interrupt 1 ep1 yes 64 bulk/iso/interrupt 2 ep2 yes 64 bulk/iso/interrupt 3 ep3 no 64 control/bulk/interrupt 4 ep4 yes 64 bulk/iso/interrupt 5 ep5 yes 64 bulk/iso/interrupt 6 ep6 yes 64 bulk/iso/interrupt 7 ep7 yes 64 bulk/iso/interrupt
556 6222f?atarm?14-jan-11 sam7se512/256/32 38.2 block diagram figure 38-1. block diagram access to the udp is via the apb bus interface. read and write to the data fi fo are done by reading and writing 8-bit values to apb registers. the udp peripheral requires two clocks: one peripheral clock used by the master clock domain (mck) and a 48 mhz clock (udpck) used by the 12 mhz domain. a usb 2.0 full-speed pad is embedded and controlled by the serial interface engine (sie). the signal external_resume is optional. it allows the udp peripheral to wake up once in system mode. the host is then notified that the device asks for a resume. this optional feature must also be negotiated with the host during the enumeration. 38.2.1 signal description atmel bridge 12 mhz suspend/resume logic w r a p p e r w r a p p e r u s e r i n t e r f a c e serial interface engine sie mck master clock domain dual port ram fifo udpck recovered 12 mhz domain udp_int usb device embedded usb transceiver ddp ddm apb to mcu bus txoen eopn txd rxdm rxd rxdp table 38-2. signal names signal name description type udpck 48 mhz clock input mck master clock input udp_int interrupt line connected to the advanced interrupt controller (aic) input ddp usb d+ line i/o ddm usb d- line i/o
557 6222f?atarm?14-jan-11 sam7se512/256/32 38.3 product dependencies for further details on the usb device hardware implementation, see the specific product prop- erties document. the usb physical transceiver is integrated into the product. the bidirectional differential signals ddp and ddm are available from the product boundary. 38.3.1 i/o lines ddp and ddm are not controlled by any pio controllers. the embedded usb physical trans- ceiver is controlled by the usb device peripheral. to reserve an i/o line to check vbus, the program mer must first program the pio controller to assign this i/o in input pio mode. 38.3.2 power management the usb device peripheral requires a 48 mhz cl ock. this clock must be generated by a pll with an accuracy of 0.25%. thus, the usb device receives two clocks from the power management controller (pmc): the master clock, mck, used to drive the peripheral user interface, and the udpck, used to inter- face with the bus usb signals (recovered 12 mhz domain). warning: the udp peripheral clock in the power management controller (pmc) must be enabled before any read/write operations to the udp registers including the udp_txvc register. 38.3.3 interrupt the usb device interface has an interrupt line connected to the interrupt controller. handling the usb device interrupt requires programming the interrupt controller before config- uring the udp.
558 6222f?atarm?14-jan-11 sam7se512/256/32 38.4 typical connection figure 38-2. board schematic to interface device peripheral 38.4.1 usb device transceiver the usb device transceiver is embedded in the product. a few discrete components are required as follows: ? the application detects all device states as def ined in chapter 9 of the usb specification; ?vbus monitoring ? to reduce power consumption the host is disconnected ? for line termination. 38.4.2 vbus monitoring vbus monitoring is required to detect host connection. vbus monitoring is done using a stan- dard pio with internal pullup disabled. when the host is switched off, it should be considered as a disconnect, the pullup must be disabled in order to prevent powering the host through the pull- up resistor. when the host is disconnected and the transceiver is enabled, then ddp and ddm are floating. this may lead to over consumption. a solution is to connect 330 k pulldowns on ddp and ddm. these pulldowns do not alter ddp and ddm signal integrity. a termination serial resistor must be connected to ddp and ddm. the resistor value is defined in the electrical specification of the product (r ext ). r ext r ext ddm ddp pio 27 k 47 k 330 k type b connector 1 2 34 5v bus monitoring 330 k
559 6222f?atarm?14-jan-11 sam7se512/256/32 38.5 functional description 38.5.1 usb v2.0 full-speed introduction the usb v2.0 full-speed provides communication services between host and attached usb devices. each device is offered with a collection of communication flows (pipes) associated with each endpoint. software on the host communicates with a usb device through a set of commu- nication flows. figure 38-3. example of usb v2.0 full-speed communication control the control transfer endpoint ep0 is always used when a us b device is first configured (usb v. 2.0 specifications). 38.5.1.1 usb v2.0 full-speed transfer types a communication flow is carried over one of f our transfer types defined by the usb device. ep0 usb host v2.0 software client 1 software client 2 data flow: bulk out transfer data flow: bulk in transfer data flow: control transfer data flow: control transfer ep1 ep2 usb device 2.0 block 1 usb device 2.0 block 2 ep5 ep4 ep0 data flow: isochronous in transfer data flow: isochronous out transfer usb device endpoint configuration requires that in the first instance control transfer must be ep0. table 38-3. usb communication flow transfer direction bandwidth supported endpoint size error detection retrying control bidirectional not guaranteed 8, 16, 32, 64 yes automatic isochronous unidirectional guaranteed 64 yes no interrupt unidirectional not guaranteed 64 yes yes bulk unidirectional not guaranteed 8, 16, 32, 64 yes yes
560 6222f?atarm?14-jan-11 sam7se512/256/32 38.5.1.2 usb bus transactions each transfer results in one or more transactions over the usb bus. there are three kinds of transactions flowing acro ss the bus in packets: 1. setup transaction 2. data in transaction 3. data out transaction 38.5.1.3 usb transfer event definitions as indicated below, transfers are sequential events carried out on the usb bus. notes: 1. control transfer must use endpoints with no ping-pong attributes. 2. isochronous transfers must use endpoints with ping-pong attributes. 3. control transfers can be aborted using a stall handshake. a status transaction is a special type of host-to- device transaction used only in a control transfer. the control transfer must be performed using endpoints with no ping-pong attributes. according to the control sequence (read or write), the usb device sends or receives a status transaction. table 38-4. usb transfer events control transfers (1) (3) ? setup transaction > data in transactions > status out transaction ? setup transaction > data out transactions > status in transaction ? setup transaction > status in transaction interrupt in transfer (device toward host) ? data in transaction > data in transaction interrupt out transfer (host toward device) ? data out transaction > data out transaction isochronous in transfer (2) (device toward host) ? data in transaction > data in transaction isochronous out transfer (2) (host toward device) ? data out transaction > data out transaction bulk in transfer (device toward host) ? data in transaction > data in transaction bulk out transfer (host toward device) ? data out transaction > data out transaction
561 6222f?atarm?14-jan-11 sam7se512/256/32 figure 38-4. control read and write sequences notes: 1. during the status in stage, the host waits for a zero length packet (data in transaction with no data) from the device using data1 pid. refer to chapter 8 of the universal serial bus specification, rev. 2.0, for more information on the protocol layer. 2. during the status out stage, the host emits a zero length packet to the device (data out transaction with no data). 38.5.2 handling transactions with usb v2.0 device peripheral 38.5.2.1 setup transaction setup is a special type of host-to-device transaction used during control transfers. control trans- fers must be performed using endpoints with no ping-pong attributes. a setup transaction needs to be handled as soon as possible by the firmware. it is used to transmit requests from the host to the device. these requests are then handled by the usb device and may require more argu- ments. the arguments are sent to the device by a data out transaction which follows the setup transaction. these requests may also return data. the data is carried out to the host by the next data in transaction which follows the setup transaction. a status transaction ends the control transfer. when a setup transfer is received by the usb endpoint: ? the usb device automatically acknowledges the setup packet ? rxsetup is set in the udp_csrx register ? an endpoint interrupt is generated while the rxsetup is not cleared. this interrupt is carried out to the microcontroller if interrupts are enabled for this endpoint. thus, firmware must det ect the rxsetup polling the udp_csrx or catching an interrupt, read the setup packet in the fifo , then clear the rxsetup. rxsetup cannot be clear ed before the setup packet has been read in the fifo. otherwise, the usb device would accept the next data out transfer and overwrite the setup packet in the fifo. control read setup tx data out tx data out tx data stage control write setup stage setup stage setup tx setup tx no data control data in tx data in tx status stage status stage status in tx status out tx status in tx data stage setup stage status stage
562 6222f?atarm?14-jan-11 sam7se512/256/32 figure 38-5. setup transaction followed by a data out transaction 38.5.2.2 data in transaction data in transactions are used in control, is ochronous, bulk and interrupt transfers and conduct the transfer of data from the device to the host. data in transactions in isochronous transfer must be done using endpoints with ping-pong attributes. 38.5.2.3 using endpoints without ping-pong attributes to perform a data in transaction using a non ping-pong endpoint: 1. the application checks if it is possible to write in the fifo by polling txpktrdy in the endpoint?s udp_csrx regist er (txpktrdy must be cleared). 2. the application writes the first packet of data to be sent in the endpoint?s fifo, writing zero or more byte values in the endpoint?s udp_fdrx register, 3. the application notifies the usb peripheral it has finished by setting the txpktrdy in the endpoint?s udp_csrx register. 4. the application is notified that the endpoint?s fifo has been released by the usb device when txcomp in the endpoint?s udp_csrx register has been set. then an interrupt for the corresponding endpoint is pending while txcomp is set. 5. the microcontroller writes the second packet of data to be sent in the endpoint?s fifo, writing zero or more byte values in the endpoint?s udp_fdrx register, 6. the microcontroller notifi es the usb peripheral it has finished by setting the txpk- trdy in the endpoint?s udp_csrx register. 7. the application clears the txcomp in the endpoint?s udp_csrx. after the last packet has been sent, the application must clear txcomp once this has been set. txcomp is set by the usb device when it has received an ack pid signal for the data in packet. an interrupt is pending while txcomp is set. warning: tx_comp must be cleared after tx_pktrdy has been set. note: refer to chapter 8 of the universal serial bus specification, rev 2.0, for more information on the data in protocol layer. rx_data_bko (udp_csrx) ack pid data out data out pid nak pid ack pid data setup setup pid usb bus packets rxsetup flag set by usb device cleared by firmware set by usb device peripheral fifo (dpr) content data setup data xx xx out interrupt pending setup received setup handled by firmware data out received data out data out pid
563 6222f?atarm?14-jan-11 sam7se512/256/32 figure 38-6. data in transfer for non ping-pong endpoint 38.5.2.4 using endpoints with ping-pong attribute the use of an endpoint with ping-pong attributes is necessary during isochronous transfer. this also allows handling the maximum bandwidth defined in the usb specification during bulk trans- fer. to be able to guarantee a constant or the maximum bandwidth, the microcontroller must prepare the next data payload to be sent while the current one is being sent by the usb device. thus two banks of memory are used. while one is available for the microcontroller, the other one is locked by the usb device. figure 38-7. bank swapping data in transfer for ping-pong endpoints when using a ping-pong endpoint, the following procedures are required to perform data in transactions: usb bus packets data in 2 data in nak ack data in 1 fifo (dpr) content data in 2 load in progress data in 1 cleared by firmware dpr access by the firmware payload in fifo txcomp flag (udp_csrx) txpktrdy flag (udp_csrx) pid data in data in pid pid pid pid ack pid prevous data in tx microcontroller load data in fifo data is sent on usb bus interrupt pending interrupt pending set by the firmware set by the firmware cleared by firmware cleared by hw cleared by hw dpr access by the hardware usb device usb bus read write read and write at the same time 1 st data payload 2 nd data payload 3 rd data payload 3 rd data payload 2 nd data payload 1 st data payload data in packet data in packet data in packet microcontroller endpoint 1 bank 0 endpoint 1 bank 1 endpoint 1 bank 0 endpoint 1 bank 0 endpoint 1 bank 0 endpoint 1 bank 1
564 6222f?atarm?14-jan-11 sam7se512/256/32 1. the microcontroller checks if it is possible to write in the fifo by polling txpktrdy to be cleared in the endpoint?s udp_csrx register. 2. the microcontroller writes the first data payload to be sent in the fifo (bank 0), writing zero or more byte values in the endpoint?s udp_fdrx register. 3. the microcontroller notifies the usb peripheral it has finished writing in bank 0 of the fifo by setting the txpktrdy in the endpoint?s udp_csrx register. 4. without waiting for txpktrdy to be cleare d, the microcontrolle r writes the second data payload to be sent in the fifo (bank 1), writing zero or more byte values in the endpoint?s udp_fdrx register. 5. the microcontroller is notified that the first bank has been released by the usb device when txcomp in the endpoint?s udp_csrx register is set. an interrupt is pending while txcomp is being set. 6. once the microcontroller has received txco mp for the first bank, it notifies the usb device that it has prepared the second bank to be sent, raising txpktrdy in the end- point?s udp_csrx register. 7. at this step, bank 0 is available and the microcontroller can prepare a third data pay- load to be sent . figure 38-8. data in transfer for ping-pong endpoint warning: there is software critical path due to the fact that once the second bank is filled, the driver has to wait for tx_comp to set tx_pktrdy. if the delay between receiving tx_comp is set and tx_pktrdy is set too long, some data in packets may be nacked, reducing the bandwidth. warning: tx_comp must be cleared after tx_pktrdy has been set. data in data in read by usb device read by usb device bank 1 bank 0 fifo (dpr) txcomp flag (udp_csrx) interrupt cleared by firmware set by usb device txpktrdy flag (udp_mcsrx) ack pid data in pid ack pid set by firmware, data payload written in fifo bank 1 cleared by usb device, data payload fully transmitted data in pid usb bus packets set by usb device set by firmware, data payload written in fifo bank 0 written by fifo (dpr) microcontroller written by microcontroller written by microcontroller microcontroller load data in bank 0 microcontroller load data in bank 1 usb device send bank 0 microcontroller load data in bank 0 usb device send bank 1 interrupt pending
565 6222f?atarm?14-jan-11 sam7se512/256/32 38.5.2.5 data out transaction data out transactions are used in control, isochronous, bulk and interru pt transfers and con- duct the transfer of data from the host to the device. data out transactions in isochronous transfers must be done using endpoints with ping-pong attributes. 38.5.2.6 data out transaction without ping-pong attributes to perform a data out transaction, using a non ping-pong endpoint: 1. the host generates a data out packet. 2. this packet is received by the usb device endpoint. while the fifo associated to this endpoint is being used by the microcontroller, a nak pid is returned to the host. once the fifo is available, data is written to the fifo by the usb device and an ack is auto- matically carried out to the host. 3. the microcontroller is notifie d that the usb device has re ceived a data payload polling rx_data_bk0 in the endpoint?s udp_csrx register. an interrupt is pending for this endpoint while rx_data_bk0 is set. 4. the number of bytes available in the fi fo is made available by reading rxbytecnt in the endpoint?s udp_csrx register. 5. the microcontroller carries out data received from the endpoint?s memory to its mem- ory. data received is available by reading the endpoint?s udp_fdrx register. 6. the microcontroller notifies the usb device that it has finished the transfer by clearing rx_data_bk0 in the endpoint?s udp_csrx register. 7. a new data out packet can be accepted by the usb device. figure 38-9. data out transfer for non ping-pong endpoints an interrupt is pending while the flag rx_dat a_bk0 is set. memory transfer between the usb device, the fifo and microcontroller memory can not be done after rx_data_bk0 has been cleared. otherwise, the usb device would acce pt the next data out transfer and overwrite the current data out packet in the fifo. ack pid data out nak pid pid pid pid pid data out2 ack data out data out 1 usb bus packets rx_data_bk0 set by usb device cleared by firmware, data payload written in fifo fifo (dpr) content written by usb device microcontroller read data out 1 data out 1 data out 2 host resends the next data payload microcontroller transfers data host sends data payload data out2 data out2 host sends the next data payload written by usb device (udp_csrx) interrupt pending
566 6222f?atarm?14-jan-11 sam7se512/256/32 38.5.2.7 using endpoints with ping-pong attributes during isochronous transfer, using an endpoint wit h ping-pong attributes is obligatory. to be able to guarantee a constant bandwidth, the micr ocontroller must read the previous data pay- load sent by the host, while the current data payload is received by the usb device. thus two banks of memory are used. while one is available for the microcontroller, the other one is locked by the usb device. figure 38-10. bank swapping in data out transfers for ping-pong endpoints when using a ping-pong endpoint, the following procedures are required to perform data out transactions: 1. the host generates a data out packet. 2. this packet is received by the usb device endpoint. it is written in the endpoint?s fifo bank 0. 3. the usb device sends an ack pid packet to the host. the host can immediately send a second data out packet. it is accepted by the device and copied to fifo bank 1. 4. the microcontroller is notifi ed that the usb device has re ceived a data payload, polling rx_data_bk0 in the endpoint?s udp_csrx register. an interrupt is pending for this endpoint while rx_data_bk0 is set. 5. the number of bytes available in the fi fo is made available by reading rxbytecnt in the endpoint?s udp_csrx register. 6. the microcontroller transfers out data received from the endpoint?s memory to the microcontroller?s memory. data received is made available by reading the endpoint?s udp_fdrx register. 7. the microcontroller notifies the usb peripheral device that it has finished the transfer by clearing rx_data_bk0 in the endpoint?s udp_csrx register. 8. a third data out packet can be accepted by the usb peripheral device and copied in the fifo bank 0. 9. if a second data out packet has been received, the microcontroller is notified by the flag rx_data_bk1 set in the endpoint?s udp_csrx register. an interrupt is pending for this endpoint while rx_data_bk1 is set. usb device usb bus read write write and read at the same time 1 st data payload 2 nd data payload 3 rd data payload 3 rd data payload 2 nd data payload 1 st data payload data in packet data in packet data in packet microcontroller endpoint 1 bank 0 endpoint 1 bank 1 endpoint 1 bank 0 endpoint 1 bank 0 endpoint 1 bank 0 endpoint 1 bank 1
567 6222f?atarm?14-jan-11 sam7se512/256/32 10. the microcontroller transfers out data received from the endpoint?s memory to the microcontroller?s memory. data received is available by reading the endpoint?s udp_fdrx register. 11. the microcontroller notifies the usb device it has finished the transfer by clearing rx_data_bk1 in the endpoint?s udp_csrx register. 12. a fourth data out packet can be accepted by the usb device and copied in the fifo bank 0. figure 38-11. data out transfer for ping-pong endpoint note: an interrupt is pending while the rx_data_bk0 or rx_data_bk1 flag is set. warning : when rx_data_bk0 and rx_data_bk1 are both set, there is no way to determine which one to clear first. thus the software must keep an internal counter to be sure to clear alter- natively rx_data_bk0 then rx_data_bk1. this situation may occur when the software application is busy elsewhere and the two banks are filled by the usb host. once the application comes back to the usb driver, the two flags are set. 38.5.2.8 stall handshake a stall handshake can be used in one of two distinct occasions. (for more information on the stall handshake, refer to chapter 8 of the universal serial bus specification, rev 2.0. ) ? a functional stall is used when the halt feature associated with the endpoint is set. (refer to chapter 9 of the universal serial bus sp ecification, rev 2.0, for more information on the halt feature.) ? to abort the current request, a protocol stall is used, but uniquely with control transfer. the following procedure generates a stall packet: a p data out pid ack data out 3 data out data out 2 data out data out 1 pid data out 3 data out 1 data out1 data out 2 data out 2 pid pid pid ack cleared by firmware usb bus packets rx_data_bk0 flag rx_data_bk1 flag set by usb device, data payload written in fifo endpoint bank 1 fifo (dpr) bank 0 bank 1 write by usb device write in progress read by microcontroller read by microcontroller set by usb device, data payload written in fifo endpoint bank 0 host sends first data payload microcontroller reads data 1 in bank 0, host sends second data payload microcontroller reads data2 in bank 1, host sends third data payload cleared by firmware write by usb device fifo (dpr) (udp_csrx) (udp_csrx) interrupt pending interrupt pending
568 6222f?atarm?14-jan-11 sam7se512/256/32 1. the microcontroller sets the forcestall flag in the udp_csrx endpoint?s register. 2. the host receives the stall packet. 3. the microcontroller is notif ied that the device has sent the stall by polling the stallsent to be set. an endpoint interrup t is pending while stallsent is set. the microcontroller must clear stallsent to clear the interrupt. when a setup transaction is received after a stall handshake, stallsent must be cleared in order to prevent interrupts due to stallsent being set. figure 38-12. stall handshake (data in transfer) figure 38-13. stall handshake (data out transfer) data in stall pid pid usb bus packets cleared by firmware set by firmware forcestall stallsent set by usb device cleared by firmware interrupt pending data out pid stall pid data out usb bus packets cleared by firmware set by firmware forcestall stallsent set by usb device interrupt pending
569 6222f?atarm?14-jan-11 sam7se512/256/32 38.5.2.9 transmit data cancellation some endpoints have dual-banks whereas some endpoints have only one bank. the procedure to cancel transmission data held in these banks is described below. to see the organization of du al-bank availability refer to table 38-1 ?usb endpoint description? . 38.5.2.10 endpoints without dual-banks there are two possib ilities: in one case, txpktrdy field in udp_csr has already been set. in the other instance, txpktrdy is not set. ? txpktrdy is not set: ? reset the endpoint to clear the fifo (pointers). (see section 38.6.9 ?udp reset endpoint register? .) ? txpktrdy has already been set: ? clear txpktrdy so that no packet is ready to be sent ? reset the endpoint to clear the fifo (pointers). (see section 38.6.9 ?udp reset endpoint register? .) 38.5.2.11 endpoints with dual-banks there are two possib ilities: in one case, txpktrdy field in udp_csr has already been set. in the other instance, txpktrdy is not set. ? txpktrdy is not set: ? reset the endpoint to clear the fifo (pointers). (see section 38.6.9 ?udp reset endpoint register? .) ? txpktrdy has already been set: ? clear txpktrdy and read it ba ck until actually read at 0. ? set txpktrdy and read it ba ck until actually read at 1. ? clear txpktrdy so that no packet is ready to be sent. ? reset the endpoint to clear the fifo (pointers). (see section 38.6.9 ?udp reset endpoint register? .)
