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1 of 87 112099 features complete e1(cept) pcm-30/isdn-pri transceiver functionality onboard long- and short-haul line interface for clock/data recovery and waveshaping 32-bit or 128-bit crystal-less jitter attenuator generates line build outs for both 120 ? = and 75 ? = lines frames to fas, cas, and crc4 formats dual onboard two-frame elastic store slip buffers that can connect to asynchronous backplanes up to 8.192 mhz 8-bit parallel control port that can be used directly on either multiplexed or non-multiplexed buses extracts and inserts cas signaling detects and generates remote and ais alarms programmable output clocks for fractional e1, h0, and h12 applications fully independent transmit and receive functionality full access to both si and sa bits aligned with crc multiframe four separate loopbacks for testing functions large counters for bipolar and code violations, crc4 codeword errors, fas errors, and e bits pin compatible with ds2152 t1 enhanced single- chip transceiver 5v supply; low power cmos 100-pin 14mm 2 body lqfp package package outline ordering information DS2154l (0c to 70c) DS2154ln (-40c to +85c) description the DS2154 enhanced single-chip transceiver (esct) contains all of the necessary functions for connection to e1 lines. the device is an upward compatible version of the ds2153 single-chip transceiver. the onboard clock/data recovery circuitry coverts the ami/hdb3 e1 waveforms to a nrz serial stream. the DS2154 automatically adjusts to e1 22awg (0.6 mm) twisted-pair cables from 0 to over 2 km in length. the device can generate the necessary g.703 waveshapes for both 75-ohm coax and 120-ohm twisted cables. the onboard jitter attenuator (selectable to either 32 bits or 128 bits) can be placed in either the transmit or receive data paths. the framer locates the frame and multiframe boundaries and monitors the data stream for alarms. it is also used for extracting and inserting signaling data, si, and sa bit information. the device contains a set of internal registers which the user can access to control the operation of the unit. quick access via the parallel control port allows a single controller to handle many e1 lines. the device fully meets all of the latest e1 specifications including itu g.703, g.704, g.706, g.823, g.932, and i.431 as well as ets 300 011, 300 233, 300 166, tbr 12 and tbr 13. DS2154 enhanced e1 single chip transceive r www.dalsemi.com 1 100
DS2154 2 of 87 table of contents 1.0 introduction ............................................................................................................. 4 new features................................................................................................................... ................ 4 block diagram .................................................................................................................. .............. 5 pin list ....................................................................................................................... ..................... 7 pin description................................................................................................................ .............. 10 register map ................................................................................................................... .............. 15 2.0 parallel port ........................................................................................................ 20 3.0 control, id, and test registers...................................................................... 20 sync/resync criteria........................................................................................................... ... 22 framers loopback............................................................................................................... .......... 27 automatic alarm generation..................................................................................................... ... 28 power-up sequence.............................................................................................................. ......... 30 remote loopback ................................................................................................................ ......... 31 local loopback................................................................................................................. ............ 31 4.0 status and information registers................................................................ 32 crc 4 sync counter ............................................................................................................. ..... 35 alarm criteria ................................................................................................................. .............. 36 5.0 error count registers ...................................................................................... 40 bpv or code violation counter .................................................................................................. .40 crc4 error counter ............................................................................................................. ........ 41 e-bit counter.................................................................................................................. ............... 41 fas error counter .............................................................................................................. .......... 42 6.0 dso monitoring function ................................................................................... 43 7.0 signaling operation ............................................................................................ 46 processor based signaling ...................................................................................................... ...... 46 hardware based signaling....................................................................................................... ..... 49 8.0 per-channel code generation ........................................................................ 51 transmit side code generation.................................................................................................. .. 51 receive side code generation ................................................................................................... .. 53 9.0 clock blocking registers ................................................................................ 54 10.0 elastic stores operation ................................................................................. 56 11.0 additional (sa) and international (si) bit operation .............................. 57 hardware scheme ................................................................................................................ ......... 57 internal register scheme based on double-frame ...................................................................... 57 internal register scheme based on crc4 multiframe ................................................................ 60
DS2154 3 of 87 12.0 line interface functions ................................................................................... 62 receive clock and data recovery................................................................................................ 62 transmit waveshaping and line driving..................................................................................... 63 jitter attenuator.............................................................................................................. ............... 64 13.0 timing diagrams...................................................................................................... 67 synchronization flowchart ...................................................................................................... ..... 72 transmit data flow diagram ..................................................................................................... .. 73 14.0 characteristics .................................................................................................... 74 absolute maximum rating........................................................................................................ ... 74 dc parameters .................................................................................................................. ............ 74 ac parameters .................................................................................................................. ............ 75 timing......................................................................................................................... .................. 77 package description............................................................................................................ .......... 85
