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| LPC47S42X enhanced super i/o with lpc interface for server applications features 3.3 volt operation (5v tolerant) floppy disk controller (supports two fdcs) multi-mode parallel port two uarts 8042 keyboard controller smbus controller x-bus interface programmable wakeup event interface (nio_pme pin) smi support (nio_smi pin) gpios (39) fan speed control output fan tachometer input isa irq to serial irq conversion xnor chain pc99 and acpi 1.0 compliant isa plug-and-play compatible register set intelligent auto power management 2.88mb super i/o floppy disk controller - licensed cmos 765b floppy disk controller - software and register compatible with smsc's proprietary 82077aa compatible core - configurable open drain/push-pull output drivers - supports vertical recording format - 16-byte data fifo - 100% ibm ? compatibility - detects all overrun and underrun conditions - sophisticated power control circuitry (pcc) including multiple powerdown modes for reduced power consumption - dma enable logic - data rate and drive control registers - 480 address, up to 15 irq and three dma options enhanced digital data separator - 2 mbps, 1 mbps, 500 kbps, 300 kbps, 250 kbps data rates - programmable precompensation modes keyboard controller - 8042 software compatible - 8-bit microcomputer - 2k bytes of program rom - 256 bytes of data ram - four open drain outputs dedicated for keyboard/mouse interface - asynchronous access to two data registers and one status register - supports interrupt and polling access - 8-bit counter timer - port 92 support - fast gate a20 and kreset outputs serial ports - two full function serial ports - high speed ns16c550 compatible uarts with send/receive 16-byte fifos - supports 230k and 460k baud - programmable baud rate generator - modem control circuitry - 480 address and 15 irq options - irda 1.0, hp-sir, ask ir support
2 multi-mode parallel port with chiprotect? - standard mode ibm pc/xt ? , pc/at ? , and ps/2? compatible bidirectional parallel port - enhanced parallel port (epp) compatible - epp 1.7 and epp 1.9 (ieee 1284 compliant) - ieee 1284 compliant enhanced capabilities port (ecp) - chiprotect circuitry for protection against damage due to printer power- on - 480 address, up to 15 irq and 3 dma options - multiplexed command, address and data bus - 8-bit i/o transfers - 8-bit dma transfers - 16-bit address qualification - serial irq interface compatible with serialized irq support for pci systems - power management event (pme) interface pin 100 pin qfp package general description the LPC47S42X* is a 3.3v pc99 compliant super i/o controller. the LPC47S42X implements the lpc interface, a pin reduced isa interface which provides the same or better performance as the isa/x-bus with a substantial savings in pins used. the part provides 39 gpio pins, an smbus controller, a fan speed control output, a fan tachometer input, four isa irqs that can be routed to any of the serial irqs, and an x-bus interface. the LPC47S42X incorporates a keyboard interface, smsc's true cmos 765b floppy disk controller, advanced digital data separator, two 16c550 compatible uarts, one multi-mode parallel port which includes chiprotect circuitry plus epp and ecp, and intelligent power management. the true cmos 765b core provides 100% compatibility with ibm pc/xt and pc/at architectures in addition to providing data overflow and underflow protection. the smsc advanced digital data separator incorporates smsc's patented data separator technology, allowing for ease of testing and use. the on-chip uarts are compatible with the ns16c550. the parallel port is compatible with ibm pc/at architecture, as well as ieee 1284 epp and ecp. the LPC47S42X incorporates sophisticated power control circuitry (pcc). the pcc supports multiple low power down modes. the LPC47S42X supports the isa plug-and-play standard (version 1.0a) and provides the recommended functionality to support windows '95/?98 and pc99. the i/o address, dma channel and hardware irq of each logical device in the LPC47S42X may be reprogrammed through the internal configuration registers. there are 480 i/o address location options, a serialized irq interface, and three dma channels. standard microsystems is a registered trademark and smsc is a trademark of standard microsystems corporation. other product and company names are trademarks or registered trademarks of their respective holders. *the ?x? in the part number is a designator that changes depending upon the particular bios used inside the specific chip. ?2? denotes ami keyboard bios and ?7? denotes phoenix 42i keyboard bios. 3 table of contents features ................................ ................................ ................................ ................................ ....... 1 general description ................................ ................................ ................................ ................ 2 pin configuration ................................ ................................ ................................ ...................... 5 d escription of pin functions ................................ ................................ ................................ . 6 buffer type descriptions ................................ ................................ ................................ ............... 11 pins that require external pullup resistors ................................ ................................ .................. 12 3.3 volt operation / 5 volt tolerance ................................ ................................ .............. 13 power functionality ................................ ................................ ................................ .............. 13 vcc power ................................ ................................ ................................ ................................ .. 13 vtr support ................................ ................................ ................................ ................................ 13 internal pwrgood ................................ ................................ ................................ ..................... 13 32.768 khz trickle clock input ................................ ................................ ................................ ...... 13 indication of 32khz clock ................................ ................................ ................................ ............. 14 trickle power functionality ................................ ................................ ................................ ........... 14 maximum current values ................................ ................................ ................................ .............. 16 power management events (pme/sci) ................................ ................................ ......................... 16 functional description ................................ ................................ ................................ ......... 17 super i/o registers ................................ ................................ ................................ ...................... 17 host processor interface (lpc) ................................ ................................ ................................ ..... 17 floppy disk controller ................................ ................................ ................................ ........ 22 fdc internal registers ................................ ................................ ................................ ................. 22 command set/descriptions ................................ ................................ ................................ .......... 40 instruction set ................................ ................................ ................................ .............................. 44 serial port (uart) ................................ ................................ ................................ .................... 72 infrared interface ................................ ................................ ................................ ................. 88 parallel port ................................ ................................ ................................ ........................... 89 power management ................................ ................................ ................................ ................ 112 serial irq ................................ ................................ ................................ ................................ ... 116 routable irq to serial irq conversion capability ................................ ................................ ........ 120 8042 keyboard controller description ................................ ................................ ......... 121 keyboard interface ................................ ................................ ................................ ...................... 121 external keyboard and mouse interface ................................ ................................ ....................... 123 keyboard power management ................................ ................................ ................................ ..... 123 interrupts ................................ ................................ ................................ ................................ ..... 124 memory configurations ................................ ................................ ................................ ................ 124 register definitions ................................ ................................ ................................ ..................... 124 external clock signal ................................ ................................ ................................ ................... 125 default reset conditions ................................ ................................ ................................ ............. 125 latches on keyboard and mouse irqs ................................ ................................ ....................... 128 keyboard and mouse pme generation ................................ ................................ ........................ 130 general purpose i/o ................................ ................................ ................................ ............... 131 gpio pins ................................ ................................ ................................ ................................ ... 131 description ................................ ................................ ................................ ................................ .. 132 gpio control ................................ ................................ ................................ .............................. 135 gpio operation ................................ ................................ ................................ .......................... 136 gpio pme and smi functionality ................................ ................................ ................................ 137 either edge triggered interrupts ................................ ................................ ................................ .. 139 led functionality ................................ ................................ ................................ ........................ 139 4 watch dog timer ................................ ................................ ................................ ..................... 140 system management interrupt (smi) ................................ ................................ ................. 140 smi registers ................................ ................................ ................................ .............................. 141 acpi support register for smi generation ................................ ................................ ................... 142 pme support ................................ ................................ ................................ ................................ . 142 wake on specific key option ................................ ................................ ................................ ...... 143 fan speed control and monitoring ................................ ................................ .................. 145 fan speed control ................................ ................................ ................................ ...................... 145 fan tachometer input ................................ ................................ ................................ ................. 146 security feature ................................ ................................ ................................ .................... 150 gpio device disable register control ................................ ................................ ......................... 150 device disable register ................................ ................................ ................................ ............... 150 smbus controller ................................ ................................ ................................ .................. 150 overview ................................ ................................ ................................ ................................ ..... 150 configuration registers ................................ ................................ ................................ ............... 151 runtime registers ................................ ................................ ................................ ....................... 151 pin multiplexing ................................ ................................ ................................ ........................... 158 smbus timeouts ................................ ................................ ................................ ......................... 158 x-bus interface ................................ ................................ ................................ ....................... 160 x-bus chip select base i/o address registers ................................ ................................ ............ 163 x-bus configuration register ................................ ................................ ................................ ....... 163 runtime registers ................................ ................................ ................................ .................. 164 runtime registers block summary ................................ ................................ .............................. 164 runtime registers block description ................................ ................................ ............................ 168 configuration ................................ ................................ ................................ .......................... 200 operational description ................................ ................................ ................................ ..... 229 maximum guaranteed ratings ................................ ................................ ................................ ..... 229 dc electrical characteristics ................................ ................................ ................................ ........ 229 timing diagrams ................................ ................................ ................................ ....................... 233 ecp parallel port timing ................................ ................................ ................................ ............. 244 x-bus timing ................................ ................................ ................................ .............................. 253 package outline ................................ ................................ ................................ ..................... 261 appendix - test modes ................................ ................................ ................................ ............ 262 board test mode ................................ ................................ ................................ ......................... 262 80 arkay drive hauppauge, ny 11788 (516) 435-6000 fax (516) 273-3123 5 pin configuration LPC47S42X 100 pin qfp gp40/drvden0 gp41/drvden1/nxcs0 nmtr0 ndskchg nds0 clki32 vss ndir nstep nwdata nwgate nhdsel nindex ntrk0 nwrtprt nrdata gp42/nio_pme vtr clocki lad0 lad1 lad2 lad3 nlframe nldrq npci_reset nlpcpd gp43/ddrc/nxcs1 pci_clk ser_irq 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 nack busy pe slct vss pd7 pd6 pd5 pd4 pd3 pd2 pd1 pd0 nslctin ninit vcc gp37/na20m gp36/nkbdrst gp35/irqinb gp34/irqina vss mclk mdat kclk kdat gp33/fan/xa1 gp32/sdat/xa0 vcc gp31/fan_tach/nxcs3/xa3 gp30/sclk/nxcs2/xa2 80 79 78 77 76 75 74 73 72 71 70 69 68 67 66 65 64 63 62 61 60 59 58 57 56 55 54 53 52 51 v s s g p 1 0 / x d 0 g p 1 1 / x d 1 g p 1 2 / x d 2 g p 1 3 / x d 3 g p 1 4 / x d 4 g p 1 5 / x d 5 g p 1 6 / x d 6 g p 1 7 / x d 7 g p 6 2 / p 1 7 / i r q i n c g p 2 0 / p 1 7 / n d s 1 g p 2 1 / p 1 6 / p 1 2 g p 2 2 / p 1 2 / n m t r 1 g p 2 3 / i r q i n d g p 2 4 / s y s o p t g p 2 5 / n x r d g p 2 6 / n x w r g p 6 0 / l e d 1 g p 6 1 / l e d 2 g p 2 7 / n i o _ s m i 3 1 3 2 3 3 3 4 3 5 3 6 3 7 3 8 3 9 4 0 4 1 4 2 4 3 4 4 4 5 4 6 4 7 4 8 4 9 5 0 g p 5 7 / n d t r 2 g p 5 6 / n c t s 2 g p 5 5 / n r t s 2 g p 5 4 / n d s r 2 g p 5 3 / t x d 2 / i r t x g p 5 2 / r x d 2 / i r r x g p 5 1 / n d c d 2 v c c g p 5 0 / n r i 2 n d c d 1 n r i 1 n d t r 1 n c t s 1 n r t s 1 n d s r 1 t x d 1 r x d 1 n s t r o b e n a l f n e r r o r 1 0 0 9 9 9 8 9 7 9 6 9 5 9 4 9 3 9 2 9 1 9 0 8 9 8 8 8 7 8 6 8 5 8 4 8 3 8 2 8 1 6 d escription of pin functions note: there are no internal pullups on any of the pins in the LPC47S42X. pin # name function buffer type buffer type per function (note 1) fdd interface 1 gp40/drvden0 general purpose i/o/drive density select 0 io12 (i/o12/od12)/ (o12/od12) 2 gp41/drvden1/ nxcs0 general purpose i/o/drive density select 1/x-bus chip select 0 io12 (i/o12/od12)/ (o12/od12)/o12 3 nmtr0 motor on 0 o12 (o12/od12) 4 ndskchg disk change is is 5 nds0 drive select 0 o12 (o12/od12) 8 ndir step direction o12 (o12/od12) 9 nstep step pulse o12 (o12/od12) 10 nwdata write disk data o12 (o12/od12) 11 nwgate write gate o12 (o12/od12) 12 nhdsel head select o12 (o12/od12) 13 nindex index pulse input is is 14 ntrk0 track 0 is is 15 nwrtprt write protected is is 16 nrdata read disk data is is lpc interface 20 lad0 multiplexed command address and data 0 pci_io pci_io 21 lad1 multiplexed command address and data 1 pci_io pci_io 22 lad2 multiplexed command address and data 2 pci_io pci_io 23 lad3 multiplexed command address and data 3 pci_io pci_io 24 nlframe frame pci_i pci_i 25 nldrq encoded dma request pci_o pci_o 26 npci_reset pci reset pci_i pci_i 27 nlpcpd power down (note 2) pci_i pci_i 29 pci_clk pci clock pci_iclk pci_iclk 30 ser_irq serial irq pci_io pci_io general purpose i/o pins 17 gp42/nio_pme general purpose i/o/power management event output io12 (i/o12/od12)/ (o12/od12) 28 gp43/ddrc/nxcs1 general purpose i/o/device disable reg. control/x-bus chip select 1 io8 (i/o8/od8)/i/o8 32 gp10/xd0 general purpose i/o/x-bus data bit 0 io8 (i/o8/od8)/io8 7 pin # name function buffer type buffer type per function (note 1) 33 gp11/xd1 general purpose i/o/x-bus data bit 1 io8 (i/o8/od8)/io8 34 gp12/xd2 general purpose i/o/x-bus data bit 2 io8 (i/o8/od8)/io8 35 gp13/xd3 general purpose i/o/x-bus data bit 3 io8 (i/o8/od8)/io8 36 gp14/xd4 general purpose i/o/x-bus data bit 4 io8 (i/o8/od8)/io8 37 gp15/xd5 general purpose i/o/x-bus data bit 5 io8 (i/o8/od8)/io8 38 gp16/xd6 general purpose i/o/x-bus data bit 6 io8 (i/o8/od8)/io8 39 gp17/xd7 general purpose i/o/x-bus data bit 7 io8 (i/o8/od8)/io8 40 gp62/p17/irqinc general purpose i/o/p17/ irq input c io8 (i/o8/od8)/io8/i 41 gp20/p17/nds1 general purpose i/o/p17 /drive select 1 io12 (i/o12/od12)/ io12/(o12/od12) 42 gp21/p16/p12 general purpose i/o/p16/p12 io8 (i/o8/od8)/io8/ io8 43 gp22/p12/nmtr1 general purpose i/o/p12/motor on 1 io12 (i/o12/od12)/ io12/(o12/od12) 44 gp23/irqind general purpose i/o/irq input d io8 (i/o8/od8)/i 45 gp24/sysopt general purpose i/o/system option (note 7) io8 (i/o8/od8) 46 gp25/nxrd general purpose i/o/x-bus read strobe (note 10) io8 (i/o8/od8)/o8 47 gp26/nxwr general purpose i/o/x-bus write strobe (note 10) io8 (i/o8/od8)/o8 48 gp60/led1 general purpose i/o/led1 (note 9) io12 (i/o12/od12)/ (o12/od12) 49 gp61/led2 general purpose i/o/led2 (note 9) io12 (i/o12/od12)/ (o12/od12) 50 gp27/nio_smi general purpose i/o/nio_smi io12 (i/o12/od12)/ (o12/od12) 61 gp34/irqina general purpose i/o/irq input a io12 (i/o21/od12)/i 62 gp35/irqinb general purpose i/o/irq input b io12 (i/o12/od12)/i 8 pin # name function buffer type buffer type per function (note 1) smbus pins 51 gp30/sclk/ nxcs2/xa2 general purpose i/o/smbus clock/x-bus chip select 2/x-bus address 2 io12 (i/o12/od12)/ iod12/o12/o12 54 gp32/sdat/xa0 general purpose i/o/smbus data/x-bus address 0 io12 (i/o12/od12)/ iod12/o12 fan control pins 52 gp31/fan_tach/ nxcs3/xa3 general purpose i/o/fan tachometer input/x-bus chip select 3/x-bus address 3 io8 (i/o8/od8)/i/o8/ o8 55 gp33 /fan/xa1 general purpose i/o /fan control/x-bus address 1 (note 4) io12 (i/o12/od12)/ (o12/od12)/o12 keyboard/mouse 56 kdat keyboard data iod16 iod16 57 kclk keyboard clock iod16 iod16 58 mdat mouse data iod16 iod16 59 mclk mouse clock iod16 iod16 63 gp36/nkbdrst general purpose i/o /keyboard reset (note 8) io8 (i/o8/od8)/o8 64 gp37/a20m general purpose i/o /gate a20 (note 8) io8 (i/o8/od8)/o8 parallel port interface 66 ninit/ndir initiate output/fdc direction control op14 (od14/op14)/ od14 67 nslctin/nstep printer select input/fdc step pulse op14 (od14/op14)/ od14 68 pd0/nindex port data 0/fdc index is/op14 iop14/is 69 pd1/ntrk0 port data 1/fdc track 0 is/op14 iop14/is 70 pd2/nwrtprt port data 2/fdc write protected is/op14 iop14/is 71 pd3/nrdata port data 3/fdc read disk data is/op14 iop14/is 72 pd4/ndskchg port data 4/fdc disk change is/op14 iop14/is 73 pd5 port data 5 iop14 iop14 74 pd6/nmtr0 port data 6/fdc motor on 0 iop14 iop14/od14 75 pd7 port data 7 iop14 iop14 77 slct/nwgate printer selected status/fdc write gate io12 i/od12 78 pe/nwdata paper end/fdc write data io12 i/od12 79 busy/nmtr1 busy/fdc motor on io12 i/od12 80 nack/nds1 acknowledge/fdc drive select 1 io12 i/od12 81 nerror/nhdsel error/fdc head select io12 i/od12 82 nalf/ndrvden0 autofeed output/fdc density select op14 (od14/op14)/ od14 9 pin # name function buffer type buffer type per function (note 1) 83 nstrobe/nds0 strobe output/fdc drive select op14 (od14/op14)/ od14 serial port 1 interface 84 rxd1 receive data 1 is is 85 txd1 transmit data 1 o12 o12 86 ndsr1 data set ready 1 i i 87 nrts1 request to send 1 o8 o8 88 ncts1 clear to send 1 i i 89 ndtr1 data terminal ready 1 o6 o6 90 nri1 ring indicator 1 i i 91 ndcd1 data carrier detect 1 i i serial port 2 interface 92 gp50/nri2 general purpose i/o/ring indicator 2 io8 (i/o8/od8)/i 94 gp51/ndcd2 general purpose i/o/data carrier detect 2 io8 (i/o8/od8)/i 95 gp52/rxd2/irrx general purpose i/o/receive data 2/irrx is/o8 (is/o8/od8)/is/is 96 gp53/txd2/irtx general purpose i/o/transmit data 2/irtx (note 5, 6) io12 (i/o12/od12)/o12/ o12 97 gp54/ndsr2 general purpose i/o/data set ready 2 io8 (i/o8/od8)/i 98 gp55/nrts2 general purpose i/o/request to send 2 io8 (i/o8/od8)/o8 99 gp56/ncts2 general purpose i/o/clear to send 2 io8 (i/o8/od8)/i 100 gp57/ndtr2 general purpose i/o/data terminal ready 2 io8 (i/o8/od8)/o8 power pins 53, 65, 93 vcc +3.3 volt supply voltage 18 vtr +3.3 volt standby supply voltage (note 6) 7, 31, 60, 76 vss ground clock pins 6 clki32 32.768khz standby clock input (note 3) is is 19 clocki 14.318mhz clock input is is note: the "n" as the first letter of a signal name indicates an "active low" signal. note 1: buffer types per function on multiplexed pins are separated by a slash ?/?. buffer types in parenthesis represent multiple buffer types for a single pin function. 10 note 2: the nlpcpd pin may be tied high. the lpc interface will function properly if the npci_reset signal follows the protocol defined for the nlreset signal in the ?low pin count interface specification?. note 3: if th e 32khz input clock is not used the clki32 pin must be grounded. there is a bit in the configuration register at 0xf0 in logical device a that indicates whether or not the 32khz clock is connected. this bit determines the clock source for the fan tachometer, led and ?wake on specific key? logic. set this bit to ?1? if the clock is not connected. note 4: the fan control pin (fan) comes up as output and low following a vcc por and hard reset. this pin reverts to its non-inverting general purpose i/o output function when vcc is removed from the part. note 5: the gp53/txd2/irtx pin is an output and low when the part is under vtr power (vcc=0). the pin comes up as output and low following a vcc por and hard reset. note 6: vtr can be connected to vcc if no wake up functionality is required. note 7: the gp24/sysopt pin requires an external pulldown resistor to put the base i/o address for configuration at 0x02e. an external pullup resistor is required to move the base i/o address for configuration to 0x04e. note 8: external pullups must be placed on the nkbdrst and a20m pins. these pins are general purpose i/os that are inputs after an initial power-up (vtr por). if the nkbdrst and a20m functions are to be used, the system must ensure that these pins are high. see section ?pins that require external pullup resistor?. note 9: the led pins are powered by vtr so that the leds can be controlled when the part is under vtr power. the gp61 pin defaults to the led function active (blinking at a 1hz rate, 50% duty cycle) on initial power up (as long as the 32 khz clock input is active). note 10: external pullups are required on the nxrd and nxwr pins. 11 buffer type descriptions io12 input/output, 12ma sink, 6ma source. is/o12 input with schmitt trigger/output, 12ma s ink, 6ma source. o12 output, 12ma sink, 6ma source. od12 open drain output, 12ma sink. o6 output, 6ma sink, 3ma source. o8 output, 8ma sink, 4ma source. od8 open drain output, 8ma sink. io8 input/output, 8ma sink, 4ma source. is/o8 input with schmit t trigger/output, 8ma sink, 4ma source. od14 open drain output, 14ma sink. op14 output, 14ma sink, 14ma source. iop14 input/output, 14ma sink, 14ma source. backdrive protected. iod16 input/output (open drain), 16ma sink. o4 output, 4ma sink, 2ma sour ce. i input ttl compatible. is input with schmitt trigger. pci_io input/output. these pins meet the pci 3.3v ac and dc characteristics. (note 1) pci_o output. these pins meet the pci 3.3v ac and dc characteristics. (note 1) pci_od open drain output. thes e pins meet the pci 3.3v ac and dc characteristics. (note 1) pci_i input. these pins meet the pci 3.3v ac and dc characteristics. (note 1) pci_iclk clock input. these pins meet the pci 3.3v ac and dc characteristics and timing. (note 2) note 1. see the pci local bus specification, revision 2.1, section 4.2.2. note 2. see the pci local bus specification, revision 2.1, section 4.2.2. and 4.2.3. 12 pins that require external pullup resistors the following pins require external pullup resistors: kdat kclk mdat mclk gp36/kbdrst if kbdrst function is used gp37/a20m if a20m function is used gp20/p17/nds1 if p17 function is used gp21/p16/p12 if p16 or p12 function is used gp22/p12/nmtr1 if p12 function is used gp27/nio_smi if nio_smi function is used as open collector output gp42/nio_pme if nio_pme function is used as open collector output ser_irq gp40/drvden0 if drvden0 function is used as open collector output gp41/drvden1/xcs0 if drvden1 function is used as open collector output gp23, gp 34, gp35 and gp62 if irqinx function is used nmtr0 if used as open collector output nds0 if used as open collector output ndir if used as open collector output nstep if used as open collector output nwdata if used as open collector output nwgate if used as open collector output nhdsel if used as open collector output nindex ntrk0 nwrtprt nrdata ndskchg nxrd nxwr 13 3.3 volt operation / 5 volt tolerance the LPC47S42X is a 3.3 volt part. it is intended solely for 3.3v applications. non-lpc bus pins are 5v tolerant; that is, the input voltage is 5.5v max, and the i/o buffer output pads are backdrive protected. the lpc interface pins are 3.3 v only. these signals meet pci dc specifications for 3.3v signaling. these pins are: lad[3:0] nlframe nldrq nlpcpd the input voltage for all other pins is 5.5v max. these pins include all non-lpc bus pins and the following pins: npci_reset pci_clk ser_irq nio_pme power functionality the LPC47S42X has two power planes: vcc and vtr. vcc power the LPC47S42X is a 3.3 volt part. the vcc supply is 3.3 volts (nominal). see the operational description section and the maximum current values subsection. vtr support the LPC47S42X requires a trickle supply (v tr ) to provide sleep current for the programmable wake-up events in the pme interface when v cc is removed. the vtr supply is 3.3 volts (nominal). see the operational description section. the maximum vtr current that is required depends on the functions that are used in the part. see trickle power functionality subsection and the maximum current values subsection. if the LPC47S42X is not intended to provide wake-up capabilities on standby current, v tr can be connected to v cc . the v tr pin generates a v tr power-on-reset signal to initialize these components. note: if v tr is to be used for programmable wake-up events when v cc is removed, v tr must be at its full minimum potential at least 10 m s before v cc begins a power-on cycle. when v tr and v cc are fully powered, the potential difference between the two supplies must not exceed 500mv. internal pwrgood an internal pwrgood logical control is included to minimize the effects of pin-state uncertainty in the host interface as v cc cycles on and off. when the internal pwrgood signal is ?1? (active), v cc > 2.3v (nominal), and the LPC47S42X host interface is active. when the internal pwrgood signal is ?0? (inactive), v cc 2.3v (nominal), and the LPC47S42X host interface is inactive; that is, lpc bus reads and writes will not be decoded. the LPC47S42X device pins nio_pme, clocki32, kdat, mdat, irrx, nri1, nri2, rxd2 and most gpios (as input) are part of the pme interface and remain active when the internal pwrgood signal has gone inactive, provided v tr is powered. the gp53/txd2/irtx, gp60/led1 and gp61/led2 pins also remain active when the internal pwrgood signal has gone inactive, provided v tr is powered. see trickle power functionality section. 32.768 khz trickle clock input the LPC47S42X utilizes a 32.768 khz trickle clock input to supply a clock signal for the fan tachometer logic, wdt, led blink and wake on specific key function. see the following section for more information. 14 indication of 32khz clock there is a bit to indicate whether or not the 32khz clock input is connected to the LPC47S42X. this bit is located at bit 0 of the clocki32 register at 0xf0 in logical device a. this register is powered by vtr and reset on a vtr por. bit[0] (clk32_prsn) is defined as follows: 0=32khz clock is connected to the clki32 pin (default) 1=32khz clock is not connected to the clki32 pin (pin is grounded). bit 0 controls the source of the 32khz (nominal) clock for the cir wakeup, fan tachometer logic, the led blink logic, the wdt and the ?wake on specific key? logic. when the external 32khz clock is connected, that will be the source for the fan tachometer, led, wdt and ?wake on specific key? logic. when the external 32khz clock is not connected, an internal 32khz clock source will be derived from the 14mhz clock for the fan tachometer, led, wdt and ?wake on specific key? logic. the following functions will not work under vtr power (vcc removed) if the external 32khz clock is not connected. these functions will work under vcc power even if the external 32khz clock is not connected. fan tachometer wake on specific key led blink wdt trickle power functionality when the LPC47S42X is running under vtr only, the pme wakeup events are active and (if enabled) able to assert the nio_pme pin active low. the following lists the wakeup events: uart 1 ring indicator uart 2 ring indicator keyboard data mouse data wake on specific key logic fan tachometer (note) gpios for wakeup. see below. note. the fan tachometer can generate a pme when vcc=0. clear the enable bits for the fan tachometers before removing fan power. the following requirements apply to all i/o pins that are specified to be 5 volt tolerant. i/o buffers that are wake-up event compatible are powered by vcc. under vtr power (vcc=0), these pins may only be configured as inputs. these pins have input buffers into the wakeup logic that are powered by vtr. i/o buffers that may be configured as either push-pull or open drain under vtr power (vcc=0), are powered by vtr. this means they will, at a minimum, source their specified current from vtr even when vcc is present. the gpios that are used for pme wakeup inputs are gp10-gp17, gp20-gp27, gp30-gp37, gp41, gp43, gp50-gp57, gp60, gp61. these gpios function as follows (with the exception of gp53, gp60 and gp61 - see below): buffers are powered by vcc, but in the absence of vcc they are backdrive protected (they do not impose a load on any external vtr powered circuitry). they are wakeup compatible as inputs under vtr power. these pins have input buffers into the wakeup logic that are powered by vtr. all gpios listed above are for pme wakeup as a gpio function (or alternate function). note that gp33 cannot be used for wakeup under vtr power (vcc=0) since this is the fan control pin which comes up as output and low following a vcc por and hard reset. gp53 cannot be used for wakeup under vtr power since this has the irtx function and comes up as output and low following a vtr por, a vcc por and hard reset. also, gp33 reverts to its non-inverting gpio output function when vcc is removed from the part. gp43 reverts to the basic gpio function when vcc is removed form the part, but its programmed input/output, invert/non-invert output buffer type is retained. 15 the other gpios function as follows: gp40, gp62: buffers powered by vcc, but in the absence of vcc they are backdrive protected. these pins do not have input buffers into the wakeup logic that are powered by vtr. these pins are not used for wakeup. gp42, gp53, gp60, gp61: buffers powered by vtr. gp42 is the nio_pme pin. gp53 has irtx as the alternate function and its output buffer is powered by vtr so that the pin is always forced low on vtr por, vcc por and hard reset. the irtx pin (gp53/txd2/irtx) is powered by vtr so that it is driven low when vcc = 0v with vtr = 3.3v. this pin is driven low on vtr por, vcc por and hard reset regardless of the selected pin function and regardless of the state of internal pwrgood (i.e., when vcc=3.3v and when vcc=0v with vtr=3.3v). the gp53/txd2/irtx pin will remain low following a vcc por until the irtx function is selected and the serial port is enabled by setting the activate bit, at which time the pin will reflect the state of the ir transmit output of the ir block. if the txd2 function is selected for the pin, it will remain low following a vcc por until the serial port is enabled by setting the activate bit, at which time the pin will reflect the state of the transmit output of the serial port. if the gpio output function is selected, the pin will reflect the state of the data bit. gp60 and gp61 are used for the led functions. see the table in the gpio section for more information. 16 the following list summarizes the blocks, registers and pins that are powered by vtr. pme interface block runtime register block (includes all pme, smi, gpio and other miscellaneous registers) wake on specific key logic led control logic pins for pme wakeup: - gp42/nio_pme (output, buffer powered by vtr) - nri1 (input) - gp50/nri2 (input) - gp52/rxd2/irrx (input) - kdat (input) - mdat (input) - gpios (gp10-gp17, gp20-gp27, gp30-gp37, gp41, gp43, gp50-gp57, gp60, gp61) ? all input-only except gp53, gp60, gp61. see below. other pins - gp53/txd2/irtx (output, buffer powered by vtr) - gp60/led1 (output, buffer powered by vtr) - gp61/led2 (output, buffer powered by vtr) maximum current values refer to the ?operational description? section for the maximum current values. the maximum vtr current, i tr , is given with all outputs open (not loaded). the total maximum current for the part is the unloaded value plus the maximum current sourced by all pins that are driven by vtr. the pins that are powered by vtr are as follows: gp42/nio_pme, gp53/txd2/irtx, gp60/led1, gp61/led2. these pins, if configured as push-pull outputs, will source a minimum of 6ma at 2.4v when driving. the maximum vcc current, i cc , is given with all outputs open (not loaded). power management events (pme/sci) the LPC47S42X offers support for power management events (pmes), also referred to as system control interrupt (sci) events. the terms pme and sci are used synonymously throughout this document to refer to the indication of an event to the chipset via the assertion of the nio_pme output signal on pin 17. see the ?pme support? section. 17 functional description super i/o registers the address map, shown below in table 1, shows the addresses of the different blocks of the super i/o immediately after power up. the base addresses of the fdc, serial and parallel ports, pme register block, game port and configuration register block can be moved via the configuration registers. some addresses are used to access more than one register. host processor interface (lpc) the host processor communicates with the LPC47S42X through a series of read/write registers via the lpc interface. the port addresses for these registers are shown in table 1. register access is accomplished through i/o cycles or dma transfers. all registers are 8 bits wide. table 1 - super i/o block addresses address block name logical device notes base+(0-5) and +(7) floppy disk 0 base+(0-7) serial port com 1 4 base+(0-7) serial port com 2 5 ir support base+(0-3) base+(0-7) base+(0-3), +(400-402) base+(0-7), +(400-402) parallel port spp epp ecp ecp+epp+spp 3 60, 64 kybd 7 60 - 67 x-bus 8 base + (0-6c) runtime registers a base+(0-3) smbus b base + (0-1) configuration note 1: refer to the configuration register descriptions for setting the base address. 18 lpc interface the following sub-sections specify the implementation of the lpc bus. lpc interface signal definition the signals required for the lpc bus interface are described in the table below. lpc bus signals use pci 33mhz electrical signal characteristics. signal name type description lad[3:0] i/o lpc address/data bus. multiplexed command, address and data bus. nlframe input frame signal. indicates start of new cycle and termination of broken cycle npci_reset input pci reset. used as lpc interface reset. nldrq output encoded dma/bus master request for the lpc interface. nio_pme od power mgt event signal. allows the LPC47S42X to request wakeup. nlpcpd input powerdown signal. indicates that the LPC47S42X should prepare for power to be shut on the lpc interface. ser_irq i/o serial irq. pci_clk input pci clock. lpc cycles the following cycle types are supported by the lpc protocol. cycle type transfer size i/o write 1 byte transfer i/o read 1 byte transfer dma write 1 byte dma read 1 byte the LPC47S42X ignores cycles that it does not support. 19 field definitions the data transfers are based on specific fields that are used in various combinations, depending on the cycle type. these fields are driven onto the lad[3:0] signal lines to communicate address, control and data information over the lpc bus between the host and the LPC47S42X. see the low pin count (lpc) interface specification revision 1.0 from intel, section 4.2 for definition of these fields. nlframe usage nlframe is used by the host to indicate the start of cycles and the termination of cycles due to an abort or time-out condition. this signal is to be used by the LPC47S42X to know when to monitor the bus for a cycle. this signal is used as a general notification that the lad[3:0] lines contain information relative to the start or stop of a cycle, and that the LPC47S42X monitors the bus to determine whether the cycle is intended for it. the use of nlframe allows the LPC47S42X to enter a lower power state internally. there is no need for the LPC47S42X to monitor the bus when it is inactive, so it can decouple its state machines from the bus, and internally gate its clocks. when the LPC47S42X samples nlframe active, it immediately stops driving the lad[3:0] signal lines on the next clock and monitor the bus for new cycle information. the nlframe signal functions as described in the low pin count (lpc) interface specification reference. i/o read and write cycles the LPC47S42X is the target for i/o cycles. i/o cycles are initiated by the host for register or fifo accesses, and will generally have minimal sync times. the minimum number of wait-states between bytes is 1. epp cycles will depend on the speed of the external device, and may have much longer sync times. data transfers are assumed to be exactly 1-byte. if the cpu requested a 16 or 32-bit transfer, the host will break it up into 8-bit transfers. see the low pin count (lpc) interface specification reference, section 5.2, for the sequence of cycles for the i/o read and write cycles. dma read and write cycles dma read cycles involve the transfer of data from the host (main memory) to the LPC47S42X. dma write cycles involve the transfer of data from the LPC47S42X to the host (main memory). data will be coming from or going to a fifo and will have minimal sync times. data transfers to/from the LPC47S42X are 1 byte. see the low pin count (lpc) interface specification reference, section 6.4, for the field definitions and the sequence of the dma read and write cycles. dma protocol dma on the lpc bus is handled through the use of the nldrq lines from the LPC47S42X and special encodings on lad[3:0] from the host. the dma mechanism for the lpc bus is described in the low pin count (lpc) interface specification reference. 20 power management clockrun protocol the nclkrun pin is not implemented in the LPC47S42X. see the low pin count (lpc) interface specification reference, section 8.1. lpcpd protocol see the low pin count (lpc) interface specification reference, section 8.2. sync protocol see the low pin count (lpc) interface specification reference, section 4.2.1.8 for a table of valid sync values. typical usage the sync pattern is used to add wait states. for read cycles, the LPC47S42X immediately drives the sync pattern upon recognizing the cycle. the host immediately drives the sync pattern for write cycles. if the LPC47S42X needs to assert wait states, it does so by driving 0101 or 0110 on lad[3:0] until it is ready, at which point it will drive 0000 or 1001. the LPC47S42X will choose to assert 0101 or 0110, but not switch between the two patterns. the data (or wait state sync) will immediately follow the 0000 or 1001 value. the sync value of 0101 is intended to be used for normal wait states, wherein the cycle will complete within a few clocks. the LPC47S42X uses a sync of 0101 for all wait states in a dma transfer. the sync value of 0110 is intended to be used where the number of wait states is large. this is provided for epp cycles, where the number of wait states could be quite large (>1 microsecond). however, the LPC47S42X uses a sync of 0110 for all wait states in an i/o transfer. the sync value is driven within 3 clocks. sync timeout the sync value is driven within 3 clocks. if the host observes 3 consecutive clocks without a valid sync pattern, it will abort the cycle. the LPC47S42X does not assume any particular timeout. when the host is driving sync, it may have to insert a very large number of wait states, depending on pci latencies and retries. sync patterns and maximum number of syncs if the sync pattern is 0101, then the host assumes that the maximum number of syncs is 8. if the sync pattern is 0110, then no maximum number of syncs is assumed. the LPC47S42X has protection mechanisms to complete the cycle. this is used for epp data transfers and will utilize the same timeout protection that is in epp. sync error indication the LPC47S42X reports errors via the lad[3:0] = 1010 sync encoding. if the host was reading data from the LPC47S42X, data will still be transferred in the next two nibbles. this data may be invalid, but it will be transferred by the LPC47S42X. if the host was writing data to the LPC47S42X, the data had already been transferred. in the case of multiple byte cycles, such as dma cycles, an error sync terminates the cycle. therefore, if the host is transferring 4 bytes from a device, if the device returns the error sync in the first byte, the other three bytes will not be transferred. 21 i/o and dma start fields i/o and dma cycles use a start field of 0000. reset policy the following rules govern the reset policy: 1) when npci_reset goes inactive (high), the clock is assumed to have been running for 100usec prior to the removal of the reset signal, so that everything is stable. this is the same reset active time after clock is stable that is used for the pci bus. 2) when npci_reset goes active (low): a) the host drives the nlframe signal high, tristates the lad[3:0] signals, and ignores the nldrq signal. b) the LPC47S42X ignores nlframe, tristate the lad[3:0] pins and drive the nldrq signal inactive (high). lpc transfers wait state requirements i/o transfers the LPC47S42X inserts three wait states for an i/o read and two wait states for an i/o write cycle. a sync of 0110 is used for all i/o transfers. the exception to this is for transfers where iochrdy would normally be deasserted in an isa transfer (i.e., epp) in which case the sync pattern of 0110 is used and a large number of syncs may be inserted (up to 330 which corresponds to a timeout of 10us). dma transfers the LPC47S42X inserts three wait states for a dma read and four wait states for a dma write cycle. a sync of 0101 is used for all dma transfers. refer to example timing for the lpc cycles in the ?timing diagrams? section. 22 floppy disk controller the floppy disk controller (fdc) provides the interface between a host microprocessor and the floppy disk drives. the fdc integrates the functions of the formatter/controller, digital data separator, write precompensation and data rate selection logic for an ibm xt/at compatible fdc. the true cmos 765b core guarantees 100% ibm pc xt/at compatibility in addition to providing data overflow and underflow protection. the fdc is compatible to the 82077aa using smsc's proprietary floppy disk controller core. fdc internal registers the floppy disk controller contains eight internal registers that facilitate the interfacing between the host microprocessor and the disk drive. table 2 shows the addresses required to access these registers. registers other than the ones shown are not supported. the rest of the description assumes that the primary addresses have been selected. table 2 - status, data and control registers (shown with base addresses of 3f0 and 370) primary address secondary address r/w register 3f0 3f1 3f2 3f3 3f4 3f4 3f5 3f6 3f7 3f7 370 371 372 373 374 374 375 376 377 377 r r r/w r/w r w r/w r w status register a (sra) status register b (srb) digital output register (dor) tape drive register (tdr) main status register (msr) data rate select register (dsr) data (fifo) reserved digital input register (dir) configuration control register (ccr) status register a (sra) address 3f0 read only this register is read-only and monitors the state of the internal interrupt signal and several disk interface pins in ps/2 and model 30 modes. the sra can be accessed at any time when in ps/2 mode. in the pc/at mode the data bus pins d0 - d7 are held in a high impedance state for a read of address 3f0. ps/2 mode 7 6 5 4 3 2 1 0 int pending ndrv2 step ntrk0 hdsel nindx nwp dir reset cond. 0 1 0 n/a 0 n/a n/a 0 23 bit 0 direction active high status indicating the direction of head movement. a logic "1" indicates inward direction; a logic "0" indicates outward direction. bit 1 nwrite protect active low status of the write protect disk interface input. a logic "0" indicates that the disk is write protected. bit 2 nindex active low status of the index disk interface input. bit 3 head select active high status of the hdsel disk interface input. a logic "1" selects side 1 and a logic "0" selects side 0. bit 4 ntrack 0 active low status of the trk0 disk interface input. bit 5 step active high status of the step output disk interface output pin. bit 6 ndrv2 this function is not supported. this bit is always read as ?1?. bit 7 interrupt pending active high bit indicating the state of the floppy disk interrupt output. ps/2 model 30 mode 7 6 5 4 3 2 1 0 int pending drq step f/f trk0 nhdsel indx wp ndir reset cond. 0 0 0 n/a 1 n/a n/a 1 bit 0 ndirection active low status indicating the direction of head movement. a logic "0" indicates inward direction; a logic "1" indicates outward direction. bit 1 write protect active high status of the write protect disk interface input. a logic "1" indicates that the disk is write protected. bit 2 index active high status of the index disk interface input. 24 bit 3 nhead select active low status of the hdsel disk interface input. a logic "0" selects side 1 and a logic "1" selects side 0. bit 4 track 0 active high status of the trk0 disk interface input. bit 5 step active high status of the latched step disk interface output pin. this bit is latched with the step output going active, and is cleared with a read from the dir register, or with a hardware or software reset. bit 6 dma request active high status of the dma request pending. bit 7 interrupt pending active high bit indicating the state of the floppy disk interrupt. status register b (srb) address 3f1 read only this register is read-only and monitors the state of several disk interface pins in ps/2 and model 30 modes. the srb can be accessed at any time when in ps/2 mode. in the pc/at mode the data bus pins d0 - d7 are held in a high impedance state for a read of address 3f1. ps/2 mode 7 6 5 4 3 2 1 0 1 1 drive sel0 wdata toggle rdata toggle wgate mot en1 mot en0 reset cond. 1 1 0 0 0 0 0 0 bit 0 motor enable 0 active high status of the mtr0 disk interface output pin. this bit is low after a hardware reset and unaffected by a software reset. bit 1 motor enable 1 active high status of the mtr1 disk interface output pin. this bit is low after a hardware reset and unaffected by a software reset. bit 2 write gate active high status of the wgate disk interface output. bit 3 read data toggle every inactive edge of the rdata input causes this bit to change state. bit 4 write data toggle every inactive edge of the wdata input causes this bit to change state. 