570 6222f?atarm?14-jan-11 sam7se512/256/32 38.5.3 controlling device states a usb device has several possible states. refer to chapter 9 of the universal serial bus speci- fication, rev 2.0 . figure 38-14. usb device state diagram movement from one state to another depends on the usb bus state or on standard requests sent through control transactions via the default endpoint (endpoint 0). after a period of bus inactivity, the us b device enters suspend mode. accepting sus- pend/resume requests from the usb host is mandatory. constraints in suspend mode are very strict for bus-powered applications; devices may not consume more than 500 a on the usb bus. while in suspend mode, the host may wake up a de vice by sending a resume signal (bus activ- ity) or a usb device may send a wake up request to the host, e.g., waking up a pc by moving a usb mouse. the wake up feature is not mandatory for all devices and must be negotiated with the host. attached suspended suspended suspended suspended hub reset or deconfigured hub configured bus inactive bus activity bus inactive bus activity bus inactive bus activity bus inactive bus activity reset reset address assigned device deconfigured device configured powered default address configured power interruption
571 6222f?atarm?14-jan-11 sam7se512/256/32 38.5.3.1 not powered state self powered devices can detect 5v vbus using a pio as described in the typical connection section. when the device is not connected to a host, device power consumption can be reduced by disabling mck for the udp, disabling udp ck and disabling the transceiver. ddp and ddm lines are pulled down by 330 k resistors. 38.5.3.2 entering attached state when no device is connected, the usb ddp and ddm signals are tied to gnd by 15 k pull- down resistors integrated in the hub downstream ports. when a device is attached to a hub downstream port, the device connects a 1.5 k pull-up resistor on ddp. the usb bus line goes into idle state, ddp is pulled up by the device 1.5 k resistor to 3.3v and ddm is pulled down by the 15 k resistor of the host. to enable integrated pull-up, the puon bit in the udp_txvc register must be set. warning : to write to the udp_txvc register, mck clock must be enabled on the udp. this is done in the power management controller. after pullup connection, the device enters the powered state. in this state, the udpck and mck must be enabled in the power management controller. the transceiver can remain disabled. 38.5.3.3 from powered state to default state after its connection to a usb host, the usb devi ce waits for an end-of-bus reset. the unmask- able flag endbusres is set in the register udp_isr and an interrupt is triggered. once the endbusres interrupt has been triggered, the device enters default state. in this state, the udp software must: ? enable the default endpoint, setting the epeds flag in the udp_csr[0] register and, optionally, enabling the interrupt for endpoint 0 by writing 1 to the udp_ier register. the enumeration then begins by a control transfer. ? configure the interrupt mask register which has been reset by the usb reset detection ? enable the transceiver clearing the txvdis flag in the udp_txvc register. in this state udpck and mck must be enabled. warning : each time an endbusres interrupt is triggered, the interrupt mask register and udp_csr registers have been reset. 38.5.3.4 from default state to address state after a set address standard device request, the usb host peripheral enters the address state. warning : before the device enters in address state, it must achieve the status in transaction of the control transfer, i.e., the udp device sets its new address once the txcomp flag in the udp_csr[0] register has been received and cleared. to move to address state, the driver software sets the fadden flag in the udp_glb_stat register, sets its new address, and sets the fen bit in the udp_faddr register. 38.5.3.5 from address state to configured state once a valid set configuration standard request has been received and acknowledged, the device enables endpoints corresponding to the current configuration. this is done by setting the epeds and eptype fields in the udp_csrx regist ers and, optionally, en abling corr esponding interrupts in the udp_ier register.
572 6222f?atarm?14-jan-11 sam7se512/256/32 38.5.3.6 entering in suspend state when a suspend (no bus activity on the usb bus) is detected, the rxsusp signal in the udp_isr register is set. this triggers an interrupt if the co rresponding bit is set in the udp_imr register.this flag is cleared by writing to the ud p_icr register. then the device enters suspend mode. in this state bus powered devices must drain less than 500ua from the 5v vbus. as an exam- ple, the microcontroller switches to slow clock, disables the pl l and main oscilla tor, and goes into idle mode. it may also switch off other devices on the board. the usb device peripheral clocks can be s witched off. resume event is asynchronously detected. mck and udpck can be switched off in the power management controller and the usb transceiver can be disabled by setting the txvdis field in the udp_txvc register. warning : read, write operations to the udp registers are allowed only if mck is enabled for the udp peripheral. switching off mck for the udp peripheral must be one of the last operations after writing to the udp_txvc and acknowledging the rxsusp. 38.5.3.7 receiving a host resume in suspend mode, a resume event on the usb bus line is detected asynchronously, transceiver and clocks are disabled (however the pullup shall not be removed). once the resume is detected on the bus, the wakeup signal in the udp_isr is set. it may gen- erate an interrupt if the corresponding bit in the udp_imr register is set. this interrupt may be used to wake up the core, enable pll a nd main oscillators and configure clocks. warning : read, write operations to the udp registers are allowed only if mck is enabled for the udp peripheral. mck for the udp must be enabled before clea ring the wakeup bit in the udp_icr register and clearing txvdis in the udp_txvc register. 38.5.3.8 sending a device remote wakeup in suspend state it is possible to wake up the host sending an external resume. ? the device must wait at least 5 ms after being entered in suspend before sending an external resume. ? the device has 10 ms from the moment it starts to drain current and it forces a k state to resume the host. ? the device must force a k state from 1 to 15 ms to resume the host before sending a k state to the host, mck, udpck and the transceiver must be enabled. then to enable the remote wakeup feature, the rmwupe bit in the udp_glb_stat register must be enabled. to force the k state on the line, a transition of the esr bit from 0 to 1 has to be done in the udp_glb_stat register. this transition must be accomplished by first writing a 0 in the esr bit and then writing a 1. the k state is automatically generated and released according to the usb 2.0 specification.
573 6222f?atarm?14-jan-11 sam7se512/256/32 38.6 usb device port (udp) user interface warning: the udp peripheral clock in the power management controller (pmc) must be enabled before any read/write operations to the udp registers, including the udp_txvc register. notes: 1. reset values are not defined for udp_isr. 2. see warning above the ?register mapping? on this page. table 38-5. register mapping offset register name access reset 0x000 frame number register udp_frm_num read-only 0x0000_0000 0x004 global state register udp_glb_stat read-write 0x0000_0010 0x008 function address register udp_faddr read-write 0x0000_0100 0x00c reserved ? ? ? 0x010 interrupt enable register udp_ier write-only 0x014 interrupt disable register udp_idr write-only 0x018 interrupt mask register udp_imr read-only 0x0000_1200 0x01c interrupt status register udp_isr read-only ? (1) 0x020 interrupt clear register udp_icr write-only 0x024 reserved ? ? ? 0x028 reset endpoint register udp_rst_ep read-write 0x0000_0000 0x02c reserved ? ? ? 0x030 + 0x4 * (ept_num - 1) endpoint control and status register udp_csr read-write 0x0000_0000 0x050 + 0x4 * (ept_num - 1) endpoint fifo data register udp_fdr read-write 0x0000_0000 0x070 reserved ? ? ? 0x074 transceiver control register udp_txvc (2) read-write 0x0000_0100 0x078 - 0xfc reserved ? ? ?
574 6222f?atarm?14-jan-11 sam7se512/256/32 38.6.1 udp frame number register name: udp_frm_num access: read-only ? frm_num[10:0]: frame number as defined in the packet field formats this 11-bit value is incremented by the host on a per fr ame basis. this value is updated at each start of frame. value updated at the sof_eop (start of frame end of packet). ? frm_err: frame error this bit is set at sof_eop when the sof packet is received containing an error. this bit is reset upon receipt of sof_pid. ? frm_ok: frame ok this bit is set at sof_eop when the sof packet is received without any error. this bit is reset upon receipt of sof_pid (packet identification). in the interrupt status register, the sof interrupt is updated upon receiving sof_pid. this bit is set without waiting for eop. note: in the 8-bit register interfac e, frm_ok is bit 4 of frm_num_h and frm_err is bit 3 of frm_num_l. 31 30 29 28 27 26 25 24 --- --- --- --- --- --- --- --- 23 22 21 20 19 18 17 16 ??????frm_okfrm_err 15 14 13 12 11 10 9 8 ????? frm_num 76543210 frm_num
575 6222f?atarm?14-jan-11 sam7se512/256/32 38.6.2 udp global state register name: udp_glb_stat access: read-write this register is used to get and set the device state as specified in chapter 9 of the usb serial bus specification, rev.2.0 . ? fadden: function address enable read: 0 = device is not in address state. 1 = device is in address state. write: 0 = no effect, only a reset can bring back a device to the default state. 1 = sets device in address state. this occurs after a successful set address request. beforehand, the udp_faddr regis- ter must have been initialized with set address parameters. set address must complete the status stage before setting fadden. refer to chapter 9 of the universal serial bus specification, rev. 2.0 for more details. ? confg: configured read: 0 = device is not in configured state. 1 = device is in configured state. write: 0 = sets device in a non configured state 1 = sets device in configured state. the device is set in configured state when it is in address st ate and receives a successful set configuration request. refer to chapter 9 of the universal serial bus specification, rev. 2.0 for more details. ? esr: enable send resume 0 = mandatory value prior to starting any remote wake up procedure. 1 = starts the remote wake up procedure if this bit value was 0 and if rmwupe is enabled. 31 30 29 28 27 26 25 24 ???????? 23 22 21 20 19 18 17 16 ???????? 15 14 13 12 11 10 9 8 ?????? ?? 76543210 ? ? ? rmwupe rsminpr esr confg fadden
576 6222f?atarm?14-jan-11 sam7se512/256/32 ? rmwupe: remote wake up enable 0 = the remote wake up feature of the device is disabled. 1 = the remote wake up feature of the device is enabled.
577 6222f?atarm?14-jan-11 sam7se512/256/32 38.6.3 udp function address register name: udp_faddr access: read-write ? fadd[6:0]: function address value the function address value must be programmed by firmware once the device receives a set address request from the host, and has achieved the status stage of the no-data control sequence. refer to the universal serial bus specification, rev. 2.0 for more information. after power up or reset, the function address value is set to 0. ? fen: function enable read: 0 = function endpoint disabled. 1 = function endpoint enabled. write: 0 = disables function endpoint. 1 = default value. the function enable bit (fen) allows the microcontroller to enable or disable the function endpoints. the microcontroller sets this bit after receipt of a reset from the host. once this bit is set, the usb device is able to accept and transfer data packets from and to the host. 31 30 29 28 27 26 25 24 ???????? 23 22 21 20 19 18 17 16 ???????? 15 14 13 12 11 10 9 8 ?????? ?fen 76543210 ?fadd
578 6222f?atarm?14-jan-11 sam7se512/256/32 38.6.4 udp interrupt enable register name: udp_ier access: write-only ? ep0int: enable endpoint 0 interrupt ? ep1int: enable endpoint 1 interrupt ? ep2int: enable endpoint 2interrupt ? ep3int: enable endpoint 3 interrupt ? ep4int: enable endpoint 4 interrupt ? ep5int: enable endpoint 5 interrupt ? ep6int: enable endpoint 6 interrupt ? ep7int: enable endpoint 7 interrupt 0 = no effect. 1 = enables corresponding endpoint interrupt. ? rxsusp: enable udp suspend interrupt 0 = no effect. 1 = enables udp suspend interrupt. ? rxrsm: enable udp resume interrupt 0 = no effect. 1 = enables udp resume interrupt. ? sofint: enable start of frame interrupt 0 = no effect. 1 = enables start of frame interrupt. 31 30 29 28 27 26 25 24 ???????? 23 22 21 20 19 18 17 16 ???????? 15 14 13 12 11 10 9 8 ? ? wakeup ? sofint extrsm rxrsm rxsusp 76543210 ep7int ep6int ep5int ep4int ep3int ep2int ep1int ep0int
579 6222f?atarm?14-jan-11 sam7se512/256/32 ? wakeup: enable udp bus wakeup interrupt 0 = no effect. 1 = enables usb bus interrupt.
580 6222f?atarm?14-jan-11 sam7se512/256/32 38.6.5 udp interrupt disable register name: udp_idr access: write-only ? ep0int: disable endpoint 0 interrupt ? ep1int: disable endpoint 1 interrupt ? ep2int: disable endpoint 2 interrupt ? ep3int: disable endpoint 3 interrupt ? ep4int: disable endpoint 4 interrupt ? ep5int: disable endpoint 5 interrupt ? ep6int: disable endpoint 6 interrupt ? ep7int: disable endpoint 7 interrupt 0 = no effect. 1 = disables corresponding endpoint interrupt. ? rxsusp: disable udp suspend interrupt 0 = no effect. 1 = disables udp suspend interrupt. ? rxrsm: disable udp resume interrupt 0 = no effect. 1 = disables udp resume interrupt. ? sofint: disable start of frame interrupt 0 = no effect. 1 = disables start of frame interrupt 31 30 29 28 27 26 25 24 ???????? 23 22 21 20 19 18 17 16 ???????? 15 14 13 12 11 10 9 8 ? ? wakeup ? sofint extrsm rxrsm rxsusp 76543210 ep7int ep6int ep5int ep4int ep3int ep2int ep1int ep0int
581 6222f?atarm?14-jan-11 sam7se512/256/32 ? wakeup: disable usb bus interrupt 0 = no effect. 1 = disables usb bus wakeup interrupt.
582 6222f?atarm?14-jan-11 sam7se512/256/32 38.6.6 udp interrupt mask register name: udp_imr access: read-only ? ep0int: mask endpoint 0 interrupt ? ep1int: mask endpoint 1 interrupt ? ep2int: mask endpoint 2 interrupt ? ep3int: mask endpoint 3 interrupt ? ep4int: mask endpoint 4 interrupt ? ep5int: mask endpoint 5 interrupt ? ep6int: mask endpoint 6 interrupt ? ep7int: mask endpoint 7 interrupt 0 = corresponding endpoint interrupt is disabled. 1 = corresponding endpoint interrupt is enabled. ? rxsusp: mask udp suspend interrupt 0 = udp suspend interrupt is disabled. 1 = udp suspend interrupt is enabled. ? rxrsm: mask udp resume interrupt. 0 = udp resume interrupt is disabled. 1 = udp resume interrupt is enabled. ? sofint: mask start of frame interrupt 0 = start of frame interrupt is disabled. 1 = start of frame interrupt is enabled. 31 30 29 28 27 26 25 24 ???????? 23 22 21 20 19 18 17 16 ???????? 15 14 13 12 11 10 9 8 ? ? wakeup bit12 sofint extrsm rxrsm rxsusp 76543210 ep7int ep6int ep5int ep4int ep3int ep2int ep1int ep0int
583 6222f?atarm?14-jan-11 sam7se512/256/32 ? bit12: udp_imr bit 12 bit 12 of udp_imr cannot be masked and is always read at 1. ? wakeup: usb bus wakeup interrupt 0 = usb bus wakeup interrupt is disabled. 1 = usb bus wakeup interrupt is enabled. note: when the usb block is in suspend mode, the application may po wer down the usb logic. in this case, any usb host resume request that is made must be taken into account and, thus, the reset value of th e rxrsm bit of the register udp_imr is enabled.