DS2154 4 of 87 1.0 introduction the DS2154 is a super-set version of the popular ds2153 e1 single-chip transceiver offering the new features listed below. all of the original features of the ds2153 have been retained and software created for the original devices is transferable into the DS2154. new features section option for non-multiplexed bus operation 1 and 2 crystal-less jitter attenuation 12 additional hardware signaling capability including: receive signaling reinsertion to a backplane multiframe sync availability of signaling in a separate pcm data stream signaling freezing interrupt generated on change of signaling data 7 improved receive sensitivity: 0 db to -43 db 12 per-channel code insertion in both transmit and receive paths 8 expanded access to sa and si bits 11 rcl, rlos, rra, and rais alarms now interrupt on change of state 4 8.192 mhz clock synthesizer 1 per-channel loopback 8 addition of hardware pins to indicate carrier loss and signaling freeze 1 line interface function can be completely decoupled from the framer/formatter to allow: interface to optical, hdsl, and other nrz interfaces ?tap? the transmit and receive bipolar data streams for monitoring purposes be able corrupt data and insert framing errors, crc errors, etc. 1 transmit and receive elastic stores now have independent backplane clocks 1 ability to monitor one ds0 channel in both the transmit and receive paths 6 access to the data streams in between the framer/formatter and the elastic stores 1 ais generation in the line interface that is independent of loopbacks 1 and 3 transmit current limiter to meet the 50 ma short circuit requirement 12 option to extend carrier loss criteria to a 1 ms period as per ets 300 233 3 automatic rai generation to ets 300 011 specifications 3
DS2154 5 of 87 DS2154 enhanced e1 single-chip transceiver figure 1-1
DS2154 6 of 87 functional description the analog ami/hdb3 waveform off of the e1 line is transformer coupled into the rring and rtip pins of the DS2154. the device recovers clock and data from the analog signal and passes it through the jitter attenuation mux to the receive side framer where the digital serial stream is analyzed to locate the framing/multiframe pattern. the DS2154 contains an active filter that reconstructs the analog received signal for the non-linear losses that occur in transmission. the device has a usable receive sensitivity of 0 db to -43 db which allows the device to operate on cables over 2 km in length. the receive side framer locates the fas frame and crc and cas multiframe boundaries as well as detects incoming alarms including, carrier loss, loss of synchronization, ais, and remote alarm. if needed, the receive side elastic store can be enabled in order to absorb the phase and frequency differences between the recovered e1 data stream and an asynchronous backplane clock which is provided at the rsysclk input. the clock applied at the rsysclk input can be either a 2.048 mhz clock or a 1.544 mhz clock. the rsysclk can also be a bursty clock with speeds up to 8.192 mhz. the transmit side of the DS2154 is totally independent from the receive side in both the clock requirements and characteristics. data off of a backplane can be passed through a transmit side elastic store if necessary. the transmit formatter will provide the necessary frame/multiframe data overhead for e1 transmission. once the data stream has been prepared for transmission, it is sent via the jitter attenuation mux to the waveshaping and line driver functions. the DS2154 will drive the e1 line from the ttip and tring pins via a coupling transformer. the line driver can handle both 75 ? = and 120 ? = lines and it has options for high return loss applications. the line driver contains a current limiter that will restrict the maximum current into a 1 ? = load to less than 50 ma (rms). reader?s note this data sheet assumes a particular nomenclature of the e1 operating environment. there are 32 8-bit timeslots in an e1 systems which are number 0 to 31. timeslot 0 is transmitted first and received first. these 32 timeslots are also referred to as channels with a numbering scheme of 1 to 32. timeslot 0 is identical to channel 1, timeslot 1 is identical to channel 2, and so on. each timeslot (or channel) is made up of 8 bits which are numbered 1 to 8. bit number 1 is the msb and is transmitted first. bit number 8 is the lsb and is transmitted last. throughout this data sheet, the following abbreviations will be used: fas frame alignment signal crc4 cyclical redundancy check cas channel associated signaling ccs common channel signaling mf multiframe sa additional bits si international bits e-bit crc4 error bits
DS2154 7 of 87 pin list table 1-1 pin symbol type description 1 rchblk o receive channel block. 2 nc - no connect. 3 8mclk o 8.192 mhz clock. 4 nc - no connect. 5 nc - no connect. 6 rcl o receive carrier loss. 7 nc - no connect. 8 nc - no connect. 9 nc - no connect. 10 nc - no connect. 11 bts i bus type select. 12 liuc i line interface connect. 13 8xclk o eight times clock. 14 test i test. 15 nc - no connect. 16 rtip i receive analog tip input. 17 rring i receive analog ring input. 18 rvdd - receive analog positive supply 19 rvss - receive analog signal ground. 20 rvss - receive analog signal ground. 21 mclk i master clock input. 22 xtald o quartz crystal driver. 23 nc - no connect. 24 rvss - receive analog signal ground. 25 int o interrupt. 26 nc - no connect. 27 nc - no connect. 28 nc - no connect. 29 ttip o transmit analog tip output. 30 tvss - transmit analog signal ground. 31 tvdd - transmit analog positive supply. 32 tring o transmit analog ring output. 33 tchblk o transmit channel block. 34 tlclk o transmit link clock. 35 tlink i transmit link data.
DS2154 8 of 87 pin symbol type description 36 nc - no connect. 37 tsync i/o transmit sync. 38 tposi i transmit positive data input. 39 tnegi i transmit negative data input. 40 tclki i transmit clock input. 41 tclko o transmit clock output. 42 tnego o transmit negative data output. 43 tposo o transmit positive data output. 44 dvdd - digital positive supply. 45 dvss - digital signal ground. 46 tclk i transmit clock. 47 tser i transmit serial data. 48 tsig i transmit signaling input. 49 teso o transmit elastic store output. 50 tdata i transmit data. 51 tsysclk i transmit system clock. 52 tssync i transmit system sync. 53 tchclk o transmit channel clock. 54 nc - no connect. 55 mux i bus operation. 56 d0/ad0 i/o data bus bit 0 / address/data bus bit 0. 57 d1/ad1 i/o data bus bit 1 / address/data bus bit 1. 58 d2/ad2 i/o data bus bit 2 / address/data bus bit 2. 59 d3/ad3 i/o data bus bit 3 / address/data bus bit 3. 60 dvss - digital signal ground. 61 dvdd - digital positive supply. 62 d4/ad4 i/o data bus bit 4 / address/data bus bit 4. 63 d5/ad5 i/o data bus bit 5 / address/data bus bit 5. 64 d6/ad6 i/o data bus bit 6 / address/data bus bit 6. 65 d7/ad7 i/o data bus bit 7 / address/data bus bit 7. 66 a0 i address bus bit 0. 67 a1 i address bus bit 1. 68 a2 i address bus bit 2. 69 a3 i address bus bit 3. 70 a4 i address bus bit 4. 71 a5 i address bus bit 5. 72 a6 i address bus bit 6.
DS2154 9 of 87 pin symbol type description 73 a7/ale i address bus bit 7 / address latch enable. 74 rd ( ds ) i read input (data strobe). 75 cs i chip select. 76 nc - no connect. 77 wr (r/ w ) i write input (read/write). 78 rlink o receive link data. 79 rlclk o receive link clock. 80 dvss - digital signal ground. 81 dvdd - digital positive supply. 82 rclk o receive clock. 83 dvdd - digital positive supply. 84 dvss - digital signal ground. 85 rdata o receive data. 86 rposi i receive positive data input. 87 rnegi i receive negative data input. 88 rclki i receive clock input. 89 rclko o receive clock output. 90 rnego o receive negative data output. 91 rposo o receive positive data output. 92 rchclk o receive channel clock. 93 rsigf o receive signaling freeze output. 94 rsig o receive signaling output. 95 rser o receive serial data. 96 rmsync o receive multiframe sync. 97 rfsync o receive frame sync. 98 rsync i/o receive sync. 99 rlos/lotc o receive loss of sync / loss of transmit clock. 100 rsysclk i receive system clock. note: leave all no connect (nc) pins open circuited.