25 bit 5 drive select 0 reflects the status of the drive select 0 bit of the dor (address 3f2 bit 0). this bit is cleared after a hardware reset and it is unaffected by a software reset. bit 6 reserved always read as a logic "1". bit 7 reserved always read as a logic "1". ps/2 model 30 mode 7 6 5 4 3 2 1 0 ndrv2 nds1 nds0 wdata f/f rdata f/f wgate f/f nds3 nds2 reset cond. n/a 1 1 0 0 0 1 1 bit 0 ndrive select 2 the ds2 disk interface is not supported. bit 1 ndrive select 3 the ds3 disk interface is not supported. bit 2 write gate active high status of the latched wgate output signal. this bit is latched by the active going edge of wgate and is cleared by the read of the dir register. bit 3 read data active high status of the latched rdata output signal. this bit is latched by the inactive going edge of rdata and is cleared by the read of the dir register. bit 4 write data active high status of the latched wdata output signal. this bit is latched by the inactive going edge of wdata and is cleared by the read of the dir register. this bit is not gated with wgate. bit 5 ndrive select 0 active low status of the ds0 disk interface output. bit 6 ndrive select 1 active low status of the ds1 disk interface output. bit 7 ndrv2 active low status of the drv2 disk interface input. note: this function is not supported. digital output register (dor) 26 address 3f2 read/write the dor controls the drive select and motor enables of the disk interface outputs. it also contains the enable for the dma logic and a software reset bit. the contents of the dor are unaffected by a software reset. the dor can be written to at any time. 7 6 5 4 3 2 1 0 mot en3 mot en2 mot en1 mot en0 dmaen nreset drive sel1 drive sel0 reset cond. 0 0 0 0 0 0 0 0 bit 0 and 1 drive select these two bits are binary encoded for the drive selects, thereby allowing only one drive to be selected at one time. bit 2 nreset a logic "0" written to this bit resets the floppy disk controller. this reset will remain active until a logic "1" is written to this bit. this software reset does not affect the dsr and ccr registers, nor does it affect the other bits of the dor register. the minimum reset duration required is 100ns, therefore toggling this bit by consecutive writes to this register is a valid method of issuing a software reset. bit 3 dmaen pc/at and model 30 mode: writing this bit to logic "1" will enable the dma and interrupt functions. this bit being a logic "0" will disable the dma and interrupt functions. this bit is a logic "0" after a reset and in these modes. ps/2 mode: in this mode the dma and interrupt functions are always enabled. during a reset, this bit will be cleared to a logic "0". bit 4 motor enable 0 this bit controls the mtr0 disk interface output. a logic "1" in this bit will cause the output pin to go active. bit 5 motor enable 1 this bit controls the mtr1 disk interface output. a logic "1" in this bit will cause the output pin to go active. bit 6 motor enable 2 the mtr2 disk interface output is not supported. bit 7 motor enable 3 the mtr3 disk interface output is not supported. 27 drive dor value 0 1 1ch 2dh tape drive register (tdr) address 3f3 read/write the tape drive register (tdr) is included for 82077 software compatibility and allows the user to assign tape support to a particular drive during initialization. any future references to that drive automatically invokes tape support. the tdr tape select bits tdr.[1:0] determine the tape drive number. table 3 illustrates the tape select bit encoding. note that drive 0 is the boot device and cannot be assigned tape support. the remaining tape drive register bits tdr.[7:2] are tristated when read. the tdr is unaffected by a software reset. table 3 - tape select bits tape sel1 (tdr.1) tape sel0 (tdr.0) drive selected 0 0 1 1 0 1 0 1 none 1 2 3 table 4 - internal 2 drive decode - normal digital output register drive select outputs (active low) motor on outputs (active low) bit 5 bit 4 bit1 bit 0 nds1 nds0 nmtr1 nmtr0 x 1 0 0 1 0 nbit 5 nbit 4 1 x 0 1 0 1 nbit 5 nbit 4 0 0 x x 1 1 nbit 5 nbit 4 table 5 - internal 2 drive decode - drives 0 and 1 swapped digital output register drive select outputs (active low) motor on outputs (active low) bit 5 bit 4 bit1 bit 0 nds1 nds0 nmtr1 nmtr0 x 1 0 0 0 1 nbit 4 nbit 5 1 x 0 1 1 0 nbit 4 nbit 5 0 0 x x 1 1 nbit 4 nbit 5 28 normal floppy mode normal mode. register 3f3 contains only bits 0 and 1. when this register is read, bits 2 - 7 are ?0?. db7 db6 db5 db4 db3 db2 db1 db0 reg 3f3 0 0 0 0 0 0 tape sel1 tape sel0 enhanced floppy mode 2 (os2) register 3f3 for enhanced floppy mode 2 operation. db7 db6 db5 db4 db3 db2 db1 db0 reg 3f3 reserved reserved drive type id floppy boot drive tape sel1 tape sel0 table 6 - drive type id digital output register register 3f3 - drive type id bit 1 bit 0 bit 5 bit 4 0 0 l0-crf2 - b1 l0-crf2 - b0 0 1 l0-crf2 - b3 l0-crf2 - b2 1 0 l0-crf2 - b5 l0-crf2 - b4 1 1 l0-crf2 - b7 l0-crf2 - b6 note: l0-crf2-bx = logical device 0, configuration register f2, bit x. data rate select register (dsr) address 3f4 write only this register is write only. it is used to program the data rate, amount of write precompensation, power down status, and software reset. the data rate is programmed using the configuration control register (ccr) not the dsr, for pc/at and ps/2 model 30 applications. other applications can set the data rate in the dsr. the data rate of the floppy controller is the most recent write of either the dsr or ccr. the dsr is unaffected by a software reset. a hardware reset will set the dsr to 02h, which corresponds to the default precompensation setting and 250 kbps. 7 6 5 4 3 2 1 0 s/w reset power down 0 pre- comp2 pre- comp1 pre- comp0 drate sel1 drate sel0 reset cond. 0 0 0 0 0 0 1 0 bit 0 and 1 data rate select these bits control the data rate of the floppy controller. see table 8 for the settings corresponding to the individual data rates. the data rate select bits are unaffected by a software reset, and are set to 250 kbps after a hardware reset. 29 bit 2 through 4 precompensation select these three bits select the value of write precompensation that will be applied to the wdata output signal. table 7 shows the precompensation values for the combination of these bits settings. track 0 is the default starting track number to start precompensation. this starting track number can be changed by the configure command. bit 5 undefined should be written as a logic "0". bit 6 low power a logic "1" written to this bit will put the floppy controller into manual low power mode. the floppy controller clock and data separator circuits will be turned off. the controller will come out of manual low power mode after a software reset or access to the data register or main status register. bit 7 software reset this active high bit has the same function as the dor reset (dor bit 2) except that this bit is self clearing. note: the dsr is shadowed in the floppy data rate select shadow register, located at the offset 0x1f in the runtime register block. table 7 - precompensation delays precomp 432 precompensation delay (nsec) <2mbps 2mbps 111 001 010 011 100 101 110 000 0.00 41.67 83.34 125.00 166.67 208.33 250.00 default 0 20.8 41.7 62.5 83.3 104.2 125 default default: see table 10 30 table 8 - data rates drive rate data rate data rate densel drate(1) drt1 drt0 sel1 sel0 mfm fm 1 0 0 0 1 1 1meg --- 1 1 1 0 0 0 0 500 250 1 0 0 0 0 0 1 300 150 0 0 1 0 0 1 0 250 125 0 1 0 0 1 1 1 1meg --- 1 1 1 0 1 0 0 500 250 1 0 0 0 1 0 1 500 250 0 0 1 0 1 1 0 250 125 0 1 0 1 0 1 1 1meg --- 1 1 1 1 0 0 0 500 250 1 0 0 1 0 0 1 2meg --- 0 0 1 1 0 1 0 250 125 0 1 0 drive rate table (recommended) 00 = 360k, 1.2m, 720k, 1.44m and 2.88m vertical format 01 = 3-mode drive 10 = 2 meg tape note 1: the drate and densel values are mapped onto the drvden pins. table 9 - drvden mapping0 dt1 dt0 drvden1 (1) drvden0 (1) drive type 0 0 drate0 densel 4/2/1 mb 3.5" 2/1 mb 5.25" fdds 2/1.6/1 mb 3.5" (3-mode) 1 0 drate0 drate1 0 1 drate0 ndensel ps/2 1 1 drate1 drate0 table 10 - default precompensation delays data rate precompensation delays 2 mbps 1 mbps 500 kbps 300 kbps 250 kbps 20.8 ns 41.67 ns 125 ns 125 ns 125 ns 31 main status register address 3f4 read only the main status register is a read-only register and indicates the status of the disk controller. the main status register can be read at any time. the msr indicates when the disk controller is ready to receive data via the data register. it should be read before each byte transferring to or from the data register except in dma mode. no delay is required when reading the msr after a data transfer. 7 6 5 4 3 2 1 0 rqm dio non dma cmd busy reserved reserved drv1 busy drv0 busy bit 0 - 1 drv x busy these bits are set to 1s when a drive is in the seek portion of a command, including implied and overlapped seeks and recalibrates. bit 4 command busy this bit is set to a 1 when a command is in progress. this bit will go active after the command byte has been accepted and goes inactive at the end of the results phase. if there is no result phase (seek, recalibrate commands), this bit is returned to a 0 after the last command byte. bit 5 non-dma this mode is selected in the specify command and will be set to a 1 during the execution phase of a command. this is for polled data transfers and helps differentiate between the data transfer phase and the reading of result bytes. bit 6 dio indicates the direction of a data transfer once a rqm is set. a 1 indicates a read and a 0 indicates a write is required. bit 7 rqm indicates that the host can transfer data if set to a 1. no access is permitted if set to a 0. data register (fifo) address 3f5 read/write all command parameter information, disk data and result status are transferred between the host processor and the floppy disk controller through the data register. data transfers are governed by the rqm and dio bits in the main status register. the data register defaults to fifo disabled mode after any form of reset. this maintains pc/at hardware compatibility. the default values can be changed through the configure command (enable full fifo operation with threshold control). the advantage of the fifo is that it allows the system a larger dma latency without causing a disk error. table 11 gives several examples of the delays with a fifo. 32 the data is based upon the following formula: threshold # x 1 data rate x 8 - 1.5 m s = delay at the start of a command, the fifo action is always disabled and command parameters are sent based upon the rqm and dio bit settings. as the command execution phase is entered, the fifo is cleared of any data to ensure that invalid data is not transferred. an overrun or underrun will terminate the current command and the transfer of data. disk writes will complete the current sector by generating a 00 pattern and valid crc. reads require the host to remove the remaining data so that the result phase may be entered. table 11 - fifo service delay fifo threshold examples maximum delay to servicing at 2 mbps data rate 1 byte 2 bytes 8 bytes 15 bytes 1 x 4 m s - 1.5 m s = 2.5 m s 2 x 4 m s - 1.5 m s = 6.5 m s 8 x 4 m s - 1.5 m s = 30.5 m s 15 x 4 m s - 1.5 m s = 58.5 m s fifo threshold examples maximum delay to servicing at 1 mbps data rate 1 byte 2 bytes 8 bytes 15 bytes 1 x 8 m s - 1.5 m s = 6.5 m s 2 x 8 m s - 1.5 m s = 14.5 m s 8 x 8 m s - 1.5 m s = 62.5 m s 15 x 8 m s - 1.5 m s = 118.5 m s fifo threshold examples maximum delay to servicing at 500 kbps data rate 1 byte 2 bytes 8 bytes 15 bytes 1 x 16 m s - 1.5 m s = 14.5 m s 2 x 16 m s - 1.5 m s = 30.5 m s 8 x 16 m s - 1.5 m s = 126.5 m s 15 x 16 m s - 1.5 m s = 238.5 m s digital input register (dir) address 3f7 read only this register is read-only in all modes. 33 pc-at mode 7 6 5 4 3 2 1 0 dsk chg 0 0 0 0 0 0 0 reset cond. n/a n/a n/a n/a n/a n/a n/a n/a bit 0 - 6 undefined the data bus outputs d0 - 6 are read as ?0?. bit 7 dskchg this bit monitors the pin of the same name and reflects the opposite value seen on the disk cable or the value programmed in the force disk change register (see runtime register at offset 0x1e). ps/2 mode 7 6 5 4 3 2 1 0 dsk chg 1 1 1 1 drate sel1 drate sel0 nhigh ndens reset cond. n/a n/a n/a n/a n/a n/a n/a 1 bit 0 nhigh dens this bit is low whenever the 500 kbps or 1 mbps data rates are selected, and high when 250 kbps and 300 kbps are selected. bits 1 - 2 data rate select these bits control the data rate of the floppy controller. see table 8 for the settings corresponding to the individual data rates. the data rate select bits are unaffected by a software reset, and are set to 250 kbps after a hardware reset. bits 3 - 6 undefined always read as a logic "1" bit 7 dskchg this bit monitors the pin of the same name and reflects the opposite value seen on the disk cable or the value programmed in the force disk change register (see runtime register at offset 0x1e). model 30 mode 7 6 5 4 3 2 1 0 dsk chg 0 0 0 dmaen noprec drate sel1 drate sel0 reset cond. n/a 0 0 0 0 0 1 0 34 bits 0 - 1 data rate select these bits control the data rate of the floppy controller. see table 8 for the settings corresponding to the individual data rates. the data rate select bits are unaffected by a software reset, and are set to 250 kbps after a hardware reset. bit 2 noprec this bit reflects the value of noprec bit set in the ccr register. bit 3 dmaen this bit reflects the value of dmaen bit set in the dor register bit 3. bits 4 - 6 undefined always read as a logic "0" bit 7 dskchg this bit monitors the pin of the same name and reflects the opposite value seen on the disk cable or the value programmed in the force disk change register (see runtime register at offset 0x1e). configuration control register (ccr) address 3f7 write only pc/at and ps/2 modes 7 6 5 4 3 2 1 0 0 0 0 0 0 0 drate sel1 drate sel0 reset cond. n/a n/a n/a n/a n/a n/a 1 0 bit 0 and 1 data rate select 0 and 1 these bits determine the data rate of the floppy controller. see table 8 for the appropriate values. bit 2 - 7 reserved should be set to a logical "0". ps/2 model 30 mode 7 6 5 4 3 2 1 0 0 0 0 0 0 noprec drate sel1 drate sel0 reset cond. n/a n/a n/a n/a n/a n/a 1 0 bit 0 and 1 data rate select 0 and 1 these bits determine the data rate of the floppy controller. see table 8 for the appropriate values. 35 bit 2 no precompensation this bit can be set by software, but it has no functionality. it can be read by bit 2 of the dsr when in model 30 register mode. unaffected by software reset. bit 3 - 7 reserved should be set to a logical "0" table 9 shows the state of the densel pin. the densel pin is set high after a hardware reset and is unaffected by the dor and the dsr resets. status register encoding during the result phase of certain commands, the data register contains data bytes that give the status of the command just executed. table 12 - status register 0 bit no. symbol name description 7,6 ic interrupt code 00 - normal termination of command. the specified command was properly executed and completed without error. 01 - abnormal termination of command. command execution was started, but was not successfully completed. 10 - invalid command. the requested command could not be executed. 11 - abnormal termination caused by polling. 5 se seek end the fdc completed a seek, relative seek or recalibrate command (used during a sense interrupt command). 4 ec equipment check the trk0 pin failed to become a "1" after: 1. 8 0 step pulses in the recalibrate command. 2. the relative seek command caused the fdc to step outward beyond track 0. 3 unused. this bit is always "0". 2 h head address the current head address. 1,0 ds1,0 drive select the current selected drive. 36 table 13 - status register 1 bit no. symbol name description 7 en end of cylinder the fdc tried to access a sector beyond the final sector of the track (255d). will be set if tc is not issued after read or write data command. 6 unused. this bit is always "0". 5 de data error the fdc detected a crc error in either the id field or the data field of a sector. 4 or overrun/ underrun becomes set if the fdc does not receive cpu or dma service within the required time interval, resulting in data overrun or underrun. 3 unused. this bit is always "0". 2 nd no data any one of the following: 1. read data, read deleted data command - the fdc did not find the specified sector. 2. read id command - the fdc cannot read the id field without an error. 3. read a track command - the fdc cannot find the proper sector sequence. 1 nw not writeable wp pin became a "1" while the fdc is executing a write data, write deleted data, or format a track command. 0 ma missing address mark any one of the following: 1. the fdc did not detect an id address mark at the specified track after encountering the index pulse from the nindex pin twice. 2. the fdc cannot detect a data address mark or a deleted data address mark on the specified track. 37 table 14 - status register 2 bit no. symbol name description 7 unused. this bit is always "0". 6 cm control mark any one of the following: read data command - the fdc encountered a deleted data address mark. read deleted data command - the fdc encountered a data address mark. 5 dd data error in data field the fdc detected a crc error in the data field. 4 wc wrong cylinder the track address from the sector id field is different from the track address maintained inside the fdc. 3 unused. this bit is always "0". 2 unused. this bit is always "0". 1 bc bad cylinder the track address from the sector id field is different from the track address maintained inside the fdc and is equal to ff hex, which indicates a bad track with a hard error according to the ibm soft-sectored format. 0 md missing data address mark the fdc cannot detect a data address mark or a deleted data address mark. table 15- status register 3 bit no. symbol name description 7 unused. this bit is always "0". 6 wp write protected indicates the status of the wrtprt pin. 5 unused. this bit is always "1". 4 t0 track 0 indicates the status of the trk0 pin. 3 unused. this bit is always "1". 2 hd head address indicates the status of the hdsel pin. 1,0 ds1,0 drive select indicates the status of the ds1, ds0 pins. reset there are three sources of system reset on the fdc: the npci_reset pin, a reset generated via a bit in the dor, and a reset generated via a bit in the dsr. at power on, a power on reset initializes the fdc. all resets take the fdc out of the power down state. all operations are terminated upon a npci_reset, and the fdc enters an idle state. a reset while a disk write is in progress will corrupt the data and crc. on exiting the reset state, various internal registers are cleared, including the configure command information, and the fdc waits for a new command. drive polling will start unless disabled by a new configure command. 38 npci_reset pin (hardware reset) the npci_reset pin is a global reset and clears all registers except those programmed by the specify command. the dor reset bit is enabled and must be cleared by the host to exit the reset state. dor reset vs. dsr reset (software reset) these two resets are functionally the same. both will reset the fdc core, which affects drive status information and the fifo circuits. the dsr reset clears itself automatically while the dor reset requires the host to manually clear it. dor reset has precedence over the dsr reset. the dor reset is set automatically upon a pin reset. the user must manually clear this reset bit in the dor to exit the reset state. modes of operation the fdc has three modes of operation, pc/at mode, ps/2 mode and model 30 mode. these are determined by the state of the interface mode bits in ld0-crf0[3,2]. pc/at mode the pc/at register set is enabled, the dma enable bit of the dor becomes valid (controls the interrupt and dma functions), and densel is an active high signal. ps/2 mode this mode supports the ps/2 models 50/60/80 configuration and register set. the dma bit of the dor becomes a "don't care". the dma and interrupt functions are always enabled, and densel is active low. model 30 mode this mode supports ps/2 model 30 configuration and register set. the dma enable bit of the dor becomes valid (controls the interrupt and dma functions), and densel is active low. dma transfers dma transfers are enabled with the specify command and are initiated by the fdc by activating a dma request cycle. dma read, write and verify cycles are supported. the fdc supports two dma transfer modes: single transfer and burst transfer. burst mode is enabled via logical device 0-crf0-bit[1] (ld0- crf0[1]). controller phases for simplicity, command handling in the fdc can be divided into three phases: command, execution, and result. each phase is described in the following sections. command phase after a reset, the fdc enters the command phase and is ready to accept a command from the host. for each of the commands, a defined set of command code bytes and parameter bytes has to be written to the fdc before the command phase is complete. (please refer to table 16 for the command set descriptions). these bytes of data must be transferred in the order prescribed. before writing to the fdc, the host must examine the rqm and dio bits of the main status register. rqm and dio must be equal to "1" and "0" respectively before command bytes may be written. rqm is set false by the fdc after each write cycle until the received byte is processed. the fdc asserts rqm again to request each parameter byte of the command unless an illegal command condition is detected. after the last parameter byte is received, rqm remains "0" and the fdc automatically enters the next phase as defined by the command definition. 39 the fifo is disabled during the command phase to provide for the proper handling of the "invalid command" condition. execution phase all data transfers to or from the fdc occur during the execution phase, which can proceed in dma or non- dma mode as indicated in the specify command. after a reset, the fifo is disabled. each data byte is transferred by a read/write or dma cycle depending on the dma mode. the configure command can enable the fifo and set the fifo threshold value. the following paragraphs detail the operation of the fifo flow control. in these descriptions, 40 dma mode - transfers from the host to the fifo. the fdc generates a dma request cycle when entering the execution phase of the data transfer commands. the dma controller responds by placing data in the fifo. the dma request remains active until the fifo becomes full. the dma request cycle is reasserted when the fifo has 41 table 16 - description of command symbols symbol name description c cylinder address the currently selected address; 0 to 255. d data pattern the pattern to be written in each sector data field during formatting. d0, d1 drive select 0-1 designates which drives are perpendicular drives on the perpendicular mode command. a "1" indicates a perpendicular drive. dir direction control if this bit is 0, then the head will step out from the spindle during a relative seek. if set to a 1, the head will step in toward the spindle. ds0, ds1 disk drive select ds1 ds0 drive 0 0 drive 0 0 1 drive 1 dtl special sector size by setting n to zero (00), dtl may be used to control the number of bytes transferred in disk read/write commands. the sector size (n = 0) is set to 128. if the actual sector (on the diskette) is larger than dtl, the remainder of the actual sector is read but is not passed to the host during read commands; during write commands, the remainder of the actual sector is written with all zero bytes. the crc check code is calculated with the actual sector. when n is not zero, dtl has no meaning and should be set to ff hex. ec enable count when this bit is "1" the "dtl" parameter of the verify command becomes sc (number of sectors per track). efifo enable fifo this active low bit when a 0, enables the fifo. a "1" disables the fifo (default). eis enable implied seek when set, a seek operation will be performed before executing any read or write command that requires the c parameter in the command phase. a "0" disables the implied seek. eot end of track the final sector number of the current track. gap alters gap 2 length when using perpendicular mode. gpl gap length the gap 3 size. (gap 3 is the space between sectors excluding the vco synchronization field). h/hds head address selected head: 0 or 1 (disk side 0 or 1) as encoded in the sector id field. hlt head load time the time interval that fdc waits after loading the head and before initializing a read or write operation. refer to the specify command for actual delays. hut head unload time the time interval from the end of the execution phase (of a read or write command) until the head is unloaded. refer to the specify command for actual delays. lock lock defines whether efifo, fifothr, and pretrk parameters of the configure command can be reset to their default values by a "software reset". (a reset caused by writing to the appropriate bits of either the dsr or dor) mfm mfm/fm mode selector a one selects the double density (mfm) mode. a zero selects single density (fm) mode. 42 table 16 - description of command symbols symbol name description mt multi-track selector when set, this flag selects the multi-track operating mode. in this mode, the fdc treats a complete cylinder under head 0 and 1 as a single track. the fdc operates as this expanded track started at the first sector under head 0 and ended at the last sector under head 1. with this flag set, a multitrack read or write operation will automatically continue to the first sector under head 1 when the fdc finishes operating on the last sector under head 0. n sector size code this specifies the number of bytes in a sector. if this parameter is "00", then the sector size is 128 bytes. the number of bytes transferred is determined by the dtl parameter. otherwise the sector size is (2 raised to the "n'th" power) times 128. all values up to "07" hex are allowable. "07"h would equal a sector size of 16k. it is the user's responsibility to not select combinations that are not possible with the drive. n sector size 00 128 bytes 01 256 bytes 02 512 bytes 03 1024 bytes ? ? 07 16k bytes ncn new cylinder number the desired cylinder number. nd non-dma mode flag when set to 1, indicates that the fdc is to operate in the non-dma mode. in this mode, the host is interrupted for each data transfer. when set to 0, the fdc operates in dma mode. ow overwrite the bits d0-d3 of the perpendicular mode command can only be modified if ow is set to 1. ow id defined in the lock command. pcn present cylinder number the current position of the head at the completion of sense interrupt status command. poll polling disable when set, the internal polling routine is disabled. when clear, polling is enabled. pretrk precompensation start track number programmable from track 00 to ffh. r sector address the sector number to be read or written. in multi-sector transfers, this parameter specifies the sector number of the first sector to be read or written. rcn relative cylinder number relative cylinder offset from present cylinder as used by the relative seek command. sc number of sectors per track the number of sectors per track to be initialized by the format command. the number of sectors per track to be verified during a verify command when ec is set. 43 table 16 - description of command symbols symbol name description sk skip flag when set to 1, sectors containing a deleted data address mark will automatically be skipped during the execution of read data. if read deleted is executed, only sectors with a deleted address mark will be accessed. when set to "0", the sector is read or written the same as the read and write commands. srt step rate interval the time interval between step pulses issued by the fdc. programmable from 0.5 to 8 milliseconds in increments of 0.5 ms at the 1 mbit data rate. refer to the specify command for actual delays. st0 st1 st2 st3 status 0 status 1 status 2 status 3 registers within the fdc which store status information after a command has been executed. this status information is available to the host during the result phase after command execution. wgate write gate alters timing of we to allow for pre-erase loads in perpendicular drives. 44 instruction set table 17 - instruction set read data data bus phase r/w d7 d6 d5 d4 d3 d2 d1 d0 remarks command w mt mfm sk 0 0 1 1 0 command codes w 0 0 0 0 0 hds ds1 ds0 w c sector id information prior to command execution. w h w r w n w eot w gpl w dtl execution data transfer between the fdd and system. result r st0 status information after com- mand execution. r st1 r st2 r c sector id information after com mand execution. r h r r r n 45 read deleted data data bus phase r/w d7 d6 d5 d4 d3 d2 d1 d0 remarks command w mt mfm sk 0 1 1 0 0 command codes w 0 0 0 0 0 hds ds1 ds0 w c sector id information prior to command execution. w h w r w n w eot w gpl w dtl execution data transfer between the fdd and system. result r st0 status information after com- mand execution. r st1 r st2 r c sector id information after com mand execution. r h r r r n 46 write data data bus phase r/w d7 d6 d5 d4 d3 d2 d1 d0 remarks command w mt mfm 0 0 0 1 0 1 command codes w 0 0 0 0 0 hds ds1 ds0 w c sector id information prior to command execution. w h w r w n w eot w gpl w dtl execution data transfer between the fdd and system. result r st0 status information after com- mand execution. r st1 r st2 r c sector id information after command execution. r h r r r n 47 write deleted data data bus phase r/w d7 d6 d5 d4 d3 d2 d1 d0 remarks command w mt mfm 0 0 1 0 0 1 command codes w 0 0 0 0 0 hds ds1 ds0 w c sector id information prior to command execution. w h w r w n w eot w gpl w dtl execution data transfer between the fdd and system. result r st0 status information after com mand execution. r st1 r st2 r c sector id information after command execution. r h r r r n 48 read a track data bus phase r/w d7 d6 d5 d4 d3 d2 d1 d0 remarks command w 0 mfm 0 0 0 0 1 0 command codes w 0 0 0 0 0 hds ds1 ds0 w c sector id information prior to command execution. w h w r w n w eot w gpl w dtl execution data transfer between the fdd and system. fdc reads all of cylinders' contents from index hole to eot. result r st0 status information after com mand execution. r st1 r st2 r c sector id information after command execution. r h r r r n 49 verify data bus phase r/w d7 d6 d5 d4 d3 d2 d1 d0 remarks command w mt mfm sk 1 0 1 1 0 command codes w ec 0 0 0 0 hds ds1 ds0 w c sector id information prior to command execution. w h w r w n w eot w gpl w dtl/sc execution no data transfer takes place. result r st0 status information after com mand ex ecution. r st1 r st2 r c sector id information after command execution. r h r r r n version data bus phase r/w d7 d6 d5 d4 d3 d2 d1 d0 remarks command w 0 0 0 1 0 0 0 0 command code result r 1 0 0 1 0 0 0 0 enhanced controller 50 format a track data bus phase r/w d7 d6 d5 d4 d3 d2 d1 d0 remarks command w 0 mfm 0 0 1 1 0 1 command codes w 0 0 0 0 0 hds ds1 ds0 w n bytes/sector w sc sectors/cylinder w gpl gap 3 w d filler byte execution for each sector repeat: w c input sector parameters w h w r w n fdc formats an entire cylinder result r st0 status information after command execution r st1 r st2 r undefined r undefined r undefined r undefined 51 recalibrate data bus phase r/w d7 d6 d5 d4 d3 d2 d1 d0 remarks command w 0 0 0 0 0 1 1 1 command codes w 0 0 0 0 0 0 ds1 ds0 execution head retracted to track 0 interrupt. sense interrupt status data bus phase r/w d7 d6 d5 d4 d3 d2 d1 d0 remarks command w 0 0 0 0 1 0 0 0 command codes result r st0 status information at the end of each seek operation. r pcn specify data bus phase r/w d7 d6 d5 d4 d3 d2 d1 d0 remarks command w 0 0 0 0 0 0 1 1 command codes w srt hut w hlt nd 52 sense drive status data bus phase r/w d7 d6 d5 d4 d3 d2 d1 d0 remarks command w 0 0 0 0 0 1 0 0 command codes w 0 0 0 0 0 hds ds1 ds0 result r st3 status information about fdd seek data bus phase r/w d7 d6 d5 d4 d3 d2 d1 d0 remarks command w 0 0 0 0 1 1 1 1 command codes w 0 0 0 0 0 hds ds1 ds0 w ncn execution head positioned over proper cylinder on diskette. configure data bus phase r/w d7 d6 d5 d4 d3 d2 d1 d0 remarks command w 0 0 0 1 0 0 1 1 configure information w 0 0 0 0 0 0 0 0 w 0 eis efifo poll fifothr execution w pretrk 53 relative seek data bus phase r/w d7 d6 d5 d4 d3 d2 d1 d0 remarks command w 1 dir 0 0 1 1 1 1 w 0 0 0 0 0 hds ds1 ds0 w rcn dumpreg data bus phase r/w d7 d6 d5 d4 d3 d2 d1 d0 remarks command w 0 0 0 0 1 1 1 0 *note: registers placed in fifo execution result r pcn-drive 0 r pcn-drive 1 r pcn-drive 2 r pcn-drive 3 r srt hut r hlt nd r sc/eot r lock 0 d3 d2 d1 d0 gap wgate r 0 eis efifo poll fifothr r pretrk 54 read id data bus phase r/w d7 d6 d5 d4 d3 d2 d1 d0 remarks command w 0 mfm 0 0 1 0 1 0 commands w 0 0 0 0 0 hds ds1 ds0 execution the first correct id information on the cylinder is stored in data register result r r r r r r r st0 st1 st2 c h r n status information after command execution. 55 perpendicular mode data bus phase r/w d7 d6 d5 d4 d3 d2 d1 d0 remarks command w 0 0 0 1 0 0 1 0 command codes ow 0 d3 d2 d1 d0 gap wgate invalid codes data bus phase r/w d7 d6 d5 d4 d3 d2 d1 d0 remarks command w invalid codes invalid command codes (noop - fdc goes into stand- by state) result r st0 st0 = 80h lock data bus phase r/w d7 d6 d5 d4 d3 d2 d1 d0 remarks command w lock 0 0 1 0 1 0 0 command codes result r 0 0 0 lock 0 0 0 0 sc is returned if the last command that was issued was the format command. eot is returned if the last command was a read or write. note: these bits are used internally only. they are not reflected in the drive select pins. it is the user's responsibility to maintain correspondence between these bits and the drive select pins (dor). 56 data transfer commands all of the read data, write data and verify type commands use the same parameter bytes and return the same results information, the only difference being the coding of bits 0-4 in the first byte. an implied seek will be executed if the feature was enabled by the configure command. this seek is completely transparent to the user. the drive busy bit for the drive will go active in the main status register during the seek portion of the command. if the seek portion fails, it is reflected in the results status normally returned for a read/write data command. status register 0 (st0) would contain the error code and c would contain the cylinder on which the seek failed. read data a set of nine (9) bytes is required to place the fdc in the read data mode. after the read data command has been issued, the fdc loads the head (if it is in the unloaded state), waits the specified head settling time (defined in the specify command), and begins reading id address marks and id fields. when the sector address read off the diskette matches with the sector address specified in the command, the fdc reads the sector's data field and transfers the data to the fifo. after completion of the read operation from the current sector, the sector address is incremented by one and the data from the next logical sector is read and output via the fifo. this continuous read function is called "multi-sector read operation". upon receipt of the tc cycle, or an implied tc (fifo overrun/underrun), the fdc stops sending data but will continue to read data from the current sector, check the crc bytes, and at the end of the sector, terminate the read data command. n determines the number of bytes per sector (see table 18 below). if n is set to zero, the sector size is set to 128. the dtl value determines the number of bytes to be transferred. if dtl is less than 128, the fdc transfers the specified number of bytes to the host. for reads, it continues to read the entire 128- byte sector and checks for crc errors. for writes, it completes the 128-byte sector by filling in zeros. if n is not set to 00 hex, dtl should be set to ff hex and has no impact on the number of bytes transferred. table 18 - sector sizes n sector size 00 01 02 03 .. 07 128 bytes 256 bytes 512 bytes 1024 bytes ... 16 kbytes the amount of data which can be handled with a single command to the fdc depends upon mt (multi- track) and n (number of bytes/sector). the multi-track function (mt) allows the fdc to read data from both sides of the diskette. for a particular cylinder, data will be transferred starting at sector 1, side 0 and completing the last sector of the same track at side 1. 57 if the host terminates a read or write operation in the fdc, the id information in the result phase is dependent upon the state of the mt bit and eot byte. refer to table 19. at the completion of the read data command, the head is not unloaded until after the head unload time interval (specified in the specify command) has elapsed. if the host issues another command before the head unloads, then the head settling time may be saved between subsequent reads. if the fdc detects a pulse on the nindex pin twice without finding the specified sector (meaning that the diskette's index hole passes through index detect logic in the drive twice), the fdc sets the ic code in status register 0 to "01" indicating abnormal termination, sets the nd bit in status register 1 to "1" indicating a sector not found, and terminates the read data command. after reading the id and data fields in each sector, the fdc checks the crc bytes. if a crc error occurs in the id or data field, the fdc sets the ic code in status register 0 to "01" indicating abnormal termination, sets the de bit flag in status register 1 to "1", sets the dd bit in status register 2 to "1" if crc is incorrect in the id field, and terminates the read data command. table 21 describes the effect of the sk bit on the read data command execution and results. except where noted in table 20, the c or r value of the sector address is automatically incremented (see table 22). table 19 - effects of mt and n bits mt n maximum transfer capacity final sector read from disk 0 1 0 1 0 1 1 1 2 2 3 3 256 x 26 = 6,656 256 x 52 = 13,312 512 x 15 = 7,680 512 x 30 = 15,360 1024 x 8 = 8,192 1024 x 16 = 16,384 26 at side 0 or 1 26 at side 1 15 at side 0 or 1 15 at side 1 8 at side 0 or 1 16 at side 1 table 20 - skip bit vs rea d data command sk bit value data address mark type encountered results sector read? cm bit of st2 set? description of results 0 normal data yes no normal termination. 0 deleted data yes yes address not incremented. next sector not searched for. 1 normal data yes no normal termination. 1 deleted data no yes normal termination. sector not read ("skipped"). 58 read deleted data this command is the same as the read data command, only it operates on sectors that contain a deleted data address mark at the beginning of a data field. table 21 describes the effect of the sk bit on the read deleted data command execution and results. except where noted in table 21, the c or r value of the sector address is automatically incremented (see table 22). table 21 - skip bit vs. read deleted data command sk bit value data address mark type encountered results sector read? cm bit of st2 set? description of results 0 0 1 1 normal data deleted data normal data deleted data yes yes no yes yes no yes no address not incremented. next sector not searched for. normal termination. normal termination. sector not read ("skipped"). normal termination. read a track this command is similar to the read data command except that the entire data field is read continuously from each of the sectors of a track. immediately after encountering a pulse on the nindex pin, the fdc starts to read all data fields on the track as continuous blocks of data without regard to logical sector numbers. if the fdc finds an error in the id or data crc check bytes, it continues to read data from the track and sets the appropriate error bits at the end of the command. the fdc compares the id information read from each sector with the specified value in the command and sets the nd flag of status register 1 to a ?1? if there no comparison. multi-track or skip operations are not allowed with this command. the mt and sk bits (bits d7 and d5 of the first command byte respectively) should always be set to "0". this command terminates when the eot specified number of sectors has not been read. if the fdc does not find an id address mark on the diskette after the second occurrence of a pulse on the nindex pin, then it sets the ic code in status register 0 to "01" (abnormal termination), sets the ma bit in status register 1 to "1", and terminates the command. 59 table 22 - result phase mt head final sector transferred to id information at result phase host c h r n 0 0 less than eot nc nc r + 1 nc equal to eot c + 1 nc 01 nc 1 less than eot nc nc r + 1 nc equal to eot c + 1 nc 01 nc 1 0 less than eot nc nc r + 1 nc equal to eot nc lsb 01 nc 1 less than eot nc nc r + 1 nc equal to eot c + 1 lsb 01 nc nc: no change, the same value as the one at the beginning of command execution. lsb: least significant bit, the lsb of h is complemented. write data after the write data command has been issued, the fdc loads the head (if it is in the unloaded state), waits the specified head load time if unloaded (defined in the specify command), and begins reading id fields. when the sector address read from the diskette matches the sector address specified in the command, the fdc reads the data from the host via the fifo and writes it to the sector's data field. after writing data into the current sector, the fdc computes the crc value and writes it into the crc field at the end of the sector transfer. the sector number stored in "r" is incremented by one, and the fdc continues writing to the next data field. the fdc continues this "multi-sector write operation". upon receipt of a terminal count signal or if a fifo over/under run occurs while a data field is being written, then the remainder of the data field is filled with zeros. the fdc reads the id field of each sector and checks the crc bytes. if it detects a crc error in one of the id fields, it sets the ic code in status register 0 to "01" (abnormal termination), sets the de bit of status register 1 to "1", and terminates the write data command. the write data command operates in much the same manner as the read data command. the following items are the same. please refer to the read data command for details: transfer capacity en (end of cylinder) bit nd (no data) bit head load, unload time interval id information when the host terminates the command definition of dtl when n = 0 and when n does not = 0 write deleted data this command is almost the same as the write data command except that a deleted data address mark is written at the beginning of the data field instead of the normal data address mark. this command is typically used to mark a bad sector containing an error on the floppy disk. 60 verify the verify command is used to verify the data stored on a disk. this command acts exactly like a read data command except that no data is transferred to the host. data is read from the disk and crc is computed and checked against the previously-stored value. because data is not transferred to the host, the tc cycle cannot be used to terminate this command. by setting the ec bit to "1", an implicit tc will be issued to the fdc. this implicit tc will occur when the sc value has decremented to 0 (an sc value of 0 will verify 256 sectors). this command can also be terminated by setting the ec bit to "0" and the eot value equal to the final sector to be checked. if ec is set to "0", dtl/sc should be programmed to 0ffh. refer to table 22 and table 23 for information concerning the values of mt and ec versus sc and eot value. definitions: # sectors per side = number of formatted sectors per each side of the disk. # sectors remaining = number of formatted sectors left which can be read, including side 1 of the disk if mt is set to "1". 61 table 23 - verify command result phase mt ec sc/eot value termination result 0 0 sc = dtl eot # sectors per side success termination result phase valid 0 0 sc = dtl eot > # sectors per side unsuccessful termination result phase invalid 0 1 sc # sectors remaining and eot # sectors per side successful termination result phase valid 0 1 sc > # sectors remaining or eot > # sectors per side unsuccessful termination result phase invalid 1 0 sc = dtl eot # sectors per side successful termination result phase valid 1 0 sc = dtl eot > # sectors per side unsuccessful termination result phase invalid 1 1 sc # sectors remaining and eot # sectors per side successful termination result phase valid 1 1 sc > # sectors remaining or eot > # sectors per side unsuccessful termination result phase invalid note: if mt is set to "1" and the sc value is greater than the number of remaining formatted sectors on side 0, verifying will continue on side 1 of the disk. format a track the format command allows an entire track to be formatted. after a pulse from the nindex pin is detected, the fdc starts writing data on the disk including gaps, address marks, id fields, and data fields per the ibm system 34 or 3740 format (mfm or fm respectively). the particular values that will be written to the gap and data field are controlled by the values programmed into n, sc, gpl, and d which are specified by the host during the command phase. the data field of the sector is filled with the data byte specified by d. the id field for each sector is supplied by the host; that is, four data bytes per sector are needed by the fdc for c, h, r, and n (cylinder, head, sector number and sector size respectively). after formatting each sector, the host must send new values for c, h, r and n to the fdc for the next sector on the track. the r value (sector number) is the only value that must be changed by the host after each sector is formatted. this allows the disk to be formatted with nonsequential sector addresses (interleaving). this incrementing and formatting continues for the whole track until the fdc encounters a pulse on the nindex pin again and it terminates the command. table 24 contains typical values for gap fields which are dependent upon the size of the sector and the number of sectors on each track. actual values can vary due to drive electronics. 62 format fields system 34 (double density) format gap4a 80x 4e sync 12x 00 iam gap1 50x 4e sync 12x 00 idam c y l h d s e c n o c r c gap2 22x 4e sync 12x 00 data am data c r c gap3 gap 4b 3x c2 fc 3x a1 fe 3x a1 fb f8 system 3740 (single density) format gap4a 40x ff sync 6x 00 iam gap1 26x ff sync 6x 00 idam c y l h d s e c n o c r c gap2 11x ff sync 6x 00 data am data c r c gap3 gap 4b fc fe fb or f8 perpendicular format gap4a 80x 4e sync 12x 00 iam gap1 50x 4e sync 12x 00 idam c y l h d s e c n o c r c gap2 41x 4e sync 12x 00 data am data c r c gap3 gap 4b 3x c2 fc 3x a1 fe 3x a1 fb f8 63 table 24 - typical values for formatting format sector size n sc gpl1 gpl2 5.25" drives fm 128 128 512 1024 2048 4096 ... 00 00 02 03 04 05 ... 12 10 08 04 02 01 07 10 18 46 c8 c8 09 19 30 87 ff ff mfm 256 256 512* 1024 2048 4096 ... 01 01 02 03 04 05 ... 12 10 09 04 02 01 0a 20 2a 80 c8 c8 0c 32 50 f0 ff ff 3.5" drives fm 128 256 512 0 1 2 0f 09 05 07 0f 1b 1b 2a 3a mfm 256 512** 1024 1 2 3 0f 09 05 0e 1b 35 36 54 74 gpl1 = suggested gpl values in read and write commands to avoid splice point between data field and id field of contiguous sections. gpl2 = suggested gpl value in format a track command. *pc/at values (typical) **ps/2 values (typical). applies with 1.0 mb and 2.0 mb drives. note: all values except sector size are in hex. 64 control commands control commands differ from the other commands in that no data transfer takes place. three commands generate an interrupt when complete: read id, recalibrate, and seek. the other control commands do not generate an interrupt. read id the read id command is used to find the present position of the recording heads. the fdc stores the values from the first id field it is able to read into its registers. if the fdc does not find an id address mark on the diskette after the second occurrence of a pulse on the nindex pin, it then sets the ic code in status register 0 to "01" (abnormal termination), sets the ma bit in status register 1 to "1", and terminates the command. the following commands will generate an interrupt upon completion. they do not return any result bytes. it is highly recommended that control commands be followed by the sense interrupt status command. otherwise, valuable interrupt status information will be lost. recalibrate this command causes the read/write head within the fdc to retract to the track 0 position. the fdc clears the contents of the pcn counter and checks the status of the ntrk0 pin from the fdd. as long as the ntrk0 pin is low, the dir pin remains 0 and step pulses are issued. when the ntrk0 pin goes high, the se bit in status register 0 is set to "1" and the command is terminated. if the ntrk0 pin is still low after 79 step pulses have been issued, the fdc sets the se and the ec bits of status register 0 to "1" and terminates the command. disks capable of handling more than 80 tracks per side may require more than one recalibrate command to return the head back to physical track 0. the recalibrate command does not have a result phase. the sense interrupt status command must be issued after the recalibrate command to effectively terminate it and to provide verification of the head position (pcn). during the command phase of the recalibrate operation, the fdc is in the busy state, but during the execution phase it is in a non-busy state. at this time, another recalibrate command may be issued, and in this manner parallel recalibrate operations may be done on up to four drives at once. upon power up, the software must issue a recalibrate command to properly initialize all drives and the controller. seek the read/write head within the drive is moved from track to track under the control of the seek command. the fdc compares the pcn, which is the current head position, with the ncn and performs the following operation if there is a difference: pcn < ncn: direction signal to drive set to "1" (step in) and issues step pulses. pcn > ncn: direction signal to drive set to "0" (step out) and issues ste p pulses. 