584 6222f?atarm?14-jan-11 sam7se512/256/32 38.6.7 udp interrupt status register name: udp_isr access: read-only ? ep0int: endpoint 0 interrupt status ? ep1int: endpoint 1 interrupt status ? ep2int: endpoint 2 interrupt status ? ep3int: endpoint 3 interrupt status ? ep4int: endpoint 4 interrupt status ? ep5int: endpoint 5 interrupt status ? ep6int: endpoint 6 interrupt status ? ep7int: endpoint 7interrupt status 0 = no endpoint0 interrupt pending. 1 = endpoint0 interrupt has been raised. several signals can generate this interrupt. the reason can be found by reading udp_csr0: rxsetup set to 1 rx_data_bk0 set to 1 rx_data_bk1 set to 1 txcomp set to 1 stallsent set to 1 ep0int is a sticky bit. interrupt remains valid until ep0int is cleared by writing in the corresponding udp_csr0 bit. ? rxsusp: udp suspend interrupt status 0 = no udp suspend interrupt pending. 1 = udp suspend interrupt has been raised. the usb device sets this bit when it detects no ac tivity for 3ms. the usb device enters suspend mode. 31 30 29 28 27 26 25 24 ???????? 23 22 21 20 19 18 17 16 ???????? 15 14 13 12 11 10 9 8 ? ? wakeup endbusres sofint extrsm rxrsm rxsusp 76543210 ep7int ep6int ep5int ep4int ep3int ep2int ep1int ep0int
585 6222f?atarm?14-jan-11 sam7se512/256/32 ? rxrsm: udp resume interrupt status 0 = no udp resume interrupt pending. 1 =udp resume interrupt has been raised. the usb device sets this bit when a udp resume signal is detected at its port. after reset, the state of this bit is undefined, the application must clear this bit by setting the rxrsm flag in the udp_icr register. ? sofint: start of frame interrupt status 0 = no start of frame interrupt pending. 1 = start of frame interrupt has been raised. this interrupt is raised each time a sof token has been detected. it can be used as a synchronization signal by using isochronous endpoints. ? endbusres: end of bus reset interrupt status 0 = no end of bus reset interrupt pending. 1 = end of bus reset interrupt has been raised. this interrupt is raised at the end of a udp reset sequence. the usb device must prepare to receive requests on the end- point 0. the host starts the enumeration, then performs the configuration. ? wakeup: udp resume interrupt status 0 = no wakeup interrupt pending. 1 = a wakeup interrupt (usb host sent a resume or reset) occurred since the last clear. after reset the state of this bit is undefined, the application must clear this bit by setting the wakeup flag in the udp_icr register.
586 6222f?atarm?14-jan-11 sam7se512/256/32 38.6.8 udp interrupt clear register name: udp_icr access: write-only ? rxsusp: clear udp suspend interrupt 0 = no effect. 1 = clears udp suspend interrupt. ? rxrsm: clear udp resume interrupt 0 = no effect. 1 = clears udp resume interrupt. ? sofint: clear start of frame interrupt 0 = no effect. 1 = clears start of frame interrupt. ? endbusres: clear end of bus reset interrupt 0 = no effect. 1 = clears end of bus reset interrupt. ? wakeup: clear wakeup interrupt 0 = no effect. 1 = clears wakeup interrupt. 31 30 29 28 27 26 25 24 ???????? 23 22 21 20 19 18 17 16 ???????? 15 14 13 12 11 10 9 8 ? ? wakeup endbusres sofint extrsm rxrsm rxsusp 76543210 ????????
587 6222f?atarm?14-jan-11 sam7se512/256/32 38.6.9 udp reset en dpoint register name: udp_rst_ep access: read-write ? ep0: reset endpoint 0 ? ep1: reset endpoint 1 ? ep2: reset endpoint 2 ? ep3: reset endpoint 3 ? ep4: reset endpoint 4 ? ep5: reset endpoint 5 ? ep6: reset endpoint 6 ? ep7: reset endpoint 7 this flag is used to reset the fifo associated with the endpoint and the bit rxbytecount in the register udp_csrx.it also resets the data toggle to data0. it is useful after removing a halt cond ition on a bulk endpoint. refer to chapter 5.8.5 in the usb serial bus specification, rev.2.0 . warning: this flag must be cleared at the end of the reset. it does not clear udp_csrx flags. 0 = no reset. 1 = forces the corresponding endpoint fif0 pointers to 0, therefore rxbytecnt fi eld is read at 0 in udp_csrx register. resetting the endpoint is a two-step operation: 1. set the corresponding epx field. 2. clear the corresponding epx field. 31 30 29 28 27 26 25 24 ???????? 23 22 21 20 19 18 17 16 ???????? 15 14 13 12 11 10 9 8 ?????? ?? 76543210 ep7 ep6 ep5 ep4 ep3 ep2 ep1 ep0
588 6222f?atarm?14-jan-11 sam7se512/256/32 38.6.10 udp endpoint control and status register name: udp_csrx [x = 0..y] access: read-write warning : due to synchronization between mck and udpck, the soft ware application must wait for the end of the write operation before executing an other write by pollin g the bits which must be set/cleared. /// bitmap for all status bits in csr that are not effected by a value 1. #define reg_no_effect_1_all at91c_udp_rx_data_bk0\ | at91c_udp_rx_data_bk1\ | at91c_udp_stallsent\ | at91c_udp_rxsetup\ | at91c_udp_txcomp /// sets the specified bit(s) in the udp_csr register. /// \param endpoint the endpoint number of the csr to process. /// \param flags the bitmap to set to 1. #define set_csr(endpoint, flags) \ { \ volatile unsigned int reg; \ reg = at91c_base_udp->udp_csr[endpoint] ; \ reg |= reg_no_effect_1_all; \ reg |= (flags); \ at91c_base_udp->udp_csr[endpoint] = reg; \ while ( (at91c_base_udp->udp_csr[endpoint] & (flags)) != (flags)); \ } /// clears the specified bit(s) in the udp_csr register. /// \param endpoint the endpoint number of the csr to process. /// \param flags the bitmap to clear to 0. #define clear_csr(endpoint, flags) \ { \ volatile unsigned int reg; \ reg = at91c_base_udp->udp_csr[endpoint]; \ reg |= reg_no_effect_1_all; \ 31 30 29 28 27 26 25 24 ????? r xbytecnt 23 22 21 20 19 18 17 16 rxbytecnt 15 14 13 12 11 10 9 8 epeds ? ? ? dtgle eptype 76543210 dir rx_data_ bk1 force stall txpktrdy stallsent isoerror rxsetup rx_data_ bk0 txcomp
589 6222f?atarm?14-jan-11 sam7se512/256/32 reg &= ~(flags); \ at91c_base_udp->udp_csr[endpoint] = reg; \ while ( (at91c_base_udp->udp_csr[endpoint] & (flags)) == (flags)); \ } note: in a preemptive environment, set or clear the flag and wait for a time of 1 udpck clock cycle and 1peripheral clock cycle. how- ever, rx_data_bk0, txpktrdy, rx_data_bk1 require wait time s of 3 udpck clock cycles and 5 peripheral clock cycles before accessing dpr. ? txcomp: generates an in packet with data previously written in the dpr this flag generates an interr upt while it is set to one. write (cleared by the firmware): 0 = clear the flag, clear the interrupt. 1 = no effect. read (set by the usb peripheral): 0 = data in transaction has not been acknowledged by the host. 1 = data in transaction is achieved, acknowledged by the host. after having issued a data in transaction setting txpktrdy, the device firmware waits for txcomp to be sure that the host has acknowledged the transaction. ? rx_data_bk0: receive data bank 0 this flag generates an interr upt while it is set to one. write (cleared by the firmware): 0 = notify usb peripheral device that data have been read in the fifo's bank 0. 1 = to leave the read value unchanged. read (set by the usb peripheral): 0 = no data packet has been received in the fifo's bank 0. 1 = a data packet has been received, it has been stored in the fifo's bank 0. when the device firmware has polled this bit or has been interr upted by this signal, it must transfer data from the fifo to the microcontroller memory. the nu mber of bytes received is ava ilable in rxbytcent field. ba nk 0 fifo values are read through the udp_fdrx register. once a transfer is done, the device firmware must release bank 0 to the usb peripheral device by clearing rx_data_bk0. after setting or clearing this bit, a wait time of 3 udpck clock cycles and 3 peripheral cloc k cycles is required before accessing dpr. ? rxsetup: received setup this flag generates an interr upt while it is set to one. read: 0 = no setup packet available. 1 = a setup data packet has been sent by the host and is available in the fifo.
590 6222f?atarm?14-jan-11 sam7se512/256/32 write: 0 = device firmware notifies the usb peripheral device that it has read the setup data in the fifo. 1 = no effect. this flag is used to notify the usb device firmware that a valid setup data packet has been sent by the host and success- fully received by the usb device. the usb device firmware may transfer setup data from the fifo by reading the udp_fdrx register to the microcontroller memory. once a transfer has been done, rxsetup must be cleared by the device firmware. ensuing data out transaction is not accepted while rxsetup is set. ? stallsent: stall sent (control, bulk interrupt endpoints)/isoerror (isochronous endpoints) this flag generates an interr upt while it is set to one. stallsent: this ends a stall handshake. read: 0 = the host has not acknowledged a stall. 1 = host has acknowledged the stall. write: 0 = resets the stallsent flag, clears the interrupt. 1 = no effect. this is mandatory for the device firmware to clear this flag. otherwise the interrupt remains. refer to chapters 8.4.5 and 9.4.5 of the universal serial bus s pecification, rev. 2.0 for more information on the stall handshake. isoerror: a crc error has been detected in an isochronous transfer. read: 0 = no error in the prev ious isochronous transfer. 1 = crc error has been detected, data available in the fifo are corrupted. write: 0 = resets the isoerror flag, clears the interrupt. 1 = no effect. ? txpktrdy: transmit packet ready this flag is cleared by the usb device. this flag is set by the usb device firmware. read: 0 = there is no data to send. 1 = the data is waiting to be sent upon reception of token in.
591 6222f?atarm?14-jan-11 sam7se512/256/32 write: 0 = can be used in the procedure to cancel transmission data. (see, section 38.5.2.9 ?transmit data cancellation? on page 569 ) 1 = a new data payload has been written in the fifo by the firmware and is ready to be sent. this flag is used to generate a data in transaction (device to host). device firmware checks that it can write a data payload in the fifo, checking that txpktrdy is cl eared. transfer to the fifo is done by writing in the udp_fdrx register. once the data payload has been transferred to the fifo, the firmwar e notifies the usb device setting txpktrdy to one. usb bus transactions can start. txcomp is set once the data payload has been received by the host. after setting or clearing this bit, a wait time of 3 udpck clock cycles and 3 peripheral cloc k cycles is required before accessing dpr. ? forcestall: force stall (used by control, bulk and isochronous endpoints) read: 0 = normal state. 1 = stall state. write: 0 = return to normal state. 1 = send stall to the host. refer to chapters 8.4.5 and 9.4.5 of the universal serial bus s pecification, rev. 2.0 for more information on the stall handshake. control endpoints: during the data stage and status stage, this bit indicates that the microcontroller cannot complete the request. bulk and interrupt endpoints: this bit notifies the host that the endpoint is halted. the host acknowledges the stall, device fi rmware is notified by the stallsent flag. ? rx_data_bk1: receive data bank 1 (only used by endpoints with ping-pong attributes) this flag generates an interr upt while it is set to one. write (cleared by the firmware): 0 = notifies usb device that data have been read in the fifo?s bank 1. 1 = to leave the read value unchanged. read (set by the usb peripheral): 0 = no data packet has been received in the fifo's bank 1. 1 = a data packet has been received, it has been stored in fifo's bank 1. when the device firmware has polled this bit or has been interr upted by this signal, it must transfer data from the fifo to microcontroller memory. the number of bytes received is available in rxbytecnt field. bank 1 fifo values are read through udp_fdrx register. once a transfer is done, the device firmware must release bank 1 to the usb device by clear- ing rx_data_bk1. after setting or clearing this bit, a wait time of 3 udpck clock cycles and 3 peripheral cloc k cycles is required before accessing dpr.
592 6222f?atarm?14-jan-11 sam7se512/256/32 ? dir: transfer direction (only available for control endpoints) read-write 0 = allows data out transactio ns in the control data stage. 1 = enables data in transactions in the control data stage. refer to chapter 8.5.3 of the universal serial bus specification, rev. 2.0 for more information on the control data stage. this bit must be set before ud p_csrx/rxsetup is cleared at t he end of the setup st age. accordi ng to the request sent in the setup data packet, the data stage is either a device to host (dir = 1) or host to device (dir = 0) data transfer. it is not necessary to check this bit to reve rse direction for the status stage. ? eptype[2:0]: endpoint type read-write ? dtgle: data toggle read-only 0 = identifies data0 packet. 1 = identifies data1 packet. refer to chapter 8 of the universal serial bus specification, rev. 2.0 for more information on data0, data1 packet definitions. ? epeds: endpoint enable disable read: 0 = endpoint disabled. 1 = endpoint enabled. write: 0 = disables endpoint. 1 = enables endpoint. control endpoints are always enabled. reading or writing this field has no effect on control endpoints. note: after reset, all endpoints are configured as control endpoints (zero). value name description 000 ctrl control 001 iso_out isochronous out 101 iso_in isochronous in 010 bulk_out bulk out 110 bulk_in bulk in 011 int_out interrupt out 111 int_in interrupt in
593 6222f?atarm?14-jan-11 sam7se512/256/32 ? rxbytecnt[10:0]: number of bytes available in the fifo read-only when the host sends a data packet to the device, the usb device stores the data in the fifo and notifies the microcon- troller. the microcontr oller can load the data from the fifo by reading rxbytec ent bytes in the udp_fdrx register.
594 6222f?atarm?14-jan-11 sam7se512/256/32 38.6.11 udp fifo data register name: udp_fdrx [x = 0..y] access: read-write ? fifo_data[7:0]: fifo data value the microcontroller can push or pop values in the fifo through this register. rxbytecnt in the corresponding udp_csrx re gister is the number of bytes to be read from the fifo (sent by the host). the maximum number of bytes to write is fixed by the max packet size in the standard endpoint descriptor. it can not be more than the physical memory size associated to the endpoint. refer to the universal serial bus specification, rev. 2.0 for more information. 31 30 29 28 27 26 25 24 ???????? 23 22 21 20 19 18 17 16 ???????? 15 14 13 12 11 10 9 8 ?????? ?? 76543210 fifo_data
595 6222f?atarm?14-jan-11 sam7se512/256/32 38.6.12 udp transceiver control register name: udp_txvc access: read-write warning: the udp peripheral clock in the power management controller (pmc) must be enabled before any read/write operations to the udp registers including the udp_txvc register. ? txvdis: transceiver disable when udp is disabled, power consumption can be reduced significantly by disab ling the embedded transceiver. this can be done by setting txvdis field. to enable the transceiver, txvdis must be cleared. ? puon: pullup on 0: the 1.5k integrated pullup on ddp is disconnected. 1: the 1.5 k integrated pullup on ddp is connected. note : if the usb pullup is not connected on ddp, the user shou ld not write in any udp register other than the udp_txvc register. this is because if ddp and ddm are floating at 0, or pulled down, then se0 is received by the device with the con- sequence of a usb reset. 31 30 29 28 27 26 25 24 ???????? 23 22 21 20 19 18 17 16 ???????? 15 14 13 12 11 10 9 8 ?????? puon txvdis 76543210 ?????? ??
596 6222f?atarm?14-jan-11 sam7se512/256/32
597 6222f?atarm?14-jan-11 sam7se512/256/32 39. analog-to-digital converter (adc) 39.1 overview the adc is based on a successive approximatio n register (sar) 10-bit analog-to-digital con- verter (adc). it also integrates an 8-to-1 analog multiplexer, making possible the analog-to- digital conversions of 8 analog lines. the conversions extend from 0v to advref. the adc supports an 8-bit or 10-bit resolution mode, and conversion results are reported in a common register for all channels, as well as in a channel-dedicated register. software trigger, external trigger on rising edge of the adtrg pin or internal triggers from timer counter out- put(s) are configurable. the adc also integrates a sleep mode and a conversion sequencer and connects with a pdc channel. these features reduce both power consumption and processor intervention. finally, the user can configure adc timings, such as startup time and sample & hold time. 39.2 block diagram figure 39-1. analog-to-digital conv erter block diagram adc interrupt adc adtrg vddana advref gnd trigger selection control logic successive approximation register analog-to-digital converter timer counter channels user interface aic peripheral bridge apb pdc asb dedicated analog inputs analog inputs multiplexed with i/o lines ad- ad- ad- pio ad- ad- ad-
598 6222f?atarm?14-jan-11 sam7se512/256/32 39.3 signal description 39.4 product dependencies 39.4.1 power management the adc is automatically clocked after the first conversion in normal mode. in sleep mode, the adc clock is automatically stopped after each conversion. as the logic is small and the adc cell can be put into sleep mode, the power management controller has no effect on the adc behavior. 39.4.2 interrupt sources the adc interrupt line is connected on one of th e internal sources of the advanced interrupt controller. using the adc interrupt requires the aic to be programmed first. 39.4.3 analog inputs the analog input pins can be multiplexed with pio lines. in this case, the assignment of the adc input is automatically done as soon as the corresponding channel is enabled by writing the reg- ister adc_cher. by default, after reset, the pio line is configured as input with its pull-up enabled and the adc input is connected to the gnd. 39.4.4 i/o lines the pin adtrg may be shared with other peripheral functions through the pio controller. in this case, the pio controller should be set acco rdingly to assign the pin adtrg to the adc function. 39.4.5 timer triggers timer counters may or may not be used as hardware triggers depending on user requirements. thus, some or all of the timer counters may be non-connected. 39.4.6 conversion performances for performance and electrical characteristics of the adc, see the dc characteristics section. table 39-1. adc pin description pin name description vddana analog power supply advref reference voltage ad0 - ad 7 analog input channels adtrg external trigger
599 6222f?atarm?14-jan-11 sam7se512/256/32 39.5 functional description 39.5.1 analog-to-digital conversion the adc uses the adc clock to perform conversi ons. converting a single analog value to a 10- bit digital data requires sample and hold clock cycles as defined in the field shtim of the ?adc mode register? on page 606 and 10 adc clock cycles. the adc clock frequency is selected in the prescal field of the mode register (adc_mr). the adc clock range is between mck/2, if prescal is 0, and mck/128, if prescal is set to 63 (0x3f). prescal must be programmed in order to provide an adc clock frequency accord- ing to the parameters given in the product definition section. 39.5.2 conversion reference the conversion is performed on a full range be tween 0v and the reference voltage pin advref. analog inputs between these voltages convert to values based on a linear conversion. 39.5.3 conversion resolution the adc supports 8-bit or 10-bit resolutions. the 8- bit selection is performed by setting the bit lowres in the adc mode register (adc_mr). by default, after a reset, the resolution is the highest and the data field in the data registers is fully used. by setting the bit lowres, the adc switches in the lowest resolution and the conversion results can be read in the eight lowest significant bits of the data registers. the two hi ghest bits of the data field in the corresponding adc_cdr register and of the ldata field in the adc_lcdr register read 0. moreover, when a pdc channel is connected to the adc, 10-bit resolution sets the transfer request sizes to 16-bit. setting the bit lowres autom atically switches to 8-bit data transfers. in this case, the destination buffers are optimized.