DS2154 10 of 87 DS2154 pin description table 1-2 transmit side digital pins transmit clock [tclk]. a 2.048 mhz primary clock. used to clock data through the transmit side formatter. must be present for the parallel control port to operate properly. if not present, the loss of transmit clock (lotc) function can provide a clock. transmit serial data [tser]. transmit nrz serial data. sampled on the falling edge of tclk when the transmit side elastic store is disabled. sampled on the falling edge of tsysclk when the transmit side elastic store is enabled. transmit channel clock [tchclk]. a 256 khz clock which pulses high during the lsb of each channel. synchronous with tclk when the transmit side elastic store is disabled. synchronous with tsysclk when the transmit side elastic store is enabled. useful for parallel to serial conversion of channel data. transmit channel block [tchblk]. a user-programmable output that can be forced high or low during any of the 32 e1 channels. synchronous with tclk when the transmit side elastic store is disabled. synchronous with tsysclk when the transmit side elastic store is enabled. useful for blocking clocks to a serial uart or lapd controller in applications where not all e1 channels are used such as fractional e1, 384 kbps (h0), 768 kbps, 1920 kbps (h12) or isdn-pri. also useful for locating individual channels in drop-and-insert applications, for external per-channel loopback, and for per- channel conditioning. see section 9 for details. transmit system clock [tsysclk]. 1.544 mhz or 2.048 mhz clock. only used when the transmit side elastic store function is enabled. should be tied low in applications that do not use the transmit side elastic store. can be burst at rates up to 8.192 mhz. transmit link clock [tlclk]. 4 khz to 20 khz demand clock (sa bits) for the tlink input. see section 11 for details. transmit link data [tlink]. if enabled, this pin will be sampled on the falling edge of tclk for data insertion into any combination of the sa bit positions (sa4 to sa8). see section 11 for details. transmit sync [tsync]. a pulse at this pin will establish either frame or multiframe boundaries for the transmit side. this pin can also be programmed to output either a frame or multiframe pulse. always synchronous with tclk. transmit frame sync [tssync]. only used when the transmit side elastic store is enabled. a pulse at this pin will establish either frame or multiframe boundaries for the transmit side. should be tied low in applications that do not use the transmit side elastic store. always synchronous with tsysclk. transmit signaling input [tsig]. when enabled, this input will be sample signaling bits for insertion into outgoing pcm e1 data stream. sampled on the falling edge of tclk when the transmit side elastic store is disabled. sampled on the falling edge of tsysclk when the transmit side elastic store is enabled. see section 13 for timing examples. transmit elastic store data output [teso]. updated on the rising edge of tclk with data out of the transmit side elastic store whether the elastic store is enabled or not. this pin is normally tied to tdata.
DS2154 11 of 87 transmit data [tdata]. sampled on the falling edge of tclk with data to be clocked through the transmit side formatter. this pin is normally tied to teso. transmit positive data output [tposo]. updated on the rising edge of tclko with the bipolar data out of the transmit side formatter. can be programmed to source nrz data via the output data format (tcr1.7) control bit. this pin is normally tied to tposi. transmit negative data output [tnego]. updated on the rising edge of tclko with the bipolar data out of the transmit side formatter. this pin is normally tied to tnegi. transmit clock output [tclko]. buffered clock that is used to clock data through the transmit side formatter (i.e. either tclk or rclko if loss of transmit clock is enabled and in effect or rclki if remote loopback is enabled). this pin is normally tied to tclki. transmit positive data input [tposi]. sampled on the falling edge of tclki for data to be transmitted out onto the e1 line. can be internally connected to tposo by tying the liuc pin high. transmit negative data input [tnegi]. sampled on the falling edge of tclki for data to be transmitted out onto the e1 line. can be internally connected to tnego by tying the liuc pin high. transmit clock input [tclki]. line interface transmit clock. can be internally connected to tclko by tying the liuc pin high. receive side digital pins receive link data [rlink]. updated with the full recovered e1 data stream on the rising edge of rclk. receive link clock [rlclk]. 4 khz to 20 khz clock (sa bits) for the rlink output. see section 11 for details. receive clock [rclk]. 2.048 mhz clock that is used to clock data through the receive side framer. receive channel clock [rchclk]. 256 khz clock which pulses high during the lsb of each channel. synchronous with rclk when the receive side elastic store is disabled. synchronous with rsysclk when the receive side elastic store is enabled. useful for parallel to serial conversion of channel data. receive channel block [rchblk]. a user-programmable output that can be forced high or low during any of the 32 e1 channels. synchronous with rclk when the receive side elastic store is disabled. synchronous with rsysclk when the receive side elastic store is enabled. useful for blocking clocks to a serial uart or lapd controller in applications where not all e1 channels are used such as fractional e1, 384k bps service, 768k bps, or isdn-pri. also useful for locating individual channels in drop-and- insert applications, for external per-channel loopback, and for per-channel conditioning. see section 9 for details. receive serial data [rser]. received nrz serial data. updated on rising edges of rclk when the receive side elastic store is disabled. updated on the rising edges of rsysclk when the receive side elastic store is enabled.
DS2154 12 of 87 receive sync [rsync]. an extracted pulse, one rclk wide, is output at this pin which identifies either frame or cas/crc multiframe boundaries. if the receive side elastic store is enabled, then this pin can be enabled to be an input at which a frame or multiframe boundary pulse synchronous with rsysclk is applied. receive frame sync [rfsync]. an extracted 8 khz pulse, one rclk wide, is output at this pin which identifies frame boundaries. receive multiframe sync [rmsync]. an extracted pulse, one rsysclk wide, is output at this pin which identifies multiframe boundaries. if the receive side elastic store is disabled, then this output will output multiframe boundaries associated with rclk. receive data [rdata]. updated on the rising edge of rclk with the data out of the receive side framer. receive system clock [rsysclk]. 1.544 mhz or 2.048 mhz clock. only used when the elastic store function is enabled. should be tied low in applications that do not use the elastic store. can be burst at rates up to 8.192 mhz. receive signaling output [rsig]. outputs signaling bits in a pcm format. updated on rising edges of rclk when the receive side elastic store is disabled. updated on the rising edges of rsysclk when the receive side elastic store is enabled. see section 13 for timing examples. receive loss of sync / loss of transmit clock [rlos/lotc]. a dual function output that is controlled by the tcr2.0 control bit. this pin can be programmed to either toggle high when the synchronizer is searching for the frame and multiframe or to toggle high if the tclk pin has not been toggled for 5 s. receive carrier loss [rcl]. set high when the line interface detects a loss of carrier. [note: a test mode exists to allow the DS2154 to detect carrier loss at rposi and rnegi in place of detection at rtip and rring]. receive signaling freeze [rsigf]. set high when the signaling data is frozen via either automatic or manual intervention. used to alert downstream equipment of the condition. 8 mhz clock [8mclk]. 8.192 mhz output clock that is referenced to the clock that is output at the rclk pin. receive positive data output [rposo]. updated on the rising edge of rclko with the bipolar data out of the line interface. this pin is normally tied to rposi. receive negative data output [rnego]. updated on the rising edge of rclko with the bipolar data out of the line interface. this pin is normally tied to rnegi. receive clock output [rclko]. buffered recovered clock from the e1 line. this pin is normally tied to rclki. receive positive data input [rposi]. sampled on the falling edge of rclki for data to be clocked through the receive side framer. rposi and rnegi can be tied together for a nrz interface. can be internally connected to rposo by tying the liuc pin high.