65 the rate at which step pulses are issued is controlled by srt (stepping rate time) in the specify command. after each step pulse is issued, ncn is compared against pcn, and when ncn = pcn the se bit in status register 0 is set to "1" and the command is terminated. during the command phase of the seek or recalibrate operation, the fdc is in the busy state, but during the execution phase it is in the non-busy state. at this time, another seek or recalibrate command may be issued, and in this manner, parallel seek operations may be done on up to four drives at once. note that if implied seek is not enabled, the read and write commands should be preceded by: 1) seek command - step to the proper track 2) sense interrupt status command - terminate t he seek command 3) read id - verify head is on proper track 4) issue read/write command. the seek command does not have a result phase. therefore, it is highly recommended that the sense interrupt status command is issued after the seek command to terminate it and to provide verification of the head position (pcn). the h bit (head address) in st0 will always return to a "0". when exiting powerdown mode, the fdc clears the pcn value and the status information to zero. prior to issuing the powerdown command, it is highly recommended that the user service all pending interrupts through the sense interrupt status command. sense interrupt status an interrupt signal is generated by the fdc for one of the following reasons: 1. upon entering the result phase of: a. read data command b. read a track command c. read id command d. read deleted data command e. write data command f. format a track command g. write deleted data command h. verify command 2. end of seek, relative seek, or recalibrate command 3. fdc requires a data transfer during the execution phase in the non-dma mode the sense interrupt status command resets the interrupt signal and, via the ic code and se bit of status register 0, identifies the cause of the interrupt. table 25 - interrupt identification se ic interrupt due to 0 1 1 11 00 01 polling normal termination of seek or recalibrate command abnormal termination of seek or recalibrate command 66 the seek, relative seek, and recalibrate commands have no result phase. the sense interrupt status command must be issued immediately after these commands to terminate them and to provide verification of the head position (pcn). the h (head address) bit in st0 will always return a "0". if a sense interrupt status is not issued, the drive will continue to be busy and may affect the operation of the next command. sense drive status sense drive status obtains drive status information. it has not execution phase and goes directly to the result phase from the command phase. status register 3 contains the drive status information. specify the specify command sets the initial values for each of the three internal times. the hut (head unload time) defines the time from the end of the execution phase of one of the read/write commands to the head unload state. the srt (step rate time) defines the time interval between adjacent step pulses. note that the spacing between the first and second step pulses may be shorter than the remaining step pulses. the hlt (head load time) defines the time between when the head load signal goes high and the read/write operation starts. the values change with the data rate speed selection and are documented in table 26. the values are the same for mfm and fm. the choice of dma or non-dma operations is made by the nd bit. when this bit is "1", the non-dma mode is selected, and when nd is "0", the dma mode is selected. in dma mode, data transfers are signaled by the dma request cycles. non-dma mode uses the rqm bit and the interrupt to signal data transfers. configure the configure command is issued to select the special features of the fdc. a configure command need not be issued if the default values of the fdc meet the system requirements. table 26 - drive control delays (ms) hut srt 2m 1m 500k 300k 250k 2m 1m 500k 300k 250k 0 1 .. e f 64 4 .. 56 60 128 8 .. 112 120 256 16 .. 224 240 426 26.7 .. 373 400 512 32 .. 448 480 4 3.75 .. 0.5 0.25 8 7.5 .. 1 0.5 16 15 .. 2 1 26.7 25 .. 3.33 1.67 32 30 .. 4 2 hlt 2m 1m 500k 300k 250k 00 01 02 .. 7f 7f 64 0.5 1 .. 63 63.5 128 1 2 .. 126 127 256 2 4 .. 252 254 426 3.3 6.7 .. 420 423 512 4 8 . 504 508 67 configure default values: eis - no implied seeks efifo - fifo disabled poll - polling enabled fifothr - fifo threshold set to 1 byte pretrk - pre-compensation set to track 0 eis - enable implied seek. when set to "1", the fdc will perform a seek operation before executing a read or write command. defaults to no implied seek. efifo - a "1" disables the fifo (default). this means data transfers are asked for on a byte-by-byte basis. defaults to "1", fifo disabled. the threshold defaults to "1". poll - disable polling of the drives. defaults to "0", polling enabled. when enabled, a single interrupt is generated after a reset. no polling is performed while the drive head is loaded and the head unload delay has not expired. fifothr - the fifo threshold in the execution phase of read or write commands. this is programmable from 1 to 16 bytes. defaults to one byte. a "00" selects one byte; "0f" selects 16 bytes. pretrk - pre-compensation start track number. programmable from track 0 to 255. defaults to track 0. a "00" selects track 0; "ff" selects track 255. version the version command checks to see if the controller is an enhanced type or the older type (765a). a value of 90 h is returned as the result byte. relative seek the command is coded the same as for seek, except for the msb of the first byte and the dir bit. dir head step direction control rcn relative cylinder number that determines how many tracks to step the head in or out from the current track number. 68 dir action 0 1 step head out step head in the relative seek command differs from the seek command in that it steps the head the absolute number of tracks specified in the command instead of making a comparison against an internal register. the seek command is good for drives that support a maximum of 256 tracks. relative seeks cannot be overlapped with other relative seeks. only one relative seek can be active at a time. relative seeks may be overlapped with seeks and recalibrates. bit 4 of status register 0 (ec) will be set if relative seek attempts to step outward beyond track 0. as an example, assume that a floppy drive has 300 useable tracks. the host needs to read track 300 and the head is on any track (0-255). if a seek command is issued, the head will stop at track 255. if a relative seek command is issued, the fdc will move the head the specified number of tracks, regardless of the internal cylinder position register (but will increment the register). if the head was on track 40 (d), the maximum track that the fdc could position the head on using relative seek will be 295 (d), the initial track + 255 (d). the maximum count that the head can be moved with a single relative seek command is 255 (d). the internal register, pcn, will overflow as the cylinder number crosses track 255 and will contain 39 (d). the resulting pcn value is thus (rcn + pcn) mod 256. functionally, the fdc starts counting from 0 again as the track number goes above 255 (d). it is the user's responsibility to compensate fdc functions (precompensation track number) when accessing tracks greater than 255. the fdc does not keep track that it is working in an "extended track area" (greater than 255). any command issued will use the current pcn value except for the recalibrate command, which only looks for the track0 signal. recalibrate will return an error if the head is farther than 79 due to its limitation of issuing a maximum of 80 step pulses. the user simply needs to issue a second recalibrate command. the seek command and implied seeks will function correctly within the 44 (d) track (299-255) area of the "extended track area". it is the user's responsibility not to issue a new track position that will exceed the maximum track that is present in the extended area. to return to the standard floppy range (0-255) of tracks, a relative seek should be issued to cross the track 255 boundary. a relative seek can be used instead of the normal seek, but the host is required to calculate the difference between the current head location and the new (target) head location. this may require the host to issue a read id command to ensure that the head is physically on the track that software assumes it to be. different fdc commands will return different cylinder results which may be difficult to keep track of with software without the read id command. perpendicular mode the perpendicular mode command should be issued prior to executing read/write/format commands that access a disk drive with perpendicular recording capability. with this command, the length of the gap2 field and vco enable timing can be altered to accommodate the unique requirements of these drives. table 27 describes the effects of the wgate and gap bits for the perpendicular mode command. upon a reset, the fdc will default to the conventional mode (wgate = 0, gap = 0). 69 selection of the 500 kbps and 1 mbps perpendicular modes is independent of the actual data rate selected in the data rate select register. the user must ensure that these two data rates remain consistent. the gap2 and vco timing requirements for perpendicular recording type drives are dictated by the design of the read/write head. in the design of this head, a pre-erase head precedes the normal read/write head by a distance of 200 micrometers. this works out to about 38 bytes at a 1 mbps recording density. whenever the write head is enabled by the write gate signal, the pre-erase head is also activated at the same time. thus, when the write head is initially turned on, flux transitions recorded on the media for the first 38 bytes will not be preconditioned with the pre-erase head since it has not yet been activated. to accommodate this head activation and deactivation time, the gap2 field is expanded to a length of 41 bytes. the format field shown on page 58 illustrates the change in the gap2 field size for the perpendicular format. on the read back by the fdc, the controller must begin synchronization at the beginning of the sync field. for the conventional mode, the internal pll vco is enabled (vcoen) approximately 24 bytes from the start of the gap2 field. but, when the controller operates in the 1 mbps perpendicular mode (wgate = 1, gap = 1), vcoen goes active after 43 bytes to accommodate the increased gap2 field size. for both cases, and approximate two-byte cushion is maintained from the beginning of the sync field for the purposes of avoiding write splices in the presence of motor speed variation. for the write data case, the fdc activates write gate at the beginning of the sync field under the conventional mode. the controller then writes a new sync field, data address mark, data field, and crc. with the pre-erase head of the perpendicular drive, the write head must be activated in the gap2 field to insure a proper write of the new sync field. for the 1 mbps perpendicular mode (wgate = 1, gap = 1), 38 bytes will be written in the gap2 space. since the bit density is proportional to the data rate, 19 bytes will be written in the gap2 field for the 500 kbps perpendicular mode (wgate = 1, gap =0). it should be noted that none of the alterations in gap2 size, vco timing, or write gate timing affect normal program flow. the information provided here is just for background purposes and is not needed for normal operation. once the perpendicular mode command is invoked, fdc software behavior from the user standpoint is unchanged. the perpendicular mode command is enhanced to allow specific drives to be designated perpendicular recording drives. this enhancement allows data transfers between conventional and perpendicular drives without having to issue perpendicular mode commands between the accesses of the different drive types, nor having to change write pre-compensation values. when both gap and wgate bits of the perpendicular mode command are both programmed to "0" (conventional mode), then d0, d1, d2, d3, and d4 can be programmed independently to "1" for that drive to be set automatically to perpendicular mode. in this mode the following set of conditions also apply: 1. the gap2 written to a perpendicular drive during a write operation will depend upon the programmed data rate. 2. the write pr e-compensation given to a perpendicular mode drive will be 0ns. 3. for d0-d3 programmed to "0" for conventional mode drives any data written will be at the currently programmed write pre-compensation. note: bits d0-d3 can only be overwritten when ow is pr ogrammed as a "1".if either gap or wgate is a "1" then d0-d3 are ignored. 70 software and hardware resets have the following effect on the perpendicular mode command: 1. "software" resets (via the dor or dsr registers) will only clear gap and wgate bits to " 0". d0-d3 are unaffected and retain their previous value. 2. "hardware" resets will clear all bits (gap, wgate and d0-d3) to "0", i.e all conventional mode. table 27 - effects of wgate and gap bits wgate gap mode length of gap2 format field portion of gap 2 written by write data operation 0 0 1 1 0 1 0 1 conventional perpendicular (500 kbps) reserved (conventional) perpendicular (1 mbps) 22 bytes 22 bytes 22 bytes 41 bytes 0 bytes 19 bytes 0 bytes 38 bytes lock in order to protect systems with long dma latencies against older application software that can disable the fifo the lock command has been added. this command should only be used by the fdc routines, and application software should refrain from using it. if an application calls for the fifo to be disabled then the configure command should be used. the lock command defines whether the efifo, fifothr, and pretrk parameters of the configure command can be reset by the dor and dsr registers. when the lock bit is set to logic "1" all subsequent "software resets by the dor and dsr registers will not change the previously set parameters to their default values. all "hardware" reset from the npci_reset pin will set the lock bit to logic "0" and return the efifo, fifothr, and pretrk to their default values. a status byte is returned immediately after issuing a lock command. this byte reflects the value of the lock bit set by the command byte. enhanced dumpreg the dumpreg command is designed to support system run-time diagnostics and application software development and debug. to accommodate the lock command and the enhanced perpendicular mode command the eighth byte of the dumpreg command has been modified to contain the additional data from these two commands. 71 compatibility the LPC47S42X was designed with software compatibility in mind. it is a fully backwards- compatible solution with the older generation 765a/b disk controllers. the fdc also implements on-board registers for compatibility with the ps/2, as well as pc/at and pc/xt, floppy disk controller subsystems. after a hardware reset of the fdc, all registers, functions and enhancements default to a pc/at, ps/2 or ps/2 model 30 compatible operating mode, depending on how the ident and mfm bits are configured by the system bios. direct support for two floppy drives the nmtr1 function is on pin 43. nmtr1 is the second alternate function on the gp22 pin. pin 43 has the io12 buffer type. the nmtr1 function is selectable as open drain or push pull as nmtr0 is through bit 6 of the fdd mode register in crf0 of ld 0. this overrides the selection of the output type through bit 7 of the gpio control register. it is also controlled by bit 7 of the fdd mode register. the nds1 function is on pin 41. nds1 is the second alternate function on the gp20 pin. pin 41 has io12 buffer type. the nds1 function is selectable as open drain or push pull as nds0 is through bit 6 of the fdd mode register in crf0 of ld 0. this overrides the selection of the output type through bit 7 of the gpio control register. it is also controlled by bit 7 of the fdd mode register. see the runtime registers section for register information. disk change support for second floppy bit[1] in the force disk change register supports the second floppy. setting either of the force disk change bits active forces the internal fdd ndskchg active when the appropriate drive has been selected. the force disk change register is defined in the runtime registers section. force write protect support for second floppy bit[0] in the device disable register and fdd option register support floppy write protect. see the runtime registers section for device disable register description and the configuration registers section for fdd option register description. 72 serial port (uart) the LPC47S42X incorporates two full function uarts. they are compatible with the ns16450, the 16450 ace registers and the ns16c550a. the uarts perform serial-to-parallel conversion on received characters and parallel-to-serial conversion on transmit characters. the data rates are independently programmable from 460.8k baud down to 50 baud. the character options are programmable for 1 start; 1, 1.5 or 2 stop bits; even, odd, sticky or no parity; and prioritized interrupts. the uarts each contain a programmable baud rate generator that is capable of dividing the input clock or crystal by a number from 1 to 65535. the uarts are also capable of supporting the midi data rate. refer to the configuration registers for information on disabling, power down and changing the base address of the uarts. the interrupt from a uart is enabled by programming out2 of that uart to a logic "1". out2 being a logic "0" disables that uart's interrupt. the second uart also supports irda 1.0, hp-sir, ask-ir infrared modes of operation. note: the uarts 1 and 2 may be configured to share an interrupt. refer to the configuration section for more information. register description addressing of the accessible registers of the serial port is shown below. the base addresses of the serial ports are defined by the configuration registers (see configuration section). the serial port registers are located at sequentially increasing addresses above these base addresses. the LPC47S42X contains two serial ports, each of which contain a register set as described below. table 28 - addressing the serial port dlab* a2 a1 a0 register name 0 0 0 0 receive buffer (read) 0 0 0 0 transmit buffer (write) 0 0 0 1 interrupt enable (read/write) x 0 1 0 interrupt identification (read) x 0 1 0 fifo control (write) x 0 1 1 line control (read/write) x 1 0 0 modem control (read/write) x 1 0 1 line status (read/write) x 1 1 0 modem status (read/write) x 1 1 1 scratchpad (read/write) 1 0 0 0 divisor lsb (read/write) 1 0 0 1 divisor msb (read/write *note: dlab is bit 7 of the line control register the following section describes the operation of the registers. receive buffer register (rb) address offset = 0h, dlab = 0, read only this register holds the received incoming data byte. bit 0 is the least significant bit, which is transmitted and received first. received data is double buffered; this uses an additional shift register to receive the serial data stream and convert it to a parallel 8 bit word which is transferred to the receive buffer register. the shift register is not accessible. 73 transmit buffer register (tb) address offset = 0h, dlab = 0, write only this register contains the data byte to be transmitted. the transmit buffer is double buffered, utilizing an additional shift register (not accessible) to convert the 8 bit data word to a serial format. this shift register is loaded from the transmit buffer when the transmission of the previous byte is complete. interrupt enable register (ier) address offset = 1h, dlab = 0, read/write the lower four bits of this register control the enables of the five interrupt sources of the serial port interrupt. it is possible to totally disable the interrupt system by resetting bits 0 through 3 of this register. similarly, setting the appropriate bits of this register to a high, selected interrupts can be enabled. disabling the interrupt system inhibits the interrupt identification register and disables any serial port interrupt out of the LPC47S42X. all other system functions operate in their normal manner, including the line status and modem status registers. the contents of the interrupt enable register are described below. bit 0 this bit enables the received data available interrupt (and timeout interrupts in the fifo mode) when set to logic "1". bit 1 this bit enables the transmitter holding register empty interrupt when set to logic "1". bit 2 this bit enables the received line status interrupt when set to logic "1". the error sources causing the interrupt are overrun, parity, framing and break. the line status register must be read to determine the source. bit 3 this bit enables the modem status interrupt when set to logic "1". this is caused when one of the modem status register bits changes state. bits 4 through 7 these bits are always logic "0". fifo control register (fcr) address offset = 2h, dlab = x, write this is a write only register at the same location as the iir. this register is used to enable and clear the fifos, set the rcvr fifo trigger level. note: dma is not supported. the uart1 and uart2 fcr?s are shadowed in the uart1 fifo control shadow register (runtime register at offset 0x20) and uart2 fifo control shadow register (runtime register at offset 0x1d). bit 0 setting this bit to a logic "1" enables both the xmit and rcvr fifos. clearing this bit to a logic "0" disables both the xmit and rcvr fifos and clears all bytes from both fifos. when changing from fifo mode to non-fifo (16450) mode, data is automatically cleared from the fifos. this bit must be a 1 when other bits in this register are written to or they will not be properly programmed. 74 bit 1 setting this bit to a logic "1" clears all bytes in the rcvr fifo and resets its counter logic to 0. the shift register is not cleared. this bit is self-clearing. bit 2 setting this bit to a logic "1" clears all bytes in the xmit fifo and resets its counter logic to 0. the shift register is not cleared. this bit is self-clearing. bit 3 writing to this bit has no effect on the operation of the uart. the rxrdy and txrdy pins are not available on this chip. bit 4,5 reserved bit 6,7 these bits are used to set the trigger level for the rcvr fifo interrupt. bit 7 bit 6 rcvr fifo trigger level (bytes) 0 0 1 0 1 4 1 0 8 1 1 14 interrupt identification register (iir) address offset = 2h, dlab = x, read by accessing this register, the host cpu can determine the highest priority interrupt and its source. four levels of priority interrupt exist. they are in descending order of priority: 1. receiver line status (highest priority) 2. received data ready 3. transmitter holding register empty 4. modem status (lowest priority) information indicating that a prioritized interrupt is pending and the source of that interrupt is stored in the interrupt identification register (refer to interrupt control table). when the cpu accesses the iir, the serial port freezes all interrupts and indicates the highest priority pending interrupt to the cpu. during this cpu access, even if the serial port records new interrupts, the current indication does not change until access is completed. the contents of the iir are described below. 75 bit 0 this bit can be used in either a hardwired prioritized or polled environment to indicate whether an interrupt is pending. when bit 0 is a logic "0", an interrupt is pending and the contents of the iir may be used as a pointer to the appropriate internal service routine. when bit 0 is a logic "1", no interrupt is pending. bits 1 and 2 these two bits of the iir are used to identify the highest priority interrupt pending as indicated by the interrupt control table. bit 3 in non-fifo mode, this bit is a logic "0". in fifo mode this bit is set along with bit 2 when a timeout interrupt is pending. bits 4 and 5 these bits of the iir are always logic "0". bits 6 and 7 these two bits are set when the fifo control register bit 0 equals 1. table 29 - interrupt control fifo mode only interrupt identification register interrupt set and reset functions bit 3 bit 2 bit 1 bit 0 priority level interrupt type interrupt source interrupt reset control 0 0 0 1 - none none - 0 1 1 0 highest receiver line status overrun error, parity error, framing error or break interrupt reading the line status register 0 1 0 0 second received data available receiver data available read receiver buffer or the fifo drops below the trigger level. 1 1 0 0 second character timeout indication no characters have been removed from or input to the rcvr fifo during the last 4 char times and there is at least 1 char in it during this time reading the receiver buffer register 0 0 1 0 third transmitter holding register empty transmitter holding register empty reading the iir register (if source of interrupt) or writing the transmitter holding register 76 fifo mode only interrupt identification register interrupt set and reset functions bit 3 bit 2 bit 1 bit 0 priority level interrupt type interrupt source interrupt reset control 0 0 0 0 fourth modem status clear to send or data set ready or ring indicator or data carrier detect reading the modem status register line control register (lcr) address offset = 3h, dlab = 0, read/write start lsb data 5-8 bits msb parity stop figure 1 - serial data this register contains the format information of the serial line. the bit definitions are: bits 0 and 1 these two bits specify the number of bits in each transmitted or received serial character. the encoding of bits 0 and 1 is as follows: the start, stop and parity bits are not included in the word length. bit 1 bit 0 word length 0 0 1 1 0 1 0 1 5 bits 6 bits 7 bits 8 bits 77 bit 2 this bit specifies the number of stop bits in each transmitted or received serial character. the following table summarizes the information. bit 2 word length number of stop bits 0 -- 1 1 5 bits 1.5 1 6 bits 2 1 7 bits 2 1 8 bits 2 note: the receiver will ignore all stop bits beyond the first, regardless of the number used in transmitting. bit 3 parity enable bit. when bit 3 is a logic "1", a parity bit is generated (transmit data) or checked (receive data) between the last data word bit and the first stop bit of the serial data. (the parity bit is used to generate an even or odd number of 1s when the data word bits and the parity bit are summed). bit 4 even parity select bit. when bit 3 is a logic "1" and bit 4 is a logic "0", an odd number of logic "1"'s is transmitted or checked in the data word bits and the parity bit. when bit 3 is a logic "1" and bit 4 is a logic "1" an even number of bits is transmitted and checked. bit 5 stick parity bit. when parity is enabled it is used in conjunction with bit 4 to select mark or space parity. when lcr bits 3, 4 and 5 are 1 the parity bit is transmitted and checked as 0 (space parity). if bits 3 and 5 are 1 and bit 4 is a 0, then the parity bit is transmitted and checked as 1 (mark parity). if bit 5 is 0 stick parity is disabled. bit 6 set break control bit. when bit 6 is a logic "1", the transmit data output (txd) is forced to the spacing or logic "0" state and remains there (until reset by a low level bit 6) regardless of other transmitter activity. this feature enables the serial port to alert a terminal in a communications system. bit 7 divisor latch access bit (dlab). it must be set high (logic "1") to access the divisor latches of the baud rate generator during read or write operations. it must be set low (logic "0") to access the receiver buffer register, the transmitter holding register, or the interrupt enable register. modem control register (mcr) address offset = 4h, dlab = x, read/write this 8 bit register controls the interface with the modem or data set (or device emulating a modem). the contents of the modem control register are described below. bit 0 this bit controls the data terminal ready (ndtr) output. when bit 0 is set to a logic "1", the ndtr output is forced to a logic "0". when bit 0 is a logic "0", the ndtr output is forced to a logic "1". 78 bit 1 this bit controls the request to send (nrts) output. bit 1 affects the nrts output in a manner identical to that described above for bit 0. bit 2 this bit controls the output 1 (out1) bit. this bit does not have an output pin and can only be read or written by the cpu. bit 3 output 2 (out2). this bit is used to enable an uart interrupt. when out2 is a logic "0", the serial port interrupt output is forced to a high impedance state - disabled. when out2 is a logic "1", the serial port interrupt outputs are enabled. bit 4 this bit provides the loopback feature for diagnostic testing of the serial port. when bit 4 is set to logic "1", the following occur: 1. the txd is set to the marking state (logic "1"). 2. the receiver serial input (rxd) is disconnected. 3. the output of the transmitter shift register is "looped back" into the receiver shift register input. 4. all modem control inputs (ncts, ndsr, nri and ndcd) are disconnected. 5. the four modem control outputs (ndtr, nrts, out1 and out2) are internally connected to the four modem control inputs (ndsr, ncts, ri, dcd). 6. the modem control output pins are forced inactive high. 7. data that is transmitted is immediately received. this feature allows the processor to verify the transmit and receive data paths of the serial port. in the diagnostic mode, the receiver and the transmitter interrupts are fully operational. the modem control interrupts are also operational but the interrupts' sources are now the lower four bits of the modem control register instead of the modem control inputs. the interrupts are still controlled by the interrupt enable register. bits 5 through 7 these bits are permanently set to logic zero. line status register (lsr) address offset = 5h, dlab = x, read/write 79 bit 0 data ready (dr). it is set to a logic "1" whenever a complete incoming character has been received and transferred into the receiver buffer register or the fifo. bit 0 is reset to a logic "0" by reading all of the data in the receive buffer register or the fifo. bit 1 overrun error (oe). bit 1 indicates that data in the receiver buffer register was not read before the next character was transferred into the register, thereby destroying the previous character. in fifo mode, an overrunn error will occur only when the fifo is full and the next character has been completely received in the shift register, the character in the shift register is overwritten but not transferred to the fifo. the oe indicator is set to a logic "1" immediately upon detection of an overrun condition, and reset whenever the line status register is read. bit 2 parity error (pe). bit 2 indicates that the received data character does not have the correct even or odd parity, as selected by the even parity select bit. the pe is set to a logic "1" upon detection of a parity error and is reset to a logic "0" whenever the line status register is read. in the fifo mode this error is associated with the particular character in the fifo it applies to. this error is indicated when the associated character is at the top of the fifo. bit 3 framing error (fe). bit 3 indicates that the received character did not have a valid stop bit. bit 3 is set to a logic "1" whenever the stop bit following the last data bit or parity bit is detected as a zero bit (spacing level). the fe is reset to a logic "0" whenever the line status register is read. in the fifo mode this error is associated with the particular character in the fifo it applies to. this error is indicated when the associated character is at the top of the fifo. the serial port will try to resynchronize after a framing error. to do this, it assumes that the framing error was due to the next start bit, so it samples this 'start' bit twice and then takes in the 'data'. bit 4 break interrupt (bi). bit 4 is set to a logic "1" whenever the received data input is held in the spacing state (logic "0") for longer than a full word transmission time (that is, the total time of the start bit + data bits + parity bits + stop bits). the bi is reset after the cpu reads the contents of the line status register. in the fifo mode this error is associated with the particular character in the fifo it applies to. this error is indicated when the associated character is at the top of the fifo. when break occurs only one zero character is loaded into the fifo. restarting after a break is received, requires the serial data (rxd) to be logic "1" for at least 1/2 bit time. note: bits 1 through 4 are the error conditions that produce a receiver line status interrupt whenever any of the corresponding conditions are detected and the interrupt is enabled. bit 5 transmitter holding register empty (thre). bit 5 indicates that the serial port is ready to accept a new character for transmission. in addition, this bit causes the serial port to issue an interrupt when the transmitter holding register interrupt enable is set high. the thre bit is set to a logic "1" when a character is transferred from the transmitter holding register into the transmitter shift register. the bit is reset to logic "0" whenever the cpu loads the transmitter holding register. in the fifo mode this bit is set when the xmit fifo is empty, it is cleared when at least 1 byte is written to the xmit fifo. bit 5 is a read only bit. 80 bit 6 transmitter empty (temt). bit 6 is set to a logic "1" whenever the transmitter holding register (thr) and transmitter shift register (tsr) are both empty. it is reset to logic "0" whenever either the thr or tsr contains a data character. bit 6 is a read only bit. in the fifo mode this bit is set whenever the thr and tsr are both empty. bit 7 this bit is permanently set to logic "0" in the 450 mode. in the fifo mode, this bit is set to a logic "1" when there is at least one parity error, framing error or break indication in the fifo. this bit is cleared when the lsr is read if there are no subsequent errors in the fifo. modem status register (msr) address offset = 6h, dlab = x, read/write this 8 bit register provides the current state of the control lines from the modem (or peripheral device). in addition to this current state information, four bits of the modem status register (msr) provide change information. these bits are set to logic "1" whenever a control input from the modem changes state. they are reset to logic "0" whenever the modem status register is read. bit 0 delta clear to send (dcts). bit 0 indicates that the ncts input to the chip has changed state since the last time the msr was read. bit 1 delta data set ready (ddsr). bit 1 indicates that the ndsr input has changed state since the last time the msr was read. bit 2 trailing edge of ring indicator (teri). bit 2 indicates that the nri input has changed from logic "0" to logic "1". bit 3 delta data carrier detect (ddcd). bit 3 indicates that the ndcd input to the chip has changed state. note: whenever bit 0, 1, 2, or 3 is set to a logic "1", a modem status interrupt is generated. 81 bit 4 this bit is the complement of the clear to send (ncts) input. if bit 4 of the mcr is set to logic "1", this bit is equivalent to nrts in the mcr. bit 5 this bit is the complement of the data set ready (ndsr) input. if bit 4 of the mcr is set to logic "1", this bit is equivalent to dtr in the mcr. bit 6 this bit is the complement of the ring indicator (nri) input. if bit 4 of the mcr is set to logic "1", this bit is equivalent to out1 in the mcr. bit 7 this bit is the complement of the data carrier detect (ndcd) input. if bit 4 of the mcr is set to logic "1", this bit is equivalent to out2 in the mcr. scratchpad register (scr) address offset =7h, dlab =x, read/write this 8 bit read/write register has no effect on the operation of the serial port. it is intended as a scratchpad register to be used by the programmer to hold data temporarily. programmable baud rate generator (and divisor latches dlh, dll) the serial port contains a programmable baud rate generator that is capable of dividing the internal pll clock by any divisor from 1 to 65535. the internal pll clock is divided down to generate a 1.8462mhz frequency for baud rates less than 38.4k, a 1.8432mhz frequency for 115.2k, a 3.6864mhz frequency for 230.4k and a 7.3728mhz frequency for 460.8k. this output frequency of the baud rate generator is 16x the baud rate. two 8 bit latches store the divisor in 16 bit binary format. these divisor latches must be loaded during initialization in order to insure desired operation of the baud rate generator. upon loading either of the divisor latches, a 16 bit baud counter is immediately loaded. this prevents long counts on initial load. if a 0 is loaded into the brg registers the output divides the clock by the number 3. if a 1 is loaded the output is the inverse of the input oscillator. if a two is loaded the output is a divide by 2 signal with a 50% duty cycle. if a 3 or greater is loaded the output is low for 2 bits and high for the remainder of the count. the input clock to the brg is a 1.8462 mhz clock. table 30 shows the baud rates possible. effect of the reset on register file the reset function table (table 31) details the effect of the reset input on each of the registers of the serial port. fifo interrupt mode operation when the rcvr fifo and receiver interrupts are enabled (fcr bit 0 = "1", ier bit 0 = "1"), rcvr interrupts occur as follows: a. the receive data available interrupt will be issued when the fifo has reached its programmed trigger level; it is cleared as soon as the fifo drops below its programmed trigger level. b. the iir receive data available indication also occurs when the fifo trigger level is reached. it is cleared when the fifo drops below the trigger level. 82 c. the receiver line status interrupt (iir=06h), has higher priority than the received data available (iir=04h) interrupt. d. the data ready bit (lsr bit 0) is set as soon as a character is transferred from the shift register to the rcvr fifo. it is reset when the fifo is empty. when rcvr fifo and receiver interrupts are enabled, rcvr fifo timeout interrupts occur as follows: a. a fifo timeout interrupt occurs if all the following conditions exist: - at least one character is in the fifo. - the most recent serial character received was longer than 4 continuous character times ago. (if 2 stop bits are programmed, the second one is included in this time delay). - the most recent cpu read of the fifo was longer than 4 continuous character times ago. - this will cause a maximum character received to interrupt issued delay of 160 msec at 300 baud with a 12 bit character. b. character times are calculated by using the rclk input for a clock signal (this makes the delay proportional to the baudrate). c. when a timeout interrupt has occurred it is cleared and the timer reset when the cpu reads one character from the rcvr fifo. d. when a timeout interrupt has not occurred the timeout timer is reset after a new character is received or after the cpu reads the rcvr fifo. when the xmit fifo and transmitter interrupts are enabled (fcr bit 0 = "1", ier bit 1 = "1"), xmit interrupts occur as follows: a. the transmitter holding register interrupt (02h) occurs when the xmit fifo is empty; it is cleared as soon as the transmitter holding register is written to (1 of 16 characters may be written to the xmit fifo while servicing this interrupt) or the iir is read. b. the transmitter fifo empty indications will be delayed 1 character time minus the last stop bit time whenever the following occurs: thre=1 and there have not been at least two bytes at the same time in the transmitter fifo since the last thre=1. the transmitter interrupt after changing fcr0 will be immediate, if it is enabled. character timeout and rcvr fifo trigger level interrupts have the same priority as the current received data available interrupt; xmit fifo empty has the same priority as the current transmitter holding register empty interrupt. fifo polled mode operation with fcr bit 0 = "1" resetting ier bits 0, 1, 2 or 3 or all to zero puts the uart in the fifo polled mode of operation. since the rcvr and xmitter are controlled separately, either one or both can be in the polled mode of operation. in this mode, the user's program will check rcvr and xmitter status via the lsr. lsr definitions for the fifo polled mode are as follows: - bit 0=1 as long as there is one byte in the rcvr fifo. - bits 1 to 4 specify which error(s) have occurred. character error status is handled the same way as when in the interrupt mode, the iir is not affected since eir bit 2=0. - bit 5 indicates when the xmit fifo is empty. - bit 6 indicates that both the xmit fifo and shift register are empty. - bit 7 indicates whether there are any errors in the rcvr fifo. 83 there is no trigger level reached or timeout condition indicated in the fifo polled mode, however, the rcvr and xmit fifos are still fully capable of holding characters. table 30 - baud rates desired baud rate divisor used to generate 16x clock percent error difference between desired and actual 1 high speed bit 2 50 2304 0.001 x 75 1536 - x 110 1047 - x 134.5 857 0.004 x 150 768 - x 300 384 - x 600 192 - x 1200 96 - x 1800 64 - x 2000 58 0.005 x 2400 48 - x 3600 32 - x 4800 24 - x 7200 16 - x 9600 12 - x 19200 6 - x 38400 3 0.030 x 57600 2 0.16 x 115200 1 0.16 x 230400 32770 0.16 1 460800 32769 0.16 1 note 1 : the percentage error for all baud rates, except where indicated otherwise, is 0.2%. note 2 : the high speed bit is located in the device configuration space. 84 table 31 - reset function register/signal reset control reset state interrupt enable register reset all bits low interrupt identification reg. reset bit 0 is high; bits 1 - 7 low fifo control reset all bits low line control reg. reset all bits low modem control reg. reset all bits low line status reg. reset all bits low except 5, 6 high modem status reg. reset bits 0 - 3 low; bits 4 - 7 input txd1, txd2 reset high intrpt (rcvr errs) reset/read lsr low intrpt (rcvr data ready) reset/read rbr low intrpt (thre) reset/readiir/write thr low out2b reset high rtsb reset high dtrb reset high out1b reset high rcvr fifo reset/ fcr1*fcr0/_fcr0 all bits low xmit fifo reset/ fcr1*fcr0/_fcr0 all bits low 85 table 32 - register summary for an individual uart channel register address* register name register symbol bit 0 bit 1 addr = 0 dlab = 0 receive buffer register (read only) rbr data bit 0 (note 1) data bit 1 addr = 0 dlab = 0 transmitter holding register (write only) thr data bit 0 data bit 1 addr = 1 dlab = 0 interrupt enable register ier enable received data available interrupt (erdai) enable transmitter holding register empty interrupt (ethrei) addr = 2 interrupt ident. register (read only) iir "0" if interrupt pending interrupt id bit addr = 2 fifo control register (write only) fcr (note 7) fifo enable rcvr fifo reset addr = 3 line control register lcr word length select bit 0 (wls0) word length select bit 1 (wls1) addr = 4 modem control register mcr data terminal ready (dtr) request to send (rts) addr = 5 line status register lsr data ready (dr) overrun error (oe) addr = 6 modem status register msr delta clear to send (dcts) delta data set ready (ddsr) addr = 7 scratch register (note 4) scr bit 0 bit 1 addr = 0 dlab = 1 divisor latch (ls) ddl bit 0 bit 1 addr = 1 dlab = 1 divisor latch (ms) dlm bit 8 bit 9 *dlab is bit 7 of the line control register (addr = 3). note 1: bit 0 is the least significant bit. it is the first bit serially transmitted or received. note 2: when operating in the xt mode, this bit will be set any time that the transmitter shift register is empty. 86 table 32 - register summary for an individual uart channel (continued) bit 2 bit 3 bit 4 bit 5 bit 6 bit 7 data bit 2 data bit 3 data bit 4 data bit 5 data bit 6 data bit 7 data bit 2 data bit 3 data bit 4 data bit 5 data bit 6 data bit 7 enable receiver line status interrupt (elsi) enable modem status interrupt (emsi) 0 0 0 0 interrupt id bit interrupt id bit (note 5) 0 0 fifos enabled (note 5) fifos enabled (note 5) xmit fifo reset dma mode select (note 6) reserved reserved rcvr trigger lsb rcvr trigger msb number of stop bits (stb) parity enable (pen) even parity select (eps) stick parity set break divisor latch access bit (dlab) out1 (note 3) out2 (note 3) loop 0 0 0 parity error (pe) framing error (fe) break interrupt (bi) transmitter holding register (thre) transmitter empty (temt) (note 2) error in rcvr fifo (note 5) trailing edge ring indicator (teri) delta data carrier detect (ddcd) clear to send (cts) data set ready (dsr) ring indicator (ri) data carrier detect (dcd) bit 2 bit 3 bit 4 bit 5 bit 6 bit 7 bit 2 bit 3 bit 4 bit 5 bit 6 bit 7 bit 10 bit 11 bit 12 bit 13 bit 14 bit 15 note 3: this bit no longer has a pin associated with it. note 4: when operating in the xt mode, this register is not available. note 5: these bits are always zero in the non-fifo mode. note 6: writing a one to this bit has no effect. dma modes are not supported in this chip. note 7: the uart1 and uart2 fcr?s are shadowed in the uart1 fifo control shadow register (runtime register at offset 0x20) and uart2 fifo control shadow register (runtime register at offset 0x1d). 87 notes on serial port operation fifo mode operation general the rcvr fifo will hold up to 16 bytes regardless of which trigger level is selected. tx and rx fifo operation the tx portion of the uart transmits data through txd as soon as the cpu loads a byte into the tx fifo. the uart will prevent loads to the tx fifo if it currently holds 16 characters. loading to the tx fifo will again be enabled as soon as the next character is transferred to the tx shift register. these capabilities account for the largely autonomous operation of the tx. the uart starts the above operations typically with a tx interrupt. the chip issues a tx interrupt whenever the tx fifo is empty and the tx interrupt is enabled, except in the following instance. assume that the tx fifo is empty and the cpu starts to load it. when the first byte enters the fifo the tx fifo empty interrupt will transition from active to inactive. depending on the execution speed of the service routine software, the uart may be able to transfer this byte from the fifo to the shift register before the cpu loads another byte. if this happens, the tx fifo will be empty again and typically the uart's interrupt line would transition to the active state. this could cause a system with an interrupt control unit to record a tx fifo empty condition, even though the cpu is currently servicing that interrupt. therefore, after the first byte has been loaded into the fifo the uart will wait one serial character transmission time before issuing a new tx fifo empty interrupt. this one character tx interrupt delay will remain active until at least two bytes have the tx fifo empties after this condition, the tx been loaded into the fifo, concurrently. when interrupt will be activated without a one character delay. rx support functions and operation are quite different from those described for the transmitter. the rx fifo receives data until the number of bytes in the fifo equals the selected interrupt trigger level. at that time if rx interrupts are enabled, the uart will issue an interrupt to the cpu. the rx fifo will continue to store bytes until it holds 16 of them. it will not accept any more data when it is full. any more data entering the rx shift register will set the overrun error flag. normally, the fifo depth and the programmable trigger levels will give the cpu ample time to empty the rx fifo before an overrun occurs. one side-effect of having a rx fifo is that the selected interrupt trigger level may be above the data level in the fifo. this could occur when data at the end of the block contains fewer bytes than the trigger level. no interrupt would be issued to the cpu and the data would remain in the uart. to prevent the software from having to check for this situation the chip incorporates a timeout interrupt. the timeout interrupt is activated when there is a least one byte in the rx fifo, and neither the cpu nor the rx shift register has accessed the rx fifo within 4 character times of the last byte. the timeout interrupt is cleared or reset when the cpu reads the rx fifo or another character enters it. these fifo related features allow optimization of cpu/uart transactions and are especially useful given the higher baud rate capability (256 kbaud). 88 infrared interface the infrared interface provides a two-way wireless communications port using infrared as a transmission medium. several ir implementations have been provided for the second uart in this chip (logical device 5), irda, and amplitude shift keyed ir. the ir transmission can use the standard uart2 txd2 and rxd2 pins. these can be selected through the configuration registers. irda 1.0 allows serial communication at baud rates up to 115.2 kbps. each word is sent serially beginning with a zero value start bit. a zero is signaled by sending a single ir pulse at the beginning of the serial bit time. a one is signaled by sending no ir pulse during the bit time. please refer to the ac timing for the parameters of these pulses and the irda waveform. the amplitude shift keyed ir allows asynchronous serial communication at baud rates up to 19.2k baud. each word is sent serially beginning with a zero value start bit. a zero is signaled by sending a 500khz waveform for the duration of the serial bit time. a one is signaled by sending no transmission during the bit time. please refer to the ac timing for the parameters of the ask-ir waveform. if the half duplex option is chosen, there is a time-out when the direction of the transmission is changed. this time-out starts at the last bit transferred during a transmission and blocks the receiver input until the timeout expires. if the transmit buffer is loaded with more data before the time-out expires, the timer is restarted after the new byte is transmitted. if data is loaded into the transmit buffer while a character is being received, the transmission will not start until the time-out expires after the last receive bit has been received. if the start bit of another character is received during this time-out, the timer is restarted after the new character is received. the ir half duplex time-out is programmable via crf2 in logical device 5. this register allows the time-out to be programmed to any value between 0 and 10msec in 100usec increments. figure 2 shows the block diagram of the ir components in the LPC47S42X: ace uart irda sir sharp ask com ace registers output mux ir com host interface ir options register, bit 6 figure 2 89 ir transmit pin the following description pertains to the irtx pin of the LPC47S42X. following a vtr por, the irtx pin will be output and low. it will remain low until one of the following conditions are met: gp53/txd2/irtx pin. this pin defaults to the gpio function. 