600 6222f?atarm?14-jan-11 sam7se512/256/32 39.5.4 conversion results when a conversion is completed, the resulting 10-bit digital value is stored in the channel data register (adc_cdr) of the current channel and in the adc last converted data register (adc_lcdr). the channel eoc bit in the status register (adc_sr) is set and th e drdy is set. in the case of a connected pdc channel, drdy rising triggers a data transfer request. in any case, either eoc and drdy can trigger an interrupt. reading one of the adc_cdr registers clears the corresponding eoc bit. reading adc_lcdr clears the drdy bit and the eoc bit corresponding to the last converted channel. figure 39-2. eocx and drdy flag behavior if the adc_cdr is not read befo re further incoming data is converted, the corresponding over- run error (ovre) flag is set in the status register (adc_sr). in the same way, new data converted when drdy is high sets the bit govre (general overrun error) in adc_sr. the ovre and govre flags are automatically cleared when adc_sr is read. conversion time read the adc_cdrx eocx drdy read the adc_lcdr chx (adc_chsr) (adc_sr) (adc_sr) write the adc_cr with start = 1 conversion time write the adc_cr with start = 1
601 6222f?atarm?14-jan-11 sam7se512/256/32 figure 39-3. govre and ovrex flag behavior warning: if the corresponding channel is disabled during a conversion or if it is disabled and then reenabled during a conversion, its associated data and its corresponding eoc and ovre flags in adc_sr are unpredictable. eoc0 govre ch0 (adc_chsr) (adc_sr) (adc_sr) adtrg eoc1 ch1 (adc_chsr) (adc_sr) ovre0 (adc_sr) undefined data data a data b adc_lcdr undefined data data a adc_cdr0 undefined data data b adc_cdr1 data c data c conversion conversion read adc_sr drdy (adc_sr) read adc_cdr1 read adc_cdr0 conversion
602 6222f?atarm?14-jan-11 sam7se512/256/32 39.5.5 conversion triggers conversions of the active analog channels are started with a software or a hardware trigger. the software trigger is provided by writing the control register (adc_ cr) with the bit start at 1. the hardware trigger can be one of the tioa outputs of the timer counter channels, or the external trigger input of the adc (adtrg). the hardware trigger is selected with the field trg- sel in the mode register (adc_mr). the selected hardware trigger is enabled with the bit trgen in the mode register (adc_mr). if a hardware trigger is selected, the start of a c onversion is detected at each rising edge of the selected signal. if one of the tioa outputs is selected, the corresponding timer counter channel must be programmed in waveform mode. only one start command is necessary to initiate a conversion sequence on all the channels. the adc hardware logic automatically performs the conversions on the active channels, then waits for a new request. the channel enable (adc_cher) and channel disable (adc_chdr) reg- isters enable the analog channels to be enabled or disabled independently. if the adc is used with a pdc, only the transfe rs of converted data from enabled channels are performed and the resulting data buffers should be interpreted accordingly. warning: enabling hardware triggers does not disable the software trigger functionality. thus, if a hardware trigger is selected, the start of a conversion can be initiated either by the hardware or the software trigger. 39.5.6 sleep mode and conversion sequencer the adc sleep mode maximizes power saving by aut omatically deactivating the adc when it is not being used for conversions. sleep mode is se lected by setting the bit sleep in the mode register adc_mr. the sleep mode is automatically managed by a conversion sequencer, which can automati- cally process the conversions of all channels at lowest power consumption. when a start conversion request occurs, the adc is automatically activated. as the analog cell requires a start-up time, the logic waits during this time and starts the conversion on the enabled channels. when all conversions are complete, the adc is deactivated until the next trigger. trig- gers occurring during the sequence are not taken into account. the conversion sequencer allows automatic pr ocessing with minimum processor intervention and optimized power consumption. conversion sequences can be performed periodically using a timer/counter output. the periodic acquisition of several samples can be processed automat- ically without any intervention of the processor thanks to the pdc. note: the reference voltage pins always remain connected in normal mode as in sleep mode.
603 6222f?atarm?14-jan-11 sam7se512/256/32 39.5.7 adc timings each adc has its own minimal startup time that is programmed through the field startup in the mode register adc_mr. in the same way, a minimal sample and hold time is necessary for the adc to guarantee the best converted final value between two channels selection. this time has to be programmed through the shtim bitfield in the mode register adc_mr. warning: no input buffer amplifier to isolate the source is included in the adc. this must be taken into consideration to program a precise value in the shtim field. see the section adc characteristics in the product datasheet.
604 6222f?atarm?14-jan-11 sam7se512/256/32 39.6 analog-to-digital con verter (adc) user interface table 39-2. adc register mapping offset register name access reset state 0x00 control register adc_cr write-only ? 0x04 mode register adc_mr read/write 0x00000000 0x08 reserved ? ? ? 0x0c reserved ? ? ? 0x10 channel enable register adc_cher write-only ? 0x14 channel disable register adc_chdr write-only ? 0x18 channel status register adc_chsr read-only 0x00000000 0x1c status register adc_sr read-only 0x000c0000 0x20 last converted data regi ster adc_lcdr read-only 0x00000000 0x24 interrupt enable register adc_ier write-only ? 0x28 interrupt disable register adc_idr write-only ? 0x2c interrupt mask register adc_imr read-only 0x00000000 0x30 channel data register 0 adc_cdr0 read-only 0x00000000 0x34 channel data register 1 adc_cdr1 read-only 0x00000000 ... ... ... ... ... 0x4c channel data register 7 adc_cdr7 read-only 0x00000000 0x50 - 0xfc reserved ? ? ?
605 6222f?atarm?14-jan-11 sam7se512/256/32 39.6.1 adc control register name: adc_cr access: write-only ? swrst: software reset 0 = no effect. 1 = resets the adc simulating a hardware reset. ? start: start conversion 0 = no effect. 1 = begins analog-to-digital conversion. 31 30 29 28 27 26 25 24 ???????? 23 22 21 20 19 18 17 16 ???????? 15 14 13 12 11 10 9 8 ???????? 76543210 ?????? start swrst
606 6222f?atarm?14-jan-11 sam7se512/256/32 39.6.2 adc mode register name: adc_mr access: read/write ? trgen: trigger enable ? trgsel: trigger selection ? lowres: resolution ? sleep: sleep mode 31 30 29 28 27 26 25 24 ???? shtim 23 22 21 20 19 18 17 16 ? ? ? startup 15 14 13 12 11 10 9 8 ?? prescal 76543210 ? ? sleep lowres trgsel trgen trgen selected trgen 0 hardware triggers are disabled. starting a conversion is only possible by software. 1 hardware trigger selected by trgsel field is enabled. trgsel selected trgsel 0 0 0 tioa ouput of the timer counter channel 0 0 0 1 tioa ouput of the timer counter channel 1 0 1 0 tioa ouput of the timer counter channel 2 011reserved 100reserved 101reserved 1 1 0 external trigger 111reserved lowres selected resolution 0 10-bit resolution 1 8-bit resolution sleep selected mode 0 normal mode 1 sleep mode
607 6222f?atarm?14-jan-11 sam7se512/256/32 ? prescal: prescaler rate selection adcclock = mck / ( (prescal+1) * 2 ) ? startup: start up time startup time = (startup+1) * 8 / adcclock ? shtim: sample & hold time sample & hold time = (shtim+1) / adcclock
608 6222f?atarm?14-jan-11 sam7se512/256/32 39.6.3 adc channel enable register name: adc_cher access: write-only ? chx: channel x enable 0 = no effect. 1 = enables the corresponding channel. 39.6.4 adc channel disable register name: adc_chdr access: write-only ? chx: channel x disable 0 = no effect. 1 = disables the corresponding channel. warning: if the corresponding channel is disabled during a conversion or if it is disabled then reenabled during a conver- sion, its associated data and its corresponding eoc and ovre flags in adc_sr are unpredictable. 31 30 29 28 27 26 25 24 ???????? 23 22 21 20 19 18 17 16 ???????? 15 14 13 12 11 10 9 8 ???????? 76543210 ch7 ch6 ch5 ch4 ch3 ch2 ch1 ch0 31 30 29 28 27 26 25 24 ???????? 23 22 21 20 19 18 17 16 ???????? 15 14 13 12 11 10 9 8 ???????? 76543210 ch7 ch6 ch5 ch4 ch3 ch2 ch1 ch0
609 6222f?atarm?14-jan-11 sam7se512/256/32 39.6.5 adc channel status register name: adc_chsr access: read-only ? chx: channel x status 0 = corresponding c hannel is disabled. 1 = corresponding channel is enabled. 31 30 29 28 27 26 25 24 ???????? 23 22 21 20 19 18 17 16 ???????? 15 14 13 12 11 10 9 8 ???????? 76543210 ch7 ch6 ch5 ch4 ch3 ch2 ch1 ch0
610 6222f?atarm?14-jan-11 sam7se512/256/32 39.6.6 adc status register name: adc_sr access: read-only ? eocx: end of conversion x 0 = corresponding analog channel is disabl ed, or the conversion is not finished. 1 = corresponding analog channel is enabled and conversion is complete. ? ovrex: overrun error x 0 = no overrun error on the corresponding channel since the last read of adc_sr. 1 = there has been an overrun error on the corres ponding channel since the last read of adc_sr. ? drdy: data ready 0 = no data has been converted since the last read of adc_lcdr. 1 = at least one data has been conv erted and is ava ilable in adc_lcdr. ? govre: general overrun error 0 = no general overrun error occurred since the last read of adc_sr. 1 = at least one general overrun error has occurred since the last read of adc_sr. ? endrx: end of rx buffer 0 = the receive counter register has not reach ed 0 since the last write in adc_rcr or adc_rncr. 1 = the receive counter register has reached 0 since the last write in adc_rcr or adc_rncr. ? rxbuff: rx buffer full 0 = adc_rcr or adc_rncr ha ve a value other than 0. 1 = both adc_rcr and adc_rncr have a value of 0. 31 30 29 28 27 26 25 24 ???????? 23 22 21 20 19 18 17 16 ????rxbuffendrxgovredrdy 15 14 13 12 11 10 9 8 ovre7 ovre6 ovre5 ovre4 ovre3 ovre2 ovre1 ovre0 76543210 eoc7 eoc6 eoc5 eoc4 eoc3 eoc2 eoc1 eoc0
611 6222f?atarm?14-jan-11 sam7se512/256/32 39.6.7 adc last conv erted data register name: adc_lcdr access: read-only ? ldata: last data converted the analog-to-digital conversion data is pl aced into this register at the end of a conversion and remains until a new conver- sion is completed. 39.6.8 adc interrupt enable register name: adc_ier access: write-only ? eocx: end of conversion interrupt enable x ? ovrex: overrun error interrupt enable x ? drdy: data ready interrupt enable ? govre: general overrun error interrupt enable ? endrx: end of receive buffer interrupt enable ? rxbuff: receive buffer full interrupt enable 0 = no effect. 1 = enables the corresponding interrupt. 31 30 29 28 27 26 25 24 ???????? 23 22 21 20 19 18 17 16 ???????? 15 14 13 12 11 10 9 8 ?????? ldata 76543210 ldata 31 30 29 28 27 26 25 24 ???????? 23 22 21 20 19 18 17 16 ????rxbuffendrxgovredrdy 15 14 13 12 11 10 9 8 ovre7 ovre6 ovre5 ovre4 ovre3 ovre2 ovre1 ovre0 76543210 eoc7 eoc6 eoc5 eoc4 eoc3 eoc2 eoc1 eoc0
612 6222f?atarm?14-jan-11 sam7se512/256/32 39.6.9 adc interrupt disable register name: adc_idr access: write-only ? eocx: end of conversion interrupt disable x ? ovrex: overrun error interrupt disable x ? drdy: data ready interrupt disable ? govre: general overrun error interrupt disable ? endrx: end of receive buffer interrupt disable ? rxbuff: receive buffer full interrupt disable 0 = no effect. 1 = disables the corresponding interrupt. 31 30 29 28 27 26 25 24 ???????? 23 22 21 20 19 18 17 16 ????rxbuffendrxgovredrdy 15 14 13 12 11 10 9 8 ovre7 ovre6 ovre5 ovre4 ovre3 ovre2 ovre1 ovre0 76543210 eoc7 eoc6 eoc5 eoc4 eoc3 eoc2 eoc1 eoc0
613 6222f?atarm?14-jan-11 sam7se512/256/32 39.6.10 adc interrupt mask register name: adc_imr access: read-only ? eocx: end of conversion interrupt mask x ? ovrex: overrun erro r interrupt mask x ? drdy: data ready interrupt mask ? govre: general overrun error interrupt mask ? endrx: end of receive buffer interrupt mask ? rxbuff: receive buffer full interrupt mask 0 = the corresponding interrupt is disabled. 1 = the corresponding interrupt is enabled. 31 30 29 28 27 26 25 24 ???????? 23 22 21 20 19 18 17 16 ????rxbuffendrxgovredrdy 15 14 13 12 11 10 9 8 ovre7 ovre6 ovre5 ovre4 ovre3 ovre2 ovre1 ovre0 76543210 eoc7 eoc6 eoc5 eoc4 eoc3 eoc2 eoc1 eoc0
614 6222f?atarm?14-jan-11 sam7se512/256/32 39.6.11 adc channel data register name: adc_cdrx access: read-only ? data: converted data the analog-to-digital conversion data is pl aced into this register at the end of a conversion and remains until a new conver- sion is completed. the convert data re gister (cdr) is only loaded if the corr esponding analog channel is enabled. 31 30 29 28 27 26 25 24 ???????? 23 22 21 20 19 18 17 16 ???????? 15 14 13 12 11 10 9 8 ?????? data 76543210 data
615 6222f?atarm?14-jan-11 sam7se512/256/32 40. sam7se512/256/32 elec trical characteristics 40.1 absolute maximum ratings table 40-1. absolute maximum ratings* operating temperature (industrial).........-40 ? c to + 85 ? c *notice: stresses beyond those listed under ?absolute maxi- mum ratings? may cause permanent damage to the device. this is a stress rating only and func- tional operation of the device at these or other con- ditions beyond those indicated in the operational sections of this specification is not implied. expo- sure to absolute maximu m rating conditions for extended periods may affect device reliability. storage temperature............................-60c to + 150c voltage on input pins with respect to ground............................-0.3v to + 5.5v maximum operating voltage (vddcore, and vddpll)........... ........... ........... ......2.0v maximum operating voltage (vddio, vddin and vddflash).............................4.0v total dc output current on all i/o lines 128-lead lqfp/144-ball lfbga...........................200 ma
616 6222f?atarm?14-jan-11 sam7se512/256/32 40.2 dc characteristics the following characteristics are applicable to the operating temperature range: t a = -40c to 85c, unless otherwise specified. table 40-2. dc characteristics symbol parameter conditions min typ max units v vddcore dc supply core 1.65 1.95 v v vddpll dc supply pll 1.65 1.95 v v vddio dc supply i/os 3.3v domain 3.0 3.6 v v vddio dc supply i/os 1.8v domain 1.65 1.95 v vddflash dc supply flash 3.0 3.6 v v il input low-level voltage v vddio from 3.0v to 3.6v -0.3 0.8 v v vddio from 1.65v to 1.95v -0.3 0.3 x v vddio v v ih input high-level voltage v vddio from 3.0v to 3.6v 2.0 v vddio +0.3v v v vddio from 1.65v to 1.95v 0.7 x v vddio v vddio +0.3v v v hys hysteresis voltage v vddio from 3.0v to 3.6v 0.4 0.7 v v vddio from 1.65v to 1.95v 0.3 0.6 v v ol output low-level voltage i o max, v vddio from 3.0v to 3.6v 0.4 v i o max, v vddio from 1.65v to 1.95v 0.25 x v vddio v oh output high-level voltage i o max, v vddio from 3.0v to 3.6v v vddio -0.4 v i o max, v vddio from 1.65v to 1.95v 0.75 x v vddio i leak input leakage current pa0-pa3, pull-up resistors disabled (typ: t a = 25c, max: t a = 85c) 40 400 na other pios, pull-up resistors disabled (typ: t a = 25c, max: t a = 85c) 20 200 na r pullup pull-up resistor pa0-pa31, pb0-pb31,pc0-pc23, v vddio from 3.0v to 3.6v 80 103 145 k pa0-pa31, pb0-pb31,pc0-pc23, v vddio from 1.65v to 1.95v 95 147 320 k r pulldown pull-down resistor, (tst, erase, jtagsel) v vddio from 3.0v to 3.6v, pins connected to v vddio 81528k c in input capacitance 14 pf
617 6222f?atarm?14-jan-11 sam7se512/256/32 i sc static current (sam7se512/256) on v vddcore = 1.85v, mck = 500hz t a = 25c 12 60 a all inputs driven at 1 (including tms, tdi, tck, nrst) flash in standby mode all peripherals off t a = 85c 40 300 i sc static current (sam7se32) on v vddcore = 1.85v, mck = 500hz t a = 25c 10 40 a all inputs driven at 1 (including tms, tdi, tck, nrst) flash in standby mode all peripherals off t a = 85c 20 150 i o output current pa 0 - pa 3 , v vddio from 3.0v to 3.6v 16 ma pa 0 - pa 3 , v vddio from 1.65v to 1.95v 8 ma pa4-pa31, pb0-pb31, pc0-pc23 and nrst, v vddio from 3.0v to 3.6v 8ma pa4-pa31, pb0-pb31, pc0-pc23 and nrst, v vddio from 1.65v to 1.95v 4ma table 40-2. dc characteristics (continued) symbol parameter conditions min typ max units table 40-3. 1.8v voltage regulator characteristics symbol parameter conditions min typ max units v vddin supply voltage 3.0 3.3 3.6 v v vddout output voltage i o = 20 ma 1.81 1.85 1.89 v i vddin current consumption after startup, no load 90 a after startup, idle mode, no load 10 25 a t start startup time c load = 2.2 f, after v ddin > 2.7v 150 s i o maximum dc output current v ddin = 3.3v 100 ma i o maximum dc output current v ddin = 3.3v, in idle mode 1 ma table 40-4. brownout detector characteristics symbol parameter conditions min typ max units v bot18- vddcore threshold level 1.65 1.68 1.71 v v hyst18 vddcore hysteresis v hyst18 = v bot18+ - v bot18- 50 65 mv v bot33- vddflash threshold level 2.70 2.80 2.90 v v hyst33 vddflash hysteresis v hyst33 = v bot33+ - v bot33- 70 120 mv