DS2154 13 of 87 receive negative data input [rnegi]. sampled on the falling edge of rclki for data to be clocked through the receive side framer. rposi and rnegi can be tied together for a nrz interface. can be internally connected to rnego by tying the liuc pin high. receive clock input [rclki]. clock used to clock data through the receive side framer. this pin is normally tied to rclko. can be internally connected to rclko by tying the liuc pin high. rclki must be present for the parallel control port to operate properly. parallel control port pins interrupt [int]. flags host controller during conditions and change of conditions defined in the status registers 1 and 2. active low, open drain output. 3-state control [test]. set high to 3-state all output and i/o pins (including the parallel control port). set low for normal operation. useful in board level testing. bus operation [mux]. set low to select non-multiplexed bus operation. set high to select multiplexed bus operation. data bus [d0 to d7] or address/data bus [ad0 to ad7]. in non-multiplexed bus operation (mux=0), serves as the data bus. in multiplexed bus operation (mux=1), serves as a 8-bit multiplexed address / data bus. address bus [a0 to a6]. in non-multiplexed bus operation (mux=0), serves as the address bus. in multiplexed bus operation (mux=1), these pins are not used and should be tied low. bus type select [bts]. strap high to select motorola bus timing; strap low to select intel bus timing. this pin controls the function of the rd\(ds), ale(as), and wr\(r/w\) pins. if bts=1, then these pins assume the function listed in parenthesis (). read input [ rd ] (data strobe [ ds ]). rd and ds are active low signals when mux=11. ds is active high when mux = 0. see bus timing diagrams. chip select [cs]. must be low to read or write to the device. cs is an active low signal. a7 or address latch enable [ale] (address strobe [as]). in non-multiplexed bus operation (mux=0), serves as the upper address bit. in multiplexed bus operation (mux=1), serves to demultiplex the bus on a positive-going edge. write input [wr] (read/write [r/w]). wr is an active low signal. line interface pins master clock input [mclk]. 2.048 mhz ( 50 ppm) clock source with ttl levels is applied at this pin. this clock is used internally for both clock/data recovery and for jitter attenuation. a quartz crystal of 2.048 mhz may be applied across mclk and xtald instead of the ttl level clock source. quartz crystal driver [xtald]. a quartz crystal of 2.048 mhz may be applied across mclk and xtald instead of a ttl level clock source at mclk. leave open circuited if a ttl clock source is applied at mclk.
DS2154 14 of 87 eight times clock [8xclk] . 16.384 mhz clock that is frequency locked to the 2.048 mhz clock provided from the clock/data recovery block (if the jitter attenuator is enabled on the receive side) or from the tclki pin (if the jitter attenuator is enabled on the transmit side). can be internally disabled via the test2 register if not needed. line interface connect [liuc]. tie low to separate the line interface circuitry from the framer/formatter circuitry and activate the tposi/tnegi/tclki/rposi/rnegi/ rclki pins. tie high to connect the line interface circuitry to the framer/formatter circuitry and deactivate the tposi/tnegi/tclki/rposi/rnegi/rclki pins. when liuc is tied high, the tposi/tnegi/tclki/rposi/rnegi/rclki pins should be tied low. receive tip and ring [ rtip and rring]. analog inputs for clock recovery circuitry. these pins connect via a 1:1 transformer to either the e1 line. see section 12 for an example. transmit tip and ring [ttip and tring]. analog line driver outputs. these pins connect via a 1:1.15 or 1:1.36 step-up transformer to the e1 line. see section 12 for an example. supply pins digital positive supply [dvdd]. 5.0 volts 5%. should be tied to the rvdd and tvdd pins. receive analog positive supply [rvdd]. 5.0 volts 5%. should be tied to the dvdd and tvdd pins. transmit analog positive supply [tvdd]. 5.0 volts 5%. should be tied to the rvdd and dvdd pins. digital signal ground [dvss]. 0.0 volts. should be tied to the rvss and tvss pins. receive analog signal ground [rvss]. 0.0 volts. should be tied to the dvss and tvss pins. transmit analog ground [tvss]. 0.0 volts. should be tied to the rvss and dvss pins.