1. this pin will remain low following a vcc por until the irtx function is selected for the pin and serial port 2 is enabled by setting the activate bit, at which time the pin will reflect the state of the ir transmit output of the ir block (if ir is enabled through the ir options register for serial port 2). 2. this pin will remain low following a vcc por until the txd2 function is selected for the pin and serial port 2 is enabled by setting the activate bit, at which the pin will reflect the state of the transmit output of serial port 2. 3. this pin will remain low following a vcc por until the corresponding gpio data bit (gp5 register bit 3) is set or the polarity bit in the gp53 control register is set. parallel port the LPC47S42X incorporates an ibm xt/at compatible parallel port. this supports the optional ps/2 type bi-directional parallel port (spp), the enhanced parallel port (epp) and the extended capabilities port (ecp) parallel port modes. refer to the configuration registers for information on disabling, power down, changing the base address of the parallel port, and selecting the mode of operation. the LPC47S42X also provides a mode for support of the floppy disk controller on the parallel port. the parallel port also incorporates smsc's chiprotect circuitry, which prevents possible damage to the parallel port due to printer power-up. the functionality of the parallel port is achieved through the use of eight addressable ports, with their associated registers and control gating. the control and data port are read/write by the cpu, the status port is read/write in the epp mode. the address map of the parallel port is shown below data port base address + 00h status port base address + 01h control port base address + 02h epp addr port base address + 03h epp data port 0 base address + 04h epp data port 1 base address + 05h epp data port 2 base address + 06h epp data port 3 base address + 07h 90 the bit map of these registers is: d0 d1 d2 d3 d4 d5 d6 d7 note data port pd0 pd1 pd2 pd3 pd4 pd5 pd6 pd7 1 status port tmout 0 0 nerr slct pe nack nbusy 1 control port strobe autofd ninit slc irqe pcd 0 0 1 epp addr port pd0 pd1 pd2 pd3 pd4 pd5 pd6 pd7 2 epp data port 0 pd0 pd1 pd2 pd3 pd4 pd5 pd6 pd7 2 epp data port 1 pd0 pd1 pd2 pd3 pd4 pd5 pd6 pd7 2 epp data port 2 pd0 pd1 pd2 pd3 pd4 pd5 pd6 pd7 2 epp data port 3 pd0 pd1 pd2 pd3 pd4 pd5 pd6 pd7 2 note 1: these registers are available in all modes. note 2: these registers are only available in epp mode. table 33 - parallel port connector host connector pin number standard epp ecp 1 83 nstrobe nwrite nstrobe 2-9 68-75 pd<0:7> pdata<0:7> pdata<0:7> 10 80 nack intr nack 11 79 busy nwait busy, periphack(3) 12 78 pe (user defined) perror, nackreverse(3) 13 77 slct (user defined) select 14 82 nalf ndatastb nautofd, hostack(3) 15 81 nerror (user defined) nfault(1) nperiphrequest(3) 16 66 ninit nreset ninit(1) nreverserqst(3) 17 67 nslctin naddrstrb nselectin(1,3) (1) = compatible mode (3) = high speed mode note: for the cable interconnection required for ecp support and the slave connector pin numbers, refer to the ieee 1284 extended capabilities port protocol and isa standard , rev. 1.14, july 14, 1993. this document is available from microsoft. 91 ibm xt/at compatible, bi-directional and epp modes data port address offset = 00h the data port is located at an offset of '00h' from the base address. the data register is cleared at initialization by reset. during a write operation, the data register latches the contents of the internal data bus. the contents of this register are buffered (non inverting) and output onto the pd0 - pd7 ports. during a read operation in spp mode, pd0 - pd7 ports are buffered (not l atched) and output to the host cpu. status port address offset = 01h the status port is located at an offset of '01h' from the base address. the contents of this register are latched for the duration of a read cycle. the bits of the status port are defined as follows: bit 0 tmout - time out this bit is valid in epp mode only and indicates that a 10 usec time out has occurred on the epp bus. a logic o means that no time out error has occurred; a logic 1 means that a time out error has been detected. this bit is cleared by a reset. writing a one to this bit clears the time out status bit. on a write, this bit is self clearing and does not require a write of a zero. writing a zero to this bit has no effect. bits 1, 2 - are not implemented as register bits, during a read of the printer status register these bits are a low level. bit 3 nerr - nerror the level on the nerror input is read by the cpu as bit 3 of the printer status register. a logic 0 means an error has been detected; a logic 1 means no error has been detected. bit 4 slct - printer selected status the level on the slct input is read by the cpu as bit 4 of the printer status register. a logic 1 means the printer is on line; a logic 0 means it is not selected. bit 5 pe - paper end the level on the pe input is read by the cpu as bit 5 of the printer status register. a logic 1 indicates a paper end; a logic 0 indicates the presence of paper. bit 6 nack - nacknowledge the level on the nack input is read by the cpu as bit 6 of the printer status register. a logic 0 means that the printer has received a character and can now accept another. a logic 1 means that it is still processing the last character or has not received the data. bit 7 nbusy - nbusy the complement of the level on the busy input is read by the cpu as bit 7 of the printer status register. a logic 0 in this bit means that the printer is busy and cannot accept a new character. a logic 1 means that it is ready to accept the next character. 92 control port address offset = 02h the control port is located at an offset of '02h' from the base address. the control register is initialized by the reset input, bits 0 to 5 only being affected; bits 6 and 7 are hard wired low. bit 0 strobe - strobe this bit is inverted and output onto the nstrobe output. bit 1 autofd - autofeed this bit is inverted and output onto the nautofd output. a logic 1 causes the printer to generate a line feed after each line is printed. a logic 0 means no autofeed. bit 2 ninit - ninitiate output this bit is output onto the ninit output without inversion. bit 3 slctin - printer select input this bit is inverted and output onto the nslctin output. a logic 1 on this bit selects the printer; a logic 0 means the printer is not selected. bit 4 irqe - interrupt request enable the interrupt request enable bit when set to a high level may be used to enable interrupt requests from the parallel port to the cpu. an interrupt request is generated on the irq port by a positive going nack input. when the irqe bit is programmed low the irq is disabled. bit 5 pcd - parallel control direction parallel control direction is not valid in printer mode. in printer mode, the direction is always out regardless of the state of this bit. in bi-directional, epp or ecp mode, a logic 0 means that the printer port is in output mode (write); a logic 1 means that the printer port is in input mode (read). bits 6 and 7 during a read are a low level, and cannot be written. epp address port address offset = 03h the epp address port is located at an offset of '03h' from the base address. the address register is cleared at initialization by reset. during a write operation, the contents of the internal data bus db0- db7 are buffered (non inverting) and output onto the pd0 - pd7 ports. an lpc i/o write cycle causes an epp address write cycle to be performed, during which the data is latched for the duration of the epp write cycle. during a read operation, pd0 - pd7 ports are read. an lpc i/o read cycle causes an epp address read cycle to be performed and the data output to the host cpu, the deassertion of addrstb latches the pdata for the duration of the read cycle. this register is only available in epp mode. epp data port 0 address offset = 04h the epp data port 0 is located at an offset of '04h' from the base address. the data register is cleared at initialization by reset. during a write operation, the contents of the internal data bus db0-db7 are buffered (non inverting) and output onto the pd0 - pd7 ports. an lpc i/o write cycle causes an epp 93 data write cycle to be performed, during which the data is latched for the duration of the epp write cycle. during a read operation, pd0 - pd7 ports are read. an lpc i/o read cycle causes an epp read cycle to be performed and the data output to the host cpu, the deassertion of datastb latches the pdata for the duration of the read cycle. this register is only available in epp mode. epp data port 1 address offset = 05h the epp data port 1 is located at an offset of '05h' from the base address. refer to epp data port 0 for a description of operation. this register is only available in epp mode. epp data port 2 address offset = 06h the epp data port 2 is located at an offset of '06h' from the base address. refer to epp data port 0 for a description of operation. this register is only available in epp mode. epp data port 3 address offset = 07h the epp data port 3 is located at an offset of '07h' from the base address. refer to epp data port 0 for a description of operation. this register is only available in epp mode. epp 1.9 operation when the epp mode is selected in the configuration register, the standard and bi-directional modes are also available. if no epp read, write or address cycle is currently executing, then the pdx bus is in the standard or bi-directional mode, and all output signals (strobe, autofd, init) are as set by the spp control port and direction is controlled by pcd of the control port. in epp mode, the system timing is closely coupled to the epp timing. for this reason, a watchdog timer is required to prevent system lockup. the timer indicates if more than 10usec have elapsed from the start of the epp cycle to nwait being deasserted (after command). if a time-out occurs, the current epp cycle is aborted and the time-out condition is indicated in status bit 0. during an epp cycle, if strobe is active, it overrides the epp write signal forcing the pdx bus to always be in a write mode and the nwrite signal to always be asserted. software constraints before an epp cycle is executed, the software must ensure that the control register bit pcd is a logic "0" (i.e., a 04h or 05h should be written to the control port). if the user leaves pcd as a logic "1", and attempts to perform an epp write, the chip is unable to perform the write (because pcd is a logic "1") and will appear to perform an epp read on the parallel bus, no error is indicated. epp 1.9 write the timing for a write operation (address or data) is shown in timing diagram epp write data or address cycle. the chip inserts wait states into the lpc i/o write cycle until it has been determined that the write cycle can complete. the write cycle can complete under the following circumstances: 1. if the epp bus is not ready (nwait is active low) when ndata stb or naddrstb goes active then the write can complete when nwait goes inactive high. 94 2. if the epp bus is ready (nwait is inactive high) then the chip must wait for it to go active low before changing the state of ndatastb, nwrite or naddrstb. the write can complete once nwait is determined inactive. write sequence of operation 1. the host initiates an i/o write cycle to the selected epp register. 2. if wait is not asserted, the chip must wait until wait is asserted. 3. the chip places address or data on pdata bus, clears pdir, and asserts nwrite. 4. chip asserts ndatastb or naddrstrb indicating that pdata bus contains valid information, and the write signal is valid. 5. peripheral deasserts nwait, indicating that any setup requirements have been sati sfied and the chip may begin the termination phase of the cycle. 6. a. the chip deasserts ndatastb or naddrstrb, this marks the beginning of the termination phase. if it has not already done so, the peripheral should latch the information byte now. b. the chip latches the data from the internal data bus for the pdata bus and drives the sync that indicates that no more wait states are required followed by the tar to complete the write cycle. 7. peripheral asserts nwait, indicating to the host that any hold time requirements have been satisfied and acknowledging the termination of the cycle. 8. chip may modify nwrite and npdata in preparation for the next cycle. epp 1.9 read the timing for a read operation (data) is shown in timing diagram epp read data cycle. the chip inserts wait states into the lpc i/o read cycle until it has been determined that the read cycle can complete. the read cycle can complete under the following circumstances: 1 if the epp bus is not ready (nwait is active low) when ndatast b goes active then the read can complete when nwait goes inactive high. 2. if the epp bus is ready (nwait is inactive high) then the chip must wait for it to go active low before changing the state of write or before ndatastb goes active. the read can complete once nwait is determined inactive. read sequence of operation 1. the host initiates an i/o read cycle to the selected epp register. 2. if wait is not asserted, the chip must wait until wait is asserted. 3. the chip tri-states the pdata bus and deass erts nwrite. 4. chip asserts ndatastb or naddrstrb indicating that pdata bus is tri-stated, pdir is set and the nwrite signal is valid. 5. peripheral drives pdata bus valid. 6. peripheral deasserts nwait, indicating that pdata is valid and the chip may b egin the termination phase of the cycle. 7. a) the chip latches the data from the pdata bus for the internal data bus and deasserts ndatastb or naddrstrb. this marks the beginning of the termination phase. b) the chip drives the sync that indicates that n o more wait states are required and drives valid data onto the lad[3:0] signals, followed by the tar to complete the read cycle. 8. peripheral tri-states the pdata bus and asserts nwait, indicating to the host that the pdata bus is tri- stated. 9. chip may modify nwrite, pdir and npdata in preparation for the next cycle. 95 epp 1.7 operation when the epp 1.7 mode is selected in the configuration register, the standard and bi-directional modes are also available. if no epp read, write or address cycle is currently executing, then the pdx bus is in the standard or bi-directional mode, and all output signals (strobe, autofd, init) are as set by the spp control port and direction is controlled by pcd of the control port. in epp mode, the system timing is closely coupled to the epp timing. for this reason, a watchdog timer is required to prevent system lockup. the timer indicates if more than 10usec have elapsed from the start of the epp cycle to the end of the cycle. if a time-out occurs, the current epp cycle is aborted and the time- out condition is indicated in status bit 0. software constraints before an epp cycle is executed, the software must ensure that the control register bits d0, d1 and d3 are set to zero. also, bit d5 (pcd) is a logic "0" for an epp write or a logic "1" for and epp read. epp 1.7 write the timing for a write operation (address or data) is shown in timing diagram epp 1.7 write data or address cycle. the chip inserts wait states into the i/o write cycle when nwait is active low during the epp cycle. this can be used to extend the cycle time. the write cycle can complete when nwait is inactive high. write sequence of operation 1. the host sets pdir bit in the control register to a logic "0". this asserts nwrite. 2. the host init iates an i/o write cycle to the selected epp register. 3. the chip places address or data on pdata bus. 4. chip asserts ndatastb or naddrstrb indicating that pdata bus contains valid information, and the write signal is valid. 5. if nwait is asserted, the chip inserts wait states into i/o write cycle until the peripheral deasserts nwait or a time-out occurs. 6. the chip drives the final sync, deasserts ndatastb or naddrstrb and latches the data from the internal data bus for the pdata bus. 7. chip may mod ify nwrite, pdir and npdata in preparation of the next cycle. 96 epp 1.7 read the timing for a read operation (data) is shown in timing diagram epp 1.7 read data cycle. the chip inserts wait states into the i/o read cycle when nwait is active low during the epp cycle. this can be used to extend the cycle time. the read cycle can complete when nwait is inactive high. read sequence of operation 1 . the host sets pdir bit in the control register to a logic "1". this deasserts nwrite and tri-states the pdata bus. 2 . the host initiates an i/o read cycle to t he selected epp register. 3 . chip asserts ndatastb or naddrstrb indicating that pdata bus is tri-stated, pdir is set and the nwrite signal is valid. 4 . if nwait is asserted, the chip inserts wait states into the i/o read cycle until the peripheral deasserts nwait or a time-out occurs. 5 . the peripheral drives pdata bus valid. 6 . the peripheral deasserts nwait, indicating that pdata is valid and the chip may begin the termination phase of the cycle. 7 . the chip drives the final sync and deasserts ndatastb or naddrstrb. 8 . peripheral tri-states the pdata bus. 9 . chip may modify nwrite, pdir and npdata in pr eparation of the next cycle. table 34 - epp pin descriptions epp signal epp name type epp description nwrite nwrite o this signal is active low. it denotes a write operation. pd<0:7> address/data i/o bi-directional epp byte wide address and data bus. intr interrupt i this signal is active high and positive edge triggered. (pass through with no inversion, same as spp). wait nwait i this signal is active low. it is driven inactive as a positive acknowledgement from the device that the transfer of data is completed. it is driven active as an indication that the device is ready for the next transfer. datastb ndata strobe o this signal is active low. it is used to denote data read or write operation. reset nreset o this signal is active low. when driven active, the epp device is reset to its initial operational mode. addrstb naddress strobe o this signal is active low. it is used to denote address read or write operation. pe paper end i same as spp mode. slct printer selected status i same as spp mode. nerr error i same as spp mode. note 1: spp and epp can use 1 common register. note 2: nwrite is the only epp output that can be over-ridden by spp control port during an epp cycle. for correct epp read cycles, pcd is required to be a low. 97 extended capabilities parallel port ecp provides a number of advantages, some of which are listed below. the individual features are explained in greater detail in the remainder of this section. high performance half -duplex forward and reverse channel interlocked handshake, for fast reliable transfer optional single byte rle compression for improved throughput (64:1) channel addressing for low -cost peripherals maintains link and data layer separation permits the use of active output drivers permits the use of adaptive signal timing peer -to -peer capability. vocabulary the following terms are used in this document: assert: when a signal asserts it transitions to a "true" state, when a signal deasserts it transitions to a "false" state. forward: host to peripheral communication. reverse: peripheral to host communication pword: a port word; equal in size to the width of the lpc interface. for this implementation, pword is always 8 bits. 1 a high level. 0 a low level. these terms may be considered synonymous: periphclk, nack hostack, nautofd periphack, busy nperiphrequest, nfault nreverserequest, ninit nackreverse, perror xflag, select ecpmode, nselectln hostclk, nstrobe reference document: ieee 1284 extended capabilities port protocol and isa interface standard , rev 1.14, july 14, 1993. this document is available from microsoft. the bit map of the extended parallel port registers is: d7 d6 d5 d4 d3 d2 d1 d0 note data pd7 pd6 pd5 pd4 pd3 pd2 pd1 pd0 ecpafifo addr/rle address or rle field 2 dsr nbusy nack perror select nfault 0 0 0 1 dcr 0 0 direction ackinten selectin ninit autofd strobe 1 cfifo parallel port data fifo 2 ecpdfifo ecp data fifo 2 tfifo test fifo 2 cnfga 0 0 0 1 0 0 0 0 cnfgb compress intrvalue parallel port irq parallel port dma ecr mode nerrintren dmaen serviceintr full empty note 1: these registers are available in all modes. 98 note 2: all fifos use one common 16 byte fifo. note 3: the ecp parallel port config reg b reflects the irq and dma channel selected by the configuration registers. ecp implementation standard this specification describes the standard interface to the extended capabilities port (ecp). all lpc devices supporting ecp must meet the requirements contained in this section or the port will not be supported by microsoft. for a description of the ecp protocol, please refer to the ieee 1284 extended capabilities port protocol and isa interface standard , rev. 1.14, july 14, 1993. this document is available from microsoft. description the port is software and hardware compatible with existing parallel ports so that it may be used as a standard lpt port if ecp is not required. the port is designed to be simple and requires a small number of gates to implement. it does not do any "protocol" negotiation, rather it provides an automatic high burst - bandwidth channel that supports dma for ecp in both the forward and reverse directions. small fifos are employed in both forward and reverse directions to smooth data flow and improve the maximum bandwidth requirement. the size of the fifo is 16 bytes deep. the port supports an automatic handshake for the standard parallel port to improve compatibility mode transfer speed. the port also supports run length encoded (rle) decompression (required) in hardware. compression is accomplished by counting identical bytes and transmitting an rle byte that indicates how many times the next byte is to be repeated. decompression simply intercepts the rle byte and repeats the following byte the specified number of times. hardware support for compression is optional. 99 table 35 - ecp pin descriptions name type description nstrobe o during write operations nstrobe registers data or address into the slave on the asserting edge (handshakes with busy). pdata 7:0 i/o contains address or data or rle data. nack i indicates valid data driven by the peripheral when asserted. this signal handshakes with nautofd in reverse. periphack (busy) i this signal deasserts to indicate that the peripheral can accept data. this signal handshakes with nstrobe in the forward direction. in the reverse direction this signal indicates whether the data lines contain ecp command information or data. the peripheral uses this signal to flow control in the forward direction. it is an "interlocked" handshake with nstrobe. periphack also provides command information in the reverse direction. perror (nackreverse) i used to acknowledge a change in the direction the transfer (asserted = forward). the peripheral drives this signal low to acknowledge nreverserequest. it is an "interlocked" handshake with nreverserequest. the host relies upon nackreverse to determine when it is permitted to drive the data bus. select i indicates printer on line. nautofd (hostack) o requests a byte of data from the peripheral when asserted, handshaking with nack in the reverse direction. in the forward direction this signal indicates whether the data lines contain ecp address or data. the host drives this signal to flow control in the reverse direction. it is an "interlocked" handshake with nack. hostack also provides command information in the forward phase. nfault (nperiphrequest) i generates an error interrupt when asserted. this signal provides a mechanism for peer -to -peer communication. this signal is valid only in the forward direction. during ecp mode the peripheral is permitted (but not required) to drive this pin low to request a reverse transfer. the request is merely a "hint" to the host; the host has ultimate control over the transfer direction. this signal would be typically used to generate an interrupt to the host cpu. ninit o sets the transfer direction (asserted = reverse, deasserted = forward). this pin is driven low to place the channel in the reverse direction. the peripheral is only allowed to drive the bi -directional data bus while in ecp mode and hostack is low and nselectin is high. nselectin o always deasserted in ecp mode. register definitions the register definitions are based on the standard ibm addresses for lpt. all of the standard printer ports are supported. the additional registers attach to an upper bit decode of the standard lpt port definition to avoid conflict with standard isa devices. the port is equivalent to a generic parallel port interface and may be operated in that mode. the port registers vary depending on the mode field in the ecr. the table below lists these dependencies. operation of the devices in modes other that those specified is undefined. 100 table 36 - ecp register definitions name address (note 1) ecp modes function data +000h r/w 000-001 data register ecpafifo +000h r/w 011 ecp fifo (address) dsr +001h r/w all status register dcr +002h r/w all control register cfifo +400h r/w 010 parallel port data fifo ecpdfifo +400h r/w 011 ecp fifo (data) tfifo +400h r/w 110 test fifo cnfga +400h r 111 configuration register a cnfgb +401h r/w 111 configuration register b ecr +402h r/w all extended control register note 1: these addresses are added to the parallel port base address as selected by configuration register or jumpers. note 2: all addresses are qualified with aen. refer to the aen pin definition. table 37 - mode descriptions mode description* 000 spp mode 001 ps/2 parallel port mode 010 parallel port data fifo mode 011 ecp parallel port mode 100 epp mode (if this option is enabled in the configuration registers) 101 reserved 110 test mode 111 configuration mode *refer to ecr register description data and ecpafifo port address offset = 00h modes 000 and 001 (data port) the data port is located at an offset of '00h' from the base address. the data register is cleared at initialization by reset. during a write operation, the data register latches the contents of the data bus. the contents of this register are buffered (non inverting) and output onto the pd0 - pd7 ports. during a read operation, pd0 - pd7 ports are read and output to the host cpu. mode 011 (ecp fifo - address/rle) a data byte written to this address is placed in the fifo and tagged as an ecp address/rle. the hardware at the ecp port transmits this byte to the peripheral automatically. the operation of this register is ony defined for the forward direction (direction is 0). refer to the ecp parallel port forward timing diagram, located in the timing diagrams section of this data sheet. 101 device status register (dsr) address offset = 01h the status port is located at an offset of '01h' from the base address. bits 0 - 2 are not implemented as register bits, during a read of the printer status register these bits are a low level. the bits of the status port are defined as follows: bit 3 nfault the level on the nfault input is read by the cpu as bit 3 of the device status register. bit 4 select the level on the select input is read by the cpu as bit 4 of the device status register. bit 5 perror the level on the perror input is read by the cpu as bit 5 of the device status register. printer status register. bit 6 nack the level on the nack input is read by the cpu as bit 6 of the device status register. bit 7 nbusy the complement of the level on the busy input is read by the cpu as bit 7 of the device status register. device control register (dcr) address offset = 02h the control register is located at an offset of '02h' from the base address. the control register is initialized to zero by the reset input, bits 0 to 5 only being affected; bits 6 and 7 are hard wired low. bit 0 strobe - strobe this bit is inverted and output onto the nstrobe output. bit 1 autofd - autofeed this bit is inverted and output onto the nautofd output. a logic 1 causes the printer to generate a line feed after each line is printed. a logic 0 means no autofeed. bit 2 ninit - ninitiate output this bit is output onto the ninit output without inversion. bit 3 selectin this bit is inverted and output onto the nslctin output. a logic 1 on this bit selects the printer; a logic 0 means the printer is not selected. bit 4 ackinten - interrupt request enable the interrupt request enable bit when set to a high level may be used to enable interrupt requests from the parallel port to the cpu due to a low to high transition on the nack input. refer to the description of the interrupt under operation, interrupts. 102 bit 5 direction if mode=000 or mode=010, this bit has no effect and the direction is always out regardless of the state of this bit. in all other modes, direction is valid and a logic 0 means that the printer port is in output mode (write); a logic 1 means that the printer port is in input mode (read). bits 6 and 7 during a read are a low level, and cannot be written. cfifo (parallel port data fifo) address offset = 400h mode = 010 bytes written or dmaed from the system to this fifo are transmitted by a hardware handshake to the peripheral using the standard parallel port protocol. transfers to the fifo are byte aligned. this mode is only defined for the forward direction. ecpdfifo (ecp data fifo) address offset = 400h mode = 011 bytes written or dmaed from the system to this fifo, when the direction bit is 0, are transmitted by a hardware handshake to the peripheral using the ecp parallel port protocol. transfers to the fifo are byte aligned. data bytes from the peripheral are read under automatic hardware handshake from ecp into this fifo when the direction bit is 1. reads or dmas from the fifo will return bytes of ecp data to the system. tfifo (test fifo mode) address offset = 400h mode = 110 data bytes may be read, written or dmaed to or from the system to this fifo in any direction. data in the tfifo will not be transmitted to the to the parallel port lines using a hardware protocol handshake. however, data in the tfifo may be displayed on the parallel port data lines. the tfifo will not stall when overwritten or underrun. if an attempt is made to write data to a full tfifo, the new data is not accepted into the tfifo. if an attempt is made to read data from an empty tfifo, the last data byte is re-read again. the full and empty bits must always keep track of the correct fifo state. the tfifo will transfer data at the maximum isa rate so that software may generate performance metrics. the fifo size and interrupt threshold can be determined by writing bytes to the fifo and checking the full and serviceintr bits. the writeintrthreshold can be determined by starting with a full tfifo, setting the direction bit to 0 and emptying it a byte at a time until serviceintr is set. this may generate a spurious interrupt, but will indicate that the threshold has been reached. the readintrthreshold can be determined by setting the direction bit to 1 and filling the empty tfifo a byte at a time until serviceintr is set. this may generate a spurious interrupt, but will indicate that the threshold has been reached. 103 data bytes are always read from the head of tfifo regardless of the value of the direction bit. for example if 44h, 33h, 22h is written to the fifo, then reading the tfifo will return 44h, 33h, 22h in the same order as was written. cnfga (configuration register a) address offset = 400h mode = 111 this register is a read only register. when read, 10h is returned. this indicates to the system that this is an 8-bit implementation. (pword = 1 byte) cnfgb (configuration register b) address offset = 401h mode = 111 bit 7 compress this bit is read only. during a read it is a low level. this means that this chip does not support hardware rle compression. it does support hardware de-compression! bit 6 intrvalue returns the value of the interrupt to determine possible conflicts. bits [5:3] parallel port irq (read-only) refer to table 38b. bits [2:0] parallel port dma (read-only) refer to table 38c. ecr (extended control register) address offset = 402h mode = all this register controls the extended ecp parallel port functions. bits 7,6,5 these bits are read/write and select the mode. bit 4 nerrintren read/write (valid only in ecp mode) 1: disables the interrupt generated on the asserting edge of nfault. 0: enables an interrupt pulse on the high to low edge of nfault. note that an interrupt will be generated if nfault is asserted (interrupting) and this bit is written from a 1 to a 0. this prevents interrupts from being lost in the time between the read of the ecr and the write of the ecr. bit 3 dmaen read/write 1: enables dma (dma starts when serviceintr is 0). 0: disa bles dma unconditionally. 104 bit 2 serviceintr read/write 1: disables dma and all of the service interrupts. 0: enables one of the following 3 cases of interrupts. once one of the 3 service interrupts has occurred serviceintr bit shall be set to a 1 by hardware. it must be reset to 0 to re-enable the interrupts. writing this bit to a 1 will not cause an interrupt. case dmaen=1: during dma (this bit is set to a 1 when terminal count is reached). case dmaen=0 direction=0: this bit shall be set to 1 whenever there are writeintrthreshold or more bytes free in the fifo. case dmaen=0 direction=1: this bit shall be set to 1 whenever there are readintrthreshold or more valid bytes to be read from the fifo. bit 1 full read only 1: the fifo cannot accept another b yte or the fifo is completely full. 0: the fifo has at least 1 free byte. bit 0 empty read only 1: the fifo is completely empty. 0: the fifo contains at least 1 byte of data. 105 table 38a - extended control register r/w mode 000: standard parallel port mode . in this mode the fifo is reset and common collector drivers are used on the control lines (nstrobe, nautofd, ninit and nselectin). setting the direction bit will not tri -state the output drivers in this mode. 001: ps/2 parallel port mode. same as above except that direction may be used to tri -state the data lines and reading the data register returns the value on the data lines and not the value in the data register. all drivers have active pull -ups (push -pull). 010: parallel port fifo mode. this is the same as 000 except that bytes are written or dmaed to the fifo. fifo data is automatically transmitted using the standard parallel port protocol. note that this mode is only useful when direction is 0. all drivers have active pull -ups (push -pull). 011: ecp parallel port mode. in the forward direction (direction is 0) bytes placed into the ecpdfifo and bytes written to the ecpafifo are placed in a single fifo and transmitted automatically to the peripheral using ecp protocol. in the reverse direction (direction is 1) bytes are moved from the ecp parallel port and packed into bytes in the ecpdfifo. all drivers have active pull -ups (push -pull). 100: selects epp mode: in this mode, epp is selected if the epp supported option is selected in configuration register l3-crf0. all drivers have active pull -ups (push -pull). 101: reserved 110: test mode. in this mode the fifo may be written and read, but the data will not be transmitted on the parallel port. all drivers have active pull -ups (p ush -pull). 111: configuration mode. in this mode the confga, confgb registers are accessible at 0x400 and 0x401. all drivers have active pull -ups (push -pull). table 38b table 38c irq selected config reg b bits 5:3 dma selected config reg b bits 2:0 15 110 3 011 14 101 2 010 11 100 1 001 10 011 all others 000 9 010 7 001 5 111 all others 000 106 operation mode switching/software control software will execute p1284 negotiation and all operation prior to a data transfer phase under programmed i/o control (mode 000 or 001). hardware provides an automatic control line handshake, moving data between the fifo and the ecp port only in the data transfer phase (modes 011 or 010). setting the mode to 011 or 010 will cause the hardware to initiate data transfer. if the port is in mode 000 or 001 it may switch to any other mode. if the port is not in mode 000 or 001 it can only be switched into mode 000 or 001. the direction can only be changed in mode 001. once in an extended forward mode the software should wait for the fifo to be empty before switching back to mode 000 or 001. in this case all control signals will be deasserted before the mode switch. in an ecp reverse mode the software waits for all the data to be read from the fifo before changing back to mode 000 or 001. since the automatic hardware ecp reverse handshake only cares about the state of the fifo it may have acquired extra data which will be discarded. it may in fact be in the middle of a transfer when the mode is changed back to 000 or 001. in this case the port will deassert nautofd independent of the state of the transfer. the design shall not cause glitches on the handshake signals if the software meets the constraints above. ecp operation prior to ecp operation the host must negotiate on the parallel port to determine if the peripheral supports the ecp protocol. this is a somewhat complex negotiation carried out under program control in mode 000. after negotiation, it is necessary to initialize some of the port bits. the following are required: set direction = 0, enabling the drivers. set strobe = 0, causing the nstrobe signal to default to the deasserted state. set autofd = 0, causing the nautofd signal to default to the deasserted state. set mode = 011 (ecp mode) ecp address/rle bytes or data bytes may be sent automatically by writing the ecpafifo or ecpdfifo respectively. note that all fifo data transfers are byte wide and byte aligned. address/rle transfers are byte -wide and only allowed in the forward direction. the host may switch directions by first switching to mode = 001, negotiating for the forward or reverse channel, setting direction to 1 or 0, then setting mode = 011. when direction is 1 the hardware shall handshake for each ecp read data byte and attempt to fill the fifo. bytes may then be read from the ecpdfifo as long as it is not empty. ecp transfers may also be accomplished (albeit slowly) by handshaking individual bytes under program control in mode = 001, or 000. 107 termination from ecp mode termination from ecp mode is similar to the termination from nibble/byte modes. the host is permitted to terminate from ecp mode only in specific well -defined states. the termination can only be executed while the bus is in the forward direction. to terminate while the channel is in the reverse direction, it must first be transitioned into the forward direction. command/data ecp mode supports two advanced features to improve the effectiveness of the protocol for some applications. the features are implemented by allowing the transfer of normal 8 bit data or 8 bit commands. when in the forward direction, normal data is transferred when hostack is high and an 8 bit command is transferred when hostack is low. the most significant bit of the command indicates whether it is a run -length count (for compression) or a channel address. when in the reverse direction, normal data is transferred when periphack is high and an 8 bit command is transferred when periphack is low. the most significant bit of the command is always zero. reverse channel addresses are seldom used and may not be supported in hardware. table 39 - forward channel commands (hostack low) reverse channel commands (peripack low) d7 d[6:0] 0 run -length count (0 -127) (mode 0011 0x00 only) 1 channel address (0 -127) data compression the ecp port supports run length encoded (rle) decompression in hardware and can transfer compressed data to a peripheral. run length encoded (rle) compression in hardware is not supported. to transfer compressed data in ecp mode, the compression count is written to the ecpafifo and the data byte is written to the ecpdfifo. compression is accomplished by counting identical bytes and transmitting an rle byte that indicates how many times the next byte is to be repeated. decompression simply intercepts the rle byte and repeats the following byte the specified number of times. when a run -length count is received from a peripheral, the subsequent data byte is replicated the specified number of times. a run -length count of zero specifies that only one byte of data is represented by the next data byte, whereas a run -length count of 127 indicates that the next byte should be expanded to 128 bytes. to prevent data expansion, however, run -length counts of zero should be avoided. pin definition the drivers for nstrobe, nautofd, ninit and nselectin are open-collector in mode 000 and are push-pull in all other modes. 108 lpc connections the interface can never stall causing the host to hang. the width of data transfers is strictly controlled on an i/o address basis per this specification. all fifo -dma transfers are byte wide, byte aligned and end on a byte boundary. (the pword value can be obtained by reading configuration register a, cnfga, described in the next section). single byte wide transfers are always possible with standard or ps/2 mode using program control of the control signals. interrupts the interrupts are enabled by serviceintr in the ecr register. serviceintr = 1 disables the dma and all of the service interrupts. serviceintr = 0 enables the selected interrupt condition. if the interrupting condition is valid, then the interrupt is generated immediately when this bit is changed from a 1 to a 0. this can occur during programmed i/o if the number of bytes removed or added from/to the fifo does not cross the threshold. an interrupt is generated when: 1 . for dma transfers: when serviceintr is 0, dmaen is 1 and the dma tc cycle is received. 2 . for programmed i/o: a . when serviceintr is 0, dmaen is 0 , direction is 0 and there are writeintrthreshold or more free bytes in the fifo. also, an interrupt is generated when serviceintr is cleared to 0 whenever there are writeintrthreshold or more free bytes in the fifo. b . when ser viceintr is 0, dmaen is 0, direction is 1 and there are readintrthreshold or more bytes in the fifo. also, an interrupt is generated when serviceintr is cleared to 0 whenever there are readintrthreshold or more bytes in the fifo. 3 . when nerrintren is 0 and nfault transitions from high to low or when nerrintren is set from 1 to 0 and nfault is asserted. 4 . when ackinten is 1 and the nack signal transitio ns from a low to a high. fifo operation the fifo threshold is set in the chip configuration registers. all data transfers to or from the parallel port can proceed in dma or programmed i/o (non-dma) mode as indicated by the selected mode. the fifo is used by selecting the parallel port fifo mode or ecp parallel port mode. (fifo test mode will be addressed separately.) after a reset, the fifo is disabled. each data byte is transferred by a programmed i/o cycle or dma cycle depending on the selection of dma or programmed i/o mode. the following paragraphs detail the operation of the fifo flow control. in these descriptions, 109 dma transfers dma transfers are always to or from the ecpdfifo, tfifo or cfifo. dma utilizes the standard pc dma services. to use the dma transfers, the host first sets up the direction and state as in the programmed i/o case. then it programs the dma controller in the host with the desired count and memory address. lastly it sets dmaen to 1 and serviceintr to 0. the ecp requests dma transfers from the host by encoding the nldrq pin. the dma will empty or fill the fifo using the appropriate direction and mode. when the terminal count in the dma controller is reached, an interrupt is generated and serviceintr is asserted, disabling dma. in order to prevent possible blocking of refresh requests a dma cycle shall not be requested for more than 32 dma cycles in a row. the fifo is enabled directly by the host initiating a dma cycle for the requested channel, and addresses need not be valid. an interrupt is generated when a tc cycle is received. (note: the only way to properly terminate dma transfers is with a tc cycle.) dma may be disabled in the middle of a transfer by first disabling the host dma controller. then setting serviceintr to 1, followed by setting dmaen to 0, and waiting for the fifo to become empty or full. restarting the dma is accomplished by enabling dma in the host, setting dmaen to 1, followed by setting serviceintr to 0. dma mode - transfers from the fifo to the host (note: in the reverse mode, the peripheral may not continue to fill the fifo if it runs out of data to transfer, even if the chip continues to request more data from the peripheral.) the ecp requests a dma cycle whenever there is data in the fifo. the dma controller responds to the request by reading data from the fifo. the ecp stop requesting dma cycles when the fifo becomes empty or when a tc cycle is received, indicating that no more data is required. if the ecp stops requesting dma cycles due to the fifo going empty, then a dma cycle is requested again as soon as there is one byte in the fifo. if the ecp stops requesting dma cycles due to the tc cycle, then a dma cycle is requested again when there is one byte in the fifo, and serviceintr has been re-enabled. programmed i/o mode or non-dma mode the ecp or parallel port fifos may also be operated using interrupt driven programmed i/o. software can determine the writeintrthreshold, readintrthreshold, and fifo depth by accessing the fifo in test mode. programmed i/o transfers are to the ecpdfifo at 400h and ecpafifo at 000h or from the ecpdfifo located at 400h, or to/from the tfifo at 400h. to use the programmed i/o transfers, the host first sets up the direction and state, sets dmaen to 0 and serviceintr to 0. the ecp requests programmed i/o transfers from the host by activating the interrupt. the programmed i/o will empty or fill the fifo using the appropriate direction and mode. note: a threshold of 16 is equivalent to a threshold of 15. these two cases are treated the same. 110 programmed i/o - transfers from the fifo to the host in the reverse direction an interrupt occurs when serviceintr is 0 and readintrthreshold bytes are available in the fifo. if at this time the fifo is full it can be emptied completely in a single burst, otherwise readintrthreshold bytes may be read from the fifo in a single burst. readintrthreshold =(16- 111 for acpi compliance the fdd pins that are multiplexed onto the parallel port function independently of the state of the parallel port controller. for example, if the fdc is enabled onto the parallel port the multiplexed fdd interface functions normally regardless of the parallel port power control, cr22.3. table 40 illustrates this functionality. table 40 - modified parallel port fdd control parallel port power parallel port fdc control parallel port fdc state parallel port state cr22.3 ld3:crf1.1 ld3:crf1.0 1 0 0 off on 0 0 0 off off x 1 x on off x 1 (note 1 ) note 1 : the parallel port control register reads as ?cable not connected? when the parallel port fdc is enabled; i.e., strobe = autofd = slc = 0 and ninit = 1. table 41 - fdc parallel port pins connector pin # qfp chip pin # spp mode pin direction fdc mode pin direction 1 83 nstrobe i/o (nds0) i/(o) note1 2 68 pd0 i/o nindex i 3 69 pd1 i/o ntrk0 i 4 70 pd2 i/o nwp i 5 71 pd3 i/o nrdata i 6 72 pd4 i/o ndskchg i 7 73 pd5 i/o - - 8 74 pd6 i/o (nmtr0) i/(o) note1 9 75 pd7 i/o - - 10 80 nack i nds1 o 11 79 busy i nmtr1 o 12 78 pe i nwdata o 13 77 slct i nwgate o 14 82 nalf i/o drvden0 o 15 81 nerror i nhdsel o 16 66 ninit i/o ndir o 17 67 nslctin i/o nstep o note 1: these pins are outputs in mode ppfd2, inputs in mode ppfd1. 112 power management power management capabilities are provided for the following logical devices: floppy disk, uart 1, uart 2 and the parallel port. for each logical device, two types of power management are provided: direct powerdown and auto powerdown. fdc power management direct power management is controlled by cr22. refer to cr22 for more information. auto power management is enabled by cr23-b0. when set, this bit allows fdc to enter powerdown when all of the following conditions have been met: 1. the motor enable pins of register 3f2h are inactive (zero). 2. the p art must be idle; msr=80h and int = 0 (int may be high even if msr = 80h due to polling interrupts). 3. the head unload timer must have expired. 4. the auto powerdown timer (10msec) must have timed out. an internal timer is initiated as soon as the auto powerdown command is enabled. the part is then powered down when all the conditions are met. disabling the auto powerdown mode cancels the timer and holds the fdc block out of auto powerdown. dsr from powerdown if dsr powerdown is used when the part is in auto powerdown, the dsr power down will override the auto powerdown. however, when the part is awakened from dsr powerdown, the auto powerdown will once again become effective. wake up from auto powerdown if the part enters the powerdown state through the auto powerdown mode, then the part can be awakened by reset or by appropriate access to certain registers. if a hardware or software reset is used then the part will go through the normal reset sequence. if the access is through the selected registers, then the fdc resumes operation as though it was never in powerdown. besides activating the npci_reset pin or one of the software reset bits in the dor or dsr, the following register accesses will wake up the part: 1. enabling any one of the motor enab le bits in the dor register (reading the dor does not awaken the part). 2. a read from the msr register. 3. a read or write to the data register. once awake, the fdc will reinitiate the auto powerdown timer for 10 ms. the part will powerdown again when all the powerdown conditions are satisfied. 