618 6222f?atarm?14-jan-11 sam7se512/256/32 i dd current consumption bod on (gpnvm0 bit active) 24 30 a bod off (gpnvm0 bit inactive) 1 a t start startup time 100 200 s table 40-4. brownout detector characteristics symbol parameter conditions min typ max units table 40-5. dc flash characteristics sam7se32 symbol parameter conditions min max units i sb standby current @25c onto vddcore = 1.8v onto vddflash = 3.3v 3 25 a a @85c onto vddcore = 1.8v onto vddflash = 3.3v 5 125 a a i cc active current random read @ 30mhz onto vddcore = 1.8v onto vddflash = 3.3v 3.4 0.4 ma ma write onto vddcore = 1.8v onto vddflash = 3.3v 400 2.2 a ma table 40-6. dc flash characteristics sam7se512/256 symbol parameter conditions min max units i sb standby current @25c onto vddcore = 1.8v onto vddflash = 3.3v 10 40 a a @85c onto vddcore = 1.8v onto vddflash = 3.3v 20 120 a a i cc active current random read @ 30mhz (one bank for sam7se512) onto vddcore = 1.8v onto vddflash = 3.3v 4.5 0.8 ma ma write (one bank for sam7se512) onto vddcore = 1.8v onto vddflash = 3.3v 400 5.5 a ma
619 6222f?atarm?14-jan-11 sam7se512/256/32 40.3 power consumption ? typical power consumption of plls , slow clock and main oscillator. ? power consumption of power supply in two different modes: active and ultra low-power. ? power consumption by peripheral: calculated as the difference in current measurement after having enabled then disabled the corresponding clock. 40.3.1 power consumption versus modes the values in table 40-7 and table 40-8 on page 620 are measured values of the power con- sumption with operating conditions as follows: ?v ddio = v ddin = v ddflash = 3.3v ?v ddcore = v ddpll = 1.85v ?t a = 25 c ? there is no consumption on the i/os of the device figure 40-1. measure schematics: 1.8v vddin voltage regulator vddout vddcore vddpll 3.3v vddio vddflash amp1 amp2
620 6222f?atarm?14-jan-11 sam7se512/256/32 the figures shown below in table 40-7 represent the power consumption typically measured on the power supplies.. notes: 1. ?flash is in standby mode?, means the flash is not accessed at all. 2. low power consumption figures stated above cannot be guaranteed when accessing the flash in ultra low power mode. in order to meet given low power consumption figures, it is recom- mended to either stop the processor or jump to sram. 40.3.2 peripheral power consumption in active mode table 40-7. power consumption for different modes mode conditions consumption unit active (sam7se512/256/32) voltage regulator is on. brown out detector is activated. flash is read. arm core clock is 48 mhz. analog-to-digital converter activated. all peripheral clocks activated. usb transceiver enabled. onto amp1 onto amp2 31 29 ma ultra low power (2) (sam7se512/256/32) voltage regulator is in low-power mode. brown out detector is de-activated. flash is in standby mode. (1) arm core in idle mode. mck @ 500 hz. analog-to-digital converter de-activated. all peripheral clocks de-activated. usb transceiver disabled. ddm and ddp pins must be left floating. onto amp1 onto amp2 26 12 a table 40-8. power consumption on v ddcore (1) peripheral consumption (typ) unit pio controller 12 a/mhz usart 30 udp 24 pwm 15 twi 6 spi 18 ssc 35 timer counter channels 7 arm7tdmi 170 system peripherals (sam7se512/256/32) 265
621 6222f?atarm?14-jan-11 sam7se512/256/32 note: 1. note: v ddcore = 1.85v, t a = 25 c 40.4 crystal oscillators characteristics 40.4.1 rc oscillator characteristics table 40-9. rc oscillator characteristics symbol parameter conditions min typ max unit 1/(t cprc ) rc oscillator frequency v ddpll = 1.65v 22 32 42 khz duty cycle 45 50 55 % t st startup time v ddpll = 1.65v 75 s i osc current consumption aft er startup time 1.9 a
622 6222f?atarm?14-jan-11 sam7se512/256/32 40.4.2 main oscillator characteristics notes: 1. c s is the shunt capacitance. 2. r s = 100-200 ; c shunt = 2.0 - 2.5 pf; c m = 2 ? 1.5 ff (typ, worst case) usin g 1 k ohm serial resistor on xout. 3. r s = 50-100 ; c shunt = 2.0 - 2.5 pf; c m = 4 - 3 ff (typ, worst case). 4. r s = 25-50 ; c shunt = 2.5 - 3.0 pf; c m = 7 -5 ff (typ, worst case). 5. r s = 20-50 ; c shunt = 3.2 - 4.0 pf; c m = 10 - 8 ff (typ, worst case). 6. c l and c lext ? table 40-10. main oscillator characteristics symbol parameter conditions min typ max unit 1/(t cpmain ) crystal oscillator frequency 3 16 20 mhz c l1 , c l2 sam7se512/256 internal load capacitance (c l1 = c l2 ) integrated load capacitance ((xin or xout)) 34 40 46 pf c l1 , c l2 sam7se32 internal load capacitance (c l1 = c l2 ) integrated load capacitance (xin or xout) 18 22 26 pf c l (6) sam7se512/256 equivalent load capacitance integrated load capacitance (xin and xout in series) 17 20 23 pf c l (6) sam7se32 equivalent load capacitance integrated load capacitance (xin and xout in series) 91113pf duty cycle 30 50 70 % t st startup time v ddpll = 1.2 to 2v c s = 3 pf (1) 1/(t cpmain ) = 3 mhz c s = 7 pf (1) 1/(t cpmain ) = 16 mhz c s = 7 pf (1) 1/(t cpmain ) = 20 mhz 14.5 1.4 1 ms i ddst standby current consumption standby mode 1 a p on drive level @3 mhz @8 mhz @16 mhz @20 mhz 15 30 50 50 w i dd on current dissipation @3 mhz (2) @8 mhz (3) @16 mhz (4) @20 mhz (5) 150 150 300 400 250 250 450 550 a c lext (6) maximum external capacitor on xin and xout 10 pf xin xout c lext c l c lext at91sam7se
623 6222f?atarm?14-jan-11 sam7se512/256/32 40.4.3 crystal characteristics 40.4.4 xin clock characteristics note: 1. these characteristics apply only when the main oscillator is in bypass mode (i.e., when moscen = 0 and oscbypass = 1 in the ckgr_mor register, see the cloc k generator main oscillator register. figure 40-2. xin clock timing table 40-11. crystal characteristics symbol parameter conditions min typ max unit esr equivalent series resistor rs fundamental @3 mhz fundamental @8 mhz fundamental @16 mhz fundamental @20 mhz 200 100 80 50 c m motional capacitance 8ff c shunt shunt capacitance 7pf table 40-12. xin clock electrical characteristics symbol parameter conditions min max units 1/(t cpxin ) xin clock frequency (1) 50.0 mhz t cpxin xin clock period (1) 20.0 ns t chxin xin clock high half-period (1) 8.0 ns t clxin xin clock low half-period (1) 8.0 ns t clch rise time (1) 400 ns t chcl fall time (1) 400 ns c in xin input capacitance (sam7se512/256) (1) 46 pf c in xin input capacitance (sam7se32) (1) 26 pf r in xin pull-down resistor (1) 500 k v xin_il v xin input low-level voltage (1) -0.3 0.3 x v ddpll v v xin_ih v xin input high-level voltage (1) 0.7 x v ddpll 1.95 v i ddbp bypass current consumption (1) 15 w/mhz t cpxin t cpxin t cpxin t chxin t clch t chcl v xin_il v xin_ih
624 6222f?atarm?14-jan-11 sam7se512/256/32 40.5 pll characteristics note: startup time depends on pll rc filter. a calculation tool is provided by atmel. table 40-13. phase lock loop characteristics symbol parameter conditions min typ max unit f out output frequency field out of ckgr_pll is: 00 80 160 mhz 10 150 220 mhz f in input frequency 1 32 mhz i pll current consumption active mode 4 ma standby mode 1 a
625 6222f?atarm?14-jan-11 sam7se512/256/32 40.6 usb transceiver characteristics 40.6.1 electrical characteristics 40.6.2 switching characteristics table 40-14. electrical parameters symbol parameter conditions min typ max unit input levels v il low level 0.8 v v ih high level 2.0 v v di differential input sensitivity |(d+) - (d-)| 0.2 v v cm differential input common mode range 0.8 2.5 v c in transceiver capacitance capacitance to ground on each line 9.18 pf i hi-z state data line leakage 0v < v in < 3.3v -10 +10 a r ext recommended external usb series resistor in series with each usb pin with 5% 27 output levels v ol low level output measured with r l of 1.425 kohm tied to 3.6v 0.0 0.3 v v oh high level output measured with r l of 14.25 kohm tied to gnd 2.8 3.6 v v crs output signal crossover voltage measure conditions described in figure 40-3 1.3 2.0 v consumption i vddio current consumption transceiver enabled in input mode ddp=1 and ddm=0 105 200 a i vddcore current consumption 80 150 a pull-up resistor r pui bus pull-up resistor on upstream port (idle bus) 0.900 1.575 k r pua bus pull-up resistor on upstream port (upstream port receiving) 1.425 3.090 k table 40-15. in full speed symbol parameter conditions min typ max unit t fr transition rise time c load = 50 pf 4 20 ns t fe transition fall time c load = 50 pf 4 20 ns t frfm rise/fall time matching 90 111.11 %
626 6222f?atarm?14-jan-11 sam7se512/256/32 figure 40-3. usb data signal rise and fall times 10% 10% 90% v crs t r t f differential data lines rise time fall time fosc = 6mhz/750khz r ext =27 ohms c load buffer (b) (a)
627 6222f?atarm?14-jan-11 sam7se512/256/32 40.7 adc characteristics notes: 1. corresponds to 13 clock cycles at 5 mhz: 3 clock cycles for track and hold ac quisition time and 10 clock cycles for conversion. 2. corresponds to 15 clock cycles at 8 mh z: 5 clock cycles for track and hold acqu isition time and 10 clock cycles for conversion. the user can drive adc input with impedance up to: ?z out (shtim -470) x 10 in 8-bit resolution mode ?z out (shtim -589) x 7.69 in 10-bit resolution mode with shtim (sample and hold time register) expressed in ns and z out expressed in ohms. table 40-16. channel conversion time and adc clock parameter conditions min typ max units adc clock frequency 10-bit resolution mode 5 mhz 8-bit resolution mode 8 startup time return from idle mode 20 s track and hold acquisition time 600 ns conversion time adc clock = 5 mhz 2 s adc clock = 8 mhz 1.25 throughput rate adc clock = 5 mhz 384 (1) ksps adc clock = 8 mhz 533 (2) table 40-17. external voltage reference input parameter conditions min typ max units advref input voltage range 2.6 v ddin v 8-bit resolution mode 2.5 advref average current on 13 samples with adc clock = 5 mhz 200 250 a current consumption on vddin 0.55 1 ma table 40-18. analog inputs parameter min typ max units input voltage range 0v advref input leakage current 1a input capacitance 12 14 pf table 40-19. transfer characteristics parameter conditions min typ max units resolution 10 bit integral non-linearity 2 lsb differential non-linearity no missing code 1 lsb offset error 2 lsb gain error 2 lsb absolute accuracy 4 lsb
628 6222f?atarm?14-jan-11 sam7se512/256/32 for more information on data converter terminology, please refer to the application note: data converter terminology, atmel lit 6022. 40.8 ac characteristics 40.8.1 master clock characteristics 40.8.2 i/o characteristics criteria used to define the maximum frequency of the i/os: ? output duty cycle (30%-70%) ? minimum output swing: 100mv to vddio - 100mv ? addition of rising and falling time inferior to 75% of the period notes: 1. pin group 1 = sdck 2. pin group 2 = pa4 to pa31, pb0 to pb31 and pc0-pc23 table 40-20. master clock waveform parameters symbol parameter conditions min max units 1/(t cpmck ) master clock frequency v ddcore = 1.8v 55 mhz 1/(t cpmck ) master clock frequency v ddcore = 1.65v 48 mhz table 40-21. i/o characteristics symbol parameter conditions min max units freqmax i01 pin group 1 (1) frequency load: 30 pf (4) 48.2 mhz load: 30 pf (5) 25 mhz pulseminh i01 pin group 1 (1) high level pulse width load: 30 pf (4) 20 ns load: 30 pf (5) 40 pulseminl i01 pin group 1 (1) low level pulse width load: 30 pf (4) 20 ns load: 30 pf (5) 40 freqmax i02 pin group 2 (2) frequency load: 40 pf (4) 25 mhz load: 40 pf (5) 16 mhz pulseminh i02 pin group 2 (2) high level pulse width load: 40 pf (4) 20 ns load: 40 pf (5) 31 ns pulseminl i02 pin group 2 (2) low level pulse width load: 40 pf (4) 20 ns load: 40 pf (5) 31 ns freqmax i03 pin group 3 (3) frequency load: 40 pf (4) 30 mhz load: 40 pf (5) 20 mhz pulseminh i03 pin group 3 (3) high level pulse width load: 40 pf (4) 16.6 ns load: 40 pf (5) 31 ns pulseminl i03 pin group 3 (3) low level pulse width load: 40 pf (4) 16.6 ns load: 40 pf (5) 31 ns
629 6222f?atarm?14-jan-11 sam7se512/256/32 3. pin group 3 = pa0 to pa3 4. v vddio from 3.0v to 3.6v, maximum external capacitor = 40 pf 5. v vddio from 1.65v to 1.95v, maximum external capacitor = 40 pf 40.8.3 spi characteristics figure 40-4. spi master mode with (cpol= ncpha = 0) or (cpol= ncpha= 1) figure 40-5. spi master mode with (cpol = 0 and ncpha=1) or (cpol=1 and ncpha= 0) figure 40-6. spi slave mode with (cpol=0 and ncpha=1) or (cpol=1 and ncpha=0) spck miso mosi spi 2 spi 0 spi 1 spck miso mosi spi 5 spi 3 spi 4 spck miso mosi spi 6 spi 7 spi 8
630 6222f?atarm?14-jan-11 sam7se512/256/32 figure 40-7. spi slave mode with (cpol = ncph a = 0) or (cpol= ncpha= 1) notes: 1. 3.3v domain: v vddio from 3.0v to 3.6v, maximum external capacitor = 40 pf. 2. 1.8v domain: v vddio from 1.65v to 1.95v, maximum external capacitor = 20 pf. 3. t cpmck : master clock period in ns. spck miso mosi spi 9 spi 10 spi 11 table 40-22. sam7se512/256 spi timings symbol parameter conditions min max units spi 0 miso setup time before spck rises (master) 3.3v domain (1) 26 + (t cpmck )/2 (3) ns 1.8v domain (2) 34 + (t cpmck )/2 (3) ns spi 1 miso hold time after spck rises (master) 3.3v domain (1) 0ns 1.8v domain (2) 0ns spi 2 spck rising to mosi delay (master) 3.3v domain (1) 7ns 1.8v domain (2) 10 ns spi 3 miso setup time befo re spck falls (master) 3.3v domain (1) 26 + (t cpmck )/2 (3) ns 1.8v domain (2) 34 + (t cpmck )/2 (3) ns spi 4 miso hold time afte r spck falls (master) 3.3v domain (1) 0ns 1.8v domain (2) 0ns spi 5 spck falling to mosi delay (master) 3.3v domain (1) 7ns 1.8v domain (2) 10 ns spi 6 spck falling to miso delay (slave) 3.3v domain (1) 22.5 ns 1.8v domain (2) 30.5 ns spi 7 mosi setup time before spck rises (slave) 3.3v domain (1) 1ns 1.8v domain (2) 2.5 ns spi 8 mosi hold time after spck rises (slave) 3.3v domain (1) 2ns 1.8v domain (2) 2ns spi 9 spck rising to miso delay (slave) 3.3v domain (1) 23 ns 1.8v domain (2) 28 ns spi 10 mosi setup time before spck falls (slave) 3.3v domain (1) 1ns 1.8v domain (2) 1 spi 11 mosi hold time after spck falls (slave) 3.3v domain (1) 2ns 1.8v domain (2) 2ns
631 6222f?atarm?14-jan-11 sam7se512/256/32 notes: 1. 3.3v domain: v vddio from 3.0v to 3.6v, maximum external capacitor = 40 pf. 2. 1.8v domain: v vddio from 1.65v to 1.95v, maximum external capacitor = 20 pf. 3. t cpmck : master clock period in ns. note that in spi master mode the atsam7se512/256/32 does not sample the data (miso) on the opposite edge where data clocks out (mosi) but the same edge is used as shown in figure 40-4 and figure 40-5 . sam7se32 spi timings symbol parameter conditions min max units spi 0 miso setup time before spck rises (master) 3.3v domain (1) 26 + (t cpmck )/2 (3) ns 1.8v domain (2) 45 + (t cpmck )/2 (3) ns spi 1 miso hold time after spck rises (master) 3.3v domain (1) 0ns 1.8v domain (2) 0ns spi 2 spck rising to mosi delay (master) 3.3v domain (1) 4ns 1.8v domain (2) 12 ns spi 3 miso setup time befo re spck falls (master) 3.3v domain (1) 26 + (t cpmck )/2 (3) ns 1.8v domain (2) 34 + (t cpmck )/2 (3) ns spi 4 miso hold time afte r spck falls (master) 3.3v domain (1) 0ns 1.8v domain (2) 0ns spi 5 spck falling to mosi delay (master) 3.3v domain (1) 4ns 1.8v domain (2) 6ns spi 6 spck falling to miso delay (slave) 3.3v domain (1) 23.7 ns 1.8v domain (2) 42 ns spi 7 mosi setup time before spck rises (slave) 3.3v domain (1) 1ns 1.8v domain (2) 1ns spi 8 mosi hold time after spck rises (slave) 3.3v domain (1) 3ns 1.8v domain (2) 3ns spi 9 spck rising to miso delay (slave) 3.3v domain (1) 24 ns 1.8v domain (2) 40 ns spi 10 mosi setup time before spck falls (slave) 3.3v domain (1) 1ns 1.8v domain (2) 1 spi 11 mosi hold time after spck falls (slave) 3.3v domain (1) 3ns 1.8v domain (2) 3ns