DS2154 15 of 87 DS2154 register map table 1-3 address r/w register name register abbreviation 00 r bpv or code violation count 1. vcr1 01 r bpv or code violation count 2. vcr2 02 r crc4 error count 1 / fas error count 1. crccr1 03 r crc4 error count 2. crccr2 04 r e-bit count 1 / fas error count 2. ebcr1 05 r e-bit count 2. ebcr2 06 r/w status 1. sr1 07 r/w status 2. sr2 08 r/w recive information. rir 09 - not present. - 0a - not present. - 0b - not present. - 0c - not present. - 0d - not present. - 0e - not present. - 0f r device id register. idr 10 r/w receive control 1. rcr1 11 r/w receive control 2. rcr2 12 r/w transmit control 1. tcr1 13 r/w transmit control 2. tcr2 14 r/w common control 1. ccr1 15 r/w test 1. test1 (set to 00h) 16 r/w interrupt mask 1. imr1 17 r/w interrupt mask 2. imr2 18 r/w line interface control. licr 19 r/w test 2. test2 (set to 00h) 1a r/w common control 2. ccr2 1b r/w common control 3. ccr3 1c r/w transmit sa bit control. tsacr 1d - not present. - 1e r synchronizer status. ssr 1f r receive non-align frame. rnaf 20 r/w transmit align frame. taf 21 r/w transmit non-align frame. tnaf 22 r/w transmit channel blocking 1. tcbr1
DS2154 16 of 87 address r/w register name register abbreviation 23 r/w transmit channel blocking 2. tcbr2 24 r/w transmit channel blocking 3. tcbr3 25 r/w transmit channel blocking 4. tcbr4 26 r/w transmit idle 1. tir1 27 r/w transmit idle 2. tir2 28 r/w transmit idle 3. tir3 29 r/w transmit idle 4. tir4 2a r/w transmit idle definition. tidr 2b r/w receive channel blocking 1. rcbr1 2c r/w receive channel blocking 2. rcbr2 2d r/w receive channel blocking 3. rcbr3 2e r/w receive channel blocking 4. rcbr4 2f r receive align frame. raf 30 r receive signaling 1. rs1 31 r receive signaling 2. rs2 32 r receive signaling 3. rs3 33 r receive signaling 4. rs4 34 r receive signaling 5. rs5 35 r receive signaling 6. rs6 36 r receive signaling 7. rs7 37 r receive signaling 8. rs8 38 r receive signaling 9. rs9 39 r receive signaling 10. rs10 3a r receive signaling 11. rs11 3b r receive signaling 12. rs12 3c r receive signaling 13. rs13 3d r receive signaling 14. rs14 3e r receive signaling 15. rs15 3f r receive signaling 16. rs16 40 r/w transmit signaling 1. ts1 41 r/w transmit signaling 2. ts2 42 r/w transmit signaling 3. ts3 43 r/w transmit signaling 4. ts4 44 r/w transmit signaling 5. ts5 45 r/w transmit signaling 6. ts6 46 r/w transmit signaling 7. ts7 47 r/w transmit signaling 8. ts8
DS2154 17 of 87 address r/w register name register abbreviation 48 r/w transmit signaling 9. ts9 49 r/w transmit signaling 10. ts10 4a r/w transmit signaling 11. ts11 4b r/w transmit signaling 12. ts12 4c r/w transmit signaling 13. ts13 4d r/w transmit signaling 14. ts14 4e r/w transmit signaling 15. ts15 4f r/w transmit signaling 16. ts16 50 r/w transmit si bits align frame. tsiaf 51 r/w transmit si bits non-align frame. tsinaf 52 r/w transmit remote alarm bits. tra 53 r/w transmit sa4 bits. tsa4 54 r/w transmit sa5 bits. tsa5 55 r/w transmit sa6 bits. tsa6 56 r/w transmit sa7 bits. tsa7 57 r/w transmit sa8 bits. tsa8 58 r receive si bits align frame. rsiaf 59 r receive si bits non-align frame. rsinaf 5a r receive remote alarm bits. rra 5b r receive sa4 bits. rsa4 5c r receive sa5 bits. rsa5 5d r receive sa6 bits. rsa6 5e r receive sa7 bits. rsa7 5f r receive sa8 bits. rsa8 60 r/w transmit channel 1. tc1 61 r/w transmit channel 2. tc2 62 r/w transmit channel 3. tc3 63 r/w transmit channel 4. tc4 64 r/w transmit channel 5. tc5 65 r/w transmit channel 6. tc6 66 r/w transmit channel 7. tc7 67 r/w transmit channel 8. tc8 68 r/w transmit channel 9. tc9 69 r/w transmit channel 10. tc10 6a r/w transmit channel 11. tc11 6b r/w transmit channel 12. tc12 6c r/w transmit channel 13. tc13
DS2154 18 of 87 address r/w register name register abbreviation 6d r/w transmit channel 14. tc14 6e r/w transmit channel 15. tc15 6f r/w transmit channel 16. tc16 70 r/w transmit channel 17. tc17 71 r/w transmit channel 18. tc18 72 r/w transmit channel 19. tc19 73 r/w transmit channel 20. tc20 74 r/w transmit channel 21. tc21 75 r/w transmit channel 22. tc22 76 r/w transmit channel 23. tc23 77 r/w transmit channel 24. tc24 78 r/w transmit channel 25. tc25 79 r/w transmit channel 26. tc26 7a r/w transmit channel 27. tc27 7b r/w transmit channel 28. tc28 7c r/w transmit channel 29. tc29 7d r/w transmit channel 30. tc30 7e r/w transmit channel 31. tc31 7f r/w transmit channel 32. tc32 80 r/w receive channel 1. rc1 81 r/w receive channel 2. rc2 82 r/w receive channel 3. rc3 83 r/w receive channel 4. rc4 84 r/w receive channel 5. rc5 85 r/w receive channel 6. rc6 86 r/w receive channel 7. rc7 87 r/w receive channel 8. rc8 88 r/w receive channel 9. rc9 89 r/w receive channel 10. rc10 8a r/w receive channel 11. rc11 8b r/w receive channel 12. rc12 8c r/w receive channel 13. rc13 8d r/w receive channel 14. rc14 8e r/w receive channel 15. rc15 8f r/w receive channel 16. rc16 90 r/w receive channel 17. rc17 91 r/w receive channel 18. rc18
DS2154 19 of 87 address r/w register name register abbreviation 92 r/w receive channel 19. rc19 93 r/w receive channel 20. rc20 94 r/w receive channel 21. rc21 95 r/w receive channel 22. rc22 96 r/w receive channel 23. rc23 97 r/w receive channel 24. rc24 98 r/w receive channel 25. rc25 99 r/w receive channel 26. rc26 9a r/w receive channel 27. rc27 9b r/w receive channel 28. rc28 9c r/w receive channel 29. rc29 9d r/w receive channel 30. rc30 9e r/w receive channel 31. rc31 9f r/w receive channel 32. rc32 a0 r/w transmit channel control 1. tcc1 a1 r/w transmit channel control 2. tcc2 a2 r/w transmit channel control 3. tcc3 a3 r/w transmit channel control 4. tcc4 a4 r/w receive channel control 1. rcc1 a5 r/w receive channel control 2. rcc2 a6 r/w receive channel control 3. rcc3 a7 r/w receive channel control 4. rcc4 a8 r/w common control 4. ccr4 a9 r transmit ds0 monitor. tds0m aa r/w common control 5. ccr5 ab r receive ds0 monitor. rds0m ac r/w test 3. test3 (set to 00h) ad r/w not used. (set to 00h) ae r/w not used. (set to 00h) af r/w not used. (set to 00h) notes: 1. test registers 1, 2, and 3 are used only by the factory; these registers must be cleared (set to all 0s) on power-up initialization to insure proper operation. 2. register banks bxh, cxh, dxh, exh, and fxh are not accessible.