113 register behavior table 40 illustrates the at and ps/2 (including model 30) configura tion registers available and the type of access permitted. in order to maintain software transparency, access to all the registers must be maintained. as table 40 shows, two sets of registers are distinguished based on whether their access results in the part remaining in powerdown state or exiting it. access to all other registers is possible without awakening the part. these registers can be accessed during powerdown without changing the status of the part. a read from these registers will reflect the true status as shown in the register description in the fdc description. a write to the part will result in the part retaining the data and subsequently reflecting it when the part awakens. access ing the part during powerdown may cause an increase in the power consumption by the part. the part will revert back to its low power mode when the access has been completed. pin behavior the LPC47S42X is specifically designed for systems in which power conservation is a primary concern. this makes the behavior of the pins during powerdown very important. the pins of the LPC47S42X can be divided into two major categories: system interface and floppy disk drive interface. the floppy disk drive pins are disabled so that no power will be drawn through the part as a result of any voltage applied to the pin within the part's power supply range. most of the system interface pins are left active to monitor system accesses that may wake up the part. table 42 - pc/at and ps/2 available registers available registers base + address pc-at ps/2 (model 30) access permitted access to these registers does not wake up the part 00h ---- sra r 01h ---- srb r 02h dor (1) dor (1) r/w 03h --- --- --- 04h dsr (1) dsr (1) w 06h --- --- --- 07h dir dir r 07h ccr ccr w access to these registers wakes up the part 04h msr msr r 05h data data r/w note 1: writing to the dor or d sr does not wake up the part, however, writing any of the motor enable bits or doing a software reset (via dor or dsr reset bits) will wake up the part. 114 system interface pins table 43 gives the state of the interface pins in the powerdown state. pins unaffected by the powerdown are labeled "unchanged". table 43 ? state of system pins in auto powerdown system pins state in auto powerdown lad[3:0] unchanged nldrq unchanged nlpcpd unchanged nlframe unchanged npci_reset unchanged pci_clk unchanged ser_irq unchanged fdd interface pins all pins in the fdd interface which can be connected directly to the floppy disk drive itself are either disabled or tristated. pins used for local logic control or part programming are unaffected. table 44 depicts the state of the floppy disk drive interface pins in the powerdown state. table 44 - state of floppy disk drive interface pins in powerdown fdd pins state in auto powerdown input pins nrdata input nwrtprt input ntrk0 input nindex input ndskchg input output pins nmtr0 tristated nds0 tristated ndir active nstep active nwdata tristated nwgate tristated nhdsel active drvden[0:1] active uart power management direct power management is controlled by cr22. refer to cr22 for more information. auto power management is enabled by cr23-b4 and b5. when set, these bits allow the following auto power management operations: 1. the transmitter enters auto powerdown when the transmit buffer and shift register are empty. 2. the receiver enters powerdown when the following conditions are all met: a . receive fifo is empty b . the receiver is waiting for a start bit. 115 note: while in powerdown the ring indicator interrupt is still valid and transitions when the ri input changes. exit auto powerdown the transmitter exits powerdown on a write to the xmit buffer. the receiver exits auto powerdown when rxdx changes state. parallel port direct power management is controlled by cr22. refer to cr22 for more information. auto power management is enabled by cr23-b3. when set, this bit allows the ecp or epp logical parallel port blocks to be placed into powerdown when not being used. the epp logic is in powerdown under any of the following conditions: 1. epp is not enabled in the configuration registers. 2. epp is not selected through ecr whil e in ecp mode. the ecp logic is in powerdown under any of the following conditions: 1. ecp is not enabled in the configuration registers. 2 spp, ps/2 parallel port or epp mode is selected through ecr while in ecp mode. exit auto powerdown the parallel port logic can change powerdown modes when the ecp mode is changed through the ecr register or when the parallel port mode is changed through the configuration registers. 116 serial irq the LPC47S42X supports the serial interrupt to transmit interrupt information to the host system. the serial interrupt scheme adheres to the serial irq specification for pci systems, version 6.0. timing diagrams for ser_irq cycle a) start frame timing with source sampled a low pulse on irq1. r t s r t s ser_irq pci_clk host controller irq irq1 drive source r t none irq0 frame irq1 frame s r t irq2 frame none start start frame h sl or h 1 note: h=host control; r=recovery; t=turn-around; sl=slave control; s=sample note 1: start frame pulse can be 4-8 clocks wide depending on the location of the device in the pci bridge hierarchy in a synchronous bridge design. b) stop frame timing with host using 17 ser_irq sampling period. note: h=host control; r=recovery; t=turn-around; s=sample; i=idle note 1: stop pulse is 2 clocks wide for quiet mode, 3 clocks wide for continuous mode. note 2: there may be none, one or more idle states during the stop frame. note 3: the next ser_irq cycle?s start frame pulse may or may not start immediately after the turn- around clock of the stop frame. s r t s ser_irq pci_clk host controller irq15 driver r t none irq14 irq15 s r t iochck# none stop r t stop frame h i start next cycle 1 2 3 frame frame frame 117 ser_irq cycle control there are two modes of operation for the ser_irq start frame. 1) quiet (active) mode : any device may initiate a start frame by driving the ser_irq low for one clock, while the ser_irq is idle. after driving low for one clock the ser_irq is immediately tri- stated without at any time driving high. a start frame may not be initiated while the ser_irq is active. the ser_irq is idle between stop and start frames. the ser_irq is active between start and stop frames. this mode of operation allows the ser_irq to be idle when there are no irq/data transitions which should be most of the time. once a start frame has been initiated the host controller will take over driving the ser_irq low in the next clock and will continue driving the ser_irq low for a programmable period of three to seven clocks. this makes a total low pulse width of four to eight clocks. finally, the host controller will drive the ser_irq back high for one clock, then tri-state. any ser_irq device (i.e., the LPC47S42X) which detects any transition on an irq/data line for which it is responsible must initiate a start frame in order to update the host controller unless the ser_irq is already in an ser_irq cycle and the irq/data transition can be delivered in that ser_irq cycle. 2) continuous (idle) mode : only the host controller can initiate a start frame to update irq/data line information. all other ser_irq agents become passive and may not initiate a start frame. ser_irq will be driven low for four to eight clocks by host controller. this mode has two functions. it can be used to stop or idle the ser_irq or the host controller can operate ser_irq in a continuous mode by initiating a start frame at the end of every stop frame. an ser_irq mode transition can only occur during the stop frame. upon reset, ser_irq bus is defaulted to continuous mode, therefore only the host controller can initiate the first start frame. slaves must continuously sample the stop frames pulse width to determine the next ser_irq cycle?s mode. ser_irq data frame once a start frame has been initiated, the LPC47S42X will watch for the rising edge of the start pulse and start counting irq/data frames from there. each irq/data frame is three clocks: sample phase, recovery phase, and turn-around phase. during the sample phase the LPC47S42X drives the ser_irq low, if and only if, its last detected irq/data value was low. if its detected irq/data value is high, ser_irq is left tri-stated. during the recovery phase the LPC47S42X drives the ser_irq high, if and only if, it had driven the ser_irq low during the previous sample phase. during the turn- around phase the LPC47S42X tri-states the ser_irq. the LPC47S42X will drive the ser_irq line low at the appropriate sample point if its associated irq/data line is low, regardless of which device initiated the start frame. the sample phase for each irq/data follows the low to high transition of the start frame pulse by a number of clocks equal to the irq/data frame times three, minus one. (e.g. the irq5 sample clock is the sixth irq/data frame, (6 x 3) - 1 = 17th clock after the rising edge of the start pulse). 118 ser_irq sampling periods ser_irq period signal sampled # of clocks past start 1 not used 2 2 irq1 5 3 nio_smi/irq2 8 4 irq3 11 5 irq4 14 6 irq5 17 7 irq6 20 8 irq7 23 9 irq8 26 10 irq9 29 11 irq10 32 12 irq11 35 13 irq12 38 14 irq13 41 15 irq14 44 16 irq15 47 the ser_irq data frame supports irq2 from a logical device on period 3, which can also be used for the system management interrupt (nsmi). when using period 3 for irq2 the user should mask off the smi via the smi enable register. likewise, when using period 3 for nsmi the user should not configure any logical devices as using irq2. ser_irq period 14 is used to transfer irq13. logical devices 0 (fdc), 3 (par port), 4 (ser port 1), 5 (ser port 2) and 7 (kbd) shall have irq13 as a choice for their primary interrupt. the smi is enabled onto the smi frame of the serial irq via bit 6 of smi enable register 2 and onto the smi pin via bit 7 of the smi enable register 2. stop cycle control once all irq/data frames have completed the host controller will terminate ser_irq activity by initiating a stop frame. only the host controller can initiate the stop frame. a stop frame is indicated when the ser_irq is low for two or three clocks. if the stop frame?s low time is two clocks then the next ser_irq cycle?s sampled mode is the quiet mode; and any ser_irq device may initiate a start frame in the second clock or more after the rising edge of the stop frame?s pulse. if the stop frame?s low time is three clocks then the next ser_irq cycle?s sampled mode is the continuos mode; and only the host controller may initiate a start frame in the second clock or more after the rising edge of the stop frame?s pulse. latency latency for irq/data updates over the ser_irq bus in bridge-less systems with the minimum host supported irq/data frames of seventeen, will range up to 96 clocks (3.84 m s with a 25mhz pci bus or 2.88us with a 33mhz pci bus). if one or more pci to pci bridge is added to a system, the latency for irq/data updates from the secondary or tertiary buses will be a few clocks longer for synchronous buses, and approximately double for asynchronous buses. 119 eoi/isr read latency any serialized irq scheme has a potential implementation issue related to irq latency. irq latency could cause an eoi or isr read to precede an irq transition that it should have followed. this could cause a system fault. the host interrupt controller is responsible for ensuring that these latency issues are mitigated. the recommended solution is to delay eois and isr reads to the interrupt controller by the same amount as the ser_irq cycle latency in order to ensure that these events do not occur out of order. ac/dc specification issue all ser_irq agents must drive / sample ser_irq synchronously related to the rising edge of pci bus clock. the ser_irq pin uses the electrical specification of pci bus. electrical parameters will follow pci spec. section 4, sustained tri-state. reset and initialization the ser_irq bus uses npci_reset as its reset signal. the ser_irq pin is tri-stated by all agents while npci_reset is active. with reset, ser_irq slaves are put into the (continuous) idle mode. the host controller is responsible for starting the initial ser_irq cycle to collect system?s irq/data default values. the system then follows with the continuous/quiet mode protocol (stop frame pulse width) for subsequent ser_irq cycles. it is host controller?s responsibility to provide the default values to 8259?s and other system logic before the first ser_irq cycle is performed. for ser_irq system suspend, insertion, or removal application, the host controller should be programmed into continuous (idle) mode first. this is to guarantee ser_irq bus is in idle state before the system configuration changes. 120 routable irq to serial irq conversion capability irqinx functions are on pins 61 (irqina), 62 (irqinb), 40 (irqinc) and 44 (irqind) and are muxed onto the gpio pins as inputs. the irqinx pin?s irq time slot in the serial irq stream is selected via a 4-bit control register for each irqinx function. a value of 0000 disables the irq function. these pins are implemented such that internal functions take precedence over the irqin pins, i.e. if the irqin control register is set to 0x06 and the internal floppy is set to 0x06, the floppy alone will drive the serial irq stream in the irq6 time slot. see configuration registers located at an offset 0xf4 and 0xf5 in logical device a. the internal irqs that are used for the devices in the part are given precedence over the irqs on the gpio pins. that is, if the irqx is selected for an activated logical device in the part through register 0x70, and it is enabled for use (see description below), then if the same irqx is programmed on its associated gpio pin, the external irqx will be blocked from the serial irq frame. if however the irqx is selected for an activated logical device in the part through register 0x70, and it is not enabled for use, then if the same irqx is programmed on its associated gpio pin, this external irq will go onto the serial irq frame. if the logical device is not activated then the irqx is not considered enabled. therefore, if an irq is selected for the logical device through register 0x70 and the logical device is activated, then the enable bit for the device, if present, is used to control whether the internal irq or the external irq on a gpio is placed onto the serial stream. the following devices have an enable bit: fdc, uart 1, uart2, the parallel port and the smbus controller. see ?note a. logical device irq and dma operation? in the ?configuration? section.. the following devices do not have an enable bit: keyboard, mouse, wdt. for these devices, the interrupt is enabled as follows: programming an irq in register 0x70 of logical device 7 enables the keyboard interrupt, programming an irq in register 0x72 of logical device 7 enables the mouse interrupt and programming an interrupt in the wdt_cfg register enables the wdt interrupt. note that the logical device must also be activated for the interrupt to be enabled. user note: in order to use the isa irqs muxed onto the gpio pins, the corresponding irq must not be used for any of the devices in the LPC47S42X. 121 8042 keyboard controller description the LPC47S42X is a super i/o and universal keyboard controller that is de signed for intelligent keyboard manage ment in desktop computer applica tions. the universal keyboard controller uses an 8042 microcontro ller cpu core. this section concentrates on the LPC47S42X en hancements to the 8042. for ge neral infor mation about the 8042, refer to the "hard- ware description of the 8042" in the 8-bit embedded controller hand book. 8042a p27 p10 p26 tst0 p23 tst1 p22 p11 kdat kclk mclk mdat keyboard and mouse interface ls05 kirq is the keyboard irq mirq is the mouse irq port 21 is used to create a gatea20 signal from the LPC47S42X. keyboard interface the LPC47S42X lpc interface is functionally compatible with the 8042 style host interface. it consists of the d0-7 data signals; the read and write signals and the status register, input data register, and output data register. table 45 shows how the interface decodes the control signals. in addition to the above signals, the host interface includes keyboard and mouse irqs. 122 table 45 - i/o address map address command block function (note 1) 0x60 write kdata keyboard data write (c/d=0) read kdata keyboard data read 0x64 write kdctl keyboard command write (c/d=1) read kdctl keyboard status read note 1: these registers consist of three separate 8 bit registers. status, data/command write and data read. keyboard data write this is an 8 bit write only register. when written, the c/d status bit of the status register is cleared to zero and the ibf bit is set. keyboard data read this is an 8 bit read only register. if enabled by "enable flags", when read, the kirq output is cleared and the obf flag in the status register is cleared. if not enabled, the kirq and/or auxobf1 must be cleared in software. keyboard command write this is an 8 bit write only register. when written, the c/d status bit of the status register is set to one and the ibf bit is set. keyboard status read this is an 8 bit read only register. refer to the description of the status register for more information. cpu-to-host communication the LPC47S42X cpu can write to the out put data register via register dbb. a write to this register auto matically sets bit 0 (obf) in the status register. see table 46. table 46 - host interface flags 8042 instruction flag out dbb set obf, and, if enabled, the kirq output signal goes high host-to-cpu communication the host system can send both commands and data to the input data regis ter. the cpu differentiates between commands and data by reading the value of bit 3 of the status register. when bit 3 is "1", the cpu interprets the register contents as a command. when bit 3 is "0", the cpu interprets the register contents as data. during a host write operation, bit 3 is set to "1" if sa2 = 1 or reset to "0" if sa2 = 0. kirq if "en flags" has been executed and p24 is set to a one: the obf flag is gated onto kirq. the kirq signal can be connected to sys tem interrupt to signify that the LPC47S42X cpu has written to the output data register via "out dbb,a". if p24 is set to a zero, kirq is forced low. on power-up, after a valid rst pulse has been delivered to the device, kirq is reset to 0. kirq will normally reflects the status of writes "dbb". (kirq is normally selected as irq1 for keyboard support.) if "en flags? has not been executed: kirq can be controlled by writing to p24. writing a zero to p24 forces kirq low; a high forces kirq high. 123 mirq if "en flags" has been executed and p25 is set to a one:; ibf is inverted and gated onto mirq. the mirq signal can be connected to sys tem interrupt to signify that the lpc47s4 2x cpu has read the dbb register. if "en flags? has not been executed, mirq is controlled by p25, writing a zero to p25 forces mirq low, a high forces mirq high. (mirq is normally selected as irq12 for mouse support). gate a20 a general purpose p21 is used as a software controlled gate a20 or user defined output. 8042 pins the 8042 functions p17, p16 and p12 are implemented as in a true 8042 part. reference the 8042 spec for all timing. a port signal of 0 drives the output to 0. a port signal of 1 causes the port enable signal to drive the output to 1 within 20-30nsec. after 500nsec (six 8042 clocks) the port enable goes away and the external pull-up maintains the output signal as 1. in 8042 mode, the pins can be programmed as open drain. when programmed in open drain mode, the port enables do not come into play. if the port signal is 0 the output will be 0. if the port signal is 1, the output tristates: an external pull-up can pull the pin high, and the pin can be shared. in 8042 mode, the pins cannot be programmed as input nor inverted through the gp configuration registers. external keyboard and mouse interface industry-standard pc-at-compatible keyboards employ a two-wire, bidirectional ttl interface for data transmission. several sources also supply ps/2 mouse products that employ the same type of interface. to facilitate system expansion, the LPC47S42X provides four signal pins that may be used to implement this interface directly for an external keyboard and mouse. the LPC47S42X has four high-drive, open-drain output, bidirectional port pins that can be used for external serial interfaces, such as external keyboard and ps/2-type mouse interfaces. they are kclk, kdat, mclk, and mdat. p26 is inverted and output as kclk. the kclk pin is connected to test0. p27 is inverted and output as kdat. the kdat pin is connected to p10. p23 is inverted and output as mclk. the mclk pin is connected to test1. p22 is inverted and output as mdat. the mdat pin is connected to p11. note: external pull-ups may be required. keyboard power management the keyboard provides support for two power-saving modes: soft powerdown mode and hard powerdown mode. in soft powerdown mode, the clock to the alu is stopped but the timer/counter and interrupts are still active. in hard power down mode the clock to the 8042 is stopped. soft power down mode this mode is entered by executing a halt instruction. the execution of program code is halted until either reset is driven active or a data byte is written to the dbbin register by a master cpu. if this mode is exited using the interrupt, and the ibf interrupt is enabled, then program execution resumes with a call to the interrupt routine, otherwise the next instruction is executed. if it is exited using reset then a normal reset sequence is initiated and program execution starts from program memory location 0. hard power down mode this mode is entered by executing a stop instruction. the oscillator is stopped by disabling the oscillator driver cell. when either reset is driven active or a data byte is written to the dbbin register by a master cpu, this mode will be exited (as above). however, as the oscillator cell will require an 124 initialization time, either reset must be held active for sufficient time to allow the oscillator to stabilize. program execution will resume as above. interrupts the LPC47S42X provides the two 8042 interrupts: ibf and the timer/counter overflow. memory configurations the LPC47S42X provides 2k of on-chip rom and 256 bytes of on-chip ram. register definitions host i/f data register the input data register and output data register are each 8 bits wide. a write to this 8 bit register will load the keyboard data read buffer, set the obf flag and set the kirq output if enabled. a read of this register will read the data from the keyboard data or command write buffer and clear the ibf flag. refer to the kirq and status register descriptions for more information. host i/f status register the status register is 8 bits wide. table 47 shows the contents of the status register. table 47 - status register d7 d6 d5 d4 d3 d2 d1 d0 ud ud ud ud c/d ud ibf obf status register this register is cleared on a reset. this register is read-only for the host and read/write by the LPC47S42X cpu. ud writable by LPC47S42X cpu. these bits are user-definable. c/d (command data)-this bit specifies whether the input data register contains data or a command (0 = data, 1 = command). during a host data/command write operation, this bit is set to "1" if sa2 = 1 or reset to "0" if sa2 = 0. ibf (input buffer full)- this flag is set to 1 whenever the host system writes data into the input data register. setting this flag activates the LPC47S42X cpu's nibf (mirq) interrupt if enabled. when the LPC47S42X cpu reads the input data register (dbb), this bit is automatically reset and the interrupt is cleared. there is no output pin associated with this internal signal. obf (o utput buffer full) - this flag is set to whenever the LPC47S42X cpu write to the output data register (dbb). when the host system reads the output data register, this bit is automatically reset. 125 external clock signal the LPC47S42X keyboard controller clock source is a 12 mhz clock generated from a 14.318 mhz clock. the reset pulse must last for at least 24 16 mhz clock periods. the pulse-width requirement applies to both internally (vcc por) and externally generated reset signals. in powerdown mode, the external clock signal is not loaded by the chip. default reset conditions the LPC47S42X has one source of hardware reset: an external reset via the npci_reset pin. refer to table 48 for the effect of each type of reset on the internal registers. table 48 - resets description hardware reset (npci_reset) kclk low kdat low mclk low mdat low host i/f data reg n/a host i/f status reg 00h n/a: not applicable gatea20 and keyboard reset the LPC47S42X provides two options for gatea20 and keyboard reset: 8042 software generated gatea20 and kreset and port 92 fast gatea20 and k reset . port 92 fast gatea20 and keyboard reset port 92 register this port can only be read or written if port 92 has been enabled via bit 2 of the krst_ga20 register (logical device 7, 0xf0) set to 1. this register is used to support the alternate reset (nalt_rst) and alternate a20 (alt_a20) functions. name port 92 location 92h default value 24h attribute read/write size 8 bits 126 port 92 register bit function 7:6 reserved. returns 00 when read 5 reserved. returns a 1 when read 4 reserved. returns a 0 when read 3 reserved. returns a 0 when read 2 reserved. returns a 1 when read 1 alt_a20 signal control. writing a 0 to this bit causes the alt_a20 signal to be driven low. writing a 1 to this bit causes the alt_a20 signal to be driven high. 0 alternate system reset. this read/write bit provides an alternate system reset function. this function provides an alternate means to reset the system cpu to effect a mode switch from protected virtual address mode to the real address mode. this provides a faster means of reset than is provided by the keyboard controller. this bit is set to a 0 by a system reset. writing a 1 to this bit will cause the nalt_rst signal to pulse active (low) for a minimum of 1 s after a delay of 500 ns. before another nalt_rst pulse can be generated, this bit must be written back to a 0. ngatea20 8042 p21 alt_a20 system na20m 0 0 0 0 1 1 1 0 1 1 1 1 bit 0 of port 92, which generates the nalt_rst signal, is used to reset the cpu under program control. this signal is and?ed together externally with the reset signal (nkbdrst) from the keyboard controller to provide a software means of resetting the cpu. this provides a faster means of reset than is provided by the keyboard controller. writing a 1 to bit 0 in the port 92 register causes this signal to pulse low for a minimum of 6s, after a delay of a minimum of 14s. before another nalt_rst pulse can be generated, bit 0 must be set to 0 either by a system reset of a write to port 92. upon reset, this signal is driven inactive high (bit 0 in the port 92 register is set to 0). if port 92 is enabled, i.e., bit 2 of krst_ga20 is set to 1, then a pulse is generated by writing a 1 to bit 0 of the port 92 register and this pulse is and?ed with the pulse generated from the 8042. this pulse is output on pin kreset and its polarity is controlled by the gpi/o polarity configuration. 127 8042 p92 pulse gen kbdrst krst_ga20 bit 2 bit 0 p20 krst nalt_rst 6us 14us ~ ~ 6us 14us ~ ~ note: when port 92 is disabled, writes are ignored and reads return undefined values. bit 1 of port 92, the alt_a20 signal, is used to force na20m to the cpu low for support of real mode compatible software. this signal is externally or?ed with the a20gate signal from the keyboard controller and cpurst to control the na20m input of the cpu. writing a 0 to bit 1 of the port 92 register forces alt_a20 low. alt_a20 low drives na20m to the cpu low, if a20gate from the keyboard controller is also low. writing a 1 to bit 1 of the port 92 register forces alt_a20 high. alt_a20 high drives na20m to the cpu high, regardless of the state of a20gate from the keyboard controller. upon reset, this signal is driven low. 128 latches on keyboard and mouse irqs the implementation of the latches on the keyboard and mouse interrupts is shown below. 8042 vcc d q kint kint new rd 60 clr klatch bit figure 3 - keyboard latch 129 8042 vcc d q mint mint new rd 60 clr mlatch bit figure 4 ? mouse latch the klatch and mlatch bits are located in the krst_ga20 register, in logical device 7 at 0xf0. these bits are defined as follows: bit[4]: mlatch ? mouse interrupt latch control bit. 0=mint is the 8042 mint anded with latched mint (default), 1=mint is the latched 8042 mint. bit[3]: klatch ? keyboard interrupt latch control bit. 0=kint is the 8042 kint anded with latched kint (default), 1=kint is the latched 8042 kint. see the configuration section for description on these registers. 130 keyboard and mouse pme generation the LPC47S42X sets the associated pme status bits when the following conditions occur: keyboard interrupt mouse interrupt active edge on keyboard data signal (kdat) active edge on mouse data signal (mdat) these events can cause a pme to be generated if the associated pme wake enable register bit and the global pme_en bit are set. refer to the pme support section for more details on the pme interface logic and refer to the runtime register section for details on the pme status and enable registers. the keyboard interrupt and mouse interrupt pmes can be generated when the part is powered by vcc. the keyboard data and mouse data pmes can be generated both when the part is powered by vcc, and when the part is powered by vtr (vcc=0). when using the keyboard and mouse for wakeup, it may be necessary to isolate the keyboard and mouse signals (kclk, kdat, mclk, mdat) from the 8042 prior to entering certain system sleep states. this is due to the fact that the normal operation of the 8042 can prevent the system from entering or exiting a sleep state, or trigger false pme events. the LPC47S42X has ?isolation? bits for the keyboard and mouse signals, which allow the keyboard and mouse data signals to go into the wakeup logic but block the keyboard clock and data signals and the mouse clock and data signals from the 8042. these bits may be used when it is necessary to isolate the 8042 keyboard and mouse signals from the 8042 before entering a system sleep state. see the smsc application note titled ?using the enhanced keyboard and mouse wakeup feature in smsc super i/o parts? for more information. the bits used to isolate the keyboard and mouse signals from the 8042 are located in logical device 7, register 0xf0 (krst_ga20) and are defined as follows: bit[6] m_iso. enables/disables isolation of mouse signals into 8042. does not affect the mdat signal to the mouse wakeup (pme) logic. 1=block mouse clock and data signals into 8042 0= do not block mouse clock and data signals into 8042 bit[5] k_iso. enables/disables isolation of keyboard signals into 8042. does not affect the kdat signal to the keyboard wakeup (pme) logic. 1= block keyboard clock and data signals into 8042 0= do not block keyboard clock and data signals into 8042 when the keyboard and/or mouse isolation bits are used, it may be necessary to reset the 8042 upon exiting the sleep state. if either of the isolation bits is set prior to entering a sleep state where vcc goes inactive (s3-s5), then the 8042 must be reset upon exiting the sleep mode. write 0x40 to global configuration register 0x2c to reset the 8042. the 8042 must then be taken out of reset by writing 0x00 to register 0x2c since the bit that resets the 8042 is not self-clearing. caution: bit 6 of configuration register 0x2c is used to put the 8042 into reset - do not set any of the other bits in register 0x2c, as this may produce undesired results. it is not necessary to reset the 8042 if the isolation bits are used for a sleep state where vcc does not go inactive (s1, s2). 131 general purpose i/o the LPC47S42X provides a set of flexible input/output control functions to the system designer through the 39 dedicated independently programmable general purpose i/o pins (gpio). the gpio pins can perform basic i/o and many of them can be individually enabled to generate an smi and a pme. gpio pins the following pins include gpio functionality. these pins are defined in the table below. gpio pin functionality pin name power well default on vtr por default on vcc por smi/pme functionality 1 gp40 /drvden0 vcc input - nio_pme 2 gp41 /drvden1/nxcs0 vcc note 1 input - pme/smi 17 gp42 /nio_pme vtr input - nio_pme 28 gp43 /ddrc /nxcs1 vcc note 1 input gpio function pme/smi 32 gp10 /xd0 vcc note 1 input - pme/smi 33 gp11 /xd1 vcc note 1 input - pme/smi 34 gp12 /xd2 vcc note 1 input - pme/smi 35 gp13 /xd3 vcc note 1 input - pme/smi 36 gp14 /xd4 vcc note 1 input - pme/smi 37 gp15 /xd5 vcc note 1 input - pme/smi 38 gp16 /xd6 vcc note 1 input - pme/smi 39 gp17 /xd7 vcc note 1 input - pme/smi 41 gp20 /p17 /nds1 vcc note 1 input - pme/smi 40 gp62 /p17 /irqinc vcc input - - 42 gp21 /p16 /irq6 vcc note 1 input - pme/smi 43 gp22 /p12 / nmtr1 vcc note 1 input - pme/smi 44 gp23 /irqind vcc note 1 input - pme 45 gp24 /sysopt vcc note 1 input - pme/smi 46 gp25 /nxrd vcc note 1 input - pme/smi 47 gp26 /nxwr vcc note 1 input - pme/smi 48 gp60 /led1 vtr note 1 input - pme/smi 49 gp61 /led2 vtr note 1 input - pme/smi 50 gp27 /nio_smi vcc note 1 input - pme/smi/ nio_smi 51 gp30 / sclk /nxcs2 /xa2 vcc note 1 input - pme/smi 52 gp31 /fan_tach /nxcs3 /xa3 vcc note 1 input - pme/smi 54 gp32 /sdat /xa0 vcc note 1 input - pme/smi 55 gp33 /fan /xa1 vcc note 1 input output, low pme/smi 61 gp34 /irq12 /irqina vcc note 1 input - pme/smi 62 gp35 /irq14 /irqinb vcc note 1 input - pme/smi 63 gp36 /nkbdrst vcc note 1 input - pme/smi 64 gp37 /a20m vcc note 1 input - pme/smi 92 gp50 /nri2 vcc note 1 input - pme/smi 132 pin name power well default on vtr por default on vcc por smi/pme functionality 94 gp51 /ndcd2 vcc no te 1 input - pme/smi 95 gp52 /rxd2/irrx vcc note 1 input - pme/smi 96 gp53 /txd2/irtx vtr note 1 output, low output, low pme/smi 97 gp54 /ndsr2 vcc note 1 input - pme/smi 98 gp55 /nrts2 vcc note 1 input - pme/smi 99 gp56 /ncts2 vcc note 1 input - pme/smi 100 gp57 /ndtr2 vcc note 1 input - pme/smi note 1: these pins have input buffers into the wakeup logic that are powered by vtr. description each gpio port has a 1-bit data register and an 8-bit configuration control register. the data register for each gpio port is represented as a bit in one of the 8-bit gpio data registers, gp1 to gp8. the bits in these registers reflect the value of the associated gpio pin as follows. pin is an input: the bit is the value of the gpio pin. pin is an output: the value written to the bit goes to the gpio pin. latched on read and write. all of the gpio registers are located in the runtime register block; see the runtime registers section. the gpio ports with their alternate functions and configuration state register addresses are listed in the table on the following page. 133 general purpose i/o port assignments pin no. /qfp default function alt. func. 1 alt func.2 alt. func. 3 data register 1 data register bit no. register offset (hex) 32 gpio x-bus data 0 0 33 gpio x-bus data 1 1 34 gpio x-bus data 2 2 35 gpio x-bus data 3 3 36 gpio x-bus data 4 4 37 gpio x-bus data 5 5 38 gpio x-bus data 6 6 39 gpio x-bus data 7 gp1 7 4b 41 gpio p17 drive select 1 0 42 gpio p16 p12 eeti 1 43 gpio p12 motor on 1 eeti 2 44 gpio irq input d 3 45 gpio 4 46 gpio x-bus read strobe 5 47 gpio x-bus write strobe 6 50 gpio nio_smi gp2 7 4c 51 gpio smbus clock x-bus chip select 2 x-bus address 2 0 52 gpio fan tachometer input x-bus chip select 3 x-bus address 3 1 54 gpio smbus data x-bus address 0 2 55 gpio fan control x-bus address 1 3 61 gpio irq input a 4 62 gpio irq input b 5 63 gpio keyboard reset 6 64 gpio gate a20 gp3 7 4d 1 gpio drive density select 0 0 2 gpio drive density select 1 eeti 1 17 gpio power management event 2 28 gpio device disable reg. control x-bus chip select 1 eeti gp4 3 4e 134 pin no. /qfp default function alt. func. 1 alt func.2 alt. func. 3 data register 1 data register bit no. register offset (hex) n/a reserved 4 n/a reserved 5 n/a reserved 6 n/a reserved 7 92 gpio ring indicator 2 0 94 gpio data carrier detect 2 1 95 gpio receive serial data 2 infrared receive 2 96 gpio transmit serial data 2 infrared transmit 3 97 gpio data set ready 2 4 98 gpio request to send 2 5 99 gpio clear to send 2 6 100 gpio date terminal ready 2 gp5 7 4f 48 gpio led1 eeti 0 49 gpio led2 eeti 1 40 gpio p17 2 n/a reserved 3 n/a reserved 4 n/a reserved 5 n/a reserved 6 n/a reserved gp6 7 50 note 1: the gpio data and configuration registers are located in pme block at the offset shown from the runtime registers block address. 135 gpio control each gpio port has an 8-bit control register that controls the behavior of the pin. these registers are defined in the ?runtime registers? section of this specification. each gpio port may be configured as either an input or an output. if the pin is configured as an output, it can be programmed as open-drain or push-pull. inputs and outputs can be configured as non- inverting or inverting. bit[0] of each gpio configuration register determines the port direction, bit[1] determines the signal polarity, and bit[7] determines the output driver type select. the gpio configuration register output type select bit[7] applies to gpio functions and the nsmi alternate functions. the polarity bit (bit 1) of the gpio control registers control the gpio pin when the pin is configured for the gpio function and when the pin is configured for the alternate function for all pins, with the exception of the ddrc function on gp43 and the either edge triggered interrupts. the basic gpio configuration options are summarized in the following table. gpio configuration summary selected function direction bit polarity bit description b0 b1 gpio 0 0 pin is a non-inverted output 0 1 pin is an inverted output 1 0 pin is a non-inverted input 1 1 pin is an inverted input 136 gpio operation the operation of the gpio ports is illustrated in the figure below. note: the following figure is for illustration purposes only and in not intended to suggest specific implementation details. note: when the following functions are selected, the associated gpio pins have bi-directional functionality: p12, p16, p17. when a gpio port is programmed as an input, reading it through the gpio data register latches either the inverted or non-inverted logic value present at the gpio pin. writing to a gpio port that is programmed as an input has no effect. when a gpio port is programmed as an output, the logic value or the inverted logic value that has been written into the gpio data register is output to the gpio pin. reading from a gpio port that is programmed as an output returns the last value written to the data register. gpio pin gpio data register bit-n sd-bit gpx_nior gpio configuration register bit-1 (polarity) gpio configuration register bit-0 (input/output) 1 0 d-type transparent gpx_niow d q q d gpio function illustration 137 host operation gpio input port gpio output port read latched value of gpio pin last write to gpio data register write no effect bit placed in gpio data register gpio read/write behavior the LPC47S42X provides 36 gpios that can directly generate a pme. see the table in the next section. the polarity bit in the gpio control registers select the edge on these gpio pins that will set the associated status bit in the pme_sts2 ? pme_sts7 registers. the default is the low-to-high edge. if the corresponding enable bit in the pme_en 2 ? pme_en7 registers and the pme_en bit in the pme_en register is set, a pme will be generated. these registers are located in the runtime registers block, which are located at the address contained in the configuration registers 0x60 and 0x61 in logical device a. the pme status bits for the gpios are cleared on a write of ?1?. in addition, the LPC47S42X provides 35 gpios that can directly generate an smi. see the table in the next section. gpio pme and smi functionality the following gpios are dedicated wakeup gpios with a status and enable bit in the pme status and enable registers: gp10-gp17 gp20-gp27 gp30-gp37 gp41, gp43 gp50-gp57 gp60, gp61 this following is the list of pme status and enable registers for their corresponding gpios: pme_sts2 and pme_en2 for gp10-gp17 pme_sts3 and pme_en3 for gp20-gp27 pme_sts4 and pme_en4 for gp30-gp33, gp41, gp43, gp60, gp61 pme_sts5 and pme_en5 for gp50-gp57 pme_sts7 and pme_en7 for gp34-gp37 the following gpios can directly generate an smi and have a status and enable bit in the smi status and enable registers. gp10-gp17 gp20-22, gp24-27 gp30-gp37 gp41, gp43 gp50-gp57 gp60, gp61 the following smi status and enable registers for these gpios: smi_sts3 and smi_en3 for gp20-22, gp24-27, gp60 smi_sts4 and smi_en4 for gp30-gp33, gp41, gp43, gp61 smi_sts5 and smi_en5 for gp50-gp57 smi_sts5 and smi_en5 for gp10-gp17 138 smi_sts7 and smi_en7 for gp34-gp37 the following gpios have ?either edge triggered interrupt? (eeti) input capability. these gpios can generate a pme and an smi on both a high-to-low and a low-to-high edge on the gpio pin. these gpios have a status bit in the msc_sts status register that is set on both edges. the corresponding bits in the pme and smi status registers are also set on both edges. gp21, gp22 gp41, gp43 gp60, gp61 the following table summarizes the pme and smi functionality for each gpio. it also shows the either edge triggered interrupt (eeti) input capability for the gpios and the power source for the buffer on the i/o pads. gpio pme smi eeti output buffer power notes gp10-gp17 yes yes no vcc gp20-gp26 yes yes gp21-gp22 vcc gp27 yes yes/nio_smi no vcc 5 gp30-gp37 yes yes no vcc 2 gp41 yes no yes vcc 1 gp42 nio_pme no no vtr gp43 yes yes yes vcc 3 gp50-gp57 yes yes no vcc 4 gp60 yes no yes vcc gp61 yes yes yes vcc gp62 yes no no vcc 1 note 1: gp40 and gp62 should not be connected to any vtr powered external circuitry. these pins are not used for wakeup. note 2: the gp33 pin cannot be used for wakeup to generate a pme while the part is under vtr power (vcc=0) since gp33 is the fan pin which comes up as output and low on a vcc por and hard reset . this pin reverts to its non-inverting gpio output function when vcc is removed from the part. note 3: gp43 defaults to the gpio function on vcc por and hard reset. note 4: gp53 pin cannot be used for wakeup to generate a pme while the part is under vtr power (vcc=0) since gp53 is the irtx pin which comes up as output and low on a vtr por, vcc por and hard reset. this pin is a non-inverting gpio output (low) when vcc is removed from the part. note 5: since gp27 can be used to generate an smi and as the nio_smi output, do not enable gp27 to generate an smi (by setting bit 7 of the smi enable register 3) if the nio_smi function is selected on the gp27 pin. use gp27 to generate an smi event only if the smi output is enabled on the serial irq stream. 139 either edge triggered interrupts six gpio pins are implemented such that they allow an interrupt (pme or smi) to be generated on both a high-to-low and a low-to-high edge transition, instead of one or the other as selected by the polarity bit. the either edge triggered interrupts (eeti) function as follows: if the eeti function is selected for the gpio pin, then the bits that control input/output, polarity and open collector/push-pull have no effect on the function of the pin. however, the polarity bit does affect the value of the gp bit (i.e., register gp2, bit 2 for gp22). a pme or smi interrupt occurs if the pme or smi enable bit is set for the corresponding gpio and the eeti function is selected on the gpio. the pme or smi status bits are set when the eeti pin transitions (on either edge) and are cleared on a write of ?1?. there are also status bits for the eetis located in the msc_sts register, which are also cleared on a write of ?1?. the msc_sts register provides the status of all of the eeti interrupts within one register. the pme, smi or msc status is valid whether or not the interrupt is enabled and whether or not the eeti function is selected for the pin. miscellaneous status register (msc_sts) is for the either edge triggered interrupt status bits. if the eeti function is selected for a gpio then both a high-to-low and a low-to-high edge will set the corresponding msc status bits. status bits are cleared on a write of ?1?. see runtime register section for more information. led functionality the LPC47S42X provides led functionality on two gpios, gp60 and gp61. these pins can be configured to turn the led on and off and blink independent of each other through the led1 and led2 runtime registers at offset 0x5d and 0x5e from the base address located in the primary base i/o address in logical device a. the led pins (gp60 and gp61) are able to control the led while the part is under vtr power with vcc removed. in order to control a led while the part is under vtr power, the gpio pin must be configured for the led function and either open drain or push-pull buffer type. in the case of open-drain buffer type, the pin is capable of sinking current to control the led. in the case of push-pull buffer type, the part will source current. the part is also able to blink the led under vtr power. the led will not blink under vtr power (vcc removed) if the external 32khz clock is not connected. the led pins can drive a led when the buffer type is configured to be push-pull and the part is powered by either vcc or vtr, since the buffers for these pins are powered by vtr. this means they will source their specified current from vtr even when vcc is present. the gp61 pin defaults to the led function active (blinking at a 1 hz rate, 50% duty cycle) on initial power up (as long as the 32 khz clock input is active). the led control registers are defined in the ?runtime register? section. 140 watch dog timer the LPC47S42X contains a watch dog timer (wdt). the watch dog time-out status bit may be mapped to an interrupt through the wdt_cfg configuration register. the LPC47S42X's wdt has a programmable time-out ranging from 1 to 255 minutes with one minute resolution, or 1 to 255 seconds with 1 second resolution. the units of the wdt timeout value are selected via bit[7] of the wdt_timeout register (ld8:crf1.7). the wdt time-out value is set through the wdt_val configuration register. setting the wdt_val register to 0x00 disables the wdt function (this is its power on default). setting the wdt_val to any other non-zero value will cause the wdt to reload and begin counting down from the value loaded. when the wdt count value reaches zero the counter stops and sets the watchdog time-out status bit in the wdt_ctrl configuration register. note: regardless of the current state of the wdt, the wdt time-out status bit can be directly set or cleared by the host cpu. there are three system events that can reset the wdt. these are a keyboard interrupt, a mouse interrupt and i/o reads/writes to address 0x201 (an external joystick port). the effect on the wdt for each of these system events may be individually enabled or disabled through bits in the wdt_cfg configuration register. when a system event is enabled through the wdt_cfg register, the occurrence of that event will cause the wdt to reload the value stored in wdt_val and reset the wdt time-out status bit if set. if all three system events are disabled the wdt will inevitably time out. the watch dog timer may be configured to generate an interrupt on the rising edge of the time-out status bit. the wdt interrupt is mapped to an interrupt channel through the wdt_cfg configuration register. when mapped to an interrupt the interrupt request pin reflects the value of the wdt time-out status bit. the host may force a watch dog time-out to occur by writing a "1" to bit 2 of the wdt_ctrl (force wd time-out) configuration register. writing a "1" to this bit forces the wdt count value to zero and sets bit 0 of the wdt_ctrl (watch dog status). bit 2 of the wdt_ctrl is self-clearing. see the runtime registers section for a description on these registers. system management interrupt (smi) the LPC47S42X implements a ?group? nio_smi output pin. the system management interrupt is a non-maskable interrupt with the highest priority level used for os transparent power management. the nsmi group interrupt output consists of the enabled interrupts from super i/o device interrupts and many of the gpios pins. the gp27/nio_smi pin, when selected for the nio_smi function, can be programmed to be active high or active low via the polarity bit in the gp27 register. the output buffer type of the pin can be programmed to be open-drain or push-pull via bit 7 of the gp27 register. the nio_smi pin function defaults to active low, open-drain output. the interrupts are enabled onto the group nsmi output via the smi enable registers 1 to 7. the nsmi output is then enabled onto the group nio_smi output pin via bit[7] in the smi enable register 2. the smi output can also be enabled onto the serial irq stream (irq2) via bit[6] in the smi enable register 2. 141 an example logic equation for the nsmi output for smi registers 1 and 2 is as follows: nsmi = (en_pint and irq_pint) or (en_u2int and irq_u2int) or (en_u1int and irq_u1int) or (en_fint and irq_fint) or (en_wdt and irq_wdt) or (en_mint and irq_mint) or (en_kint and irq_kint) or (en_smbus and irq_smbus) or (en_ri1 and irq_ri1) or (en_p12 and irq_p12) or (en_ri2 and irq_ri2) note: the prefixes en and irq are used above to indicate smi enable bit and smi status bit respectively. smi registers the smi event bits for the gpios and the fan tachometer events are located in the smi status and enable registers 3-5. the polarity of the edge used to set the status bit and generate an smi is controlled by the polarity bit of the control registers. for non-inverted polarity (default) the status bit is set on the low-to-high edge. if the eeti function is selected for a gpio then both a high-to-low and a low-to-high edge will set the corresponding smi status bit. status bits for the gpios are cleared on a write of ?1?. the smi logic for these events is implemented such that the output of the status bit for each event is combined with the corresponding enable bit in order to generate an smi. the p12 and p16 bits enable an smi event on single high-to-low edge or on both high-to-low and low- to-high edges. default is single edge. there is also a polarity select bit for p12 in the configuration register 0xf0 in logical device 7. the register that selects the edge, edge select register, is located at the address programmed in the base i/o address register in the logical device a at an offset of 21h. refer also to pme status and enable register 2. see the runtime registers sections for description on these registers. if both edges are selected for generating an smi via p16, then the smi is asserted on each edge until the p16 smi status bit is cleared. if both edges are selected for generating an smi via p12, then a short pulse (20ns) is generated on each edge. however the p12 smi status bit is set on each edge until cleared. the p12 smi is not recommended to be used in this mode of operation. note that p12 and p16 smi status bits are cleared by a write of ?1?. the smi generated by p16 is also deasserted when the p16 smi status bit is written to ?1?. however, the smi generated by p12 is cleared at the source. the smi logic for the p16 event is implemented such that the output of the status bit for the event is combined with the corresponding enable bit in order to generate an smi. the smi registers are accessed at an offset from runtime registers block (see runtime register section for more information). the smi event bits for the super i/o devices are located in the smi status and enable register 1 and 2. all of these status bits are cleared at the source except for irint, which is cleared by a read of the smi_sts2 register; these status bits are not cleared by a write of ?1?. the smi logic for these events is implemented such that each event is directly combined with the corresponding enable bit in order to generate an smi. see the ?runtime registers? section for the definition of these registers. 