632 6222f?atarm?14-jan-11 sam7se512/256/32 40.8.4 smc signals these timings are given for a maximum 10 pf load on sdck and a maximum 50 pf load on the databus. note: 1. n = number of standard wait states inserted. note: 1. n = number of standard wait states inserted. . table 40-23. sam7se512/256 general-purpose smc signals symbol parameter conditions min max units smc 7 ncs minimum pulse width (address to chip select setup) 3.3v domain (n + 1) x t cpmck - 2.5 (1) ns 1.8v domain (n + 1) x t cpmck - 3.0 (1) ns smc 8 nwait minimum pulse width t cpmck ns table 40-24. sam7se32 general- purpose smc signals symbol parameter conditions min max units smc 7 ncs minimum pulse width (address to chip select setup) 3.3v domain (n + 1) x t cpmck - 2.5 (1) ns 1.8v domain (n + 1) x t cpmck - 5.0 (1) ns smc 8 nwait minimum pulse width t cpmck ns table 40-25. sam7se512/256 smc write signals symbol parameter conditions min max units smc 15 nwr high to nub change (3) 3.3v domain 7.0 ns 1.8v domain 9.5 ns smc 16 nwr high to nlb/a0 change (3) 3.3v domain 7.5 ns 1.8v domain 10 ns smc 17 nwr high to a1 - a22 change (3) 3.3v domain 8 ns 1.8v domain 8.5 ns smc 18 nwr high to chip select inactive (3) 3.3v domain 7.0 ns 1.8v domain 9.0 ns smc 19 data out valid before nwr high (no wait states) (3) 3.3v domain 0.5 * t cpmck - 0.5 ns 1.8v domain 0.5 * t cpmck - 1 ns smc 20 data out valid before nwr high (wait states) (3) 3.3v domain n x t cpmck - 0.5 (1) ns 1.8v domain n x t cpmck - 1 (1) ns smc 21 data out valid after nwr high (no wait states) (3)) 3.3v domain 0.5 * t cpmck - 5.7 ns 1.8v domain 0.5 * t cpmck - 8 ns smc 22 data out valid after nwr high (wait states without hold cycles) (3) 3.3v domain 0.5 * t cpmck - 5.2 ns 1.8v domain 0.5 * t cpmck - 8 ns smc 23 data out valid after nwr high (wait states with hold cycles) (3) 3.3v domain h x t cpmck - 5.7 (2) ns 1.8v domain h x t cpmck - 8.0 (2) ns
633 6222f?atarm?14-jan-11 sam7se512/256/32 notes: 1. n = number of standard wait states inserted. 2. h = number of hold cycles inserted. 3. not applicable when address to chip select setup cycles are inserted. . notes: 1. n = number of standard wait states inserted. 2. h = number of hold cycles inserted. 3. not applicable when address to chip select setup cycles are inserted. smc 26 nwr minimum pulse width (no wait states) (3) 3.3v domain 0.5 * t cpmck - 1 ns 1.8v domain 0.5 * t cpmck - 1.5 ns smc 27 nwr minimum pulse width (wait states) (3) 3.3v domain n x t cpmck - 1.5 (1) ns 1.8v domain n x t cpmck - 1.5 (1) ns table 40-25. sam7se512/256 smc write signals (continued) symbol parameter conditions min max units table 40-26. sam7se32 smc write signals symbol parameter conditions min max units smc 15 nwr high to nub change (3) 3.3v domain 6.0 ns 1.8v domain 9.0 ns smc 16 nwr high to nlb/a0 change (3) 3.3v domain 6.0 ns 1.8v domain 9.0 ns smc 17 nwr high to a1 - a22 change (3) 3.3v domain 6.0 ns 1.8v domain 9.0 ns smc 18 nwr high to chip select inactive (3) 3.3v domain 5.5 ns 1.8v domain 9.0 ns smc 19 data out valid before nwr high (no wait states) (3) 3.3v domain 0.5 * t cpmck - 3.5 ns 1.8v domain 0.5 * t cpmck - 6.0 ns smc 20 data out valid before nwr high (wait states) (3) 3.3v domain n x t cpmck - 3.5 (1) ns 1.8v domain n x t cpmck - 6.0 (1) ns smc 21 data out valid after nwr high (no wait states) (3)) 3.3v domain 0.5 * t cpmck - 5.5 ns 1.8v domain 0.5 * t cpmck - 12 ns smc 22 data out valid after nwr high (wait states without hold cycles) (3) 3.3v domain 0.5 * t cpmck - 5.2 ns 1.8v domain 0.5 * t cpmck - 8 ns smc 23 data out valid after nwr high (wait states with hold cycles) (3) 3.3v domain h x t cpmck - 6.0 (2) ns 1.8v domain h x t cpmck - 12 (2) ns smc 26 nwr minimum pulse width (no wait states) (3) 3.3v domain 0.5 * t cpmck - 2.0 ns 1.8v domain 0.5 * t cpmck - 6.5 ns smc 27 nwr minimum pulse width (wait states) (3) 3.3v domain n x t cpmck - 2.5 (1) ns 1.8v domain n x t cpmck - 7.0 (1) ns
634 6222f?atarm?14-jan-11 sam7se512/256/32 notes: 1. early read protocol. 2. standard read protocol. 3. n = number of standard wait states inserted. 4. h = number of hold cycles inserted. 5. not applicable when address to chip select setup cycles are inserted. table 40-27. sam7se512/256 smc read signals symbol parameter conditions min max units smc 35 nrd high to nub change 3.3v domain (h x t cpmck ) - 2 (4) (h x t cpmck )+ 1 (4) ns 1.8v domain (h x t cpmck ) - 2 (4) (h x t cpmck )+ 1 (4) ns smc 36 nrd high to nlb/a0 change 3.3v domain (h x t cpmck ) - 1.5 (4) (h x t cpmck )+ 1.5 (4) ns 1.8v domain (h x t cpmck ) - 1.5 (4) (h x t cpmck )+ 1 (4) ns smc 37 nrd high to a1-a22 change 3.3v domain (h x t cpmck ) - 2 (4) (h x t cpmck )+ 2 (4) ns 1.8v domain (h x t cpmck ) - 2 (4) (h x t cpmck )+ 3.5 (4) ns smc 38 nrd high to chip select inactive 3.3v domain (h x t cpmck ) - 3 (4) (h x t cpmck )+ 1 (4) ns 1.8v domain (h x t cpmck ) - 3.5 (4) (h x t cpmck )+ 2 (4) ns smc 40 data setup before nrd high 3.3v domain 22.2 ns 1.8v domain 35 ns smc 41 data hold after nrd high 3.3v domain 0 ns 1.8v domain 0 ns smc 42 data setup before ncs high 3.3v domain 23.2 ns 1.8v domain 37 ns smc 43 data hold after ncs high 3.3v domain 0 ns 1.8v domain 0 ns smc 44 nrd minimum pulse width (1) (5) 3.3v domain (n +1) x t cpmck - 1 (3) ns 1.8v domain (n +1) x t cpmck - 1.5 (3) ns smc 45 nrd minimum pulse width (2) (5) 3.3v domain (2 x n +1) x 0.5 x t cpmck - 1 (3) ns 1.8v domain (2 x n +1) x 0.5 x t cpmck - 1 (3) ns table 40-28. sam7se32 smc read signals symbol parameter conditions min max units smc 35 nrd high to nub change 3.3v domain (h x t cpmck ) - 2 (4) (h x t cpmck )+ 1.5 (4) ns 1.8v domain (h x t cpmck ) - 2 (4) (h x t cpmck )+ 7 (4) ns smc 36 nrd high to nlb/a0 change 3.3v domain (h x t cpmck ) - 2 (4) (h x t cpmck )+ 1.5 (4) ns 1.8v domain (h x t cpmck ) - 1.5 (4) (h x t cpmck )+ 6.5 (4) ns smc 37 nrd high to a1-a22 change 3.3v domain (h x t cpmck ) - 3 (4) (h x t cpmck )+ 3 (4) ns 1.8v domain (h x t cpmck ) - 3 (4) (h x t cpmck )+ 8 (4) ns smc 38 nrd high to chip select inactive 3.3v domain (h x t cpmck ) - 2.5 (4) (h x t cpmck )+ 2 (4) ns 1.8v domain (h x t cpmck ) - 3 (4) (h x t cpmck )+ 2 (4) ns
635 6222f?atarm?14-jan-11 sam7se512/256/32 notes: 1. early read protocol. 2. standard read protocol. 3. n = number of standard wait states inserted. 4. h = number of hold cycles inserted. 5. not applicable when address to chip select setup cycles are inserted. smc 40 data setup before nrd high 3.3v domain 23.2 ns 1.8v domain 37 ns smc 41 data hold after nrd high 3.3v domain -0 ns 1.8v domain -0 ns smc 42 data setup before ncs high 3.3v domain 25.2 ns 1.8v domain 39 ns smc 43 data hold after ncs high 3.3v domain 0 ns 1.8v domain 0 ns smc 44 nrd minimum pulse width (1) (5) 3.3v domain (n +1) x t cpmck - 2 (3) ns 1.8v domain (n +1) x t cpmck - 6 (3) ns smc 45 nrd minimum pulse width (2) (5) 3.3v domain (2 x n +1) x 0.5 x t cpmck - 2 (3) ns 1.8v domain (2 x n +1) x 0.5 x t cpmck - 6.5 (3) ns table 40-28. sam7se32 smc read signals (continued) symbol parameter conditions min max units
636 6222f?atarm?14-jan-11 sam7se512/256/32 figure 40-8. smc signals in memory interface mode notes: 1. early read protocol 2. standard read protocol with or without setup and hold cycles. nrd (1) nrd (2) ncs nwait a1 - a22 d0 - d15 read nwr d0 - d15 to write nub/nlb/a0 smc 40 smc 41 smc 44 smc 45 smc 19 smc 21 smc 18 smc 17 smc 15 smc 16 smc 26 smc 38 smc 37 smc 35 smc 36 smc 8 smc 35 smc 36 smc 37 smc 38 smc 40 smc 41 smc 41 smc 44 smc 45 smc 27 smc 22 smc 20 smc 35 smc 36 smc 37 smc 38 smc 40 smc 45 smc 20 smc 23 smc 27
637 6222f?atarm?14-jan-11 sam7se512/256/32 figure 40-9. sm signals in lcd interface mode notes: 1. standard read protocol only. 2. with standard wait states inserted only. nrd (1) ncs nwait a1 - a22 d0 - d15 read nwr (2) d0 - d15 to write nub/nlb/a0 smc 8 smc 7 smc 7 smc 35 smc 36 smc 37 smc 39 smc 42 smc 43 smc 46 smc 24 smc 25 smc 28
638 6222f?atarm?14-jan-11 sam7se512/256/32 40.8.5 sdramc signals these timings are given for a maximum 30 pf load on sdck and a maximum 50 pf load on the databus. table 40-29. sdramc clock signal symbol parameter min max units 1.8v supply 3.3v supply 1.8v supply 3.3v supply 1/(t cpsdck ) sdram controller clock frequency 24 48.2 mhz t cpsdck sdram controller clock period 41.7 20.7 ns table 40-30. sam7se512/256 sdramc signals symbol parameter min max units 1.8v supply 3.3v supply 1.8v supply 3 .3v supply sdramc 1 sdcke high before sdck rising edge 17.5 12 ns sdramc 2 sdcke low after sdck rising edge 22 9.5 ns sdramc 3 sdcke low before sdck rising edge 11 10 ns sdramc 4 sdcke high after sdck rising edge 20.5 8 ns sdramc 5 sdcs low before sdck rising edge 11 10.5 ns sdramc 6 sdcs high after sdck rising edge 20.5 7.5 ns sdramc 7 ras low before sdck rising edge 10.5 10 ns sdramc 8 ras high after sdck rising edge 20.5 8 ns sdramc 9 sda10 change before sdck rising edge 10.5 10 ns sdramc 10 sda10 change after sdck rising edge 20.5 8 ns sdramc 11 address change before sdck rising edge 8.5 7.5 ns sdramc 12 address change after sdck rising edge 20 9 ns sdramc 13 bank change before sdck rising edge 9 8 ns sdramc 14 bank change after sdck rising edge 20.5 9 ns sdramc 15 cas low before sdck rising edge 10.5 10 ns sdramc 16 cas high after sdck rising edge 20.5 8 ns sdramc 17 dqm change before sdck rising edge 10 9.5 ns sdramc 18 dqm change after sdck rising edge 20.5 9 ns sdramc 19 d0-d15 in setup before sdck rising edge 16 12.5 ns sdramc 20 d0-d15 in hold after sdck rising edge 3 2 ns sdramc 21 d16-d31 in setup before sdck rising edge 16 12.5 ns sdramc 22 d16-d31 in hold after sdck rising edge 3 2 ns sdramc 23 sdwe low before sdck rising edge 10.5 10 ns sdramc 24 sdwe high after sdck rising edge 20.5 8 ns sdramc 25 d0-d15 out valid before sdck rising edge 6.5 5.5 ns sdramc 26 d0-d15 out valid after sdck rising edge 17 4.5 ns sdramc 27 d16-d31 out valid before sdck rising edge 6.5 5.5 ns sdramc 28 d16-d31 out valid after sdck rising edge 17 4.5 ns
639 6222f?atarm?14-jan-11 sam7se512/256/32 table 40-31. sam7se32 sdramc signals symbol parameter min max units 1.8v supply 3.3v supply 1.8v supply 3 .3v supply sdramc 1 sdcke high before sdck rising edge 11.5 6.5 ns sdramc 2 sdcke low after sdck rising edge 23.5 11.5 ns sdramc 3 sdcke low before sdck rising edge 10.5 5.5 ns sdramc 4 sdcke high after sdck rising edge 22.5 11 ns sdramc 5 sdcs low before sdck rising edge 11.5 7.5 ns sdramc 6 sdcs high after sdck rising edge 22 10.5 ns sdramc 7 ras low before sdck rising edge 12.5 8 ns sdramc 8 ras high after sdck rising edge 22 10 ns sdramc 9 sda10 change before sdck rising edge 12.5 8 ns sdramc 10 sda10 change after sdck rising edge 22 10 ns sdramc 11 address change before sdck rising edge 10 5 ns sdramc 12 address change after sdck rising edge 22 10.5 ns sdramc 13 bank change before sdck rising edge 9.5 4.5 ns sdramc 14 bank change after sdck rising edge 22.5 10.5 ns sdramc 15 cas low before sdck rising edge 12 7 ns sdramc 16 cas high after sdck rising edge 22 10.5 ns sdramc 17 dqm change before sdck rising edge 8.5 4.5 ns sdramc 18 dqm change after sdck rising edge 22 10.5 ns sdramc 19 d0-d15 in setup before sdck rising edge 8.5 8.5 ns sdramc 20 d0-d15 in hold after sdck rising edge 2 1 ns sdramc 21 d16-d31 in setup before sdck rising edge 8.5 8.5 ns sdramc 22 d16-d31 in hold after sdck rising edge 2 1 ns sdramc 23 sdwe low before sdck rising edge 12 7.5 ns sdramc 24 sdwe high after sdck rising edge 22 10.5 ns sdramc 25 d0-d15 out valid before sdck rising edge 6.5 2 ns sdramc 26 d0-d15 out valid after sdck rising edge 20 9 ns sdramc 27 d16-d31 out valid before sdck rising edge 6.5 2 ns sdramc 28 d16-d31 out valid after sdck rising edge 20 9 ns
640 6222f?atarm?14-jan-11 sam7se512/256/32 figure 40-10. sdramc signals ras a0 - a9, a11 - a13 d0 - d15 read sdck sda10 d0 - d15 to write sdramc 1 sdcke sdramc 2 sdramc 3 sdramc 4 sdcs sdramc 5 sdramc 6 sdramc 5 sdramc 6 sdramc 5 sdramc 6 sdramc 7 sdramc 8 cas sdramc 15 sdramc 16 sdramc 15 sdramc 16 sdwe sdramc 23 sdramc 24 sdramc 9 sdramc 10 sdramc 9 sdramc 10 sdramc 9 sdramc 10 sdramc 11 sdramc 12 sdramc 11 sdramc 12 sdramc 11 sdramc 12 ba0/ba1 sdramc 13 sdramc 14 sdramc 13 sdramc 14 sdramc 13 sdramc 14 sdramc 17 sdramc 18 sdramc 17 sdramc 18 dqm0 - dqm3 sdramc 19 sdramc 20 d16 - d31 read sdramc 21 sdramc 22 sdramc 25 sdramc 26 d16 - d31 to write sdramc 27 sdramc 28
641 6222f?atarm?14-jan-11 sam7se512/256/32 40.8.6 embedded flash characteristics the maximum operating frequency is given in table 40-32 and table 40-33 but is limited by the embedded flash access time when the processor is fetching code out of it. table 40-32 and table 40-33 give the device maximum operating fre- quency depending on the fws field of the mc_fmr register. th is field defines the number of wait states required to access the embedded flash memory. notes: 1. fws = flash wait states 2. it is not necessary to use 3 wait states because the flash can operate at maximum frequen cy with only 2 wait states. notes: 1. fws = flash wait states 2. it is not necessary to use 2 or 3 wait states because the flash can operate at maximum fr equency with only 1 wait state. table 40-32. embedded flash wait states (vddcore = 1.65v) fws (1) read operations maximum operating frequency (mhz) 0 1 cycle 25 1 2 cycles 44 2 3 cycles 48.2 3 (2) 4 cycles 48.2 table 40-33. embedded flash wait states (vddcore = 1.8v) fws (1) read operations maximum operating frequency (mhz) 0 1 cycle 30 1 2 cycles 55 2 (2) 3 cycles 55 3 (2) 4 cycles 55 table 40-34. ac flash characteristics parameter conditions min max units program cycle time per page including auto-erase 6 ms per page without auto-erase 3 ms full chip erase 15 ms
642 6222f?atarm?14-jan-11 sam7se512/256/32 40.8.7 jtag/ice timings 40.8.7.1 ice interface signals note: 1. v vddio from 3.0v to 3.6v, maximum external capacitor = 40pf. figure 40-11. ice interface signals table 40-35. ice interface timing specification symbol parameter conditions min max units ice 0 tck low half-period (1) 51 ns ice 1 tck high half-period (1) 51 ns ice 2 tck period (1) 102 ns ice 3 tdi, tms, setup before tck high (1) 0ns ice 4 tdi, tms, hold after tck high (1) 3ns ice 5 tdo hold time (1) 13 ns ice 6 tck low to tdo valid (1) 20 ns tck ice 3 ice 4 ice 6 tms/tdi tdo ice 5 ice 1 ice 2 ice 0
643 6222f?atarm?14-jan-11 sam7se512/256/32 40.8.7.2 jtag interface signals note: 1. v vddio from 3.0v to 3.6v, maximum external capacitor = 40pf. table 40-36. jtag interface timing specification symbol parameter conditions min max units jtag 0 tck low half-period (1) 6.5 ns jtag 1 tck high half-period (1) 5.5 ns jtag 2 tck period (1) 12 ns jtag 3 tdi, tms setup before tck high (1) 2ns jtag 4 tdi, tms hold after tck high (1) 3ns jtag 5 tdo hold time (1) 4ns jtag 6 tck low to tdo valid (1) 16 ns jtag 7 device inputs setup time (1) 0ns jtag 8 device inputs hold time (1) 3ns jtag 9 device outputs hold time (1) 6ns jtag 10 tck to device outputs valid (1) 18 ns
644 6222f?atarm?14-jan-11 sam7se512/256/32 figure 40-12. jtag interface signals tck jtag 9 tms/tdi tdo device outputs jtag 5 jtag 4 jtag 3 jtag 0 jtag 1 jtag 2 jtag 10 device inputs jtag 8 jtag 7 jtag 6
645 6222f?atarm?14-jan-11 sam7se512/256/32 41. sam7se512/256/32 mech anical characteristics
646 6222f?atarm?14-jan-11 sam7se512/256/32 41.1 package drawings figure 41-1. lqfp128 package drawing table 41-1. device and lqfp package maximum weight sam7se512/256/32 800 mg table 41-2. package reference jedec drawing reference ms-026 jesd97 classification e3 table 41-3. lqfp package characteristics moisture sensitivity level 3
647 6222f?atarm?14-jan-11 sam7se512/256/32 this package respects the recommendations of the nemi user group. figure 41-2. 144-ball lfbga package drawing this package respects the recommendations of the nemi user group. all dimensions are in mm table 41-4. device and lfbga package maximum weight sam7se512/256/32 mg table 41-5. package reference jedec drawing reference ms-026 jesd97 classification e1 table 41-6. lfbga package characteristics moisture sensitivity level 3
648 6222f?atarm?14-jan-11 sam7se512/256/32 41.2 soldering profile table 41-7 gives the recommended soldering profile from j-std-020c. note: the package is certified to be backward compatible with pb/sn soldering profile. a maximum of three reflow passes is allowed per component. table 41-7. soldering profile profile feature green package average ramp-up rate (217c to peak) 3 ? c/sec. max. preheat temperature 175c 25c 180 sec. max. temperature maintained above 217c 60 sec. to 150 sec. time within 5 ? c of actual peak temperature 20 sec. to 40 sec. peak temperature range 260 ? c ramp-down rate 6 ? c/sec. max. time 25 ? c to peak temperature 8 min. max.