DS2154 20 of 87 2.0 parallel port the DS2154 is controlled via either a non-multiplexed (mux=0) or a multiplexed (mux=1) bus by an external microcontroller or microprocessor. the DS2154 can operate with either intel or motorola bus timing configurations. if the bts pin is tied low, intel timing will be selected; if tied high, motorola timing will be selected. all motorola bus signals are listed in parenthesis (). see the timing diagrams in the a.c. electrical characteristics in section 14 for more details. 3.0 control, id and test registers the operation of the DS2154 is configured via a set of nine control registers. typically, the control registers are only accessed when the system is first powered up. once the DS2154 has been initialized, the control registers will only need to be accessed when there is a change in the system configuration. there are two receive control registers (rcr1 and rcr2), two transmit control registers (tcr1 and tcr2), and five common control registers (ccr1 to ccr5). each of the nine registers is described in this section. there is a device identification register (idr) at address 0fh. the msb of this read-only register is fixed to a 1, indicating that the DS2154 is present. the pin-for-pin compatible t1 version of the DS2154 also has an id register at address 0fh and the user can read the msb to determine which chip is present since in the DS2154 the msb will be set to a 1 and in the ds2152 it will be set to a 0. the lower 4 bits of the idr are used to display the die revision of the chip. the test registers at addresses 15, 19, and ac hex are used by the factory in testing the DS2154. on power-up, the test registers should be set to 00 hex in order for the DS2154 to operate properly.
DS2154 21 of 87 idr: device identification register (address=0f hex) (msb) (lsb) t1e1 0 0 0 id3 id2 id1 id0 symbol position name and description t1e1 idr.7 t1 or e1 chip determination bit. 0=t1 chip 1=e1 chip id3 idr.3 chip revision bit 3. msb of a decimal code that represents the chip revision. id2 idr.1 chip revision bit 2. id1 idr.2 chip revision bit 1. id0 idr.0 chip revision bit 0. lsb of a decimal code that represents the chip revision. rcr1: receive control register 1 (address=10 hex) (msb) (lsb) rsmf rsm rsio - - frc synce resync symbol position name and description rsmf rcr1.7 rsync multiframe function. only used if the rsync pin is programmed in the multiframe mode (rcr1.6=1). 0=rsync outputs cas multiframe boundaries 1=rsync outputs crc4 multiframe boundaries rsm rcr1.6 rsync mode select. 0=frame mode (see the timing in section 13) 1=multiframe mode (see the timing in section 13) rsio rcr1.5 rsync i/o select. (note: this bit must be set to 0 when rcr2.1=0). 0=rsync is an output (depends on rcr1.6) 1=rsync is an input (only valid if elastic store enabled) - rcr1.4 not assigned. should be set to 0 when written. - rcr1.3 not assigned. should be set to 0 when written. frc rcr1.2 frame resync criteria. 0=resync if fas received in error 3 consecutive times 1=resync if fas or bit 2 of non-fas is received in error 3 consecutive times synce rcr1.1 sync enable. 0=auto resync enabled 1=auto resync disabled resync rcr1.0 resync. when toggled from low to high, a resync is initiated.
DS2154 22 of 87 must be cleared and set again for a subsequent resync. sync/resync criteria table 3-1 frame or multi- frame level sync criteria resync criteria itu spec. fas fas present in frame n and n + 2, and fas not present in frame n + 1 three consecutive incorrect fas received alternate (rcr1.2=1) the above criteria is met or three consecutive incorrect bit 2 of non- fas received g.706 4.1.1 4.1.2 crc4 two valid mf alignment words found within 8 ms 915 or more crc4 code words out of 1000 received in error g.706 4.2 and 4.3.2 cas valid mf alignment word found and previous timeslot 16 contains code other than all 0s two consecutive mf alignment words received in error g.732 5.2
DS2154 23 of 87 rcr2: receive control register 2 (address=11 hex) (msb) (lsb) sa8s sa7s sa6s sa5s sa4s rbcs rese - symbol position name and description sa8s rcr2.7 sa8 bit select. set to 1 to have rlclk pulse at the sa8 bit position; set to 0 to force rlclk low during sa8 bit position. see section 13 for timing details. sa7s rcr2.6 sa7 bit select. set to 1 to have rlclk pulse at the sa7 bit position; set to 0 to force rlclk low during sa7 bit position. see section 13 for timing details. sa6s rcr2.5 sa6 bit select. set to 1 to have rlclk pulse at the sa6 bit position; set to 0 to force rlclk low during sa6 bit position. see section 13 for timing details. sa5s rcr2.4 sa5 bit select. set to 1 to have rlclk pulse at the sa5 bit position; set to 0 to force rlclk low during sa5 bit position. see section 13 for timing details. sa4s rcr2.3 sa4 bit select. set to 1 to have rlclk pulse at the sa4 bit position; set to 0 to force rlclk low during sa4 bit position. see section 13 for timing details. rbcs rcr2.2 receive side backplane clock select. 0=if rsysclk is 1.544 mhz 1=if rsysclk is 2.048 mhz rese rcr2.1 receive side elastic store enable. 0=elastic store is bypassed 1=elastic store is enabled - rcr2.0 not assigned. should be set to 0 when written.
DS2154 24 of 87 tcr1: transmit control register 1 (address=12 hex) (msb) (lsb) odf tfpt t16s tua1 tsis tsa1 tsm tsio symbol position name and description odf tcr1.7 output data format. 0=bipolar data at tposo and tnego 1=nrz data at tposo; tnego=0 tfpt tcr1.6 transmit timeslot 0 pass through. 0=fas bits/sa bits/remote alarm sourced internally from the taf and tnaf registers 1=fas bits/sa bits/remote alarm sourced from tser t16s tcr1.5 transmit timeslot 16 data select. 0=sample timeslot 16 at tser pin 1=source timeslot 16 from ts0 to ts15 registers tua1 tcr1.4 transmit unframed all 1s. 0=transmit data normally 1=transmit an unframed all 1?s code at tposo and tnego tsis tcr1.3 transmit international bit select. 0=sample si bits at tser pin 1=source si bits from taf and tnaf registers (in this mode, tcr1.6 must be set to 0) tsa1 tcr1.2 transmit signaling all 1s. 0=normal operation 1=force timeslot 16 in every frame to all 1s tsm tcr1.1 tsync mode select . 0=frame mode (see the timing in section 13) 1=cas and crc4 multiframe mode (see the timing in section 13) tsio tcr1.0 tsync i/o select. 0=tsync is an input 1=tsync is an output note: see figure 13-11 for more details about how the transmit control registers affect the operation of the DS2154.