142 acpi support register for smi generation the acpi pm1 control register is implemented in the LPC47S42X to allow the generation of an smi when the slp_en bit (pm1_cntrl2 bit 5) is written to ?1?. the slp_typx field (bits[4:2]) is also read/write but has no functionality in the part. the pm1_cntrl1 and pm1_cntrl2 registers implement the acpi pm1 control register. these registers are located at the address programmed in the base i/o address in logical device a at the offset of 0x60, 0x61. s oftware will treat these as a 16-bit register since the two 8-bit registers are adjacent. bit[5] in the smi_sts7 register is the status bit and bit[5] in the smi_en7 register is the enable bit for the generation of the smi when the slp_en bit is written to ?1?. these registers are located at the address programmed in the base i/o address in logical device a at the offset of 0x64 and 0x66. see the runtime registers section for description on these registers. pme support the LPC47S42X offers support for power management events (pmes), also referred to as system control interrupt (sci) events in an acpi system. a power management event is indicated to the chipset via the assertion of the nio_pme signal. in the LPC47S42X, the nio_pme is asserted by active transitions on the ring indicator inputs nri1 and nri2, active keyboard-data edges, active mouse-data edges, wakeup on specific key, super i/o device interrupts, watchdog timer, programmable edges on gpio pins and fan tachometer event. the gp42/nio_pme pin, when selected for the nio_pme function, can be programmed to be active high or active low via the polarity bit in the gp42 register. the output buffer type of the pin can be programmed to be open-drain or push-pull via bit 7 of the gp42 register. the nio_pme pin function defaults to active low, open-drain output. pme functionality is controlled by the pme status and enable registers in the runtime registers block, which is located at the address programmed in configuration registers 0x60 and 0x61 in logical device a. the pme enable bit, pme_en, globally controls pme wake-up events. when pme_en is inactive, the nio_pme signal can not be asserted. when pme_en is asserted, any wake source whose individual pme wake enable register bit, is asserted can cause nio_pme to become asserted. the pme wake status register indicates that an enabled wake source has occurred and if the pme_en bit is set, asserted the nio_pme signal. the pme status bit is asserted by active transitions of pme wake sources. pme_sts will become asserted independent of the state of the global pme enable, pme_en. the following pertains to the pme status bits for each event: the output of the status bit for each event is combined with the corresponding enable bit to set the pme status bit. the status bit for any pending events must be cleared in order to clear the pme_sts bit. for the gpio events, the polarity of the edge used to set the status bit and generate a pme is controlled by the polarity bit of the gpio control register. for non-inverted polarity (default) the status bit is set on the low-to-high edge. if the eeti function is selected for a gpio then both a high-to-low and a low-to-high edge will set the corresponding pme status bits. status bits are cleared on a write of ?1?. the pme wake registers also include status and enable bits for the fan tachometer input. 143 see the ?keyboard and mouse pme generation? section for information about using the keyboard and mouse signals to generate a pme. the p12 and p16 bits enable a pme event on single high-to-low edge or on both high-to-low and low- to-high edges. default is single edge. there is also a polarity select bit in the configuration register at 0xf0 in logical device 7. the register that selects the edge, edge select register, is located at the address programmed in the base i/o address register in the logical device a at an offset of 21h. refer also to pme status and enable register 9. see the runtime registers sections for description on these registers. if both edges are selected for generating a pme via p12 or p16, then the pme is asserted on each edge until the corresponding pme status bit is cleared. note that p12 and p16 status bits are cleared on by write of ?1?. the smi generated by p12 and p16 is deasserted when the associated pme status bit is cleared. in the LPC47S42X the nio_pme pin can be programmed to be an open drain, active low, driver. the LPC47S42X nio_pme pin is fully isolated from other external devices that might pull the nio_pme signal low; i.e., the nio_pme signal is capable of being driven high externally by another active device or pullup even when the LPC47S42X vcc is grounded, providing vtr power is active. the LPC47S42X nio_pme driver sinks 6ma at .55v max (see section 4.2.1.1 dc specifications, page 122, in the pci local bus specification, revision 2.1). the pme registers are run-time registers as follows. these registers are located in system i/o space at an offset from runtime registers block, the address programmed in logical device a at registers 0x60 and 0x61. the following registers are for gpio pme events: pme wake status 2 (pme_sts2), pme wake enable 2 (pme_en2) pme wake status 3 (pme_sts3), pme wake enable 3 (pme_en3) pme wake status 4 (pme_sts4), pme wake enable 4 (pme_en4) pme wake status 5 (pme_sts5), pme wake enable 5 (pme_en5) pme wake status 7 (pme_sts7), pme wake enable 7 (pme_en7) the pme wake status 6 (pme_sts6), pme wake enable 6 (pme_en6) registers are for the device interrupt pme events. the pme wake status 1 (pme_sts1), pme wake enable 1 (pme_en1) registers are for pin and internal function pme events. see pme register description in the runtime register section. wake on specific key option the LPC47S42X has logic to detect a single keyboard scan code for wakeup (pme generation). the scan code is programmed onto the keyboard scan code register, a runtime register at offset 0x5f from the base address located in the primary base i/o address in logical device a. this register is powered by vtr and reset on vtr por. the pme status bit for this event is located in the pme_sts1 register at bit 5 and the pme enable bit for this event is located in the pme_en1 register at bit 5. see the runtime register section for a definition of these registers. 144 data transmissions from the keyboard consist of an 11-bit serial data stream. a logic 1 is sent at an active high level. the following table shows the functions of the bits. bit function 1 start bit (always 0) 2 data bit 0 (least significant bit) 3 data bit 1 4 data bit 2 5 data bit 3 6 data bit 4 7 data bit 5 8 data bit 6 9 data bit 7 (most significant bit) 10 parity bit (odd parity) 11 stop bit (always 1) the timing for the keyboard clock and data signals are shown in the ?timing diagrams? section. the clk32_prsn bit (bit 0 of the clocki32 register at 0xf0 in logical device a) will determine the clock source for this feature when the part is powered by vcc. if the external 32khz clock is not connected, the 32khz internal signal is derived from the 14mhz clock when vcc is active. use the 32khz clock for this feature when the part is under trickle power. this feature will not work when the part is under trickle power (vcc removed) if the external 32khz clock is not connected. the spekey_en bit at bit 1 of the clocki32 register at 0xf0 in logical device a is used to control this feature. this bit is used to turn the logic for this feature on and off. it will disable the 32khz clock input to the logic. the logic will draw no power when disabled. the bit is defined as follows: 0= wake on specific key logic is on (default) 1= wake on specific key logic is off note: the generation of a pme for this event is controlled by the pme enable bit (located in the pme_en1 register at bit 5) when the logic for feature is turned on. 145 fan speed control and monitoring the LPC47S42X implements fan speed control outputs and fan tachometer inputs. the implementation of these features are described in the sections below. fan speed control the fan speed control for the LPC47S42X is implemented as pulse width modulators with fan clock speed selection. pin 55 is the fan speed control output fan, muxed with gpios. this fan control pin come up as output and is low following a vcc por and hard reset. this pin may not be used for wakeup events under vtr power (vcc=0). the register is defined in the ?runtime registers? section. fan speed control summary the following table illustrates the different modes for the fan. table 49 ? different modes for fan fan clock control bit (note 1) fan clock multiplier bit (note 2) fan clock source select bit (note 3) fan clock select bit (note 4) f out 6-bit duty cycle control bits[6:1] (dcc) duty cycle (%) 0 x x x 0hz ? low 0 - 0 0 0 0 15.625khz 1-63 (dcc/64) 0 0 0 1 23.438khz 100 0 0 1 0 40hz 0 0 1 1 60hz 0 1 0 0 31.25khz 0 1 0 1 46.876khz 0 1 1 0 80hz 0 1 1 1 120hz 1 x x x 0hz ? high - - note 1: this is fan register bit 0 note 2: this is fan control register bit 2 note 3: this is fan control register bit 0 note 4: this is fan register bit 7 146 fan register the fan register is located at 0x56 from base i/o in logical device a. see register description in the runtime registers section. fan clock select, d7 the fan clock select bit in the fan registers is used with the fan clock source select and the fan clock multiplier bits in the fan control register to determine the fan speed f out . see table 49 above. duty cycle control, d6 ? d1 the duty cycle control (dcc) bits determine the fan duty cycle. the LPC47S42X has ? 1.56% duty cycle resolution. when dcc = ?000000? (min. value), f out is always low. when dcc is ?111111? (max. value), f out is almost always high; i.e., high for 63/64 th and low for 1/64 th of the f out period. generally, the f out duty cycle (%) is (dcc ? 64) 100. fan clock control, d0 the fan clock control bit d0 is used to override the duty cycle control bits and force f out always high. when d0 = ?0?, the dcc bits determine the f out duty cycle. when d0 = 1, f out is always high, regardless of the state of the dcc bits. fan control register the fan control register is located at 0x58 from base i/o in logical device a. see the register description in the runtime registers section. fan count divisor, d5 ? d4 fan count divisor bit in fan control register is used to determine fan tachometer count. the choices for the divisor are 1, 2, 4 and 8. see fan tachometer input section. fan clock multiplier, d2 the fan clock multiplier bit is used with the fan clock source select bit in the fan control register and the fan clock select bit in fan register to determine the f out . when the fan clock multiplier bit = ?0?, no clock multiplier is used. when the fan clock multiplier bit = ?1?, the clock speed determined by the fan clock source select bit is doubled. fan clock source select, d0 the fan clock source select and the fan clock multiplier bits in the fan control register is used with the fan clock select bit in the fan registers to determine the fan speed f out . see table 49 above. fan tachometer input the LPC47S42X implements fan tachometer input for signals from fans equipped with tachometer outputs. the part can generate both a pme and an smi when the fan speed drops below a predetermined value. see description below. 147 the clock source for the tachometer count is the 32.768khz oscillator. the fan tachometer input gate a divided down version of the 32.768khz oscillator for one period of the fan signal into an 8-bit counter (maximum count is 255). the clock source is determined by the clk32_prsn bit in the clocki32 register in logical device a. it is either the 32.768khz clock from the clki32 pin or an internal 32.765khz clock derived from the 14mhz clock. the fan tachometer input signal and clock source is shown below. the counter is reset by the rising edge of each pulse (and by writing the preload register). the counter does not wrap; if it reaches 0xff, it remains at 0xff until it is reset by the next pulse. the 2 msbs of the count are sampled and a pme or smi is generated (if enabled through the pme_en1 enable register or the smi_en5 enable register - see the ?runtime registers? section) when these two bits are set. this corresponds to a count value of 192. t r t p f = 32.786khz ? divisor fan tachometer input clock source for counter t r = revolution time = 60/rpm (sec) t p = pulse time = t r /2 (two pulses per revolution) 148 the fan count is determined according to the following equation: 1 1.966 x 10 6 count = 2 x rpm x divisor + preload (equation 1) (term 1) term 1 in the equation above is determined by multiplying the clock source of 32.768khz by 60sec/min and dividing by the product of the revolutions per minute times the divisor. the default divisor, located in the fan control register, is 2. this results in a value for term 1 in equation 1 of 111 for a 4400 rpm. the divisor for fan is programmable via the fan control register, logical device 8, 0xfa . the choices for the divisor are 1, 2, 4 and 8. the default value is 2. the factor of ? in term 1 corresponds to two pulses per revolution. the preload value is programmable via the fan preload register. the preload is the initial value for the fan count which is used to adjust the count such that the value of 192 corresponds to the ?lower limit? of the rpm. by setting the preload value and divisor properly, the pme or smi will be generated when the rpm reaches the desired percentage of the nominal rpm to indicate a fan failure. a pme or smi is generated, if enabled through the pme or smi enable register, at a count of 192, which corresponds to the ?upper limit? for the fan count. this value is made to correspond to the ?lower limit? of the rpm for the fan by programming the divisor and preload value accordingly. typical practice is to consider 70% of normal rpm a fan failure, at which point term 1 in equation 1 for the example above will be 160. therefore, the preload value is chosen to be 32 so that when the count reaches 192, this will correspond to 70% of the normal rpm for the generation of a pme or smi. a representation of the logic for the fan tachometer implementation is shown below. 149 programmable divider 1, 2, 4, 8 counter preload latch on read sync to pme# logic 32 khz msb the following tables show examples of the desired functionality. counts are based on 2 pulses per revolution tachometer outputs with a default divisor of 2. rpm time per revolution term 1 for ?divide by 2? (default) in decimal preload count = (term 1) + preload comments 4400 13.64 ms 112 counts 32 144 typical rpm 3080 19.48 ms 160 counts 32 192 70% rpm 2640 22.73 ms 186 counts 32 218 60% rpm 2204 27.22 ms 223 counts 32 255 (maximum count) 50% rpm mode select nominal rpm time per revolution preload counts for the given speed in decimal 70% rpm time per revolution for 70% rpm divide by 1 8800 6.82 ms 32 144 6160 9.74 ms divide by 2 4400 13.64 ms 32 144 3080 19.48 ms divide by 4 2200 27.27 ms 32 144 1540 38.96 ms divide by 8 1100 54.54 ms 32 144 770 77.92 ms pin 52 is the fan tachometer input fan_tach. the fan tachometer register and fan preload register are defined in the ?runtime registers? section. 150 security feature the following register describes the functionality to support security in the LPC47S42X. gpio device disable register control the gpio pin gp43 is used for the device disable register control (ddrc) function. setting bits[3:2] of the gp43 configuration register to ?01?, selects the ddrc function for the gp43 pin. when bits[3:2]=01 the gp43 pin is an input, with non-inverted polarity. bits[3:2] cannot be cleared by writing to these bits; they are cleared by vtr por, vcc por and hard reset. that is, when the ddrc function is selected for this pin, it cannot be changed, except by a vcc por, hard reset or vtr por. when the ddrc function is selected for gp43, the device disable register is controlled by the value of the gp43 pin as follows: if the gp43 pin is high, the device disable register is read-only. if the gp43 pin is low, the device disable register is read/write. device disable register the device disable register is located in the pme register block at offset 0x22 from the runtime registers block base i/o address in logical device a. writes to this register are blocked when the gp43 pin is configured for the device disable register control function (gp43 configuration register bit 2 =1) and the gp43 pin is high. the control register for device disable register is defined in the ?runtime registers? section. smbus controller overview the LPC47S42X supports smbus. smbus is a serial communication protocol between a computer host and its peripheral devices. it provides a simple, uniform and inexpensive way to connect peripheral devices to a single computer port. a single smbus on a host can accommodate up to 125 peripheral devices. the smbus protocol includes a physical layer based on the i 2 c tm serial bus developed by philips, and several software layers. the software layers include the base protocol, the device driver interface, and several specific device protocols. for a description of the smbus protocol, please refer to the system management bus specification revision 1.0, february 15, 1995, available from intel corporation. the smbus can assert both an nio_pme and an nio_smi event when enabled and following an smbus interrupt. refer to registers pme_sts6, pme_en6, smi_sts2 and smi_en2 in the runtime registers section for more information. the smbus implementation in the LPC47S42X has the following additions over the i 2 c: (1) added timeout error (te) bit, in d6 of the smbus status register. (2) added timeout interrupt enable bit d4 in the smbus control register. 151 configuration registers see the configuration registers section for the smbus configuration registers (logical device 0x0b). runtime registers overview the smbus contains five registers: 1) control, 2) status, 3) own address, 4) data, 5) clock. the five smbus registers occupy four addresses in the host i/o space (table 50). the own address register and the clock register are used to initialize the smbus controller. normally these registers are written once following device reset. the other registers are used during actual data transmission/reception. the data register performs all serial-to-parallel interfacing. the control/status register contains status information required for bus access and/or monitoring. descriptions of these registers follow in the sections below. table 50 ? smbus runtime registers isa host interface register name host index host type control smbus base address w status smbus base address r own address smbus base address + 1 r/w data smbus base address + 2 r/w clock smbus base address + 3 r/w 152 control register overview the control/status register manages the smbus operation and provides operational status (table 51). the control/status register is located at the smbus base address. the control register is write-only and is located at the smbus base address. the control register provides register access control and control over smbus signals. the read-only component of the smbus base address is the status register, described in the status register section, below. table 51 - smbus control/status register (smbus/base address) control d7 d6 d5 d4 d3 d2 d1 d0 type w w w w w w w w bit def pinc es0 reserved tie eni sta sto ack default 0x00 on vtr por, vcc por, hard reset or soft reset status d7 d6 d5 d4 d3 d2 d1 d0 type r r r r r r r r bit def pin te sts ber lrb aas lab nbb default 0x81 on vtr por, vcc por, hard reset or soft reset bit 7 pinc control register bit d7 is the pending interrupt not control bit. writing the pinc bit to a logic ?1? deasserts all status register bits except for bit d0 nbb (bus busy). note: the pinc bit has no affect on the nbb bit. the pinc bit is self-clearing. writing this bit to a logic ?0? has no effect. bit 6 eso control register bit d6 is the enable serial output control bit. eso enables or disables the smbus serial i/o. when eso is ?1?, smbus serial communication is enabled; communication with serial shift data register is enabled and the bits in the status register are available for reading. bit 5 reserved bit 4 tie the timeout interrupt enable and the eni bits determine whether or not an interrupt is generated as a result of an smbus timeout error. when the tie bit is ?1? and eni is asserted, smbus timeout errors will generate an interrupt. when tie is ?0?, smbus timeout errors will not generate interrupts, regardless of the state of eni. the tie bit does not affect the timeout error bit te in the status register. 153 bit 3 eni this bit enables the internal smbus interrupt, nint, which is generated when the pin bit is asserted (?0?). bit 2 and bit 1 sta and sto these bits control the generation of the smbus start condition and transmission of slave address and r/nw bit, generation of repeated start condition, and generation of the stop condition (see table 52) table 52 - instruction for serial bus control sta sto present mode function operation 1 0 slv/rec start transmit start+address, remain mst/trm if r/nw=0; go to mst/rec if r/nw=1. 1 0 mst/trm repeat start same as for slv/rec 0 1 mst/rec; mst/trm stop read; stop write transmit stop go to slv/rec mode; note 1 1 1 mst data chaining send stop, start and address after last master frame without stop sent; note 2 0 0 any nop no operation; note 3 note 1: in master receiver mode, the last byte is terminated with ack bit high (?negative acknowledge?). note 2: if bot h sta and sto are set high simultaneously in master mode, a stop condition followed by a start condition + address will be generated. this allows ?chaining? of transmissions without relinquishing bus control. note 3: all other sta and sto mode combinatio ns not mentioned in table 52 are nops. bit 0 ack this bit must be set normally to logic ?1?. this causes the smbus to send an acknowledge automatically after each byte (this occurs during the 9th clock pulse). the bit must be reset (to logic ?0?) when the smbus controller is operating in master/receiver mode and requires no further data to be sent from the slave transmitter. this causes a negative acknowledge on the smbus, which halts further transmission from the slave device. status register overview the status register, the read-only component of the smbus base address, enables access to smbus operational status information. bit 7 pin pending interrupt not. this bit is a status flag which is used to synchronize serial communication and is set to logic ?0? whenever the chip requires servicing. the pin bit is normally read in polled applications to determine when an smbus byte transmission/reception is completed. when acting as transmitter, pin is set to logic ?1? (inactive) each time the data register is written. in receiver mode, the pin bit is automatically set to logic ?1? each time the data register is read. 154 after transmission or reception of one byte on the smbus (nine clock pulses, including acknowledge) the pin bit will be automatically reset to logic ?0? (active) indicating a complete byte transmission/reception. when the pin bit is subsequently set to logic ?1? (inactive) all status bits will be reset to ?0? on a ber (bus error) condition. in polled applications, the pin bit is tested to determine when a serial transmission/reception has been completed. when the eni bit (bit 4 of write-only section of the control/status register) is also set to logic ?1? the hardware interrupt is enabled. in this case, the pi flag also triggers and internal interrupt (active low) via the nint output each time pin is reset to logic ?0?. when acting as a slave transmitter or slave receiver, while pin = ?0?, the chip will suspend smbus transmission by holding the sclk line low until the pin bit is set to logic ?1? (inactive). this prevents further data from being transmitted or received until the current data byte in the data register has been read (when acting as slave receiver) or the next data byte is written to the data register (when acting as slave transmitter). 155 pin bit summary 1. the pin bit can be used in polled applications to test when a serial transmission has been completed. when the eni bit is also set, the pin flag sets the internal interrupt via the nint output. 2. in transmitter mode, after successful transmission of one byte on the smbus the pin bit will be automatically reset to logic ?0? (active) indicating a complete byte transmission. 3. in transmitter mode, pin is set to logic ?1? (inactive) each time the data register is written. 4. in receiver mode, pin is set to logic ?0? (inactive) on completion of each received byte. 5. subsequently, the sclk line will be held low until pin is set to logic ?1?. 6. in receiver mode, when the data register is read, pin is set to logic ?1? (inactive). 7. in slave receiver mode, an smbus stop condition will set pin=0 (active). 8. pin=0 if a bus error (ber) or a timeout error (te) occurs while the timeout interrupt enable is asserted (tie). bit 6 te when the timeout error bit d6 is ?1?, an smbus timeout error has occurred (see section smbus timeout ). timeout errors generate an interrupt if the tie bit is asserted (see section on bit 4 tie). if the tie bit is asserted, timeout errors will assert the pin bit. the te bit is deasserted ?0? whenever the pin bit is deasserted (see section on bit 7 pin). bit 5 sts when in slave receiver mode, this flag is asserted when an externally generated stop condition is detected (used only in slave receiver mode). bit 4 ber bus error; a misplaced start or stop condition has been detected. resets nbb (to logic ?1?; inactive), sets pin = ?0? (active). bit 3 lrb/ad0 last received bit or address 0 (general call) bit. this status bit serves a dual function, and is valid only while pin=0: lrb holds the value of the last received bit over the smbus while aas=0 (not addressed as slave). normally this will be the value of the slave acknowledgment; thus checking for slave acknowledgment is done via testing of the lrb. ado; when aas = ?1? (addressed as slave condition) the smbus controller has been addressed as a slave. under this condition, this bit becomes the ad0 bit and will be set to logic ?1? if the slave address received was the ?general call? (00h) address, or logic ?0? if it was the smbus controller?s own slave address. bit 2 aas addressed as slave bit. valid only when pin=0. when acting as slave receiver, this flag is set when an incoming address over the smbus matches the value in own address register (shifted by one bit) or if the smbus ?general call? address (00h) has been received (?general call? is indicated when ad0 status bit is also set to logic ?1?). 156 bit 1 lab lost arbitration bit. this bit is set when, in multi-master operation, arbitration is lost to another master on the smbus. bit 0 nbb bus busy bit. this is a read-only flag indicating when the smbus is in use. a zero indicates that the bus is busy, and access is not possible. this bit is set/reset (logic ?1?/logic ?0?) by start/stop conditions. own address register when the chip is addressed as slave, this register must be loaded with the 7-bit smbus address to which the chip is to respond. during initialization, the own address register must be written to, regardless whether it is later used. the addressed as slave (aas) bit in status register is set when this address is received (the value in the data register is compared with the value in own address register). note that the data and own address registers are offset by one bit; hence, programming the own address register with a value of 55h will result in the value aah being recognized as the chip?s smbus slave address. after reset, own address register has default address 00h. table 53 - smbus own address register (smbus base address +1) own addr bit d7 d6 d5 d4 d3 d2 d1 d0 type r/w r/w r/w r/w r/w r/w r/w r/w default = 0x00 on vtr por, vcc por, hard reset or soft reset bit def reser ved slave addr 6 slave addr 5 slave addr 4 slave addr 3 slave addr 2 slave addr 1 slave addr 0 data shift register the data register acts as serial shift register and read buffer interfacing to the smbus. all read and write operations to/from the smbus are done via this register. smbus data is always shifted in or out of shift register. in receiver mode the smbus data is shifted into the shift register until the acknowledge phase. further reception of data is inhibited (sclk pin held low) until the data shift register is read. in the transmitter mode data is transmitted to the smbus as soon as it is written to the shift register if the serial i/o is enabled (eso=1). 157 table 54 - smbus data register (smbus base address +2) default data d7 d6 d5 d4 d3 d2 d1 d0 0x00 on vtr por, vcc por, hard reset or soft reset r/w r/w r/w r/w r/w r/w r/w r/w r/w clock register overview the clock register controls the internal smbus clock generator, the smbus reset, and the sclk pin clock frequency (table 55). the clock register is 00h by default. table 55 - smbus clock register (smbus base address +3) d7 d6 d5 d4 d3 d2 d1 d0 default type r/w r r r r r/w r/w r name smb_rst (note 1) reserved clk_div clk_sel reserved 0x00 on vtr por, vcc por, hard reset or soft reset note 1: the smbus reset bit is not self-clearing. bit 7 smb_rst the smbus reset bit d7 is used to reinitialize all the logic and registers in the smbus block. smb_rst is active high and is not self-clearing. to properly reset the the smbus block, write the smb_rst bit to ?1? and then re-write the smb_rst bit to ?0?; i.e., the smb_rst bit must be ?0? for normal device operation. the smb_rst bit is ?0? by default. bit 6 ? bit 3 reserved bit 2 clk_div the clk_div bit d2 is used to divide the smbus input clock by two. when clk_div = ?0? (default) the smbus input clock is not divided; when clk_div = ?1?, the smbus input clock, as well as the smbus output clock sclk, is divided by two. bit 1 clk_sel the clk_sel bit d1 is used to enable the smbus input clock. when clk_sel = ?1?, the smbus inout clock is enabled and the smbus block can operate normally; when clk_sel = ?0? (default), the input clock is stopped and the smbus will not run. 158 the smbus output clock sclk frequency is determined by the clk_sel and clk_div bits (table 56). table 56 ? smbus clock select encoding smbus clock frequency controls clk_sel clk_div description 0 x clock off 1 0 sclk = 100khz 1 1 sclk = 50khz pin multiplexing sdat is multiplexed with pin gp32. sclk is multiplexed with pin gp30. smbus timeouts overview the smbus is designed to provide a predictable communications link between a system and its devices. however some devices, such as a smart battery using a microcontroller to support both bus and maintain battery data, may require more time than might normally be expected. the following specifications take such devices into account while maintaining a relatively predictable communications. the following are general comments on the smbus? timing: the bus may be at 0 khz when idle. the f smb min is intended to dissuade components from taking too long to complete a transaction. an idle bus can be detected by observing that both the clock and data remain high for longer than t high max. every device must be able to recognize and react to a start condition at f smb max. the smbus timing is in the timing diagrams section. smb us timeout the smbus controller will timeout when any clock low (sclk) exceeds the t timeout value shown in smbus timing table above. timeout errors are identified using the te bit in the smbus status register (see status register section). sample transaction diagram the following figure illustrates a data transaction on the smbus. 159 smb clk smb data 0 1 ack 0 0 0 1 1 1 start send address / byte figure 5 - sample smbus single byte transaction 160 x-bus interface the x-bus interface allows the LPC47S42X to interface to as many as 4 external components that have an 8 bit data bus and occupy up to 4 contiguous i/o address ports. depending on the mode of operation, it provides either 4 separate active low chip selects (nxcs0 ? nxcs3) and 2 address pins (xa0, xa1) or 2 active low chip selects (nxcs0, nxcs0) and 4 address pins (xa0-xa3). it also provides a read strobe (nxrd), a write strobe (nxwr) and an 8 bit data bus (xd0 ? xd7). external pullups are required on the nxrd and nxwr pins. the chip select outputs are generated by circuitry in the LPC47S42X that compares the lpc i/o address bits with the x-bus base i/o address configuration registers. the mode of operation determines the number of chip selects and address pins that the x-bus interface provides, as well as the number of bits in the base i/o addresses. the mode is chosen via bit 0 of the x-bus selection configuration register located in logical device 8 at 0xf0. in x-bus mode 1, the x-bus base i/o address configuration registers contain address bits a15 through a8 and a7 through a2, respectively. a1 and a0 pass directly through to xa1 and xa0, respectively. the chip selects only become active (low) for the lpc bus cycle in which the address match occurs. in x-bus mode 2, the x-bus base i/o address configuration registers contain address bits a15 through a8 and a7 through a4, respectively. a3, a2, a1 and a0 pass directly through to xa3, xa2, xa1 and xa0, respectively. the chip selects only become active (low) for the lpc bus cycle in which the address match occurs. the LPC47S42X performs 16-bit address qualification on the x-bus base i/o addresses. that is, the upper 4-bits, bits[15:12], must be ?0?. note: bit 6 of the osc global configuration register (cr24) must be set to ?1? for 16-bit address qualification. the read and write strobes have address setup and hold times, and pulse widths, that are compatible with x-bus timing of the intel piix4. see the timing diagrams in the ?timing? section. the strobes will only become active during an lpc cycle in which the lpc address matches the corresponding x-bus address. each x-bus chip select has an associated disable bit. this bit allows each chip select to be individually enabled or disabled. this bit is part of the x-bus low address byte configuration register. each x-bus chip select base address register has an associated ?write protect? bit that can only be set once, and is reset by vcc por and hard reset (npci_reset). when this bit is set, it prevents the base address configuration registers (high byte and low byte) for each chip select from being written. this security feature ensures that the base address and disable bit for each chip select can only be set by bios and cannot be corrupted by any virus software. this bit is part of the x-bus low address byte configuration register. 161 the following figure shows the x-bus interface in mode 1. figure 6 - bus interface, mode 1 8-bit data bus lpc command i/o read - nxrd active i/o write - nxwr active lpc data lpc address x-bus cs0 base address configuration register disable x-bus cs1 base address configuration register disable x-bus cs2 base address configuration register disable x-bus cs3 base address configuration register disable 14-bit address comparator nxcs0 14-bit address comparator nxcs1 14-bit address comparator nxcs2 14-bit address comparator nxcs3 xa0 xa1 162 the following figure shows the x-bus interface in mode 2. 8-bit data bus lpc command i/o read - nxrd active i/o write - nxwr active lpc data lpc address x-bus cs0 base address configuration register disable x-bus cs1 base address configuration register disable 12-bit address comparator nxcs0 12-bit address comparator nxcs1 xa2 xa3 xa0 xa1 figure 7 - bus interface, mode 2 163 see the ?timing? section for figures that show ?representative? lpc i/o to x-bus cycle timing. x-bus chip select base i/o address registers the base i/o address registers for the x-bus are defined in the ?configuration? section. x-bus configuration register x-bus selection register is used to select the x-bus mode and the pulse widths of the x-bus read and write strobes. this register is located in logical device 8 at an offset of 0xf0. see the configuration section for register description. 164 runtime registers runtime registers block summary the following registers are runtime registers in the LPC47S42X. they are located at the address programmed in the base i/o address in logical device a (runtime registers block) at the offset shown. these registers are powered by vtr. table 57 - runtime register block summary offset (hex) type hard reset vcc por vtr por soft reset register 00 r/w - - 0x00 - pme_sts 01 r - - - - reserved 02 r/w - - 0x00 - pme_en 03 r - - - - reserved 04 r/w - - 0x00 - pme_sts1 05 r/w - - 0x00 - pme_sts2 06 r/w - - 0x00 - pme_sts3 07 r/w - - 0x00 - pme_sts4 08 r/w - - 0x00 - pme_sts5 09 r/w note 6 note 6 0x01 note 6 note 6 pme_sts6 0a r/w - - 0x00 - pme_en1 0b r/w - - 0x00 - pme_en2 0c r/w - - 0x00 - pme_en3 0d r/w - - 0x00 - pme_en4 0e r/w - - 0x00 - pme_en5 0f r/w - - 0x00 - pme_en6 10 r/w note 6 note 6 0x02 note 6 note 6 smi_sts 1 11 r/w - - 0x00 - smi_sts 2 12 r/w - - 0x00 - smi_sts3 13 r/w - - 0x00 - smi_sts4 14 r/w - - 0x00 - smi_sts5 15 r/w - - 0x00 - smi_sts6 16 r/w - - 0x00 - smi_en1 17 r/w - - 0x00 - smi_en2 18 r/w - - 0x00 - smi_en3 19 r/w - - 0x00 - smi_en4 1a r/w - - 0x00 - smi_en5 1b r/w - - 0x00 - smi_en6 1c r/w - - 0x00 - msc_sts 1d r 0x00 0x00 0x00 - uart2 fifo control shadow 1e r/w 0x03 0x03 - - force disk change 1f r 0x02 0x02 0x02 - floppy data rate select shadow 20 r 0x00 0x00 0x00 - uart1 fifo control shadow 21 r/w - - 0x00 - edge select register 165 offset (hex) type hard reset vcc por vtr por soft reset register 22 r/w note 3 - - 0x00 - device disable register 23 r/w - - 0x01 - gp10 24 r/w - - 0x01 - gp11 25 r/w - - 0x01 - gp12 26 r/w - - 0x01 - gp13 27 r/w - - 0x01 - gp14 28 r/w - - 0x01 - gp15 29 r/w - - 0x01 - gp16 2a r/w - - 0x01 - gp17 2b r/w - - 0x01 - gp20 2c r/w - - 0x01 - gp21 2d r/w - - 0x01 - gp22 2e r/w - - 0x01 - gp23 2f r/w - - 0x01 - gp24 30 r/w - - 0x01 - gp25 31 r/w - - 0x01 - gp26 32 r/w - - 0x01 - gp27 33 r/w - - 0x01 - gp30 34 r/w - - 0x01 - gp31 35 r/w - - 0x01 - gp32 36 r/w 0x00 0x00 0x01 - gp33 37 r/w - - 0x01 - gp34 38 r/w - - 0x01 - gp35 39 r/w - - 0x01 - gp36 3a r/w - - 0x01 - gp37 3b r/w - - 0x01 - gp40 3c r/w - - 0x01 - gp41 3d r/w - - 0x01 - gp42 3e r/w - note 5 - note 5 0x01 - gp43 3f r/w - - 0x01 - gp50 40 r/w - - 0x01 - gp51 41 r/w - - 0x01 - gp52 42 r/w 0x00 0x00 0x00 - gp53 43 r/w - - 0x01 - gp54 44 r/w - - 0x01 - gp55 45 r/w - - 0x01 - gp56 46 r/w - - 0x01 - gp57 47 r/w - - 0x01 - gp60 48 r/w - - 0x04 - gp61 49 r/w - - 0x01 - gp62 4a r - - - - reserved ? read returns 0 4b r/w - - 0x00 - gp1 4c r/w - - 0x00 - gp2 4d r/w - note 4 - note 4 0x00 - gp3 166 offset (hex) type hard reset vcc por vtr por soft reset register 4e r/w - - 0x00 - gp4 4f r/w - - 0x00 - gp5 50 r/w - - 0x00 - gp6 51 r - - - - reserved ? read returns 0 52 r/w 0x00 0x00 0x00 - wdt_time_out 53 r/w 0x00 0x00 0x00 - wdt_val 54 r/w 0x00 0x00 0x00 - wdt_cfg 55 r/w note 1 0x00 note 2 0x00 0x00 - wdt_ctrl 56 r/w - - 0x00 - fan 57 r/w - - - - reserved ? read returns 0 58 r/w - - 0x10 - fan control 59 r - - 0x00 - fan tachometer 5a r - - - - reserved ? read returns 0 5b r/w - - 0x00 - fan preload 5c r/w - - - - reserved ? read returns 0 5d r/w - - 0x00 - led1 5e r/w - - 0x01 - led2 5f r/w - - 0x00 - keyboard scan code 60 r/w - - 0x00 - pm1_cntrl1 61 r/w - - 0x00 - pm1_cntrl2 62 r - - - - reserved ? read returns 0 63 r - - - - reserved ? read returns 0 64 r/w - - 0x00 - smi_sts7 65 r - - - - reserved ? read returns 0 66 r/w - - 0x00 - smi_en7 67 r - - - - reserved ? read returns 0 68 r/w - - 0x00 - pme_sts7 69 r - - - - reserved ? read returns 0 6a r - - - - reserved ? read returns 0 6b r - - - - reserved ? read returns 0 6c r/w - - 0x00 - pme_en7 6d-7f r - - - - reserved ? read returns 0 note. reserved bits return 0 on read. note 1: this register contains some bits that are read or write only. note 2: bit 0 is not cleared by hard reset. note 3: the device disable register is read-only when gp43 register bit [3:2] = 01 and the gp43 pin is high, or when bit 1 of the device disable register is ?1?. 167 note 4: bit [3] of this register is reset (cleared) on vcc por and hard reset (and vtr por), for fan output default at power-up. note 5: bits [3:2] of the gp43 register are reset (cleared) on vcc por and hard reset (and vtr por). note 6: the parallel port interrupt defaults to 1 when the parallel port activate bit is cleared. when the parallel port is activated, pint follows the nack input. 168 runtime registers block description table 58 - runtime registers block description note: reserved bits return 0 on read. name reg offset (hex) description pme_sts default = 0x00 on vtr por 00 (r/w) bit[0] pme_status = 0 (default) = 1 set when the chip would normally assert the nio_pme signal, independent of the state of the pme_en bit. bit[7:1] reserved pme_status is not affected by vcc por, soft reset or hard reset. writing a ?1? to pme_status will clear it and cause the the chip to stop asserting nio_pme, if enabled. writing a ?0? to pme_status has no effect. pme_en default = 0x00 on vtr por 02 (r/w) bit[0] pme_en = 0 nio_pme signal assertion is disabled (default) = 1 enables the chip to assert nio_pme signal bit[7:1] reserved pme_en is not affected by vcc por, soft reset or hard reset pme_sts1 default = 0x00 on vtr por 04 (r/w) pme wake status register 1 this register indicates the state of the individual pme wake sources, independent of the individual source enables or the pme_en bit. if the wake source has asserted a wake event, the associated pme wake status bit will be a ?1?. bit[0] p12 bit[1] p16 bit[2] nri1 bit[3] kbd bit[4] mouse bit[5] spekey (wake on specific key) bit[6] fan_tach bit[7] nri2 the pme wake status register is not affected by vcc por, soft reset or hard reset. writing a ?1? to bit[7:0] will clear it. writing a ?0? to any bit in pme wake status register has no effect. 169 name reg offset (hex) description pme_sts2 default = 0x00 on vtr por 05 (r/w) pme wake status register 2 this register indicates the state of the individual pme wake sources, independent of the individual source enables or the pme_en bit. if the wake source has asserted a wake event, the associated pme wake status bit will be a ?1?. bit[0] gp10 bit[1] gp11 bit[2] gp12 bit[3] gp13 bit[4] gp14 bit[5] gp15 bit[6] gp16 bit[7] gp17 the pme wake status register is not affected by vcc por, soft reset or hard reset. writing a ?1? to bit[7:0] will clear it. writing a ?0? to any bit in pme wake status register has no effect. pme_sts3 default = 0x00 on vtr por 06 (r/w) pme wake status register 3 this register indicates the state of the individual pme wake sources, independent of the individual source enables or the pme_en bit. if the wake source has asserted a wake event, the associated pme wake status bit will be a ?1?. bit[0] gp20 bit[1] gp21 bit[2] gp22 bit[3] gp23 bit[4] gp24 bit[5] gp25 bit[6] gp26 bit[7] gp27 the pme wake status register is not affected by vcc por, soft reset or hard reset. writing a ?1? to bit[7:0] will clear it. writing a ?0? to any bit in pme wake status register has no effect. 170 name reg offset (hex) description pme_sts4 default = 0x00 on vtr por 07 (r/w) pme wake status register 4 this register indicates the state of the individual pme wake sources, independent of the individual source enables or the pme_en bit. if the wake source has asserted a wake event, the associated pme wake status bit will be a ?1?. bit[0] gp30 bit[1] gp31 bit[2] gp32 bit[3] gp33 bit[4] gp41 bit[5] gp43 bit[6] gp60 bit[7] gp61 the pme wake status register is not affected by vcc por, soft reset or hard reset. writing a ?1? to bit[7:0] will clear it. writing a ?0? to any bit in pme wake status register has no effect. pme_sts5 default = 0x00 on vtr por 08 (r/w) pme wake status register 5 this register indicates the state of the individual pme wake sources, independent of the individual source enables or the pme_en bit. if the wake source has asserted a wake event, the associated pme wake status bit will be a ?1?. bit[0] gp50 bit[1] gp51 bit[2] gp52 bit[3] gp53 bit[4] gp54 bit[5] gp55 bit[6] gp56 bit[7] gp57 the pme wake status register is not affected by vcc por, soft reset or hard reset. writing a ?1? to bit[7:0] will clear it. writing a ?0? to any bit in pme wake status register has no effect. 171 name reg offset (hex) description pme_sts6 default = 0x01 on vtr por bit 0 is set to ?1? on vcc por, vtr por, hard reset and soft reset 09 (r/w) this register indicates the state of the individual pme sources, independent of the individual source enables or the pme_en bit. if the pme source has asserted an event, the associated pme status bit will be a ?1?. bit[0] pint the parallel port interrupt defaults to ?1? when the parallel port activate bit is cleared. when the parallel port is activated, pint follows the nack input. bit[1] u2int bit[2] u1int bit[3] fint bit[4] mint bit[5] kint bit[6] wdt bit[7] smb the pme status register is not affected by vcc por, soft reset or hard reset. writing a ?1? to bit[7:0] will clear it. writing a ?0? to any bit in pme status register has no effect. pme_en1 default = 0x00 on vtr por 0a (r/w) pme wake enable register 1 this register is used to enable individual pme wake sources onto the nio_pme wake bus. when the pme wake enable register bit for a wake source is active (?1?), if the source asserts a wake event so that the associated status bit is ?1? and the pme_en bit is ?1?, the source will assert the nio_pme signal. when the pme wake enable register bit for a wake source is inactive (?0?), the pme wake status register will indicate the state of the wake source but will not assert the nio_pme signal. bit[0] p12 bit[1] p16 bit[2] nri1 bit[3] kbd bit[4] mouse bit[5] spekey (wake on specific key) bit[6] fan_tach bit[7] nri2 the pme wake enable register is not affected by vcc por, soft reset or hard reset. 172 name reg offset (hex) description pme_en2 default = 0x00 on vtr por 0b (r/w) pme wake enable register 2 this register is used to enable individual pme wake sources onto the nio_pme wake bus. when the pme wake enable register bit for a wake source is active (?1?), if the source asserts a wake event so that the associated status bit is ?1? and the pme_en bit is ?1?, the source will assert the nio_pme signal. when the pme wake enable register bit for a wake source is inactive (?0?), the pme wake status register will indicate the state of the wake source but will not assert the nio_pme signal. bit[0] gp10 bit[1] gp11 bit[2] gp12 bit[3] gp13 bit[4] gp14 bit[5] gp15 bit[6] gp16 bit[7] gp17 the pme wake enable register is not affected by vcc por, soft reset or hard reset. pme_en3 default = 0x00 on vtr por 0c (r/w) pme wake status register 3 this register is used to enable individual pme wake sources onto the nio_pme wake bus. when the pme wake enable register bit for a wake source is active (?1?), if the source asserts a wake event so that the associated status bit is ?1? and the pme_en bit is ?1?, the source will assert the nio_pme signal. when the pme wake enable register bit for a wake source is inactive (?0?), the pme wake status register will indicate the state of the wake source but will not assert the nio_pme signal. bit[0] gp20 bit[1] gp21 bit[2] gp22 bit[3] gp23 bit[4] gp24 bit[5] gp25 bit[6] gp26 bit[7] gp27 the pme wake enable register is not affected by vcc por, soft reset or hard reset. 173 name reg offset (hex) description pme_en4 default = 0x00 on vtr por 0d (r/w) pme wake enable register 4 this register is used to enable individual pme wake sources onto the nio_pme wake bus. when the pme wake enable register bit for a wake source is active (?1?), if the source asserts a wake event so that the associated status bit is ?1? and the pme_en bit is ?1?, the source will assert the nio_pme signal. when the pme wake enable register bit for a wake source is inactive (?0?), the pme wake status register will indicate the state of the wake source but will not assert the nio_pme signal. bit[0] gp30 bit[1] gp31 bit[2] gp32 bit[3] gp33 bit[4] gp41 bit[5] gp43 bit[6] gp60 bit[7] gp61 the pme wake enable register is not affected by vcc por, soft reset or hard reset. pme_en5 default = 0x00 on vtr por 0e (r/w) pme wake enable register 5 this register is used to enable individual pme wake sources onto the nio_pme wake bus. when the pme wake enable register bit for a wake source is active (?1?), if the source asserts a wake event so that the associated status bit is ?1? and the pme_en bit is ?1?, the source will assert the nio_pme signal. when the pme wake enable register bit for a wake source is inactive (?0?), the pme wake status register will indicate the state of the wake source but will not assert the nio_pme signal. bit[0] gp50 bit[1] gp51 bit[2] gp52 bit[3] gp53 bit[4] gp54 bit[5] gp55 bit[6] gp56 bit[7] gp57 the pme wake enable register is not affected by vcc por, soft reset or hard reset. 