649 6222f?atarm?14-jan-11 sam7se512/256/32 42. sam7se512/256/32 ordering information table 42-1. ordering information ordering code package package type temperature operating range AT91SAM7SE512-AU lqfp128 green industrial (-40 ? c to 85 ? c) at91sam7se256-au lqfp128 green industrial (-40 ? c to 85 ? c) at91sam7se32-au lqfp128 green industrial (-40 ? c to 85 ? c) at91sam7se512-cu lfbga144 green industrial (-40 ? c to 85 ? c) at91sam7se256-cu lfbga144 green industrial (-40 ? c to 85 ? c) at91sam7se32-cu lfbga144 green industrial (-40 ? c to 85 ? c)
650 6222f?atarm?14-jan-11 sam7se512/256/32
651 6222f?atarm?14-jan-11 sam7se512/256/32 43. sam7se512/256/32 errata 43.1 marking all devices are marked with the atmel logo and the ordering code. additional marking has the following format: where ??yy?: manufactory year ? ?ww?: manufactory week ? ?v?: revision ? ?xxxxxxxxx?: lot number yyww v xxxxxxxxx arm
652 6222f?atarm?14-jan-11 sam7se512/256/32 43.2 sam7se512/256/32 errata - rev. a parts refer to section 43.1 ?marking? on page 651 . 43.2.1 analog-to-digital converter (adc) 43.2.1.1 adc: drdy bit cleared the drdy flag should be clear only after a r ead of adc_lcdr (last converted data regis- ter). a read of any adc_cdrx register (channel data register) automatically clears the drdy flag. problem fix/workaround: none 43.2.1.2 adc: drdy not cleared on disable when reading lcdr at the same instant as an end of conversion, with drdy already active, drdy is kept active regardless of the enable status of the current c hannel. this sets drdy, whereas new data is not stored. problem fix/workaround none 43.2.1.3 adc: drdy possibly skipped due to cdr read reading cdr for channel "y" at the same instan t as an end of conver sion on channel "x" with eoc[x] already active, leads to skipping to set the drdy flag if channel "x" is enabled. problem fix/workaround use of drdy functionality with access to cdr registers should be avoided. 43.2.1.4 adc: possible skip on drdy when disabling a channel drdy does not rise when disabling channel "y" at the same time as an end of "x" channel con- version, although data is stored into cdrx and lcdr. problem fix/workaround none. 43.2.1.5 adc: govre bit is not updated read of the status register at the same instant as an end of conversion leads to skipping the update of the govre (general overrun) flag. govre is neither reset nor set. for example, if reading the status while an end of conversion is occurring and: 1. govre is active but drdy is inactive, does not correspond to a new general overrun condition but the govre flag is not reset. 2. govre is inactive but drdy is active, does correspond to a new general overrun con- dition but the govre flag is not set. problem fix/workaround none 43.2.1.6 adc: govre bit is not set when reading cdr when reading cdry (channel data register y) at the same instant as an end of conversion on channel "x" with the following conditions: ? eoc[x] already active,
653 6222f?atarm?14-jan-11 sam7se512/256/32 ? drdy already active, ? govre inactive, ? previous data stored in lcdr being neither data from channel "y", nor data from channel "x". govre should be set but is not. problem fix/workaround none 43.2.1.7 adc: govre bit is not set when disabling a channel when disabling channel "y" at the same instant as an end of conversion on channel "x", eoc[x] and drdy being already active, govre does not rise. note: ovre[x] rises as expected. problem fix/workaround none 43.2.1.8 adc: ovre flag behavior when the ovre flag (on channel i) has been set but the related eoc status (of channel i) has been cleared (by a read of cdri or lcdr), reading the status register at the same instant as an end of conversion (causing the set of eoc status on channel i), does not lead to a reset of the ovre flag (on channel i) as expected. problem fix/workaround: none 43.2.1.9 adc: eoc set although channel disabled if a channel is disabled while a conversion is running and if a read of cdr is performed at the same time as an end of conversion of any channel occurs, the eoc of the channel with the con- version running may rise (whereas it has been disabled). problem fix/workaround do not take into account the eoc of a disabled channel 43.2.1.10 adc: spurious clear of eoc flag if "x" and "y" are two successi vely converted channels and "z" is yet another enabled channel ("z" being neither "x" nor "y"), reading cdr on channel "z" at the same instant as an end of con- version on channel "y" automatically clears eoc[x] instead of eoc[z]. problem fix/workaround none. 43.2.1.11 adc: sleep mode if sleep mode is activa ted while there is no activity (no co nversion is being performed), it will take effect only after a conversion occurs. problem fix/workaround to activate sleep mode as soon as possible, it is recommended to write successively, adc mode register (sleep) then adc co ntrol register (start bit fiel d); to start an analog-to-digi- tal conversion, in order put adc into slee p mode at the end of this conversion.
654 6222f?atarm?14-jan-11 sam7se512/256/32 43.2.2 flash memory 43.2.2.1 flash: power consumption with data read access with multiple load of two words when no wait state (fws = 0) is programmed and when data read access is performed with a multiple load of two words, the inte rnal flash may stay in read mode. it implies a potential increase of power consum ption on vddcore (around 2 ma). note that it does not concern the program execution; thus, no issue is present when the program is fetching out of flash. problem fix/workaround 2 workarounds are possible: ? add one wait state when performing these data read accesses (fws =1) ? after the multiple load, perform a single read data access to an address different from the previous address accesses. 43.2.3 pulse width modulation controller (pwm) 43.2.3.1 pwm: update when pwm_ccntx = 0 or 1 if the channel counter register value is 0 or 1, the channel period register or channel duty cycle register is directly modified when writing the channel update register. problem fix/workaround check the channel counter register before writing the channel update register. 43.2.3.2 pwm: update when pwm_cprdx = 0 when the channel period register equals 0, the period update is not operational. problem fix/workaround do not write 0 in the ch annel period register. 43.2.3.3 pwm: counter start value in left aligned mode, the first start value of the counter is 0. for the other periods, the counter starts at 1. problem fix/workaround none. 43.2.3.4 pwm: behavior of chidx status bits in the pwm_sr register erratic behavior of the chidx status bit in the pwm_sr register. when a channel is disabled by writing in the pwm_dis register just after enabling it (before completion of a clock period of the clock selected for the channel), the pwm line is internally disabled but the chidx status bit in the pwm_sr stays at 1. problem fix/workaround do not disable a channel before completion of one period of the selected clock. 43.2.4 real-time timer (rtt) 43.2.4.1 rtt: possible event loss when reading rtt_sr if an event (rttinc or alms) occurs within the same slow clock cycle that rtt_sr is read, the corresponding bit might be cleared. this might lead to the loss of this event.
655 6222f?atarm?14-jan-11 sam7se512/256/32 problem fix/workaround the software must handle rtt event as interrupt and should not poll rtt_sr. 43.2.5 sdram controller (sdramc) 43.2.5.1 sdramc: pdc buffer in 16-bit sdram while the core accesses sdram when the sam7se interfaces with 16-bit sdram memory and the processor accesses the sdram, either for instruction fetch or data read/write, the data transferred by the pdc from sdram buffers to the peripherals might be corrupted. transfers from peripherals to sdram buffers are not affected. problem fix/workaround map the transmit pdc buffers in internal sram or flash. 43.2.6 serial peripheral interface (spi) 43.2.6.1 spi: baudrate set to 1 when the baudrate is set at 1 (so, the serial clock frequency equals the master clock), and when the bits field (number of bits to be transmitted) in spi_csrx equals an odd value (in this case 9, 11, 13 or 15), an additional pulse will be generate d on spck. it does not occur when the bits field is equal to 8, 10, 12, 14 or 16 and the baudrate is equal to 1. problem fix/workaround none. 43.2.6.2 spi: bad serial clock generation on 2nd chip select bad serial clock generation on the 2nd chip select when scbr = 1, cpol = 1 and ncpha = 0. this occurs using spi wit h the following conditions: ? master mode ? cpol = 1 and ncpha = 0 ? multiple chip selects are used with one transfer with baud rate (scbr) equal to 1 (i.e., when serial clock frequency equals the system clock frequency) and the other transfers set with scbr are not equal to 1 ? transmitting with the slowest chip select and then with the fastest one, then an additional pulse is generated on output spck during the second transfer. problem fix/workaround do not use a multiple chip select configurati on where at least one scrx register is configured with scbr = 1 and the others differ from 1 if ncpha = 0 and cpol = 1. if all chip selects are configured with baudrate = 1, the issue does not appear. 43.2.6.3 spi: software reset must be written twice if a software reset (swrst in the spi control register) is performed, the spi may not work prop- erly (the clock is enabled before the chip select). problem fix/workaround the spi control register field swrst (software reset) needs to be written twice to be correctly set.
656 6222f?atarm?14-jan-11 sam7se512/256/32 43.2.7 synchronous serial controller (ssc) 43.2.7.1 ssc: periodic transmission limitations in master mode if the least significant bit is sent first (msbf = 0), the first tag during the frame synchro is not sent. problem fix/workaround none. 43.2.7.2 ssc: transmitter limitations in slave mode if tk is programmed as output and tf is programmed as input, it is impossible to emit data when the starting edge (risin g or falling) of synchro has a start delay equal to zero. problem fix/workaround none. 43.2.7.3 ssc: transmitter limitations in slave mode if tk is programmed as an input and tf is programmed as an output and requested to be set to low/high during data emission, the frame synchro signal is generated one bit clock period after the data start and one data bit is lost. this pr oblem does not exist when generating a periodic synchro. problem fix/workaround the data need to be delayed for one bit clock period with an external assembly. in the following schematic, td, tk and nrst are sam7se signals, txd is the delayed data to connect to the device. 43.2.7.4 ssc: last rk clock cycle when rk outputs a clock during data transfer when the ssc receiver is used with the following conditions: ? the internal clock divider is used (cks = 0 and div different from 0) ? rk pin set as output and provides the clock during data transfer (cko = 2) ? data sampled on rk falling edge (cki = 0),
657 6222f?atarm?14-jan-11 sam7se512/256/32 at the end of the data, the rk pin is set in high impedance which might be seen as an unex- pected clock cycle. problem fix/workaround enable the pull-up on rk pin. 43.2.7.5 ssc: first rk clock cycle when rk outputs a clock during data transfer when the ssc receiver is used with the following conditions: ? rx clock is divided clock (cks = 0 and div different from 0) ? rk pin set as output and provides the clock during data transfer (cko = 2) ? data sampled on rk falling edge (cki = 0), the first clock cycle time generated by the rk pin is equal to mck/(2 x (value +1)). problem fix/workaround none. 43.2.8 two wire interface (twi) 43.2.8.1 twi: switching from slave to master mode when the twi is set in slave mode and if a master write access is performed, the start event is correctly generated but the scl line is stuck at 1, so no transfer is possible. problem fix/workaround two software workarounds are possible: 1. perform a software reset before going to master mode (twi must be reconfigured). 2. perform a slave read access before switching to master mode. 43.2.9 universal synchronous asynchronous receiver transmitter (usart) 43.2.9.1 usart: cts in hardware handshaking when hardware handshaking is used and if cts goes high near the end of the starting bit, a character can be lost. cts must not go high during a time slot occurring between 2 master clock periods before the starting bit and 16 master clock periods after the rising edge of the starting bit. problem fix/workaround none. 43.2.9.2 usart: two characters sent with hardware handshaking when hardware handshaking is used and if cts go es high during the tx of a character and if the holding register (us_thr) is not empty, the content of the us_thr will also be transmitted. problem fix/workaround don?t use the pdc in transmit mode and do no t fill us_thr before txrdy is set at 1. 43.2.9.3 usart: dcd is active high instead of low dcd signal is active at ?high? level in usart block (modem mode). dcd should be active at ?low? level. problem fix/workaround
658 6222f?atarm?14-jan-11 sam7se512/256/32 add an inverter. 43.2.9.4 usart: rxbrk flag error in asynchronous mode in receiver mode, when 2 characters are consecutive (without a timeguard in between), the rxbrk is not taken into account. as a result, the rxbrk flag is not enabled correctly, and the frame error flag is set. problem fix/workaround constraints on the transmitter device connected to the at91 usart receiver: the transmitter may use the timeguard feature, or send 2 stop conditions. only 1 stop con- dition is taken into account by the receiver stat e machine; after this stop condition, as there is no valid data, the receiver st ate machine will go in idle mode and will enable the rxbrk condition.
659 6222f?atarm?14-jan-11 sam7se512/256/32 44. revision history version 6222f comments change request ref. boot rom: sam7se32 user area addresses updated in section 25.5 ?hardware and software constraints? . variables - only used in this section - changed into text (yy, yy_prod, yz, yz_p rod, drxd_pio, dtxd_pio). 7312 rfo sam7se512/256/32 errata - rev. a parts: section 43.2.2 ?flash memory? added. 7541 ?at91sam? product prefix changed to ?sam? (e xcept for chip id and ordering codes). rfo version 6222e comments change request ref. features: ?mode for general purpose two-wire uart serial communication? added to ?debug unit (dbgu)? . signal description: table 3-1, ?signal description list? , ad0-ad3 and ad4-ad7 comments reversed. system controller: figure 9-1 ?system controller block diagram? , ?periph_nreset? changed into ?power_on_reset? for rtt. 5846 5271 5222 at91sam7se512/256/32 electr ical characteristics: section 40.7 ?adc characteristics? , table 40-17 and table 40-18 edited. 6774 at91sam7se512/256/32 errata - rev. a parts: section 43.2.9.4 ?usart: rxbrk flag error in asynchronous mode? description edited. section 43.2.6.3 ?spi: software reset must be written twice? added. usart: xoff character bad behavior removed from section 43.2.9 6626 5785 5337 embedded flash controller (efc): section 19.2.4.4 ?general-purpose nvm bits? , bit values edited in last paragraph. text added below figure 19-6 ?example of partial page programming:? 6236 6774 external bus interface (ebi): note (8) added to row nwr0/nwe/cfwe in table 21-3 . note (1) added to figure 21-6 . 6774 memory controller (mc): section 18.5.2 ?mc abor t status register? , mst0, mst1, svmst 0, svmst1 edited. 5687 reset controller (rstc): section 13.2.4.4 ?software reset? , text added at the end of perrst description. 5436 usb transceiver characteristics: latest programmer datasheet used ( udp_6083s instead of udp_6083m). 6774
660 6222f?atarm?14-jan-11 sam7se512/256/32 version 6222d comments change request ref. ?two wire interface (twi)? erroneous text references to pdc functi onality removed from the twi section of the datasheet: page 353 , page 355 . (32.7.7 ?using the peripheral dma controller (pdc)? removed from page 357 ), subsequent chapter numbering effected. (32.9.45 ?pdc? removed from page 368 ), subsequent chapter numbering effected. table 32-4, ?register mapping? , reserved offset for pdc removed section 32.10.6 ?twi status register? , txbufe, rxbuff, endtx, endrx bit fields and descriptions removed. section 32.10.7 ?twi interrupt enable register? , txbufe, rxbuff, endtx, endrx bit fields and descriptions removed. section 32.10.8 ?twi interrupt disable register? ,txbufe, rxbuff, endtx, endrx bit fields and descriptions removed. section 32.10.9 ?twi interrupt mask register? ,txbufe, rxbuff, endtx, endrx bit fields and descriptions removed. 5187 version 6222c comments change request ref. overview: figure 8-1 ?sam7se memory mapping? , compact flash not shown w/ebi ch ip select 5. compact flash is shown with ebi chip select 2 section 8.1.2.1 ?flash overview? , updated at91sam7se32 ...?reads as 8192 32-bit words.? section 6. ?i/o lines considerations? , ?jtag port pins? , ?test pin? , ?reset pin? , ?erase pin? ; descriptions updated. 4804 4512 5062 pmc section 29.9.10 ?pmc master clock register? , mdiv removed from bit fields 9 and 8. 4766 twi important changes to this datasheet include a clarification of atmel twi compatibility with i2c standard. (see section 32.1 ?overview? and table 32-1 ) section 32.7 ?master mode? , rewritten. new master read-write flowcharts, new read-write transfer waveforms, bit field description modification etc. figure 32-2 ?application block diagram? , updated figure 32-5 ?master mode typical application block diagram? , updated new sections; section 32.7.4 ?master transmitter mode? and section 32.7.5 ?master receiver mode? replace ?transmitting data?. see also: figure 32-6 , figure 32-7 , figure 32-8 , figure 32-9 and figure 32-10 section 32.7.6 ?internal address? added and includes, section 32.7.6.1 ?7-bit slave addressing? and section 32.7.6.2 ?10-bit slave addressing? see also: figure 32-11 , figure 32-12 and figure 32-13 section 32.9.6 ?read write flowcharts? , updated and new flowcharts added. 4373 fixed typo in arblst bit fields; ?twi interrupt enable register? , ?twi interrupt disable register? and ?twi interrupt mask register? inserted eosacc bit field description in ?twi interrupt enable register? 4584 4586
661 6222f?atarm?14-jan-11 sam7se512/256/32 section 40. ?sam7se512/256/32 electrical characteristics? table 40-12, ?xin clock electrical characteristics? vxin_il, vxin_ih updated table 40-2, ?dc characteristics? , junction temperature removed and vddio dc supplies 3.3v and 1.8v defined table 40-7, ?power consum ption for different modes? : footnote assigned to flash in standby mode. footnote assigned to ultra low power mode. table 40-5, ?dc flash characteristics sam7se32? , max standby current updated. 5007 rfo 4657 4598 rfo section 41. ?sam7se512/256/32 mechanical characteristics? lqfp-package, jesd97 classification is e3. thermal considerations removed. 4971/5007 4657 section 43. ?sam7se512/256/32 errata? section 43.2.1 ?analog-to-digital converter (adc)? , added to errata. section 43.2.5 ?sdram controller (sdramc)? , added to errata. section 43.2.6.1 ?spi : baudrate set to 1? , problem fix/workaround = none. section 43.2.6.2 ?spi: bad serial clock generation on 2nd chip select? , added to errata. section 43.2.7.4 ?ssc: la st rk clock cycle when rk outputs a clock during data transfer? , added to errata. section 43.2.7.5 ?ssc: first rk clock cycle when rk outputs a clock during data transfer? , added to errata. section 43.2.9.3 ?usart: dcd is active high instead of low? , added to errata. section 43.2.9.4 ?usart: rxbrk flag error in asynchronous mode? , added to errata. 5007/4751 /4642 version 6222c comments change request ref. version 6222b comments change request ref. overview , section 6.1 ?jtag port pins? , section 6.3 ?reset pin? , section 6.5 ?sdck pin? , removed statement: ?not 5v tolerant?. section 7.6 ?sdram controller? mobile sdram controller added to sdramc description inl and dnl updated in section 10.14 ?analog-to-digital converter? on page 42 3826 4005 ?features? on page 2, fully static operat ion: added up to 55 mhz at 1.8v and 85c worst case conditions section 7.1 ?arm7tdmi processor? , runs at up to 55 mhz, providin g 0.9 mips/mhz (core supplied with 1.8v) section 7.8 ?peripheral dma controller? pdc priority list added. section 7.5 ?static memory controller? multiple device adaptability: compliant w/psram in synchronous operations 3924 3833 review clock generator , removed information on capacitor load value in section 28.3.1 ?main oscillator connections? figure 28-2 ?typical crystal connection? on page 272 , updated, cl1 and cl2 labels removed. 3282 3861 dbgu , debug unit chip id register, ?sramsiz: internal sram size? on page 320 updated w/at91sam7l internal ram size and ?arch: architecture i dentifier? on page 321 updated bin values for 0x60 and 0xf0, and added descriptions for cap7, at91sam7aqxx series and cap11 3828 3369 3807 ebi , table 21-3, ?ebi pins and external static device connections,? on page 138 , i/o[8:15] bits added in nand flash column, added notes to table for sdram, nand flash and references to app notes. figure 21-1 ?organization of the external bus interface? sdck is not multiplexed with pio section 21.7.6.1 ?hardware configuration? a25 removed from cfrnw in compactflash section 21.7.7.1 ?hardware configuration? a25 removed from cfrnw in compactflash true ide 3742/3743 / 3852 3924 4044/3836
662 6222f?atarm?14-jan-11 sam7se512/256/32 electrical characteristics, section 40.4.3 ?cryst al characteristics? tchxin and tchlxin updated, tclch and tchcl added to table 40-12, ?xin clock electrical characteristics? and figure 40-2 ?xin clock timing? has been added. 3966 section 40.7 ?adc characteristics? inl and dnl updated and absolute accuracy added to table 40-19, ?transfer characteristics? . reference to data converter terminology added below table. inl and dnl updated in section 10.14 ?analog-to-digital converter? on page 42 4005 section 40.8.4 ?smc signals? ,a25 address line changed to a22. table 40-25 on page 632 thru table 40-28 on page 634 and in the following two figures. figure 40-8 ?smc signals in memory interface mode? and figure 40-9 ?sm signals in lcd interface mode? smc timings updated to be concordant with signals listed in table 40-25 thru table 40-28 . 4044/3836 section 40.8.6 ?embedded flash characteristics? updated. note added t o table 40-32, ?embedded flash wait states (vddcore = 1.65v)? and added table 40-33, ?embedded flash wait states (vddcore = 1.8v)? table 40-20, ?master clock waveform parameters? , updated w/v ddcore = 1.8v, max = 55 mhz 3924 table 40-10, ?main oscillator characteristics? added schematic in footnote to c l and c lext symbols table 40-7, ?power consumption for different modes? ddm and ddp pins must be left floating. table 40-32, ?embedded flash wa it states (vddcore = 1.65v)? footnote (2) added. 3868 3829 review eccc, section 24.3 ?functional description? and section 24.3.1 ?write access? and section 24.3.2 ?read access? on page 220 updated. section 24.4.4 ?ecc parity register? and section 24.4.5 ?ecc nparity register? on page 228 instruction updated. 3970 errata, section 43.2.9.1 ?usart: cts in hardware handshaking? , updated.....?if cts goes high near the end of the starting bit, a character can be lost?........... 3955 mc , section 18.4.5 ?memory protection unit? , initialization guidelines up dated at end of section. 4045 pio , section 34.4.5 ?synchronous data output? , pio_owsr typo corrected. user interface, table 34-2, ?pio register mapping,? on page 446 , footnotes updat ed on pio_psr, pio_odsr, pio_pdsr table cells. 3289 3974 sdramc , section 23.1 ?overview? on page 199 , mobile sdram controller added to sdramc description figure 23-1 on page 199 , sdck signal in the block diagram updated. 3826 review smc , figure 22-9 , figure 22-10 , figure 22-11 , figure 22-12 , figure 22-13 and figure 22-25 replaced 32-bit bus removed from bit field description ?bat: byte access type? on page 196 ?smc chip select registers? on page 196 , section restructured with table move d from the end of the section to appear in the bit field description: ?nws: number of wait states? on page 196 . ?don?t care? and ?number of wait states? column added to this table and nrd pu lse length is defined in standard read and early read protocols. note 1 assigned to table describing bit fields ?rwsetup: read and write signal setup time? and ?rwhold: read and write signal hold time? on page 197 . global all references to a25 address line changed to be a22 (23-bit address bus) note specific to ecc controller added to ?rwhold: read and write signal hold time? bit field description. ?overview? on page 161 , address space is 64 mbytes and the address bus is 23 bits. ?external memory mapping? on page 163 , external address bus is 23 bits. figure 22-3 on page 164 , maximum address space per device is 8 mbytes. figure 22-32 on page 183 ,change in values on [d15:0] line. figure 22-45 , figure 22-46 and figure 22-47 on page 198 replaced. 3846 3847 3848/4182 3863/3864 3886 review version 6222b comments change request ref.