DS2154 25 of 87 tcr2: transmit control register 2 (address=13 hex) (msb) (lsb) sa8s sa7s sa6s sa5s sa4s odm aebe pf symbol position name and description sa8s tcr2.7 sa8 bit select. set to 1 to source the sa8 bit from the tlink pin; set to 0 to not source the sa8 bit. see section 13 for timing details. sa7s tcr2.6 sa7 bit select. set to 1 to source the sa7 bit from the tlink pin; set to 0 to not source the sa7 bit. see section 13 for timing details. sa6s tcr2.5 sa6 bit select. set to 1 to source the sa6 bit from the tlink pin; set to 0 to not source the sa6 bit. see section 13 for timing details. sa5s tcr2.4 sa5 bit select . set to 1 to source the sa5 bit from the tlink pin; set to 0 to not source the sa5 bit. see section 13 for timing details. sa4s tcr2.3 sa4 bit select. set to 1 to source the sa4 bit from the tlink pin; set to 0 to not source the sa4 bit. see section 13 for timing details. odm tcr2.2 output data mode. 0=pulses at tposo and tnego are one full tclko period wide 1=pulses at tposo and tnego are 1/2 tclko period wide aebe tcr2.1 automatic e-bit enable. 0=e-bits not automatically set in the transmit direction 1=e-bits automatically set in the transmit direction pf tcr2.0 function of rlos/lotc pin. 0=receive loss of sync (rlos) 1=loss of transmit clock (lotc)
DS2154 26 of 87 ccr1: common control register 1 (address=14 hex) (msb) (lsb) flb thdb3 tg802 tcrc4 rsm rhdb3 rg802 rcrc4 symbol position name and description flb ccr1.7 framer loopback. 0=loopback disabled 1=loopback enabled thdb3 ccr1.6 transmit hdb3 enable. 0=hdb3 disabled 1=hdb3 enabled tg802 ccr1.5 transmit g.802 enable. see section 13 for details. 0=do not force tchblk high during bit 1 of timeslot 26 1=force tchblk high during bit 1 of timeslot 26 tcrc4 ccr1.4 transmit crc4 enable. 0=crc4 disabled 1=crc4 enabled rsm ccr1.3 receive signaling mode select. 0=cas signaling mode 1=ccs signaling mode rhdb3 ccr1.2 receive hdb3 enable. 0=hdb3 disabled 1=hdb3 enabled rg802 ccr1.1 receive g.802 enable. see section 13 for details. 0=do not force rchblk high during bit 1 of timeslot 26 1=force rchblk high during bit 1 of timeslot 26 rcrc4 ccr1.0 receive crc4 enable. 0=crc4 disabled 1=crc4 enabled
DS2154 27 of 87 framer loopback when ccr1.7 is set to a 1, the DS2154 will enter a framer loopback (flb) mode. see figure 1-1 for more details. this loopback is useful in testing and debugging applications. in flb, the DS2154 will loop data from the transmit side back to the receive side. when flb is enabled, the following will occur: 1. data will be transmitted as normal at tposo and tnego. 2. data input via rposi and rnegi will be ignored. 3. the rclk output will be replaced with the tclk input. ccr2: common control register 2 (address=1a hex) (msb) (lsb) ecus vcrfs aais ara rserc lotcmc rff rfe symbol position name and description ecus ccr2.7 error counter update select. see section 5 for details. 0=update error counters once a second 1=update error counters every 62.5 ms (500 frames) vcrfs ccr2.6 vcr function select. see section 5 for details. 0=count bipolar violations (bpvs) 1=count code violations (cvs) aais ccr2.5 automatic ais generation. 0=disabled 1=enabled ara ccr2.4 automatic remote alarm generation. 0=disabled 1=enabled rserc ccr2.3 rser control. 0=allow rser to output data as received under all conditions 1=force rser to 1 under loss of frame alignment conditions lotcmc ccr2.2 loss of transmit clock mux control. determines whether the transmit side formatter should switch to the ever-present rclko if the tclk should fail to transition (see figure 1-1). 0=do not switch to rclko if tclk stops 1=switch to rclko if tclk stops rff ccr2.1 receive force freeze. freezes receive side signaling at rsig (and rser if ccr3.3=1); will override receive freeze enable (rfe). see section 7-2 for details. 0=do not force a freeze event 1=force a freeze event rfe ccr2.0 receive freeze enable. see section 7-2 for details. 0=no freezing of receive signaling data will occur 1=allow freezing of receive signaling data at rsig (and rser if ccr3.3=1).
DS2154 28 of 87 automatic alarm generation when either ccr2.4 or ccr2.5 is set to 1, the DS2154 monitors the receive side to determine if any of the following conditions are present: loss of receive frame synchronization, ais alarm (all 1s) reception, or loss of receive carrier (or signal). if any one (or more) of the above conditions is present, then the DS2154 will either force an ais alarm (if ccr2.5=1) or a remote alarm (ccr2.4=1) to be transmitted via the tposo and tnego pins. it is an illegal state to have both ccr2.4 and ccr2.5 set to 1 at the same time. if ccr2.4=1, then rai will be transmitted according to ets 300 011 specifications and a constant remote alarm will be transmitted if the DS2154 cannot find crc4 multiframe synchronization within 400 ms as per g.706.