174 name reg offset (hex) description pme_en6 default = 0x00 on vtr por 0f (r/w) pme enable register 6 this register enables the individual pme sources onto the pme_st bus. when the enable bit is ?1? and the pme source has asserted a wake event, the pme_st bus is asserted. the pme_st bus cannot be asserted if the enable bit is ?0?. bit[0] pint bit[1] u2int bit[2] u1int bit[3] fint bit[4] mint bit[5] kint bit[6] wdt bit[7] smb smi_sts1 default = 0x02 on vtr por bit 1 is set to ?1? on vcc por, vtr por, hard reset and soft reset 10 (r/w) smi status register 1 this register is used to read the status of the smi inputs. the following bits must be cleared at their source. bit[0] reserved bit[1] pint the parallel port interrupt defaults to 1 when the parallel port activate bit is cleared. when the parallel port is activated, pint follows the nack input. bit[2] u2int bit[3] u1int bit[4] fint bit[5] reserved bit[6] reserved bit[7] wdt smi_sts2 default = 0x00 on vtr por 11 (r/w) smi status register 2 this register is used to read the status of the smi inputs. bits 2-6 are cleared by a write of 1 to the bit. bit[0] mint. cleared at source. bit[1] kint. cleared at source. bit[2] smb bit[3] nri1 bit[4] p12. status bit is cleared by a write of ?1?. the smi event is cleared at the source. bit[5] nri2 bit[6] reserved bit[7] reserved 175 name reg offset (hex) description smi_sts3 default = 0x00 on vtr por 12 (r/w) smi status register 3 this register is used to read the status of the smi inputs. the following bits are cleared on a write of ?1?. bit[0] gp20 bit[1] gp21 bit[2] gp22 bit[3] gp60 bit[4] gp24 bit[5] gp25 bit[6] gp26 bit[7] gp27 smi_sts4 default = 0x00 on vtr por 13 (r/w) smi status register 4 this register is used to read the status of the smi inputs. the following bits are cleared on a write of ?1?. bit[0] gp30 bit[1] gp31 bit[2] gp32 bit[3] gp33 bit[4] gp41 bit[5] fan_tach bit[6] gp43 bit[7] gp61 smi_sts5 default = 0x00 on vtr por 14 (r/w) smi status register 5 this register is used to read the status of the smi inputs. the following bits are cleared on a write of ?1?. bit[0] gp50 bit[1] gp51 bit[2] gp52 bit[3] gp53 bit[4] gp54 bit[5] gp55 bit[6] gp56 bit[7] gp57 176 name reg offset (hex) description smi_sts6 default = 0x00 on vtr por 15 (r/w) smi status register 6 this register is used to read the status of the smi inputs. the following bits are cleared on a write of ?1?. bit[0] gp10 bit[1] gp11 bit[2] gp12 bit[3] gp13 bit[4] gp14 bit[5] gp15 bit[6] gp16 bit[7] gp17 smi_en1 default = 0x00 on vtr por 16 (r/w) smi enable register 1 this register is used to enable the different interrupt sources onto the group nsmi output. 1=enable 0=disable bit[0] reserved bit[1] en_pint bit[2] en_u2int bit[3] en_u1int bit[4] en_fint bit[5] reserved bit[6] reserved bit[7] en_wdt smi_en2 default = 0x00 on vtr por 17 (r/w) smi enable register 2 this register is used to enable the different interrupt sources onto the group nsmi output, and the group nsmi output onto the nio_smi gpi/o pin or the serial irq stream. unless otherwise noted, 1=enable 0=disable bit[0] en_mint bit[1] en_kint bit[2] en_smb bit[3] en_nri1 bit[4] en_p12 bit[5] nen_ri2 bit[6] en_smi_s bit[7] en_smi 177 name reg offset (hex) description smi_en3 default = 0x00 on vtr por 18 (r/w) smi enable register 3 this register is used to enable the different interrupt sources onto the group nsmi output. 1=enable 0=disable bit[0] gp20 bit[1] gp21 bit[2] gp22 bit[3] gp60 bit[4] gp24 bit[5] gp25 bit[6] gp26 bit[7] gp27 smi_en4 default = 0x00 on vtr por 19 (r/w) smi enable register 4 this register is used to enable the different interrupt sources onto the group nsmi output. 1=enable 0=disable bit[0] gp30 bit[1] gp31 bit[2] gp32 bit[3] gp33 bit[4] gp41 bit[5] fan_tach bit[6] gp43 bit[7] gp61 smi_en5 default = 0x00 on vtr por 1a (r/w) smi enable register 5 this register is used to enable the different interrupt sources onto the group nsmi output. 1=enable 0=disable bit[0] gp50 bit[1] gp51 bit[2] gp52 bit[3] gp53 bit[4] gp54 bit[5] gp55 bit[6] gp56 bit[7] gp57 178 name reg offset (hex) description smi_en6 default = 0x00 on vtr por 1b (r/w) smi enable register 6 this register enables the individual smi sources onto the smi_st bus. when the enable bit is ?1? and the smi source has asserted an smi event, the smi_st bus is asserted. the smi_st bus cannot be asserted if the enable bit is ?0?. bit[0] gp10 bit[1] gp11 bit[2] gp12 bit[3] gp13 bit[4] gp14 bit[5] gp15 bit[6] gp16 bit[7] gp17 msc_sts default = 0x00 on vtr por 1c (r/w) miscellaneous status register bits[5:0] can be cleared by writing a 1 to their position (writing a 0 has no effect). bit[0] either edge triggered interrupt input 0 status. this bit is set when an edge occurs on the gp21 pin. bit[1] either edge triggered interrupt input 1 status. this bit is set when an edge occurs on the gp22 pin. bit[2] either edge triggered interrupt input 2 status. this bit is set when an edge occurs on the gp41 pin. bit[3] either edge triggered interrupt input 3 status. this bit is set when an edge occurs on the gp43 pin. bit[4] either edge triggered interrupt input 4 status. this bit is set when an edge occurs on the gp60 pin. bit[5] either edge triggered interrupt input 5 status. this bit is set when an edge occurs on the gp61 pin. bit[7:6] reserved. this bit always returns zero. uart2 fifo control shadow default = 0x00 on vcc por, vtr por and hard reset 1d (r) uart fifo control shadow 2 bit[0] fifo enable bit[1] rcvr fifo reset bit[2] xmit fifo reset bit[3] dma mode select bit[5:4] reserved bit[6] rcvr trigger (lsb) bit[7] rcvr trigger (msb) 179 name reg offset (hex) description force disk change default = 0x03 on vcc por and hard reset 1e (r/w) force change 1 and force change 0 can be written to 1 are not clearable by software. force change 1 is cleared on (nstep and nds1) force change 0 is cleared on (nstep and nds0). dsk chg (fdc dir register, bit 7) = (nds0 and force change 0) or (nds1 and force change 1) or ndskchg. setting either of the force disk change bits active (1) forces the fdd ndskchg input active when the appropriate drive has been selected. bit[0] force change for fdc0 0=inactive 1=active bit[1] force change for fdc1 0=inactive 1=active bit[7:2] reserved, reads 0 floppy data rate select shadow default = 0x02 on vcc por, vtr por and hard reset 1f (r) floppy data rate select shadow bit[0] data rate select 0 bit[1] data rate select 1 bit[2] precomp 0 bit[3] precomp 1 bit[4] precomp 2 bit[5] reserved bit[6] power down bit[7] soft reset uart1 fifo control shadow default = 0x00 on vcc por, vtr por and hard reset 20 (r) uart fifo control shadow 1 bit[0] fifo enable bit[1] rcvr fifo reset bit[2] xmit fifo reset bit[3] dma mode select bit[5:4] reserved bit[6] rcvr trigger (lsb) bit[7] rcvr trigger (msb) 180 name reg offset (hex) description edge select register default = 0x00 on vtr por 21 (r/w) bit[0] edge_p12_smi 0= p12 smi status bit is set on the high-to-low edge of p1.2 1= p12 smi status bit is set on both the high-to-low and low-to-high edge of p1.2 bit[1] edge_p16_smi 0= p16 smi status bit is set on the high-to-low edge of p1.6 1= p16 smi status bit is set on both the high-to-low and low-to-high edge of p1.6 bit[2] edge_p12_pme 0= p12 pme status bit is set on the high-to-low edge of p1.2 1= p12 pme status bit is set on both the high-to-low and low-to-high edge of p1.2 bit[3] edge_p16_pme 0= p16 pme status bit is set on the high-to-low edge of p1.6 1= p16 pme status bit is set on both the high-to-low and low-to-high edge of p1.6 bits[7:4] reserved 181 name reg offset (hex) description device disable register default = 0x00 vtr por 22 read/write when gp43 register bits[3:2] = 01 and gp43 pin = 0 or gp43 register bits[3:2] 1 01 (device disable register bit[1] must be 0) read-only when gp43 register bits[3:2] =01 and gp43 pin = 1 or device disable register bit[1]=1 if ?0? (enabled), bits[7:3] have no effect on the devices; devices are controlled by their respective activate bits. if ?1? (disabled), bits[7:3] override the activate bits in the configuration registers for each logical block. bit[0] floppy write protect. 0= no effect: floppy write protection is controlled by the write protect pin or the forced write protect bit (bit 0 of register 0xf1 in logical device 0); 1= write protected. if set to 1, this bit overrides the write protect pin on the part and the forced write protect bit. nwrtprt (to the fdc core) = wp (fdc sra register, bit 1) = (floppy write protect) or nwrtprt(from the fdd interface) or (nds0 and force write protect ) or (nds1 and force write protect ). note: the force write protect bit is in the fdd option configuration register. bit[1] register lock this bit is cleared on vcc por and hard reset. 0 - no effect (default) 1 - all of the bits in this register are read only until a vcc por or hard reset bits[2] reserved. return 0 on read. bit[3]: floppy enable. 0=no effect: fdc controlled by its activate bit; 1=floppy disabled bit[4] reserved bit[5] serial port 2 enable 0=no effect: uart2 controlled by its activate bit; 1=uart2 disabled bit[6] serial port 1 enable. 0=no effect: uart1 controlled by its activate bit; 1=uart1 disabled bit[7] parallel port enable. 0=no effect: pp controlled by its activate bit; 1=pp disabled 182 name reg offset (hex) description gp10 default = 0x01 on vtr por 23 (r/w) general purpose i/0 bit 1.0 bit[0] in/out : =1 input, =0 output bit[1] polarity : =1 invert, =0 no invert bit[2] alternate function select 1=xd0 0=gpio bits[6:3] reserved bit[7] output type select 1=open drain 0=push pull gp11 default = 0x01 on vtr por 24 (r/w) general purpose i/0 bit 1.1 bit[0] in/out : =1 input, =0 output bit[1] polarity : =1 invert, =0 no invert bit[2] alternate function select 1=xd1 0=gpio bits[6:3] reserved bit[7] output type select 1=open drain 0=push pull gp12 default = 0x01 on vtr por 25 (r/w) general purpose i/0 bit 1.2 bit[0] in/out : =1 input, =0 output bit[1] polarity :=1 invert, =0 no invert bit[2] alternate function select 1=xd2 0=gpio bits[6:3] reserved bit[7] output type select 1=open drain 0=push pull gp13 default = 0x01 on vtr por 26 (r/w) general purpose i/0 bit 1.3 bit[0] in/out : =1 input, =0 output bit[1] polarity : =1 invert, =0 no invert bit[2] alternate function select 1=xd3 0=gpio bits[6:3] reserved bit[7] output type select 1=open drain 0=push pull 183 name reg offset (hex) description gp14 default = 0x01 on vtr por 27 (r/w) general purpose i/0 bit 1.4 bit[0] in/out : =1 input, =0 output bit[1] polarity : =1 invert, =0 no invert bit[2] alternate function select 1=xd4 0=gpio bits[6:3] reserved bit[7] output type select 1=open drain 0=push pull gp15 default = 0x01 on vtr por 28 (r/w) general purpose i/0 bit 1.5 bit[0] in/out : =1 input, =0 output bit[1] polarity : =1 invert, =0 no invert bit[2] alternate function select 1=xd5 0=gpio bits[6:3] reserved bit[7] output type select 1=open drain 0=push pull gp16 default = 0x01 on vtr por 29 (r/w) general purpose i/0 bit 1.6 bit[0] in/out : =1 input, =0 output bit[1] polarity : =1 invert, =0 no invert bit[2] alternate function select 1=xd6 0=gpio bits[6:3] reserved bit[7] output type select 1=open drain 0=push pull gp17 default = 0x01 on vtr por 2a (r/w) general purpose i/0 bit 1.7 bit[0] in/out : =1 input, =0 output bit[1] polarity : =1 invert, =0 no invert bit[2] alternate function select 1=xd7 0=gpio bits[6:3] reserved bit[7] output type select 1=open drain 0=push pull 184 name reg offset (hex) description gp20 default = 0x01 on vtr por 2b (r/w) general purpose i/0 bit 2.0 bit[0] in/out : =1 input, =0 output bit[1] polarity : =1 invert, =0 no invert bit[3:2] alternate function select 11=reserved 10=nds1 ? floppy drive select 1 (note 3) 01=8042 p17 function (user note 2) 00=basic gpio function bits[6:4] reserved bit[7] output type select 1=open drain 0=push pull gp21 default =0x01 on vtr por 2c (r/w) general purpose i/0 bit 2.1 bit[0] in/out : =1 input, =0 output bit[1] polarity : =1 invert, =0 no invert bit[3:2] alternate function select 11=8042 p12 function (eng. note 1) (user note 2) 10=either edge triggered interrupt input 0 (note 1) (eng. note 3) 01=8042 p16 function (user note 2) 00=basic gpio function bits[6:4] reserved bit[7] output type select 1=open drain 0=push pull gp22 default =0x01 on vtr por 2d (r/w) general purpose i/0 bit 2.2 bit[0] in/out : =1 input, =0 output bit[1] polarity : =1 invert, =0 no invert bit[3:2] alternate function select 11= nmrt1 ? floppy motor select 1 (note 3) 10= either edge triggered interrupt input 1 (note 1) 01=8042 p12 function (user note 2) 00=basic gpio function bits[6:4] reserved bit[7] output type select 1=open drain 0=push pull 185 name reg offset (hex) description gp23 default=0x01 on vtr por 2e (r/w) general purpose i/0 bit 2.2 bit[0] in/out : =1 input, =0 output bit[1] polarity : =1 invert, =0 no invert bit[2] alternate function select 1= irqind (irq input d) 0= basic gpio function bits[6:3] reserved bit[7] output type select 1=open drain 0=push pull gp24 default = 0x01 on vtr por 2f (r/w) general purpose i/0 bit 2.4 bit[0] in/out : =1 input, =0 output bit[1] polarity : =1 invert, =0 no invert bit[2] reserved bits[6:3] reserved bit[7] output type select 1=open drain 0=push pull gp25 default = 0x01 on vtr por 30 (r/w) general purpose i/0 bit 2.5 bit[0] in/out : =1 input, =0 output bit[1] polarity : =1 invert, =0 no invert bit[2] alternate function select 1= nxrd (x-bus read strobe) 0= basic gpio function bits[6:3] reserved bit[7] output type select 1=open drain 0=push pull gp26 default = 0x01 on vtr por 31 (r/w) general purpose i/0 bit 2.6 bit[0] in/out : =1 input, =0 output bit[1] polarity : =1 invert, =0 no invert bit[2] alternate function select 1= nxwr (x-bus write strobe) 0= basic gpio function bits[6:3] reserved bit[7] output type select 1=open drain 0=push pull 186 name reg offset (hex) description gp27 default = 0x01 on vtr por 32 (r/w) general purpose i/0 bit 2.7 bit[0] in/out : =1 input, =0 output bit[1] polarity : =1 invert, =0 no invert bit[2] alternate function select 1=nio_smi (note 4) 0=gpio bits[6:3] reserved bit[7] output type select 1=open drain 0=push pull gp30 default = 0x01 on vtr por 33 (r/w) general purpose i/0 bit 3.0 bit[0] in/out : =1 input, =0 output bit[1] polarity :=1 invert, =0 no invert bit[3:2] alternate function select 11= xa2 (x-bus address 2) 10= nxcs2 (x-bus chip select 2) 01= sclk ? smbus clock 00= gpio bits[6:4] reserved bit[7] output type select 1=open drain 0=push pull gp31 default = 0x01 on vtr por 34 (r/w) general purpose i/0 bit 3.1 bit[0] in/out : =1 input, =0 output bit[1] polarity : =1 invert, =0 no invert bit[3:2] alternate function select 11= xa3 (x-bus address 3) 10= nxcs3 (x-bus chip select 3) 01= fan_tach 00= gpio bits[6:4] reserved bit[7] output type select 1=open drain 0=push pull 187 name reg offset (hex) description gp32 default = 0x01 on vtr por 35 (r/w) general purpose i/0 bit 3.2 bit[0] in/out : =1 input, =0 output bit[1] polarity : =1 invert, =0 no invert bit[3:2] alternate function select 11= reserved 10= xa0 (x-bus address 0) 01= sdat 00= basic gpio function bits[6:4] reserved bit[7] output type select 1=open drain 0=push pull gp33 default = 0x01 on vtr por default = 0x00 on vcc por and hard reset (note 2) 36 (r/w) general purpose i/0 bit 3.3 bit[0] in/out : =1 input, =0 output bit[1] polarity : =1 invert, =0 no invert bit[3:2] alternate function select 11= reserved 10= xa1 (x-bus address 1) 01=nfan 00=basic gpio function bits[6:4] reserved bit[7] output type select 1=open drain 0=push pull gp34 default = 0x01 on vtr por 37 (r/w) general purpose i/0 bit 3.4 bit[0] in/out : =1 input, =0 output bit[1] polarity : =1 invert, =0 no invert bit[2] alternate function select 1=irqina (irq input a) 0=gpio bits[6:3] reserved bit[7] output type select 1=open drain 0=push pull gp35 default = 0x01 on vtr por 38 (r/w) general purpose i/0 bit 3.5 bit[0] in/out : =1 input, =0 output bit[1] polarity : =1 invert, =0 no invert bit[2] alternate function select 1=irqinb (irq input b) 0=gpio bits[6:3] reserved bit[7] output type select 1=open drain 0=push pull 188 name reg offset (hex) description gp36 default = 0x01 on vtr por 39 (r/w) general purpose i/0 bit 3.6 bit[0] in/out : =1 input, =0 output bit[1] polarity : =1 invert, =0 no invert bit[2] alternate function select 1= nkbdrst 0=basic gpio function bits[6:3] reserved bit[7] output type select 1=open drain 0=push pull gp37 default = 0x01 on vtr por 3a (r/w) general purpose i/0 bit 3.7 bit[0] in/out : =1 input, =0 output bit[1] polarity : =1 invert, =0 no invert bit[2] alternate function select 1=a20m 0=basic gpio function bits[6:3] reserved bit[7] output type select 1=open drain 0=push pull gp40 default =0x01 on vtr por 3b (r/w) general purpose i/0 bit 4.0 bit[0] in/out : =1 input, =0 output bit[1] polarity : =1 invert, =0 no invert bit[2] alternate function select 1=drvden0 (note 3) 0=basic gpio function bits[6:3] reserved bit[7] output type select 1=open drain 0=push pull gp41 default =0x01 on vtr por 3c (r/w) general purpose i/0 bit 4.1 bit[0] in/out : =1 input, =0 output bit[1] polarity : =1 invert, =0 no invert bit[3:2] alternate function select 11=nxcs0 (x-bus chip select 0) 10=either edge triggered interrupt input 2 01=drvden1 (note 3) 00=basic gpio function bits[6:4] reserved bit[7] output type select 1=open drain 0=push pull 189 name reg offset (hex) description gp42 default =0x01 on vtr por 3d (r/w) general purpose i/0 bit 4.2 bit[0] in/out : =1 input, =0 output bit[1] polarity : =1 invert, =0 no invert bit[2] alternate function select 1=nio_pme note: configuring this pin function as output with non- inverted polarity will give an active low output signal. the output type can be either open drain or push-pull. 0=basic gpio function bits[6:3] reserved bit[7] output type select 1=open drain 0=push pull gp43 default = 0x01 on vtr por bits[3:2] are reset (cleared) on vcc por, vtr por and hard reset 3e (r/w) general purpose i/0 bit 4.3 bit[0] in/out : =1 input, =0 output bit[1] polarity : =1 invert, =0 no invert bit[3:2] alternate function select 11=either edge triggered interrupt input 3 10=nxcs1 (x-bus chip select 1) 01=device disable register control. the gp43 pin is an input, with non-inverted polarity. when bits[3:2]=01, they cannot be changed by writing to these bits; they are cleared by vcc por, hard reset and vtr por. that is, when the ddrc function is selected for this pin, it cannot be changed, except by a vcc por, hard reset or vtr por. the device disable register is controlled by the value of the gp43 pin as follows: if the gp43 pin is high, the device disable register is read-only. if the gp43 pin is low, the device disable register is read/write, if bit 1 of the device disable register is cleared (0). 00=basic gpio function bits[6:4] reserved bit[7] output type select 1=open drain 0=push pull 190 name reg offset (hex) description gp50 default = 0x01 on vtr por 3f (r/w) general purpose i/0 bit 5.0 bit[0] in/out : =1 input, =0 output bit[1] polarity : =1 invert, =0 no invert bit[2] alternate function select 1= nri2 (user note 1) 0=gpio bits[6:3] reserved bit[7] output type select 1=open drain 0=push pull gp51 default = 0x01 on vtr por 40 (r/w) general purpose i/0 bit 5.1 bit[0] in/out : =1 input, =0 output bit[1] polarity : =1 invert, =0 no invert bit[2] alternate function select 1= ndcd2 0=gpio bits[6:3] reserved bit[7] output type select 1=open drain 0=push pull gp52 default = 0x01 on vtr por 41 (r/w) general purpose i/0 bit 5.2 bit[0] in/out : =1 input, =0 output bit[1] polarity : =1 invert, =0 no invert bit[3:2] alternate function select 11=reserved 10=irrx (note 5) 01=rxd2 (note 5) 00=gpio bits[6:4] reserved bit[7] output type select 1=open drain 0=push pull gp53 default = 0x00 on vtr por, vcc por and hard reset (note 2) 42 (r/w) general purpose i/0 bit 5.3 bit[0] in/out : =1 input, =0 output bit[1] polarity : =1 invert, =0 no invert bit[3:2] alternate function select 11=reserved 10=irtx (note 5) 01=txd2 (note 5) 00=gpio bits[6:4] reserved bit[7] output type select 1=open drain 0=push pull 191 name reg offset (hex) description gp54 default = 0x01 on vtr por 43 (r/w) general purpose i/0 bit 5.4 bit[0] in/out : =1 input, =0 output bit[1] polarity : =1 invert, =0 no invert bit[2] alternate function select 1= ndsr2 0=gpio bits[6:3] reserved bit[7] output type select 1=open drain 0=push pull gp55 default = 0x01 on vtr por 44 (r/w) general purpose i/0 bit 5.5 bit[0] in/out : =1 input, =0 output bit[1] polarity : =1 invert, =0 no invert bit[2] alternate function select 1= nrts2 0=gpio bits[6:3] reserved bit[7] output type select 1=open drain 0=push pull gp56 default = 0x01 on vtr por 45 (r/w) general purpose i/0 bit 5.6 bit[0] in/out : =1 input, =0 output bit[1] polarity : =1 invert, =0 no invert bit[2] alternate function select 1= ncts2 0=gpio bits[6:3] reserved bit[7] output type select 1=open drain 0=push pull gp57 default = 0x01 on vtr por 46 (r/w) general purpose i/0 bit 5.7 bit[0] in/out : =1 input, =0 output bit[1] polarity : =1 invert, =0 no invert bit[2] alternate function select 1= ndtr2 0=gpio bits[6:3] reserved bit[7] output type select 1=open drain 0=push pull 192 name reg offset (hex) description gp60 default = 0x01 on vtr por 47 (r/w) general purpose i/0 bit 6.0 bit[0] in/out : =1 input, =0 output bit[1] polarity : =1 invert, =0 no invert bit[3:2] alternate function select 11=reserved 10=either edge triggered interrupt input 4 (note 1) 01=led1 00=gpio bits[6:4] reserved bit[7] output type select 1=open drain 0=push pull gp61 default = 0x04 on vtr por (note 6) 48 (r/w) general purpose i/0 bit 6.1 bit[0] in/out : =1 input, =0 output bit[1] polarity : =1 invert, =0 no invert bit[3:2] alternate function select 11=reserved 10=either edge triggered interrupt input 5 (note 1) 01=led2 00=gpio bits[6:4] reserved bit[7] output type select 1=open drain 0=push pull gp62 default = 0x01 on vtr por 49 (r/w) general purpose i/0 bit 6.1 bit[0] in/out : =1 input, =0 output bit[1] polarity : =1 invert, =0 no invert bit[3:2] alternate function select 11=reserved 10=irqinc (irq input c) 01=p17 00=gpio bits[6:4] reserved bit[7] output type select 1=open drain 0=push pull gp1 default = 0x00 on vtr por 4b (r/w) general purpose i/0 data register 1 bit[0] gp10 bit[1] gp11 bit[2] gp12 bit[3] gp13 bit[4] gp14 bit[5] gp15 bit[6] gp16 bit[7] gp17 193 name reg offset (hex) description gp2 default = 0x00 on vtr por 4c (r/w) general purpose i/0 data register 2 bit[0] gp20 bit[1] gp21 bit[2] gp22 bit[3] gp23 bit[4] gp24 bit[5] gp25 bit[6] gp26 bit[7] gp27 gp3 default = 0x00 on vtr por bits 3 is reset on vcc por, hard reset and vtr por 4d (r/w) general purpose i/0 data register 3 bit[0] gp30 bit[1] gp31 bit[2] gp32 bit[3] gp33 bit[4] gp34 bit[5] gp35 bit[6] gp36 bit[7] gp37 gp4 default = 0x00 on vtr por 4e (r/w) general purpose i/0 data register 4 bit[0] gp40 bit[1] gp41 bit[2] gp42 bit[3] gp43 bit[7:4] reserved gp5 default = 0x00 on vtr por bit[3] is reset on vtr por, vcc por and hard reset 4f (r/w) general purpose i/0 data register 5 bit[0] gp50 bit[1] gp51 bit[2] gp52 bit[3] gp53 bit[4] gp54 bit[5] gp55 bit[6] gp56 bit[7] gp57 gp6 default = 0x00 on vtr por 50 (r/w) general purpose i/0 data register 6 bit[0] gp60 bit[1] gp61 bit[2] gp62 bit[7-3] reserved wdt_time_out default = 0x00 on vcc por, vtr por, vtr por and hard reset 52 (r/w) watch-dog timeout bit[0] reserved bit[1] reserved bits[6:2] reserved, = 00000 bit[7] wdt time-out value units select = 0 minutes (default) = 1 seconds 194 name reg offset (hex) description wdt_val default = 0x00 on vcc por, vtr por, vtr por and hard reset 53 (r/w) watch-dog timer time-out value binary coded, units = minutes (default) or seconds, selectable via bit[7] of the wdt_time_out register. 0x00 time out disabled 0x01 time-out = 1 minute (second) ......... 0xff time-out = 255 minutes (seconds) wdt_cfg default = 0x00 on vcc por, vtr por, vtr por and hard reset 54 (r/w) watch-dog timer configuration bit[0] joy-stick enable =1 wdt is reset upon an i/o read or write of port 201h =0 wdt is not affected by i/o reads or wri tes to port 201h. bit[1] keyboard enable =1 wdt is reset upon a keyboard interrupt. =0 wdt is not affected by keyboard interrupts. bit[2] mouse enable =1 wdt is reset upon a mouse interrupt. =0 wdt is not affected by mouse interrupts. bit[3] reserved bits[7:4] wdt interrupt mapping 1111 = irq15 ......... 0011 = irq3 0010 = invalid 0001 = irq1 0000 = disable 195 name reg offset (hex) description wdt_ctrl default = 0x00 on vcc por, vtr por, vtr por and hard reset 55 (r/w) watch-dog timer control bit[0] watch-dog status bit, r/w =1 wd timeo ut occurred =0 wd timer counting bit[1] reserved bit[2] force timeout, w =1 forces wd timeout event; this bit is self- clearing bit[3] p20 force timeout enable, r/w = 1 allows rising edge of p20, from the keyboard controller, to force the wd timeout event. a wd timeout event may still be forced by setting the force timeout bit, bit 2. = 0 p20 activity does not generate the wd timeout event. note: the p20 signal will remain high for a minimum of 1us and can remain high indefinitely. therefore, when p20 forced timeouts are enabled, a self-clearing edge- detect circuit is used to generate a signal which is ored with the signal generated by the force timeout bit. bit[7:4] reserved. set to 0 fan default = 0x00 on vtr por 56 (r/w) fan register bit[0] fan control 1=fan pin is high 0=bits[6:1] control the duty cycle of the fan pin. bit[6:1] duty cycle control control the duty cycle of the fan pin 000000 = pin is low 100000 = 50% duty cycle 111111 = pin is high for 63, low for 1 bit[7] fan clock select this bit is used with the fan clock source select and the fan clock multiplier bits in the fan control register (0x58) to determine the fan speed f out . see different modes for fan table (table 49) in ?fan speed control and monitoring? section. the fan speed may be doubled through bit 2 of fan control register at 0x58. 196 name reg offset (hex) description fan control default = 0x10 on vtr por 58 (r/w) fan control register bit[0] fan clock source select this bit and the fan clock multiplier bit is used with the fan clock select bit in the fan register (0x56) to determine the fan speed f out . see different modes for fan table in ?fan speed control and monitoring? section. bit[1] reserved bit[2] fan clock multiplier 0=no multiplier used 1=double the fan speed selected by bit 0 of this register and bit 7 of the fan register bit[3] reserved bit[5:4] fan count divisor. clock scalar for adjusting the tachometer count. default = 2. 00: divisor = 1 01: divisor = 2 10: divisor = 4 11: divisor = 8 bit[7:6] reserved fan tachometer register default = 0x00 on vtr por 59 (r) fan tachometer register bit[7:0] the 8-bit fan tachometer count. the number of counts of the internal clock per pulse of the fan. the count value is computed from equation 1 in the fan section. this value is the final (maximum) count of the previous pulse (latched). the value in this register may not be valid for up to 2 pulses following a write to the preload register. fan preload register default = 0x00 on vtr por 5b (r/w) fan preload register bit[7:0] the fan tachometer preload. this is the initial value used in the computation of the fan count. writing this register resets the tachometer count. led1 default = 0x00 on vtr por 5d (r/w) bit[1:0] led1 control 00=off 01=blink at 1hz rate with a 50% duty cycle (0.5 sec on, 0.5 sec off) 10=blink at ? hz rate with a 25% duty cycle (0.5 sec on, 1.5 sec off) 11=on bits[7:2] reserved 197 name reg offset (hex) description led2 default = 0x01 on vtr por 5e (r/w) bit[1:0] led2 control 00=off 01=blink at 1hz rate with a 50% duty cycle (0.5 sec on, 0.5 sec off) 10=blink at ? hz rate with a 25% duty cycle (0.5 sec on, 1.5 sec off) 11=on bits[7:2] reserved keyboard scan code default = 0x00 on vtr por 5f (r/w) keyboard scan code bit[0] lsb of scan code . . . . . . . . . bit[7] msb of scan code pm1_cntrl1 default = 0x00 on vtr por 60 r/w ? bit[0] read only ? bits[7:1] bit[0] read/write bits[7:1] read-only, reads always return 0 pm1_cntrl2 default = 0x00 on vtr por 61 r/w ? bits[4:2] read only ? bits[7,6,1,0] write only ? bit[5] bits[1:0] read-only, reads always return 0 bits[4:2] read/write bit[5] write-only. reads always return 0; writing a ?1? to bit 5 is an smi event bits[7:6] read-only, reads always return 0 smi_sts7 default = 0x00 on vtr por 64 (r/wc) smi status register 7 this register is used to read the status of the smi inputs. the following bits are cleared on a write of ?1?. bit[0] gp34 bit[1] gp35 bit[2] gp36 bit[3] gp37 bit[4] p16 bit[5] slp_en_smi this bit is the smi status bit for writing ?1? to bit 5 of the pm1_cntrl2 register. this bit is set upon writing ?1? to bit 5 of the pm1_cntrl2 register. bit[6] reserved bit[7] gp62 198 name reg offset (hex) description smi_en7 default = 0x00 on vtr por 66 (r/w) smi enable register 7 this register is used to enable the different interrupt sources onto the group nsmi output. 1=enable 0=disable bit[0] gp34 bit[1] gp35 bit[2] gp36 bit[3] gp37 bit[4] p16 bit[5] slp_en_smi bit[6] reserved bit[7] gp62 pme_sts7 default = 0x00 on vtr por 68 (r/wc) this register indicates the state of the individual pme sources, independent of the individual source enables or the pme_en bit. if the pme source has asserted an event, the associated pme status bit will be a ?1?. bit[0] gp34 bit[1] gp35 bit[2] gp36 bit[3] gp37 bit[4] reserved bit[5] reserved bit[6] reserved bit[7] gp62 the pme status register is not affected by vcc por, soft reset or hard reset. writing a ?1? to bit[4:0] will clear it. writing a ?0? to any bit in pme status register has no effect. pme_en7 default = 0x00 on vtr por 6c (r/w) pme enable register 7 when the pme wake enable register bit for a wake source is inactive (?0?), the pme wake status register will indicate the state of the wake source but will not assert the nio_pme signal. bit[0] gp34 bit[1] gp35 bit[2] gp36 bit[3] gp37 bit[4] reserved bit[5] reserved bit[6] reserved bit[7] gp62 user note: when selecting an alternate function for a gpio pin, all bits in the gpio register must be properly programmed, including in/out, polarity and output type. the polarity bit does not affect the ddrc function or the either edge triggered interrupt functions. 199 user note 1: if this pin is used for ring indicator wakeup, either the nri2 event can be enabled via bit 1 in the pme_en1 register or the gp50 pme event can be enabled via bit 0 in the pme_en5 register. user note 2: in order to use the p12, p16 and p17 functions, the corresponding gpio must be programmed for output, non-invert, and push-pull output type. the p12 function should not be selected on gp21 and gp22 simultaneously. if p12 is selected on gp21 and gp22, simultaneously, then p12 will function on gp22, not on gp21. the p17 function should not be selected on gp20 and gp62 simultaneously. if p17 is selected on gp20 and gp62, simultaneously, then p17 will function on gp62, not on gp20. note 1: if the eeti function is selected for this gpio then both a high-to-low and a low-to-high edge will set the pme, smi and msc status bits. note 2: these pins default to an output and low on vcc por and hard reset. note 3: if the fdc function is selected on this pin ( nmtr1, nds1, drvden0, drvden1) then bit 6 of the fdd mode register (configuration register 0xf0 in logical device 0) will override bit 7 in the gpio control register. bit 7 of the fdd mode register will also affect the pin if the fdc function is selected. note 4: the nio_smi pin is inactive when the internal group smi signal is inactive and when the smi enable bit (en_smi, bit 7 of the smi_en2 register) is ?0?. when the output buffer type is od, nio_smi pin is floating when inactive; when the output buffer type is push-pull, the nio_smi pin is high when inactive. note 5: if gp52 and gp53 are programmed for rxd2 and txd2 functions and serial port 2 is programmed for ir operation, then these pins will have ir functionality and when serial port 2 is disabled, the txd2 pin will tristate. if these pins are programmed for irrx and irtx then these pins will have ir functionality and when serial port 2 is disabled, the irtx pin will go to its inactive state. note 6: the gp61 pin defaults to the led function active (blinking at 1hz rate, 50y duty cycle) on initial power up (as long as the 32khz clock input is active). 200 configuration the configuration of the LPC47S42X is very flexible and is based on the configuration architecture implemented in typical plug-and-play components. the LPC47S42X is designed for motherboard applications in which the resources required by their components are known. with its flexible resource allocation architecture, the LPC47S42X allows the bios to assign resources at post. system elements primary configuration address decoder after a hard reset (npci_reset pin asserted) or vcc power on reset the LPC47S42X is in the run mode with all logical devices disabled. the logical devices may be configured through two standard configuration i/o ports (index and data) by placing the LPC47S42X into configuration mode. the bios uses these configuration ports to initialize the logical devices at post. the index and data ports are only valid when the LPC47S42X is in configuration mode. the sysopt pin is latched on the falling edge of the npci_reset or on vcc power on reset to determine the configuration register's base address. the sysopt pin is used to select the config port's i/o address at power-up. once powered up the configuration port base address can be changed through configuration registers cr26 and cr27. the sysopt pin is a hardware configuration pin which is shared with the gp24 signal on pin 45. note. an external pull-down resistor is required for the base io address to be 0x02e for configuration. an external pull-up resistor is required to move the base io address for configuration to 0x04e. the index and data ports are effective only when the chip is in the configuration state. port name sysopt= 0 10k pull-down resistor sysopt= 1 10k pull-up resistor type config port (note 1) 0x02e 0x04e write index port (note 1) 0x02e 0x04e read/write data port index port + 1 read/write note 1: the configuration port base address can be relocated through cr26 and cr27. entering the configuration state the device enters the configuration state when the following config key is successfully written to the config port. config key = <0x55> 201 exiting the configuration state the device exits the configuration state when the following config key is successfully written to the config port. config key = <0xaa> configuration sequence to program the configuration registers, the following sequence must be followed: 1. enter configuration mode 2. configure the configuration registers 3. exit configuration mode. enter configuration mode to place the chip into the configuration state the config key is sent to the chip's config port. the config key consists of 0x55 written to the config port. once the configuration key is received correctly the chip enters into the configuration state (the auto config ports are enabled). configuration mode the system sets the logical device information and activates desired logical devices through the index and data ports. in configuration mode, the index port is located at the config port address and the data port is at index port address + 1. the desired configuration registers are accessed in two steps: a. write the index of the logical device number configuration register (i.e., 0x07) to the in dex port and then write the number of the desired logical device to the data port. b. write the address of the desired configuration register within the logical device to the index port and then write or read the configuration register through the data port. note: if accessing the global configuration registers, step (a) is not required. exit configuration mode to exit the configuration state the system writes 0xaa to the config port. the chip returns to the run state. note: only two states are define d (run and configuration). in the run state the chip will always be ready to enter the configuration state. 202 programming example the following is an example of a configuration program in intel 8086 assembly language. ;----------------------------. ; enter configuration mode | ;----------------------------' mov dx,02eh mov ax,055h out dx,al ;----------------------------. ; configure register cre0, | ; logical device 8 | ;----------------------------' mov dx,02eh mov al,07h out dx,al ;point to ld# config reg mov dx,02fh mov al, 08h out dx,al;point to logical device 8 ; mov dx,02eh mov al,e0h out dx,al ; point to cre0 mov dx,02fh mov al,02h out dx,al ; update cre0 ;-----------------------------. ; exit configuration mode | ;-----------------------------' mov dx,02eh mov ax,0aah out dx,al 203 notes: hard reset: npci_reset pin asserted soft reset: bit 0 of configuration control register set to one all host accesses are blocked for 500s after vcc por (see power-up timing diagram) table 59 ? LPC47S42X configuration registers summary index type hard reset vcc por vtr por soft reset configuration register global configuration registers 0x02 w 0x00 0x00 0x00 - config control 0x03 r - - - - reserved ? reads return 0 0x07 r/w 0x00 0x00 0x00 0x00 logical device number 0x20 r 0x57 0x57 0x57 0x57 device id - hard wired 0x21 r current revision device rev - hard wired 0x22 r/w 0x00 0x00 0x00 0x00 power control 0x23 r/w 0x00 0x00 0x00 - power mgmt 0x24 r/w 0x04 0x04 0x04 - osc 0x26 r/w sysopt=0 : 0x2e sysopt=1 : 0x4e sysopt=0: 0x2e sysopt=1: 0x4e - - configuration port address byte 0 (low byte) 0x27 r/w sysopt=0 : 0x00 sysopt=1 : 0x00 sysopt=0: 0x00 sysopt=1: 0x00 - - configuration port address byte 1 (high byte) 0x28 r - - - - reserved 0x2a r/w - 0x00 0x00 - test 6 0x2b r/w - 0x00 0x00 - test 4 0x2c r/w - 0x00 0x00 - test 5 0x2d r/w - 0x00 0x00 - test 1 0x2e r/w - 0x00 0x00 - test 2 0x2f r/w - 0x00 0x00 - test 3 logical device 0 configuration registers (fdd) 0x30 r/w 0x00 0x00 0x00 0x00 activate 0x60, 0x61 r/w 0x03, 0xf0 0x03, 0xf0 0x03, 0xf0 0x03, 0xf0 primary base i/o address 0x70 r/w 0x06 0x06 0x06 0x06 primary interrupt select 0x74 r/w 0x02 0x02 0x02 0x02 dma channel select 0xf0 r/w 0x0e 0x0e 0x0e - fdd mode register 0xf1 r/w 0x00 0x00 0x00 - fdd option register 0xf2 r/w 0xff 0xff 0xff - fdd type register 204 index type hard reset vcc por vtr por soft reset configuration register 0xf4 r/w 0x00 0x00 0x00 - fdd0 0xf5 r/w 0x00 0x00 0x00 - fdd1 logical device 1 configuration registers (reserved) logical device 2 configuration registers (reserved) logical device 3 configuration registers (parallel port) 0x30 r/w 0x00 0x00 0x00 0x00 activate 0x60, 0x61 r/w 0x00, 0x00 0x00, 0x00 0x00, 0x00 0x00, 0x00 primary base i/o address 0x70 r/w 0x00 0x00 0x00 0x00 primary interrupt select 0x74 r/w 0x04 0x04 0x04 0x04 dma channel select 0xf0 r/w 0x3c 0x3c 0x3c - parallel port mode register 0xf1 r/w 0x00 0x00 0x00 - parallel port mode register 2 logical device 4 configuration registers (serial port 1) 0x30 r/w 0x00 0x00 0x00 0x00 activate 0x60, 0x61 r/w 0x00, 0x00 0x00, 0x00 0x00, 0x00 0x00, 0x00 primary base i/o address 0x70 r/w 0x00 0x00 0x00 0x00 primary interrupt select 0xf0 r/w 0x00 0x00 0x00 - serial port 1 mode register logical device 5 configuration registers (serial port 2) 0x30 r/w 0x00 0x00 0x00 0x00 activate 0x60, 0x61 r/w 0x00, 0x00 0x00, 0x00 0x00, 0x00 0x00, 0x00 primary base i/o address 0x70 r/w 0x00 0x00 0x00 0x00 primary interrupt select 0xf0 r/w 0x00 0x00 0x00 - serial port 2 mode register 0xf1 r/w 0x02 0x02 0x02 - ir options register 0xf2 r/w 0x03 0x03 0x03 - ir half duplex timeout logical device 6 configuration registers (reserved) logical device 7 configuration registers (keyboard) 0x30 r/w 0x00 0x00 0x00 0x00 activate 0x70 r/w 0x00 0x00 0x00 0x00 primary interrupt select (keyboard) 0x72 r/w 0x00 0x00 0x00 0x00 second interrupt select (mouse) 205 index type hard reset vcc por vtr por soft reset configuration register 0xf0 r/w 0x00 0x00 0x00 - kreset and gatea20 select logical device 8 configuration registers (x-bus) 0x30 r/w 0x00 0x00 0x00 0x00 activate 0x60 r/w note1 0x00 0x00 0x00 0x00 base i/o address 0 - high byte 0x61 r/w note1 0x00 0x00 0x00 0x00 note 2 base i/o address 0 - low byte 0x62 r/w note1 0x00 0x00 0x00 0x00 base i/o address 1 - high byte 0x63 r/w note1 0x00 0x00 0x00 0x00 note 2 base i/o address 1 - low byte 0x64 r/w no te1 0x00 0x00 0x00 0x00 base i/o address 2 - high byte 0x65 r/w note1 0x00 0x00 0x00 0x00 note 2 base i/o address 2 - low byte 0x66 r/w note1 0x00 0x00 0x00 0x00 base i/o address 3 - high byte 0x67 r/w note1 0x00 0x00 0x00 0x00 note 2 base i/o address 3 - low byte 0xf0 r/w note 3 note 3 0x00 - x-bus select logical device 9 configuration registers (reserved) logical device a configuration registers (runtime registers) 0x30 r/w 0x00 0x00 0x00 0x00 activate 0x60, 0x61 r/w 0x00, 0x00 0x00, 0x00 0x00, 0x00 0x00, 0x00 primary base i/o address runtime register block 0xf0 r/w - - 0x00 - clocki32 0xf4 r/w - - 0x00 - irqin routing register 1 0xf5 r/w - - 0x00 - irqin routing register 2 logical device b configuration registers (smbus) 0x30 r/w 0x00 0x00 0x00 0x00 activate 0x60, 0x61 r/w 0x00, 0x00 0x00, 0x00 0x00, 0x00 0x00, 0x00 smbus primary base i/o address runtime register block 0x70 r/w 0x00 0x00 0x00 0x00 primary interrupt select note: reserved registers are read-only, reads return 0. 206 note 1: these r egisters are read-only if the write protect bit is set in the associated base i/o address low byte register. note 2: bit 1 is reset on vcc por, vtr por and hard reset only. note 3: bit 7 is reset on vcc por, vtr por and hard reset. chip level (global) control/configuration registers[0x00-0x2f] the chip-level (global) registers lie in the address range [0x00-0x2f]. the design must use all 8 bits of the address port for register selection. all unimplemented registers and bits ignore writes and return zero when read. the index port is used to select a configuration register in the chip. the data port is then used to access the selected register. these registers are accessible only in the configuration mode. table 60 - chip level registers register address description state chip (global) control registers 0x00 - 0x01 reserved - writes are ignored, reads return 0. config control default = 0x00 on vcc por , vtr por and hard reset 0x02 w the hardware automatically clears this bit after the write, there is no need for software to clear the bits. bit 0 = 1: soft reset. refer to the "configuration registers" table for the soft reset value for each register. c n/a 0x03 - 0x06 reserved - writes are ignored, reads return 0 . logical device # default = 0x00 on vcc por, vtr por, hard reset and soft reset 0x07 r/w a write to this register selects the current logical device. this allows access to the control and configuration registers for each logical device. note: the activate command operates only on the selected logical device. c card level reserved 0x08 - 0x1f reserved - writes are ignored, reads return 0 . chip level, smsc defined device id default = 0x57 vcc por, vtr por, hard reset and soft reset 0x20 r a read only register which provides device identification. bits[7:0] = 0x57 when read. c 207 table 60 - chip level registers register address description state device rev default = current rev vcc por, vtr por, hard reset and soft reset 0x21 r a read only register which provides device revision information.. c powercontrol default = 0x00. on vcc por, vtr por, hard reset and soft reset 0x22 r/w bit[0] fdc power bit[1] reserved bit[2] reserved bit[3] parallel port power bit[4] serial port 1 power bit[5] serial port 2 power bit[6] reserved bit[7] reserved c power mgmt default = 0x00. on vcc por, vtr por and hard reset 0x23 r/w bit[0] fdc bit[1] reserved bit[2] reserved bit[3] parallel port bit[4] serial port 1 bit[5] serial port 2 bit[7:6] reserved (read as 0) for each bit above (except reserved) = 0 intelligent pwr mgmt off = 1 intelligent pwr mgmt on c osc default = 0x04, on vcc por , vtr por and hard reset 0x24 r/w bit[0] reserved bit [1] pll control = 0 pll is on (backward compatible) = 1 pll is off bits[3:2] osc = 01 osc is on, brg clock is on. = 10 same as above (01) case. = 00 osc is on, brg clock enabled. = 11 osc is off, brg clock is disabled. bit [5:4] reserved, set to zero bit [6] 16-bit address qualification = 0 12-bit address qualification = 1 16-bit address qualification note: for normal operation, bit 6 should be set. bit[7] reserved c 208 table 60 - chip level registers register address description state chip level vendor defined 0x25 reserved - writes are ignored, reads return 0. configuration address byte 0 default =0x2e (sysopt=0) =0x4e (sysopt=1) on vcc por and hard reset 0x26 bit[7:1] configuration address bits [7:1] bit[0] = 0 see note 1 c configuration address byte 1 default = 0x00 on vcc por and hard reset 0x27 bit[7:0] configuration address bits [15:8] see note 1 c n/a 0x28 bits[7:0] reserved - writes are ignored, reads return 0. chip level vendor defined 0x29 reserved - writes are ignored, reads return 0. test 6 default = 0x00, on vcc por and vtr por 0x2a r/w test modes: reserved for smsc. users should not write to this register, may produce undesired results. test 4 default = 0x00, on vcc por and vtr por 0x2b r/w test modes: reserved for smsc. users should not write to this register, may produce undesired results. c test 5 default = 0x00, on vcc por and vtr por 0x2c r/w bit[7] test mode: reserved for smsc. users should not write to this bit, may produce undesired results. bit[6] 8042 reset: 1 = put the 8042 into reset 0 = take the 8042 out of reset bits[5:0] test mode: reserved for smsc. users should not write to this bit, may produce undesired results. c test 1 default = 0x00, on vcc por and vtr por 0x2d r/w test modes: reserved for smsc. users should not write to this register, may produce undesired results. c 209 table 60 - chip level registers register address description state test 2 default = 0x00, on vcc por and vtr por 0x2e r/w test modes: reserved for smsc. users should not write to this register, may produce undesired results. c test 3 default = 0x00, on vcc por and vtr por 0x2f r/w test modes: reserved for smsc. users should not write to this register, may produce undesired results. c note 1: to allow the selection of the configuration address to a user defined locatio n, these configuration address bytes are used. there is no restriction on the address chosen, except that a0 is 0, that is, the address must be on an even byte boundary. as soon as both bytes are changed, the configuration space is moved to the specified location with no delay (note: write byte 0, then byte 1; writing cr27 changes the base address). the configuration address is only reset to its default address upon a hard reset or vcc por. note: the default configuration address is either 0x02e or 0x04 e, as specified by the sysopt pin. 210 logical device configuration/control registers [0x30-0xff] used to access the registers that are assigned to each logical unit. this chip supports eight logical units and has eight sets of logical device registers. the eight logical devices are floppy, parallel, serial 1, serial 2, keyboard controller, smbus controller, x-bus and runtime registers. a separate set (bank) of control and configuration registers exists for each logical device and is selected with the logical device # register (0x07). the index port is used to select a specific logical device register. these registers are then accessed through the data port. the logical device registers are accessible only when the device is in the configuration state. the logical register addresses are shown in the table below. table 61 ? logical device registers logical device register address description state activate (note 1) default = 0x00 on vcc por , vtr por, hard reset and soft reset (0x30) bits[7:1] reserved, set to zero. bit[0] = 1 activates the logical device currently selected through the logical device # register. = 0 logical device currently selected is inactive c logical device control (0x31-0x37) reserved - writes are ignored, reads return 0. c logical device control (0x38-0x3f) vendor defined - reserved - writes are ignored, reads return 0. c memory base address (0x40-0x5f) reserved - writes are ignored, reads return 0. c i/o base address (note 2) (see device base i/o address table) default = 0x00 on vcc por, vtr por, hard reset and soft reset (0x60-0x6f) 0x60,2,... = addr[15:8] 0x61,3,... = addr[7:0] registers 0x60 and 0x61 set the base address for the device. if more than one base address is required, the second base address is set by registers 0x62 and 0x63. refer to table 62 for the number of base address registers used by each device. unused registers will ignore writes and return zero when read. see the x-bus and smbus logical device configuration registers for a description of their respective base i/o registers. c 211 table 62 ? logical device registers logical device register address description state interrupt select defaults : 0x70 = 0x00 or 0x06 (note 3) on vcc por, vtr por, hard reset and soft reset 0x72 = 0x00, on vcc por, vtr por, hard reset and soft reset (0x70,0x72) 0x70 is implemented for each logical device. refer to interrupt configuration register description. only the keyboard controller uses interrupt select register 0x72. unused register (0x72) will ignore writes and return zero when read. interrupts default to edge high (isa compatible). c (0x71,0x73) reserved - not implemented. these register locations ignore writes and return zero when read. dma channel select default = 0x02 or 0x04 (note 4) on vcc por, vtr por, hard reset and soft reset (0x74,0x75) only 0x74 is implemented for fdc and parallel port. 0x75 is not implemented and ignores writes and returns zero when read. refer to dma channel select configuration register description. c 32-bit memory space configuration (0x76-0xa8) reserved - not implemented. these register locations ignore writes and return zero when read. logical device (0xa9-0xdf) reserved - not implemented. these register locations ignore writes and return zero when read. c logical device configuration (0xe0-0xfe) reserved - vendor defined (see smsc defined logical device configuration registers). c reserved 0xff reserved c note 1: a logical device will be active and powered up accordin g to the following equation: device on (active) = (activate bit set or pwr/control bit set). the logical device's activate bit and its pwr/control bit are linked such that setting or clearing one sets or clears the other. note 2: if the i/o base addr of the logical device is not within the base i/o range as shown in the logical device i/o map, then read or write is not valid and is ignored. note 3: the default value of the primary interrupt select register for logical device 0 is 0x06. 