663 6222f?atarm?14-jan-11 sam7se512/256/32 ssc, section 35.6.6.1 ?compare functions? on page 474 , updated review udp, table 38-2, ?usb communication flow? , supported end point size updated for transfer interrupt control endpoints are not effected by the ?epeds: endpoint enable disable? bit field in the usb_csr register. write 1 updated in ?rx_data_bk0: receive data bank 0? bit field in usb_csr register. write 0 updated in ?txpktrdy: transmit packet ready? bit field in usb_csr register. 3476 4063 4099 usart , in the us_mr register, typo fixed in bit field description ?clko: clock output select? on page 422 and div value given in bit field description ?usclks: clock selection? on page 421 section 33.5.1 ?i/o lines? on page 392 , 3rd paragraph updated. in the us_csr register the bit field description ?txempty: txempty interrup t enable? on page 424 has been updated 3306 3763 3851 3895 version 6222a comments change request ref. first issue: preliminary version 6222b comments change request ref.
664 6222f?atarm?14-jan-11 sam7se512/256/32
i 6222f?atarm?14-jan-11 sam7se512/256/32 features .......... ................. ................ ................ .............. .............. ............. 1 1 description ............ .............. .............. .............. .............. .............. ............. 3 1.1 configuration summary of the sam7se512, sam7se256 and sam7se32 ..........3 2 block diagram ............ ................ ................. ................ ................ ............. 4 3 signal description ............... .............. .............. .............. .............. ............. 5 4 package ................ ................ .............. .............. .............. .............. ............. 9 4.1 128-lead lqfp package outline .............................................................................9 4.2 128-lead lqfp pinout ...........................................................................................10 4.3 144-ball lfbga package outline ..........................................................................11 4.4 144-ball lfbga pinout ..........................................................................................12 5 power considerations ........... .............. .............. .............. .............. ........ 13 5.1 power supplies ......................................................................................................13 5.2 power consumption ..............................................................................................13 5.3 voltage regulator ..................................................................................................13 5.4 typical powering schematics ................................................................................14 6 i/o lines considerations ......... ................ ................. ................ ............. 15 6.1 jtag port pins ......................................................................................................15 6.2 test pin ................................................................................................................. 15 6.3 reset pin ...............................................................................................................1 5 6.4 erase pin ............................................................................................................15 6.5 sdck pin ..............................................................................................................16 6.6 pio controller lines ...............................................................................................16 6.7 i/o lines current drawing .....................................................................................16 7 processor and architecture .... ................ ................. ................ ............. 17 7.1 arm7tdmi processor ...........................................................................................17 7.2 debug and test features ......................................................................................17 7.3 memory controller .................................................................................................17 7.4 external bus interface ...........................................................................................18 7.5 static memory controller .......................................................................................18 7.6 sdram controller .................................................................................................19 7.7 error corrected code controller ............................................................................19 7.8 peripheral dma controller .....................................................................................20 8 memories ............... .............. .............. .............. .............. .............. ........... 21
ii 6222f?atarm?14-jan-11 sam7se512/256/32 8.1 embedded memories ............................................................................................23 8.2 external memories .................................................................................................27 9 system controller ............. ................ .............. .............. .............. ........... 28 9.1 reset controller .....................................................................................................30 9.2 clock generator ....................................................................................................30 9.3 power management controller ..............................................................................31 9.4 advanced interrupt controller ................................................................................32 9.5 debug unit .............................................................................................................33 9.6 periodic interval timer ...........................................................................................33 9.7 watchdog timer ....................................................................................................33 9.8 real-time timer .....................................................................................................33 9.9 pio controllers ......................................................................................................33 9.10 voltage regulator controller ...............................................................................34 10 peripherals ............. .............. .............. .............. .............. .............. ........... 35 10.1 user interface ......................................................................................................35 10.2 peripheral identifiers ............................................................................................35 10.3 peripheral multiplexing on pio lines ..................................................................36 10.4 pio controller a multiplexing ..............................................................................37 10.5 pio controller b multiplexing ..............................................................................38 10.6 pio controller c multiplexing ..............................................................................39 10.7 serial peripheral interface ...................................................................................39 10.8 two wire interface ..............................................................................................40 10.9 usart ................................................................................................................40 10.10 serial synchronous controller ...........................................................................40 10.11 timer counter ....................................................................................................41 10.12 pwm controller .................................................................................................41 10.13 usb device port ................................................................................................42 10.14 analog-to-digital converter ...............................................................................42 11 arm7tdmi processor o verview ................ ................ ................ ........... 43 11.1 overview ..............................................................................................................43 11.2 arm7tdmi processor .........................................................................................44 12 debug and test featur es ................. .............. .............. .............. ........... 49 12.1 overview ..............................................................................................................49 12.2 block diagram .....................................................................................................49 12.3 application examples ..........................................................................................50
iii 6222f?atarm?14-jan-11 sam7se512/256/32 12.4 debug and test pin description ..........................................................................51 12.5 functional description .........................................................................................52 13 reset controller (rstc) .... ............... .............. .............. .............. ........... 55 13.1 block diagram .....................................................................................................55 13.2 functional description .........................................................................................56 13.3 reset controller (rstc) user interface ..............................................................63 14 real-time timer (rtt) ......... .............. .............. .............. .............. ........... 67 14.1 overview ..............................................................................................................67 14.2 block diagram .....................................................................................................67 14.3 functional description .........................................................................................67 14.4 real-time timer (rtt) user interface .................................................................69 15 watchdog timer (wdt) ......... .............. .............. .............. .............. ........ 73 15.1 overview ..............................................................................................................73 15.2 block diagram .....................................................................................................73 15.3 functional description .........................................................................................74 15.4 watchdog timer (wdt) user interface ...............................................................76 16 periodic interval timer (pit) ................. .............. .............. ............ ........ 79 16.1 overview ..............................................................................................................79 16.2 block diagram .....................................................................................................79 16.3 functional description .........................................................................................80 16.4 periodic interval timer (pit) user interface ........................................................82 17 voltage regulator mode contro ller (vreg) ............. ................ ........... 85 17.1 overview ..............................................................................................................85 17.2 voltage regulator power controller (vreg) user interface ...............................86 18 memory controller (mc) .... ............... .............. .............. .............. ........... 87 18.1 overview ..............................................................................................................87 18.2 block diagram .....................................................................................................87 18.3 functional description .........................................................................................88 18.4 external memory areas .......................................................................................89 18.5 memory controller (mc) user interface ..............................................................93 19 embedded flash controller (e fc) ............... .............. .............. ........... 101 19.1 overview ...........................................................................................................101 19.2 functional description .......................................................................................101 19.3 embedded flash controller (efc ) user interface ............................................110
iv 6222f?atarm?14-jan-11 sam7se512/256/32 20 fast flash programming interface (ffpi) ............... ................ ........... 117 20.1 overview ............................................................................................................117 20.2 parallel fast flash programming ......................................................................118 20.3 serial fast flash programming .........................................................................128 21 external bus interface (eb i) ........... .............. .............. .............. ........... 135 21.1 overview ............................................................................................................135 21.2 block diagram ...................................................................................................136 21.3 i/o lines description .........................................................................................137 21.4 application example ..........................................................................................138 21.5 product dependencies ......................................................................................141 21.6 functional description .......................................................................................141 21.7 implementation examples .................................................................................148 21.8 external bus interface (ebi) user interface ......................................................157 22 static memory controller (smc) ........... ................ ................. ............. 161 22.1 overview ............................................................................................................161 22.2 block diagram ...................................................................................................161 22.3 i/o lines description .........................................................................................162 22.4 multiplexed signals ............................................................................................162 22.5 product dependencies ......................................................................................163 22.6 functional description .......................................................................................163 22.7 static memory controller (smc) user interface ................................................195 23 sdram controller (sdramc) ............... ................ ................. ............. 199 23.1 overview ............................................................................................................199 23.2 block diagram ...................................................................................................199 23.3 i/o lines description .........................................................................................200 23.4 application example ..........................................................................................200 23.5 product dependencies ......................................................................................202 23.6 functional description .......................................................................................204 23.7 sdram controller (sdramc) user interface ..................................................210 24 error corrected code controller (ecc) ............... ................. ............. 219 24.1 overview ............................................................................................................219 24.2 block diagram ...................................................................................................219 24.3 functional description .......................................................................................220 24.4 ecc user interface ...........................................................................................224
v 6222f?atarm?14-jan-11 sam7se512/256/32 25 at91sam boot program ....... ................ ................ ................. ............. 229 25.1 overview ............................................................................................................229 25.2 flow diagram ....................................................................................................229 25.3 device initialization ............................................................................................229 25.4 sam-ba boot ....................................................................................................230 25.5 hardware and software constraints ..................................................................233 26 peripheral dma controller (pdc) ................ .............. .............. ........... 235 26.1 overview ............................................................................................................235 26.2 block diagram ...................................................................................................235 26.3 functional description .......................................................................................236 26.4 peripheral dma controller (pdc) user interface .............................................238 27 advanced interrupt controller (aic) ........... .............. .............. ........... 245 27.1 overview ............................................................................................................245 27.2 block diagram ...................................................................................................245 27.3 application block diagram .................................................................................246 27.4 aic detailed block diagram ..............................................................................246 27.5 i/o line description ...........................................................................................246 27.6 product dependencies ......................................................................................247 27.7 functional description .......................................................................................248 27.8 advanced interrupt controller (aic) user interface ...........................................260 28 clock generator ................ .............. .............. .............. .............. ........... 271 28.1 overview ............................................................................................................271 28.2 slow clock rc oscillator ...................................................................................271 28.3 main oscillator ....... ............................................................................................271 28.4 divider and pll block .......................................................................................273 29 power management controller (pmc) .... ................. ................ ........... 275 29.1 overview ............................................................................................................275 29.2 master clock controller .....................................................................................275 29.3 processor clock controller ................................................................................276 29.4 usb clock controller .........................................................................................276 29.5 peripheral clock controller ................................................................................276 29.6 programmable clock output controller .............................................................277 29.7 programming sequence ....................................................................................277 29.8 clock switching details .....................................................................................281 29.9 power management controller (pmc) user interface ......................................284
vi 6222f?atarm?14-jan-11 sam7se512/256/32 30 debug unit (dbgu) .. ................ ................ ................. ................ ........... 299 30.1 overview ............................................................................................................299 30.2 block diagram ...................................................................................................300 30.3 product dependencies ......................................................................................301 30.4 uart operations ..............................................................................................301 30.5 debug unit user interface ................................................................................308 31 serial peripheral interface (spi) ............ ................ ................. ............. 323 31.1 overview ............................................................................................................323 31.2 block diagram ...................................................................................................324 31.3 application block diagram .................................................................................324 31.4 signal description .............................................................................................325 31.5 product dependencies ......................................................................................325 31.6 functional description .......................................................................................326 31.7 serial peripheral interface (spi) user interface ................................................335 32 two wire interface (twi) .... .............. .............. .............. .............. ......... 349 32.1 overview ............................................................................................................349 32.2 list of abbreviations ..........................................................................................349 32.3 block diagram ...................................................................................................350 32.4 application block diagram .................................................................................350 32.5 product dependencies ......................................................................................351 32.6 functional description .......................................................................................352 32.7 master mode ......................................................................................................353 32.8 multi-master mode .............................................................................................364 32.9 slave mode ........................................................................................................367 32.10 two-wire interface (twi) user interface .........................................................375 33 universal synchronous asynchr onous receiver transceiver (usart) ................. ................. ................ ................ ................. ............. 389 33.1 overview ............................................................................................................389 33.2 block diagram ...................................................................................................390 33.3 application block diagram .................................................................................391 33.4 i/o lines description ........................................................................................391 33.5 product dependencies ......................................................................................392 33.6 functional description .......................................................................................393 33.7 usart user interface ......................................................................................418 34 parallel input output controller (pio) .............. .............. ........... ......... 437
vii 6222f?atarm?14-jan-11 sam7se512/256/32 34.1 overview ............................................................................................................437 34.2 block diagram ...................................................................................................438 34.3 product dependencies ......................................................................................439 34.4 functional description .......................................................................................440 34.5 i/o lines programming example .......................................................................444 34.6 pio user interface .............................................................................................446 35 synchronous serial controller (ssc) .... ................. ................ ........... 463 35.1 description .........................................................................................................463 35.2 block diagram ...................................................................................................464 35.3 application block diagram .................................................................................464 35.4 pin name list ....................................................................................................465 35.5 product dependencies ......................................................................................465 35.6 functional description .......................................................................................465 35.7 ssc application examples ................................................................................477 35.8 synchronous serial controller (ssc) user interface ........................................479 36 timer/counter (tc) ........... .............. .............. .............. .............. ........... 501 36.1 overview ............................................................................................................501 36.2 block diagram ...................................................................................................502 36.3 pin name list ....................................................................................................503 36.4 product dependencies ......................................................................................503 36.5 functional description .......................................................................................504 36.6 timer/counter (tc) user interface ....................................................................517 37 pulse width modulation cont roller (pwm) ... .............. .............. ......... 535 37.1 overview ............................................................................................................535 37.2 block diagram ...................................................................................................535 37.3 i/o lines description .........................................................................................536 37.4 product dependencies ......................................................................................536 37.5 functional description .......................................................................................537 37.6 pulse width modulation (pwm) controller user interface ...............................545 38 usb device port (udp) ....... .............. .............. .............. .............. ......... 555 38.1 overview ............................................................................................................555 38.2 block diagram ...................................................................................................556 38.3 product dependencies ......................................................................................557 38.4 typical connection ............................................................................................558 38.5 functional description .......................................................................................559
viii 6222f?atarm?14-jan-11 sam7se512/256/32 38.6 usb device port (udp) user interface .............................................................573 39 analog-to-digital converter (adc) .............. .............. .............. ........... 597 39.1 overview ............................................................................................................597 39.2 block diagram ...................................................................................................597 39.3 signal description ..............................................................................................598 39.4 product dependencies ......................................................................................598 39.5 functional description .......................................................................................599 39.6 analog-to-digital converter (adc) user interface .............................................604 40 sam7se512/256/32 electrical characteristics ......... .............. ........... 615 40.1 absolute maximum ratings ...............................................................................615 40.2 dc characteristics .............................................................................................616 40.3 power consumption ..........................................................................................619 40.4 crystal oscillators characteristics ... ..................................................................621 40.5 pll characteristics ...........................................................................................624 40.6 usb transceiver characteristics .......................................................................625 40.7 adc characteristics .........................................................................................627 40.8 ac characteristics .............................................................................................628 41 sam7se512/256/32 mechanical characterist ics ............... ................ 645 41.1 package drawings .............................................................................................646 41.2 soldering profile ................................................................................................648 42 sam7se512/256/32 ordering information .. .............. .............. ........... 649 43 sam7se512/256/32 errata ....... ................ ................. ................ ........... 651 43.1 marking ..............................................................................................................651 43.2 sam7se512/256/32 errata - rev. a parts ........................................................652 44 revision history ....... ................ ................ ................. ................ ........... 659
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