212 note 4: the dm a (0x74) default address for logical device 0 (fdd) is 0x02 and for logical device 3 is 0x04. table 63 - i/o base address configuration register description logical device number logical device register index base i/o range (note 1) fixed base offsets 0x00 fdc 0x60,0x61 [0x0100:0x0ff8] on 8-byte boundaries +0 : sra +1 : srb +2 : dor +3 : tdr +4 : msr/dsr +5 : fifo +7 : dir/ccr 0x01 reserved n/a n/a n/a 0x02 reserved n/a n/a n/a [0x0100:0x0ffc] on 4-byte boundaries (epp not supported) or [0x0100:0x0ff8] on 8-byte boundaries +0 : data/ecpafifo +1 : status +2 : control +400h : cfifo/ecpdfifo/tfifo/cnfga +401h : cnfgb +402h : ecr 0x03 parallel port 0x60,0x61 (all modes supported, epp is only available when the base address is on an 8-byte boundary) +3 : epp address +4 : epp data 0 +5 : epp data 1 +6 : epp data 2 +7 : epp data 3 0x04 serial port 1 0x60,0x61 [0x0100:0x0ff8] on 8 byte boundaries +0 : rb/tb/lsb div +1 : ier/msb div +2 : iir/fcr +3 : lcr +4 : msr +5 : lcr +6 : msr +7 : scr 0x05 serial port 2 0x60,0x61 [0x0100:0x0ff8] on 8-byte boundaries +0 : rb/tb/lsb div +1 : ier/msb div +2 : iir/fcr +3 : lcr +4 : msr +5 : lcr +6 : msr +7 : scr 0x06 reserved n/a n/a n/a 0x07 kybd n/a not relocatable fixed base address: 60,64 +0 : data register +4 : command/status reg. 213 table 63 - i/o base address configuration register description logical device number logical device register index base i/o range (note 1) fixed base offsets 0x08 x-bus 0x60,0x61 mode 1: [0x0000:0x0ffc] on 4 byte boundaries mode 2: [0x0000:0x0ff0] on 16 byte boundaries +0: x-bus cs0 address 0x62,0x63 mode 1: [0x0000:0x0ffc] on 4 byte boundaries mode 2: [0x0000:0x0ff0] on 16 byte boundaries +0: x-bus cs1 address 0x64,0x65 mode 1 only [0x0000:0x0ffc] on 4 byte boundaries +0: x-bus cs2 address 0x66,0x67 mode 1 only [0x0000:0x0ffc] on 4 byte boundaries +0: x-bus cs3 address 0x09 reserved n/a n/a n/a 0x0a runtime register block 0x60,0x61 [0x0000:0x0f80] on 128-byte boundaries +00 : pme_sts . . . (see table in ?runtime registers? section for full list) 0x0b smbus 0x60, 0x61 [0x0100:0x0ff8] on 8-byte boundaries +0: control/data +1: own address +2: data +3: clock config. port config. port 0x26, 0x27 (note 2) 0x0100:0x0ffe on 2-byte boundaries see configuration registers in table 64. accessed through the index and data ports located at the configuration port address and the configuration port address +1 respectively. note 1: this chip uses address bits [a11:a0] to decode the base address of each of its logical devices. bit 6 of the osc global configuration register (cr24) must be set to ?1? and address bits [a15:a12] must be ?0? for 16 bit address qualification. note 2: the configuration port is at either 0x02e or 0x04e (for sysopt=0 or sysopt=1) at power up and can be relocated via the global configuration registers at 0x26 and 0x27. 214 table 64 - interrupt select configuration register description name reg index definition state primary interrupt select default=0x00 or 0x06 (note 1) on vcc por, vtr por, hard reset and soft reset 0x70 (r/w) bits[3:0] selects which interrupt level is used for the primary interrupt. 0x00= no interrupt selected 0x01= irq1 0x02= irq2/nsmi 0x03= irq3 0x04= irq4 0x05= irq5 0x06= irq6 0x07= irq7 0x08= irq8 0x09= irq9 0x0a= irq10 0x0b= irq11 0x0c= irq12 0x0d= irq13 0x0e= irq14 0x0f= irq15 note: all interrupts are edge high (except ecp/epp) note: nsmi is active low c note: a n interrupt is activated by setting the interrupt request level select 0 register to a non-zero value and: for the fdc logical device by setting dmaen, bit d3 of the digital output register. for the pp logical device by setting irqe, bit d4 of the contro l port and in addition for the pp logical device in ecp mode by clearing serviceintr, bit d2 of the ecr. for the serial port logical device by setting any combination of bits d0-d3 in the ier and by setting the out2 bit in the uart 's modem control (mcr) register. for the kybd logical device (refer to the kybd controller section of this spec). for the smbus logical device by setting eni bit d3 of the control register. note: irqs are disabled if not used/selected by any logical de vice. refer to note a. note: nsmi must be disabled to use irq2. note: all irq?s are available in serial irq mode. note 1: the default value of the primary interrupt select register for logical device 0 is 0x06. 215 table 65 - dma channel select configuration register description name reg index definition state dma channel select default=0x02 or 0x04 (note 1) on vcc por, vtr por, hard reset and soft reset 0x74 (r/w) bits[2:0] select the dma channel. 0x00= reserved 0x01= dma1 0x02= dma2 0x03= dma3 0x04-0x07= no dma active c note: a dma channel is activated by setting the dma channel select register to [0x01-0x03] and : for the fdc logical device by setting dmaen, bit d3 of the digital output register. for the pp logical device in ecp mode by setting dmaen, bit d3 of the ecr. note: dma channels are disabled if not used/selected by any logical device. refer to note a. note 1: the default value of the dma channel select register for logical device 0 (fdd) is 0x02 and for logical device 3 and 5 is 0x04. 216 note a. logical device irq and dma operation 1. irq and dma enable and disable: any time the irq or dma channel for a logical block is disabled by a register bit in that logical block, the irq and/or dma channel must be disabled. this is in addition to the irq and dma channel disabled by the configuration registers (active bit or address not valid). a. fdc: for the following cases, the irq and dma channel used by the fdc are disabled. digital output register (base+2) bit d3 (dmaen) set to "0". the fdc is in power down (disabled). b. serial ports: modem control register (mcr) bit d2 (out2) - when out2 is a logic "0", the serial port interrupt is disabled. c. parallel port: i. spp and epp modes: control port (base+2) bit d4 (irq e) set to "0", irq is disabled. ii. ecp mode: (1) (dma) dmaen from ecr register. see table. (2) irq - see table. mode (from ecr register) irq controlled by dma controlled by 000 printer irqe dmaen 001 spp irqe dmaen 010 fifo (on) dmaen 011 ecp (on) dmaen 100 epp irqe dmaen 101 res irqe dmaen 110 test (on) dmaen 111 config irqe dmaen d. keyboard controller: refer to the kbd section of this spec. e. smbus controller: control register bit d3 (eni) ? when eni is a logic ?0? the smbus interrupt is disabled. 217 smsc defined logical device configuration registers the smsc specific logical device configuration registers reset to their default values only on hard resets generated by vcc or vtr por (as shown) or the hard reset signal. these registers are not affected by soft resets. table 66 - floppy disk controller, logical device 0 [logical device number = 0x00] name reg index definition state fdd mode register default = 0x0e on vcc por , vtr por and hard reset 0xf0 r/w bit[0] floppy mode = 0 normal floppy mode (default) = 1 enhanced floppy mode 2 (os2) bit[1] fdc dma mode = 0 burst mode is enabled = 1 non-burst mode (default) bit[3:2] interface mode = 11 at mode (default) = 10 (reserved) = 01 ps/2 = 00 model 30 bit[4] reserved bit[5] reserved, set to zero bit[6] fdc output type control = 0 fdc outputs are od12 open drain (default) = 1 fdc outputs are o12 push-pull bit[7] fdc output control = 0 fdc outputs active (default) = 1 fdc output s tri-stated note: bits 6 & 7 do not affect the parallel port fdc pins. c 218 table 66 - floppy disk controller, logical device 0 [logical device number = 0x00] name reg index definition state fdd option register default = 0x00 on vcc por, vtr por and hard reset 0xf1 r/w bit[0] forced write protect = 0 inactive (default) = 1 fdd nwrtprt input is forced active when either of the drives has been selected. bit[1] reserved bits[3:2] density select = 00 normal (default) = 01 normal (reserved for users) = 10 1 (forced to logic "1") = 11 0 (forced to logic "0") bit[7:4] reserved. nwrtprt (to the fdc core) = wp (fdc sra register, bit 1) = (floppy write protect) or nwrtprt(from the fdd interface) or (nds0 and force write protect ) or (nds1 and force write protect ). note: floppy write protect bit is in the device disable register. note: boot floppy is always drive 0. note: the force write protect bits also apply to the parallel port fdc. c fdd type register default = 0xff on vcc por, vtr por and hard reset 0xf2 r/w bits[1:0] floppy drive a type bits[3:2] floppy drive b type bits[5:4] reserved (could be used to store floppy drive c type) bits[7:6] reserved (could be used to store floppy drive d type) note: the LPC47S42X supports two floppy drives c 0xf3 r reserved, read as 0 (read only) c fdd0 default = 0x00 on vcc por, vtr por and hard reset 0xf4 r/w bits[1:0] drive type select: dt1, dt0 bits[2] read as 0 (read only) bits[4:3] data rate table select: drt1, drt0 bits[5] read as 0 (read only) bits[6] precompensation disable pts =0 use precompensation =1 no precompensation bits[7] read as 0 (read only) c fdd1 0xf5 r/w refer to definition and default for 0xf4 c 219 table 67 - parallel port, logical device 3 [logical device number = 0x03] name reg index definition state pp mode register default = 0x3c on vcc por , vtr por and hard reset 0xf0 r/w bits[2:0] parallel port mode = 100 printer mode (default) = 000 standard and bi-directional (spp) mode = 001 epp-1.9 and spp mode = 101 epp-1.7 and spp mode = 010 ecp mode = 011 ecp and epp-1.9 mode = 111 ecp and epp-1.7 mode bit[6:3] ecp fifo threshold 0111b (default) bit[7] pp interrupt type not valid when the parallel port is in the printer mode (100) or the standard & bi-directional mode (000). = 1 pulsed low, released to high-z. = 0 irq follows nack when parallel port in epp mode or [printer, spp, epp] under ecp. irq level type when the parallel port is in ecp, test, or centronics fifo mode. c pp mode register 2 default = 0x00 on vcc por, vtr por and hard reset 0xf1 r/w bits[1:0] ppfdc - muxed pp/fdc control = 00 normal parallel port mode = 01 ppfd1: drive 0 is on the fdc pins drive 1 is on the parallel port pins = 10 ppfd2: drive 0 is on the parallel port pins drive 1 is on the parallel port pins bits[7:2] reserved. set to zero. 220 table 68 - serial port 1, logical device 4 [logical device number = 0x04] name reg index definition state serial port 1 mode register default = 0x00 on vcc por , vtr por and hard reset 0xf0 r/w bit[0] midi mode = 0 midi support disabled (default) = 1 midi sup port enabled bit[1] high speed = 0 high speed disabled(default) = 1 high speed enabled bit[6:2] reserved, set to zero bit[7]: share irq =0 uarts use different irqs =1 uarts share a common irq see note 1 below. c note 1: to properly share and irq, 1. configure uart1 (or uart2) to use the desired irq pin. 2. configure uart2 (or uart1) to use no irq selected. 3. set the share irq bit. note: if both uarts are configured to use different irqs and the share irq bit is set, then both of the uart irqs will assert when either uart generates an interrupt. uart interrupt operation table table 69 - serial port 2, logical device 5 [logical device number = 0x05] name reg index definition state serial port 2 mode register default = 0x00 on vcc por, vtr por and hard reset 0xf0 r/w bit[0] midi mode = 0 midi support disabled (default) = 1 midi support enabled bit[1] high speed = 0 high speed disabled(default) = 1 high speed enabled bit[7:2] reserved, set to zero c 221 table 69 - serial port 2, logical device 5 [logical device number = 0x05] name reg index definition state ir option register default = 0x02 on vcc por, vtr por and hard reset 0xf1 r/w bit[0] receive polarity = 0 active high (default) = 1 active low bit[1] transmit polarity = 0 active high = 1 active low (default) bit[2] duplex select = 0 full duplex (default) = 1 half duplex bits[5:3] ir mode = 000 standard com functionality (default) = 001 irda = 010 ask-ir = 011 reserved = 1xx reserved bit[6] reserved, write 0. bit[7] reserved, write 0. c ir half duplex timeout default = 0x03 on vcc por, vtr por and hard rset 0xf2 bits [7:0] these bits set the half duplex time-out for the ir port. this value is 0 to 10msec in 100usec increments. 0= blank during transmit/receive 1= blank during transmit/receive + 100usec . . . 222 table 70 - kybd, logical device 7 [logical device number = 0x07] name reg index definition state krst_ga20 default = 0x00 on vcc por, vtr por and hard reset 0xf0 r/w kreset and gatea20 select bit[7] polarity select for p12 = 0 p12 active low (default) = 1 p12 active high bit[6] m_iso. enables/disables isolation of mouse signals into 8042. does not affect mdat signal to mouse wakeup (pme) logic. 1=block mouse clock and data signals into 8042 0= do not block mouse clock and data signals into 8042 bit[5] k_iso. enables/disables isolation of keyboard signals into 8042. does not affect kdat signal to keyboard wakeup (pme) logic. 1=block keyboard clock and data signals into 8042 0= do not block keyboard clock and data signals into 8042 bit[4] mlatch = 0 mint is the 8042 mint anded with latched mint (default) = 1 mint is the latched 8042 mint bit[3] klatch = 0 kint is the 8042 kint anded with latched kint (default) = 1 kint is the latched 8042 kint bit[2] port 92 select = 0 port 92 disabled = 1 port 92 enabled bit[1] reserved bit[0] reserved 0xf1 - 0xff reserved - read as ?0? 223 table 71 ? x-bus, logical device 8 [logical device number = 0x08] name reg index definition state base i/o address 0 ? high byte note 1 default = 0x00 on vtr por, vcc por, hard reset and soft reset 0x60 r/w, read-only when the base i/o address 0 ? low byte register bit[1]=1. register 0x60 sets the high byte of the base i/o address for chip select 0. bits [7:0] =address[15:8] note: bits[15:12] must be ?0? since the chip performs 16- bit address qualification on the base i/o addresses. base i/o address 0 ? low byte note 1 default = 0x00 on vtr por, vcc por, hard reset and soft reset bit 1 is reset on vcc por, vtr por and hard reset 0x61 r/w, read-only when the base i/o address 0 ? low byte register bit[1]=1 register 0x61 sets the low byte of the base i/o address for chip select 0. bit 1 is the write protect bit for registers 60 and 61. bit 0 is the disable bit for nxcs0. bits[7:2] are x-bus mode dependent as follows: mode 1: bits [7:2] =address[7:2] mode 2: bits [7:4] =address[7:4] bit[3:2] = reserved bit[1] = register 60, 61 write protect. cleared by vcc por and hard reset only. cannot be cleared by software writing to this bit. 0=register 60 and 61 are read/write 1=register 60 and 61 are read-only bit[0] = disable bit for nxcs0. 0=enable chip select 1=disable chip select base i/o address 1 ? high byte note 1 default = 0x00 on vtr por, vcc por, hard reset and soft reset 0x62 r/w, read-only when the base i/o address 1 ? low byte register bit[1]=1 register 0x62 sets the high byte of the base i/o address for chip select 1. bits [7:0] =address[15:8] note: bits[15:12] must be ?0? since the chip performs 16- bit address qualification on the base i/o addresses. 224 table 71 ? x-bus, logical device 8 [logical device number = 0x08] name reg index definition state base i/o address 1 ? low byte note 1 default = 0x00 on vtr por, vcc por, hard reset and soft reset bit 1 is reset on vcc por, vtr por and hard reset 0x63 r/w, read-only when the base i/o address 1 ? low byte register bit[1]=1 register 0x63 sets the low byte of the base i/o address for chip select 1. bit 1 is the write protect bit for registers 62 and 63. bit 0 is the disable bit for nxcs1. bits[7:1] are x-bus mode dependent as follows: mode 1: bits [7:2] =address[7:2] mode 2: bits [7:4] =address[7:4] bit[3:2] = reserved bit[1] = register 62, 63 write protect. cleared by vcc por and hard reset only. cannot be cleared by software writing to this bit. 0=register 62 and 63 are read/write 1=register 62 and 63 are read-only bit[0] = disable bit for nxcs1. 0=enable chip select 1=disable chip select base i/o address 2 ? high byte note 1 default = 0x00 on vtr por, vcc por, hard reset and soft reset 0x64 r/w, read-only when the base i/o address 2 ? low byte register bit[1]=1 register 0x64 sets the high byte of the base i/o address for chip select 2. this register is only used in x-bus mode 1. bits [7:0] =address[15:8] note: bits[15:12] must be ?0? since the chip performs 16- bit address qualification on the base i/o addresses. base i/o address 2 ? low byte note 1 default = 0x00 on vtr por, vcc por, hard reset and soft reset bit 1 is reset on vcc por, vtr por and hard reset 0x65 r/w, read-only when the base i/o address 2 ? low byte register bit[1]=1 register 0x65 sets the low byte of the base i/o address for chip select 2. bit 1 is the write protect bit for registers 64 and 65. bit 0 is the disable bit for nxcs2. this register is only used in x-bus mode 1. bits [7:2] =address[7:2] bit[1] = register 64, 65 write protect. cleared by vcc por and hard reset only. cannot be cleared by software writing to this bit. 0=register 64 and 65 are read/write 1=register 64 and 65 are read-only bit[0] = disable bit for nxcs2. 0=enable chip select 1=disable chip select 225 table 71 ? x-bus, logical device 8 [logical device number = 0x08] name reg index definition state base i/o address 3 ? high byte note 1 default = 0x00 on vtr por, vcc por, hard reset and soft reset 0x66 r/w, read-only when the base i/o address 3 ? low byte register bit[1]=1 register 0x66 sets the high byte of the base i/o address for chip select 3. this register is only used in x-bus mode 1. bits [7:0] =address[15:8] note: bits[15:12] must be ?0? since the chip performs 16- bit address qualification on the base i/o addresses. base i/o address 3 ? low byte note 1 default = 0x00 on vtr por, vcc por, hard reset and soft reset bit 1 is reset on vcc por, vtr por and hard reset 0x67 r/w, read-only when the base i/o address 3 ? low byte register bit[1]=1 register 0x67 sets the low byte of the base i/o address for chip select 3. bit 1 is the write protect bit for registers 66 and 67. bit 0 is the disable bit for nxcs3. this register is only used in x-bus mode 1. bits [7:2] =address[7:2] bit[1] = register 66, 67 write protect. cleared by vcc por and hard reset only. cannot be cleared by software writing to this bit. 0=register 66 and 67 are read/write 1=register 66 and 67 are read-only bit[0] = disable bit for nxcs3. 0=enable chip select 1=disable chip select x-bus selection default = 0x00 on vtr por bit 7 is reset on vcc por, vtr por and hard reset 0xf0 (r/w) bit[0] x-bus mode. 0=mode 1 1=mode 2 note that the gpios must be configured properly to use the selected mode. the gpios are not automatically configured for the mode selected. bit[1] reserved bits[3:2] x-bus read/write pulse width selection. these bits select the pulse width of the x-bus read and write strobes. they extend the lpc cycle accordingly by adding wait states (sync fields) into the cycle. 11=540nsec min 10=420nsec min 01=300nsec min 00=180nsec min (default) bits[6:4] reserved bit[7] register write protect. cleared by vcc por, vtr por and hard reset only. cannot be cleared by software writing this bit. 0=x-bus selection register is read/write. 1=x-bus selection register is read-only note 1: if the i/o base address of the logical device is not within the base i/o range as shown in the logical device i/o map, then read or write is not valid and is ignored. 226 table 72 ? runtime registers, logical device a name reg index definition state clocki32 default = 0x00 on vtr por 0xf0 (r/w) bit[0] (clk32_prsn) 0=32khz clock is connected to the clki32 pin (default) 1=32khz clock is not connected to the clki32 pin (pin is grounded) bit[1] spekey_en. this bit is used to turn the logic for the ?wake on specific key? feature on and off. it will disable the 32khz clock input to the logic when turned off. the logic will draw no power when disabled. 0= ?wake on specific key? logic is on (default) 1= ?wake on specific key? logic is off bits[7:2] are reserved c irqin routing register 1 default = 0x00 on vtr por 0xf4 (r/w) bits[7:4] irqinb routing. s elects which serial interrupt is used for irqinb. see bit mapping below. bits[3:0] irqina routing. s elects which serial interrupt is used for irqina. see bit mapping below. bits[7:4] and bits[3:0] mapping: 0x00= no interrupt selected 0x01= irq1 0x02= irq2/nio_smi 0x03= irq3 0x04= irq4 0x05= irq5 0x06= irq6 0x07= irq7 0x08= irq8 0x09= irq9 0x0a= irq10 0x0b= irq11 0x0c= irq12 0x0d= irq13 0x0e= irq14 0x0f= irq15 note: nio_smi must be disabled to use irq2 for an interrupt other than smi. 227 table 72 ? runtime registers, logical device a name reg index definition state irqin routing register 2 default = 0x00 on vtr por 0xf5 bits[7:4] irqind routing. s elects which serial interrupt is used for irqind. see bit mapping below. bits[3:0] irqinc routing. s elects which serial interrupt is used for irqinc. see bit mapping below. bits[7:4] and bits[3:0] mapping: 0x00= no interrupt selected 0x01= irq1 0x02= irq2/nio_smi 0x03= irq3 0x04= irq4 0x05= irq5 0x06= irq6 0x07= irq7 0x08= irq8 0x09= irq9 0x0a= irq10 0x0b= irq11 0x0c= irq12 0x0d= irq13 0x0e= irq14 0x0f= irq15 note: nio_smi must be disabled to use irq2 for an interrupt other than smi. 228 table 73 - smbus [logical device number = 0x0b] name reg index definition state smbus primary base address high byte default = 0x00 on vcc por, vtr por, hard reset and soft reset 0x60 r/w bit[0] a8 bit[1] a9 bit[2] a10 bit[3] a11 bit[4] ?0? bit[5] ?0? bit[6] ?0? bit[7] ?0? c smbus primary base address low byte (note 1) default = 0x00 on vtr por, vcc por, hard reset and soft reset 0x61 r/w bit[0] ?0? bit[1] ?0? bit[2] ?0? bit[3] a3 bit[4] a4 bit[5] a5 bit[6] a6 bit[7] a7 c note 1: the valid address range is 0x0100 ? 0x0ff8. 229 operational description maximum guaranteed ratings operating temperature range ................................ ................................ ........................... 0 o c to +70 o c storage temperature range ................................ ................................ ............................ -55 o to +150 o c lead temperature range ................................ ................................ ... refer to jedec spec. j-std-020 positive voltage on any pin, with respect to ground ................................ ................................ .. v cc +0.3v negative voltage on any pin, with respect to ground ................................ ................................ ...... -0.3v maximum v cc ................................ ................................ ................................ ................................ . +7v note: stresses above those listed above could cause permanent damage to the device. this is a stress rating only and functional operation of the device at any other condition above those indicated in the operation sections of this specification is not implied. note: when powering this device from laboratory or system power supplies, it is important that the absolute maximum ratings not be exceeded or device failure can result. some power supplies exhibit voltage spikes on their outputs when the ac power is switched on or off. in addition, voltage transients on the ac power line may appear on the dc output. if this possibility exists, it is suggested that a clamp circuit be used. dc electrical characteristics (t a = 0 0 c ? 70 0 c, v cc = +3.3 v 10%) parameter symbol min typ max units comments i type input buffer low input level high input level v ili v ihi 2.0 0.8 v v ttl levels is type input buffer low input level high input level schmitt trigger hysteresis v ili s v ihis v hys 2.2 100 0.8 v v mv schmitt trigger schmitt trigger input leakage, i and is buffers low input leakage high input leakage i il i ih -10 -10 +10 +10 a a v in = 0 v in = v cc 230 parameter symbol min typ max units comments io6 type buffer low output level high output level output leakage v ol v oh i ol 2.4 -10 0.4 +10 v v a i ol = 6ma i oh = -3ma v in = 0 to v cc (note 1) od6 type buffer low output level output leakage v ol i ol -10 0.4 +10 v a i ol = 6ma v in = 0 to v cc o6 type buffer low output level high output level v ol v oh 2.4 0.4 v v i ol = 6ma i oh = -3ma io8 type buffer low output level high output level output leakage v ol v oh i ol 2.4 -10 0.4 +10 v v a i ol = 8ma i oh = -4ma v in = 0 to v cc (note 1) o8 type buffer low output level high output level v ol v oh 2.4 0.4 v v i ol = 8ma i oh = -4ma o12 type buffer low output level high output level v ol v oh 2.4 0.4 v v i ol = 12ma i oh = -6ma io12 type buffer low output level high output level output leakage v ol v oh i ol 2.4 -10 0.4 +10 v v a i ol = 12ma i oh = -6ma v in = 0 to v cc (note 1) 231 parameter symbol min typ max units comments od12 type buffer low output level output leakage v ol i ol -10 0.4 +10 v a i ol = 12ma v in = 0 to v cc od14 type buffer low output level output leakage v ol i ol -10 0.4 +10 v a i ol = 14ma v in = 0 to v cc op14 type buffer low output level high output level output leakage v ol v oh i ol 2.4 -10 0.4 +10 v v a i ol = 14ma i oh = -14ma v in = 0 to v cc (note 1) iop14 type buffer low output level high output level output leakage v ol v oh i ol 2.4 -10 0.4 +10 v v a i ol = 14ma i oh = -14ma v in = 0 to v cc (note 1) iod16 type buffer low output level output leakage v ol i ol -10 0.4 +10 v a i ol = 16ma v in = 0 to v cc (note 1) backdrive protect/chiprotect (all pins excluding lad[3:0], nldrq, nlpcpd, nlframe) i il 10 a v cc = 0v v in = 5.5v max 5v tolerant pins (all pins excluding lad[3:0], nldrq, nlpcpd, nlframe) i nputs and outputs in high impedance state i il 10 a v cc = 3.3v v in = 5.5v max lpc bus pins (lad[3:0], nldrq, nlpcpd, nlframe) i il 10 a v cc = 0v and v cc = 3.3v v in = 3.6v max v cc supply current active i cci 20 3 ma all outputs open, all inputs at a fixed state (i.e., 0v or 3.3v) 232 parameter symbol min typ max units comments trickle supply voltage v tr v cc min -.5v 5 v cc max v v cc must not be greater than .5v above v tr v tr supply current active i tri 1 3,4 ma all outputs open, all inputs at a fixed state (i.e., 0v or 3.3v) note 1: all output leakage?s are measured with all pins in high impedance. note 2: output leakage is measured with the low driving output off, either for a high level output or a high impedance state. note 3: contact smsc for the latest values. note 4: max i tri with v cc = 3.3v (nominal) is 1ma. max i tri with v cc = 0 is 100 a. note 5: the minimum value given for v tr applies when v cc is active. when v cc is 0v, the minimum v tr is 0v. capacitance t a = 25 0 c; fc = 1mhz; v cc = 3.3v 10% limits parameter symbol min typ max unit test condition clock input capacitance c in 20 pf input capacitance c in 10 pf output capacitance c out 20 pf all pins except pin under test tied to ac ground 233 timing diagrams for the timing diagrams shown, the following capacitive loads are used on outputs. name capacitance total (pf) ser_irq 50 nlad[3:0] 50 nldrq 50 ndir 240 nstep 240 nds0-1 240 nwdata 240 pd[0:7] 240 nstrobe 240 nalf 240 nslctin 240 kdat 240 kclk 240 mdat 240 mclk 240 fan 50 ledx 50 txd1 50 txd2 50 nxcs[0:3] 50 xa[0:3] 50 xd[0:7] 50 nxrd 50 nxwr 50 sdat 50 sclk 50 234 t3 vcc all host accesses t2 t1 figure 8 - power-up timing name description min typ max units t1 vcc slew from 2.7v to 0v 300 m s t2 vcc slew from 0v to 2.7v 100 m s t3 all host accesses after powerup (note 1) 125 500 m s note 1: internal write-protection period after vcc passes 2.7 volts on power-up 235 t1 t2 t2 clocki figure 9a - input clock timing name description min typ max units t1 clock cycle time for 14.318mhz 69.84 ns t2 clock high time/low time for 14.318mhz 20 35 ns t1 clock cycle time for 32khz 31.25 m s t2 clock high time/low time for 32khz 16.53 m s clock rise time/fall time (not shown) 5 ns t1 t3 t2 pci_clk t5 t4 figure 9b ? pci clock timing name description min typ max units t1 period 30 33.3 nsec t2 high time 12 nsec t3 low time 12 nsec t4 rise time 3 nsec t5 fall time 3 nsec t1 npci _reset figure 9c - reset timing name description min typ max units t1 npci_reset width 1 ms 236 t3 t2 t1 clk output delay tri-state output figure 10 ? output timing measurement conditions, lpc signals name description min typ max units t1 clk to signal valid delay ? bused signals 2 11 ns t2 float to active delay 2 11 ns t3 active to float delay 28 ns inputs valid t2 t1 clk input figure 11 ? input timing measurement conditions, lpc signals name description min typ max units t1 input set up time to clk ? bused signals 7 ns t2 input hold time from clk 0 ns 237 l1 l2 address data tar sync=0110 l3 tar pci_clk nlframe nlad[3:0] note: l1=start; l2=cyctyp+dir; l3=sync of 0000 figure 12 ? i/o write l1 l2 address tar sync=0110 l3 data tar pci_clk nlframe nlad[3:0] note: l1=start; l2=cyctyp+dir; l3=sync of 0000 figure 13 ? i/o read 238 start msb lsb act pci_clk nldrq figure 14 ? dma request assertion through nldrq start c+d chl size tar sync=0101 l1 data tar pci_clk nlframe nlad[3:0] note: l1=sync of 0000 figure 15 ? dma write (first byte) start c+d chl size data tar sync=0101 l1 tar pci_clk nlframe nlad[3:0] note: l1=sync of 0000 figure 16 ? dma read (first byte) 239 figure 17 ? floppy disk drive timing (at mode only) name description min typ max units t1 ndir set up to step low 4 x* t2 nstep active time low 24 x* t3 ndir hold time after nstep 96 x* t4 nstep cycle time 132 x* t5 nds0-1 hold time from nstep low (note) 20 x* t6 nindex pulse width 2 x* t7 nrdata active time low 40 ns t8 nwdata write data width low .5 y* t9 nds0-1, setup time ndir low (note) 0 ns *x specifies one mclk period and y spe cifies one wclk period. mclk = 16 x data rate (at 500 kb/s mclk = 8 mhz) wclk = 2 x data rate (at 500 kb/s wclk = 1 mhz) note: the nds0-1 setup and hold times must be met by software. t3 t1 t2 t4 t5 t6 t7 t8 ndir nstep nds0-1 nindex nrdata nwdata t9 240 t9 t8 t7 t6 t4 t5 t3 t2 t1 nwrite pd<7:0> ndatastb naddrstb nwait figure 18 ? epp 1.9 data or address write cycle name description min typ max units t1 nwait asserted to nwrite asserted (note 1) 60 185 ns t2 nwait asserted to nwrite change (note 1) 60 185 ns t3 nwait asserted to pdata invalid (note 1) 0 ns t4 pdata valid to command asserted 10 ns t5 nwrite to command asserted 5 35 ns t6 nwait asserted to command asserted (note 1) 60 210 ns t7 nwait deasserted to command deasserted (note 1) 60 190 ns t8 command asserted to nwait deasserted 0 10 m s t9 command deasserted to nwait asserted 0 ns note 1: nwait must be filtered to compensate for ringing on the parallel bus cable. wait is considered to have settled after it does not transition for a minimum of 50 nsec. 241 t12 t11 t10 t9 t7 t8 t6 t5 t4 t3 t2 t1 nwrite pd<7:0> ndatastb naddrstb nwait figure 19 ? epp 1.9 data or address read cycle name description min typ max units t1 nwait asserted to nwrite deasserted 0 185 ns t2 nwait asserted to nwrite modified (notes 1,2) 60 190 ns t3 nwait asserted to pdata hi-z (note 1) 60 180 ns t4 command asserted to pdata valid 0 ns t5 command deasserted to pdata hi-z 0 ns t6 nwait asserted to pdata driven (note 1) 60 190 ns t7 pdata hi-z to command asserted 0 30 ns t8 nwrite deasserted to command 1 ns t9 nwait asserted to command asserted 0 195 ns t10 nwait deasserted to command deasserted (note 1) 60 180 ns t11 pdata valid to nwait deasserted 0 ns t12 pdata hi-z to nwait asserted 0 m s note 1: nwait is considered to have settled after it does not transition for a minimum of 50 ns. note 2: when not executing a write cycle, epp nwrite is inactive high. 242 t5 t4 t3 t2 t1 nwrite pd<7:0> ndatastb naddrstb nwait figure 20 ? epp 1.7 data or address write cycle name description min typ max units t1 command deasserted to nwrite change 0 40 ns t2 command deasserted to pdata invalid 50 ns t3 pdata valid to command asserted 10 35 ns t4 nwrite to command 5 35 ns t5 command deasserted to nwait deasserted 0 ns 243 t3 t2 t1 nwrite pd<7:0> ndatastb naddrstb nwait figure 21 ? epp 1.7 data or address read cycle name description min typ max units t1 command asserted to pdata valid 0 ns t2 command deasserted to pdata hi-z 0 ns t3 command deasserted to nwait deasserted 0 ns 244 ecp parallel port timing parallel port fifo (mode 101) the standard parallel port is run at or near the peak 500kbytes/sec allowed in the forward direc tion using dma. the state machine does not examine nack and begins the next transfer based on busy. refer to figure 22. ecp parallel port timing the timing is designed to allow operation at approximately 2.0 mbytes/sec over a 15ft cable. if a shorter cable is used then the bandwidth will increase. forward-idle when the host has no data to send it keeps hostclk (nstrobe) high and the peripheral will leave periphclk (busy) low. forward data transfer phase the interface transfers data and commands from the host to the peripheral using an inter locked periphack and hostclk. the peripheral may indicate its desire to send data to the host by asserting nperiphrequest. the forward data transfer phase may be entered from the forward-idle phase. while in the forward phase the peripheral may asynchronously assert the nperiphrequest (nfault) to request that the channel be reversed. when the peripheral is not busy it sets periphack (busy) low. the host then sets hostclk (nstrobe) low when it is pre pared to send data. the data must be stable for the specified setup time prior to the falling edge of hostclk. the peripheral then sets periphack (busy) high to acknowledge the handshake. the host then sets hostclk (nstrobe) high. the peripheral then accepts the data and sets periphack (busy) low, complet ing the transfer. this sequence is shown in fig ure 23. the timing is designed to provide 3 cable round -trip times for data setup if data is driven simul taneously with hostclk (nstrobe). reverse -idle phase the peripheral has no data to send and keeps periphclk high. the host is idle and keeps hostack low. reverse data transfer phase the interface transfers data and commands from the peripheral to the host using an inter locked hostack and periphclk. the reverse data transfer phase may be en tered from the reverse-idle phase. after the previous byte has beed accepted the host sets hostack (nalf) low. the peripheral then sets periphclk (nack) low when it has data to send. the data must be stable for the specified setup time prior to the falling edge of periphclk. when the host is ready to accept a byte it sets hostack (nalf) high to acknowledge the handshake. the peripheral then sets periphclk (nack) high. after the host has accepted the data it sets hostack (nalf) low, completing the trans fer. this sequence is shown in figure 24. 245 output drivers to facilitate higher performance data transfer, the use of balanced cmos active drivers for critical signals (data, hostack, hostclk, periphack, periphclk) are used in ecp mode. because the use of active drivers can present compatibility problems in compatible mode (the control signals, by tradition, are speci fied as open -collector), the drivers are dynam ically changed from open -collector to totem -pole. the timing for the dynamic driver change is specified in then ieee 1284 extended capabilities port protocol and isa interface standard, rev. 1.14, july 14, 1993, available from microsoft. the dynamic driver change must be implement ed properly to prevent glitching the outputs. figure 22 - parallel port fifo timing name description min typ max units t1 pdata valid to nstrobe active 600 ns t2 nstrobe active pulse width 600 ns t3 pdata hold from nstrobe inactive (note 1) 450 ns t4 nstrobe active to busy active 500 ns t5 busy inactive to nstrobe active 680 ns t6 busy inactive to pdata invalid (note 1) 80 ns note 1: the data is held until busy goes inactive or for time t3, whichever is longer. this only applies if another data transfer is pending. if no other data transfer is pending, the data is held indefinitely. t3 t6 t1 t2 t5 t4 pd<7:0> nstrobe busy 246 figure 23 - ecp parallel port forward timing name description min typ max units t1 nalf valid to nstrobe asserted 0 60 ns t2 pdata valid to nstrobe asserted 0 60 ns t3 busy deasserted to nalf changed (notes 1,2) 80 180 ns t4 busy deasserted to pdata changed (notes 1,2) 80 180 ns t5 nstrobe deasserted to busy asserted 0 ns t6 nstrobe deasserted to busy deasserted 0 ns t7 busy deasserted to nstrobe asserted (notes 1,2) 80 200 ns t8 busy asserted to nstrobe deasserted (note 2) 80 180 ns note 1: maximum value only applies if there is data in the fifo waiting to be written out. note 2: busy is not considered asserted or deasserted until it is stable for a minimum of 75 to 130 ns. t3 t4 t1 t2 t7 t8 t6 t5 t6 nalf pd<7:0> busy nstrobe 247 figure 24 - ecp parallel port reverse timing name description min typ max units t1 pdata valid to nack asserted 0 ns t2 nalf asserted to pdata changed 0 ns t3 nack asserted to nalf deasserted (notes 1,2) 80 200 ns t4 nack deasserted to nalf asserted (note 2) 80 200 ns t5 nalf asserted to nack asserted 0 ns t6 nalf deasserted to nack deasserted 0 ns note 1: maximum value only applies if there is room in the fifo and terminal count has not been received. ecp can stall by keeping nalf low. note 2: nack is not considered asserted or deasserted until it is stable for a minimum of 75 to 130 ns. t2 t1 t5 t6 t4 t3 t4 pd<7:0> nack nalf 248 t1 t2 t2 t1 0 1 0 1 0 0 1 1 0 1 1 data irrx n irrx t1 t1 t1 t1 t1 t1 t1 t2 t2 t2 t2 t2 t2 t2 parameter min typ max units 1.4 1.4 1.4 1.4 1.4 1.4 1.4 2.71 3.69 5.53 11.07 22.13 44.27 88.55 s s s s s s s s s s s s s s pulse width at 115kbaud pulse width at 57.6kbaud pulse width at 38.4kbaud pulse width at 19.2kbaud pulse width at 9.6kbaud pulse width at 4.8kbaud pulse width at 2.4kbaud bit time at 115kbaud bit time at 57.6kbaud bit time at 38.4kbaud bit time at 19.2kbaud bit time at 9.6kbaud bit time at 4.8kbaud bit time at 2.4kbaud 1.6 3.22 4.8 9.7 19.5 39 78 8.68 17.4 26 52 104 208 416 notes: 1. receive pulse detection criteria: a received pulse is considered detected if the received pulse is a minimum of 1.41s. 2. irrx: l5, crf1 bit 0 = 1 nirrx: l5, crf1 bit 0 = 0 (default) fiigure 25 - irda receive timing 249 t1 t1 t1 t1 t1 t1 t1 t2 t2 t2 t2 t2 t2 t2 parameter min 1.41 1.41 1.41 1.41 1.41 1.41 1.41 max 2.71 3.69 5.53 11.07 22.13 44.27 88.55 units s s s s s s s s s s s s s s pulse width at 115kbaud pulse width at 57.6kbaud pulse width at 38.4kbaud pulse width at 19.2kbaud pulse width at 9.6kbaud pulse width at 4.8kbaud pulse width at 2.4kbaud bit time at 115kbaud bit time at 57.6kbaud bit time at 38.4kbaud bit time at 19.2kbaud bit time at 9.6kbaud bit time at 4.8kbaud bit time at 2.4kbaud typ 1.6 3.22 4.8 9.7 19.5 39 78 8.68 17.4 26 52 104 208 416 t1 t2 t2 t1 0 1 0 1 0 0 1 1 0 1 1 data irtx n irtx notes: 1. irda @ 115k is hpsir compatible. irda @ 2400 will allow compatibility with hp95lx and 48sx. 2. irtx: l5, crf1 bit 1 = 1 (default) nirtx: l5, crf1 bit 1 = 0 figure 26 - irda transmit timing 250 t1 t2 t3 t4 t5 t6 parameter min typ max units 0.8 0.8 0.8 0.8 1.2 1.2 1.2 1.2 s s s s s s modulated output bit time off bit time modulated output "on" modulated output "off" modulated output "on" modulated output "off" 1 1 1 1 notes: 1. irrx: l5, crf1 bit 0 = 1 nirrx: l5, crf1 bit 0 = 0 (default) mirrx, nmirrx are the modulated outputs t1 t2 t3 t4 t5 t6 0 1 0 1 0 0 1 1 0 1 1 data irrx n irrx mirrx nmirrx figure 27 - amplitude shift keyed ir receive timing 251 t1 t2 t3 t4 t5 t6 parameter min typ max units 0.8 0.8 0.8 0.8 1.2 1.2 1.2 1.2 s s s s s s modulated output bit time off bit time modulated output "on" modulated output "off" modulated output "on" modulated output "off" 1 1 1 1 notes: 1. irtx: l5, crf1 bit 1 = 1 (default) nirtx: l5, crf1 bit 1 = 0 mirtx, nmirtx are the modulated outputs t1 t2 t3 t4 t5 t6 0 1 0 1 0 0 1 1 0 1 1 data irtx n irtx mirtx nmirtx figure 28 - amplitude shift keyed ir transmit timing 252 smbus timing p t buf t r t hd;sta p s s t hd;sta t low t hd;dat t high t f t su;dat t su;sta t su;sto sclk sdat limits symbol parameter min max units comments f smb smb operating frequency 10 100 khz t buf bus free time between stop and start condition 4.7 m s t hd : sta hold time after (repeated) start condition. after this period, the first clock is generated. 4.0 m s t su : sta repeated start condition setup time 4.7 m s t su : sto stop condition setup time 4.0 m s t hd : dat data hold time 0 ns t su : dat data setup time 250 ns t timeout max. clock low time 25 35 ms see note 1 t low clock low period 4.7 m s t high clock high period 4.0 50 m s see note 2 t low : sext cumulative clock low extend time (slave device) 25 ms t low : mext cumulative clock low extend time (master device) 10 ms t f clock/data fall time 300 ns t r clock/data rise time 1000 ns note 1: a devi ce will timeout when any clock low exceeds this value. note 2: thigh max provides a simple guaranteed method for devices to detect bus idle conditions. 253 x-bus timing note: the following timing values are based on a 33mhz pci clock. timing values will vary with variations in the pci clock frequency. xa[0:3]/ nxcs[0:3] nxrd xd[0:7] valid t2 t1 t3 t4 t5 figure 30 - x-bus read timing name description min typ max units t1 nxcs[0:3] active to nxrd active 100 190 ns t2 nxrd active to nxrd inactive a: 180 b: 300 c: 420 d: 540 ns t3 nxrd inactive to nxcs[0:3] inactive 40 ns t4 xd[0:7] valid to nxrd inactive 20 ns t5 nxrd inactive to data invalid 0 ns note: cases a-d for t2 correspond to the different pulse width options for the x-bus read strobe. see the x-bus selection configuration register. 254 xa[0:3]/ nxcs[0:3] nxwr xd[0:7] valid t2 t1 t3 t4 t5 figure 31 - x-bus write timing name description min typ max units t1 nxcs[0:3] active to nxwr active 100 190 ns t2 nxwr active to nxwr inactive a: 180 b: 300 c: 420 d: 540 ns t3 nxwr inactive to nxcs[0:3] inactive 40 ns t4 xd[0:7] valid to nxwr active 22 ns t5 nxwr inactive to data invalid 45 ns note: cases a-d for t2 correspond to the different pulse width options for the x-bus write strobe. see the x-bus selection configuration register. 255 representative lpc i/o cycle to x-bus cycle timing x-bus read cycle: lpc i/o read cycle ? data from x-bus device to host xa[0:3]/ nxcs[0:3] nxrd xd[0:7] pci_clk nlframe nlad [3:0] valid address tar sync=0110 tar c+d start data sync 0000 figure 32 - x-bus and lpc i/o read cycle note: minimum read pulse width is shown. 256 x-bus write cycle: lpc i/o write cycle - data from host to x-bus device xa[0:3]/ nxcs [0:3] nxwr xd[0:7] valid pci_clk nlframe nlad [3:0] address data tar sync=0110 tar c+d start sync 0000 figure 33 - x-bus and lpc i/o write cycle note: minimum write pulse width is shown. 257 t2 t1 pci_clk ser_irq figure 34 ? setup and hold time name description min typ max units t1 ser_irq setup time to pci_clk rising 7 nsec t2 ser_irq hold time to pci_clk rising 0 nsec data (5-8 bits) t1 data txd1, 2 start parity stop (1-2 bits) figure 35 ? serial port data name description min typ max units t1 serial port data bit time t br 1 nsec note 1: t br is 1/baud rate. the baud rate is programmed through the divisor latch registers. baud rates have percentage errors indicated in the ?baud rate? table in the ?serial port? section. 258 kclk/ mclk kdat/ mdat start bit bit 0 bit 7 clk 1 clk 2 clk 9 clk 10 t1 t6 t4 t3 clk 11 t5 parity bit stop bit t2 figure 36 ? keyboard/mouse receive/send data timing name description min typ max units t1 time from data transition to falling edge of clock (receive) 5 25 sec t2 time from rising edge of clock to data transition (receive) 5 t4-5 sec t3 duration of clock inactive (receive/send) 30 50 sec t4 duration of clock active (receive/send) 30 50 sec t5 time to keyboard inhibit after clock 11 to ensure the keyboard does not start another transmission (receive) >0 50 sec t6 time from inactive to active clock transition, used to time when the auxiliary device samples data (send) 5 25 sec 259 t1 t2 fan figure 37 ? fan output timing name description min typ max units t1 pwm period (note 1) 0.021 25.8 msec t2 pwm high time (note 2) 0.00033 25.4 msec note 1: the period is 1/f out ,where f out is programmed through the fanx and fan control registers. the tolerance on f out is +/- 3%. note 2: when bit 0 of the fanx registers is 0, then the duty cycle is programmed through bits[6:1] of these registers. if bits[6:1] = ?000000? then the fanx pin is low. the duty cycle is programmable through bits[6:1] to be between 1.56% and 98.44%. when bit 0 is 1, the fanx pin is high. t3 t1 t2 fan_tach figure 38 ? fan tachometer input timing name description min typ max units t1 pulse time (1/2 revolution time=30/rpm) 4t tach 1 sec t2 pulse high time 3t tach 1 sec t3 pulse low time t tach sec note 1: t tach is the clock used for the tachometer counter. it is 30.52 * dvsr, where the divisor (dvsr) is programmed in the fan control register. 260 t2 t1 ledx figure 39 ? led output timing name description min typ max units t1 period 1 2 sec t2 blink on time 0 0.5 1 sec note 1: the blink rate is programmed through bits[1:0] in ledx register. when bits[1:0]=00, led is off. bits[1:0]=01 indicates led blink at 1hz rate with a 50% duty cycle (0.5 sec on, 0.5 sec off). bits[1:0]=10 indicates led blink at ? hz rate with a 25% duty cycle (0.5 sec on, 1.5 sec off). when bits[1:0]=11, led is on. 261 package outline figure 40 - 100 pin qfp package outline 0.10 -c- h a a1 a2 td/te 0 l1 l e1 e d1 d e w notes: 1) coplanarity is 0.100mm (.004") maximum. 2) tolerance on the position of the leads is 0.200mm (.008") maximum. 3) package body dimensions d1 and e1 do not include the mold protrusion. maximum mold protrusion is 0.25mm (.010"). 4) dimensions td and te are important for testing by robotic handler. only above combinations of (1) or (2) are acceptable. 5) controlling dimension: millimeter. dimensions in inches for reference only and not necessarily accurate. dim a a1 a2 d d1 e e1 h l l1 e 0 w td(1) te(1) td(2) te(2) min 2.80 0.1 2.57 23.4 19.9 17.4 13.9 0.1 0.65 1.8 max 3.15 0.45 2.87 24.15 20.1 18.15 14.1 0.2 0.95 2.6 min .110 .004 .101 .921 .783 .685 .547 .004 .026 .071 max .124 .018 .113 .951 .791 .715 .555 .008 .037 .102 0 .2 21.8 15.8 22.21 16.27 12 .4 22.2 16.2 22.76 16.82 0.65 bsc 0 .008 .858 .622 .874 .641 12 .016 .874 .638 .896 .662 .0256 bsc 262 appendix - test modes board test mode board test mode can be entered as follows: on the rising (deasserting) edge of npci_reset, drive nlframe low and drive lad[0] low. exit board test mode as follows: on the rising (deasserting) edge of npci_reset, drive either nlframe or lad[0] high. see the ?xnor-chain test mode? section below for a description of this board test mode. xnor-chain test mode xnor-chain test structure allows users to confirm that all pins are in contact with the motherboard during assembly and test operations. see figure 41 below. the xnor-chain test structure must be activated to perform these tests. when the xnor-chain is activated, the LPC47S42X pin functions are disconnected from the device pins, which all become input pins except for one output pin at the end of xnor-chain. the tests that are performed when the xnor-chain test structure is activated require the board-level test hardware to control the device pins and observe the results at the xnor-chain output pin. the npci_reset pin is not included in the xnor-chain. the xnor-chain output is on pin 52, gp31/fan_tach. see the following sub-sections for more details. i/o#1 i/o#2 i/o#3 i/o#n xnor out figure 41 ? xnor-chain test structure 263 introduction the LPC47S42X provides board test capability through the xnor chain. when the chip is in the xnor chain test mode, setting the state of any of the input pins to the opposite of its current state will cause the output of the chain to toggle. all pins on the chip are inputs to the xnor chain, with the exception of the following: 1. vcc (pins 53, 65 & 93) and vtr (pin 18) 2. vss (pins 7, 31, 60, & 76) 3. gp31/fan_tach (pin 52). this is the chain output. 4. npci_reset (pin 26) to put the chip in the xnor chain test mode, tie lad0 (pin 20) and nlframe (pin 24) low. then toggle npci_reset (pin 26) from a low to a high state. once the chip is put into xnor chain test mode, lad0 (pin 20) and nlframe (pin 24) become part of the chain. to exit the xnor chain test mode tie lad0 (pin 20) or nlframe (pin 24) high. then toggle npci_reset (pin 26) from a low to a high state. a vcc por will also cause the xnor chain test mode to be exited. to verify the test mode has been exited, observe the output on gp31/fan_tach (pin 52). toggling any of the input pins should not cause its state to change. setup warning: ensure power supply is off during setup. 1. connect vss (pins 7, 31, 60, & 76) to ground. 2. connect vcc (pins 53, 65 & 93) and vtr (pin 18) to vcc (3.3v). 3. connect an oscilloscope or voltmeter to gp31/fan_tach (pin 52). 4. all other pins should be tied to ground. testing 1. turn power on. 2. with lad0 (pin 20) and nlframe (pin 24) low, bring npci_reset (pin 26) high. the chip is now in xnor chain test mode. at this point, all inputs to the xnor chain are low. the output on gp31/fan_tach (pin 52) should also be low. refer to initial config on truth table 1. 3. bring pin 100 high. the output on gp31/fan_tach (pin 52) should go high. refer to step one on truth table 1. 4. in descending pin order, bring each input high. the output should switch states each time an input is toggled. continue until all inputs are high. the output on gp31/fan_tach should now be low. refer to end config on truth table 1. 5. the current state of the chip is now represented by initial config in truth table 2. 6. each input should now be brought low, starting at pin one and continuing in ascending order. continue until all inputs are low. the output on gp31/fan_tach should now be low. refer to truth table 2. 7. to exit test mode, tie lad0 (pin 20) or nlframe (pin 24) high, and toggle npci_reset from a low to a high state. 264 truth table 1 - toggling inputs in descending order pin 100 pin 99 pin 98 pin 97 pin 96 pin ... pin 1 output pin 52 initial config l l l l l l l l step 1 h l l l l l l h step 2 h h l l l l l l step 3 h h h l l l l h step 4 h h h h l l l l step 5 h h h h h l l h ? ? ? ? ? ? ? ? ? step n h h h h h h l h end config h h h h h h h l truth table 2 - toggling inputs in ascending order pin 1 pin 2 pin 3 pin 4 pin 5 pin ... pin 100 output pin 52 initial config h h h h h h h l step 1 l h h h h h h h step 2 l l h h h h h l step 3 l l l h h h h h step 4 l l l l h h h l step 5 l l l l l h h h ? ? ? ? ? ? ? ? step n l l l l l l h l end config l l l l l l l l 265 ? 1999 standard microsystems corporation (smsc) circuit diagrams utilizing smsc products are included as a means of illustrating typical applications; consequently complete information sufficient for construction purposes is not necessarily given. the information has been carefully checked and is believed to be entirely reliable. however, no responsibility is assumed for inaccuracies. furthermore, such information does not convey to the purchaser of the semiconduc tor devices described any licenses under the patent rights of smsc or ot hers. smsc reserves the right to make changes at any time in order to improve design and supply the best product possible. smsc products are not designed, intended, authorized or warranted for use in any life support or other application where product failure could cause or contribute to personal injury or severe property damage. any and all such uses without prior written approval of an officer of smsc and further testing and/or modification will be fully at the risk of the customer. LPC47S42X rev. 6/17/99 |
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