DS2154 29 of 87 ccr3: common control register 3 address=1b hex) (msb) (lsb) tese tcbfs tirfs esr rsre thse tbcs rcla symbol position name and description tese ccr3.7 transmit side elastic store enable. 0=elastic store is bypassed 1=elastic store is enabled tcbfs ccr3.6 transmit channel blocking registers (tcbr) function select. 0=tcbrs define the operation of the tchblk output pin 1=tcbrs define which signaling bits are to be inserted tirfs ccr3.5 transmit idle registers (tir) function select. see section 8 for details. 0=tirs define in which channels to insert idle code 1=tirs define in which channels to insert data from rser (i.e., per=channel loopback function) esr ccr3.4 elastic stores reset. setting this bit from a 1 to a 0 will force the elastic stores to a known depth. esr is level triggered. should be toggled after rsysclk and tsysclk have been applied and are stable. must be set and cleared again for a subsequent reset. do not leave this bit set high. rsre ccr3.3 receive side signaling re-insertion enable. see section 7-2 for details. 0=do not reinsert signaling bits into the data stream presented at the rser pin 1=reinsert the signaling bits into data stream presented at the rser pin thse ccr3.2 transmit side hardware signaling insertion enable. see section 7-2 for details. 0=do not insert signaling from the tsig pin into the data stream presented at the tser pin 1=insert signaling from the tsig pin into the data stream presented at the tser pin tbcs ccr3.1 transmit side backplane clock select. 0=if tsysclk is 1.544 mhz 1=if tsysclk is 2.048 mhz rcla ccr3.0 receive carrier loss (rcl) alternate criteria. 0=rcl declared upon 255 consecutive 0s (125 us) 1=rcl declared upon 2048 consecutive 0s (1 ms)
DS2154 30 of 87 power-up sequence on power-up, after the supplies are stable, the DS2154 should be configured for operation by writing to all of the internal registers (this includes the test registers) since the contents of the internal registers cannot be predicted on power-up. next, the lirst (ccr5.7) bit should be toggled from 0 to 1 to reset the line interface circuitry (it will take the DS2154 about 40 ms to recover from the lirst bit being toggled). finally, after the rsysclk and tsysclk inputs are stable, the esr bit should be toggled from a 0 to a 1 and then back to 0 (this step can be skipped if the elastic stores are not being used). both tclk and rclki must be present for the parallel control port to operate properly. ccr4: common control register 4 (address=a8 hex) (msb) (lsb) rlb llb liais tcm4 tcm3 tcm2 tcm1 tcm0 symbol position name and description rlb ccr4.7 remote loopback. 0=loopback disabled 1= loopback enabled llb ccr4.6 local loopback. 0=loopback disabled 1=loopback enabled liais ccr4.5 line interface ais generation enable. see figure 1-1 for details. 0=allow normal data from tposi/tnegi to be transmitted at ttip and tring 1=force unframed all 1s to be transmitted at ttip and tring tcm4 ccr4.4 transmit channel monitor bit 4. msb of a channel decode that determines which transmit channel data will appear in the tds0m register. see section 6 for details. tcm3 ccr4.3 transmit channel monitor bit 3. tcm2 ccr4.2 transmit channel monitor bit 2. tcm1 ccr4.1 transmit channel monitor bit 1. tcm0 ccr4.0 transmit channel monitor bit 0. lsb of the channel decode.
DS2154 31 of 87 remote loopback when ccr4.7 is set to a 1, the DS2154 will be forced into remote loopback (rlb). in this loopback, data input via the rposi and rnegi pins will be transmitted back to the tposo and tnego pins. data will continue to pass through the receive side framer of the DS2154 as it would normally and the data from the transmit side formatter will be ignored. please see figure 1-1 for more details. local loopback when ccr4.6 is set to a 1, the DS2154 will be forced into local loopback (llb). in this loopback, data will continue to be transmitted as normal through the transmit side of the DS2154. data being received at rtip and rring will be replaced with the data being transmitted. data in this loopback will pass through the jitter attenuator. please see figure 1-1 for more details. ccr5: common control register 5 (address=aa hex) (msb) (lsb) lirst - - rcm4 rcm3 rcm2 rcm1 rcm0 symbol position name and description lirst ccr5.7 line interface reset. setting this bit from a 0 to a 1 will initiate an internal reset that affects the clock recovery state machine and jitter attenuator. normally this bit is only toggled on power-up. must be cleared and set again for a subsequent reset. - ccr5.6 not assigned. should be set to 0 when written - ccr5.5 not assigned. should be set to 0 when written. rcm4 ccr5.4 receive channel monitor bit 4. msb of a channel decode that determines which receive channel data will appear in the rds0m register. see section 6 for details. rcm3 ccr5.3 receive channel monitor bit 3. rcm2 ccr5.2 receive channel monitor bit 2. rcm1 ccr5.1 receive channel monitor bit 1. rcm0 ccr5.0 receive channel monitor bit 0. lsb of the channel decode.
DS2154 32 of 87 4.0 status and information registers there is a set of four registers that contain information on the current real time status of the DS2154, status register 1 (sr1), status register 2 (sr2), receive information register (rir), and synchronizer status register (ssr). when a particular event has occurred (or is occurring), the appropriate bit in one of these four registers will be set to a 1. all of the bits in these registers operate in a latched fashion (except for the ssr). this means that if an event or an alarm occurs and a bit is set to a 1 in any of the registers, it will remain set until the user reads that bit. the bit will be cleared when it is read and it will not be set again until the event has occurred again (or in the case of the rsa1, rsa0, rdma, rua1, rra, rcl, and rlos alarms, the bit will remain set if the alarm is still present). the user will always precede a read of the sr1, sr2, and rir registers with a write. the byte written to the register will inform the DS2154 which bits the user wishes to read and have cleared. the user will write a byte to one of these three registers, with a 1 in the bit positions he or she wishes to read and a 0 in the bit positions he or she does not wish to obtain the latest information on. when a 1 is written to a bit location, the read register will be updated with the latest information. when a 0 is written to a bit position, the read register will not be updated and the previous value will be held. a write to the status and information registers will be immediately followed by a read of the same register. the read result should be logically and?ed with the mask byte that was just written and this value should be written back into the same register to insure that bit does indeed clear. this second write step is necessary because the alarms and events in the status registers occur asynchronously in respect to their access via the parallel port. this write-read-write scheme allows an external microcontroller or microprocessor to individually poll certain bits without disturbing the other bits in the register. this operation is key in controlling the DS2154 with higher-order software languages. the ssr register operates differently than the other three. it is a read-only register and it reports the status of the synchronizer in real time. this register is not latched and it is not necessary to precede a read of this register with a write. the sr1 and sr2 registers have the unique ability to initiate a hardware interrupt via the int output pin. each of the alarms and events in the sr1 and sr2 can be either masked or unmasked from the interrupt pins via the interrupt mask register 1 (imr1) and interrupt mask register 2 (imr2) respectively. the interrupts caused by rua1, rra, rcl, and rlos act differently than the interrupts caused by rsa1, rdma, rsa0, rslip, rmf, raf, tmf, sec, taf, lotc, rcmf, and tslip. the four interrupts will force the int pin low whenever the alarm changes state (i.e., the alarm goes active or inactive according to the set/ clear criteria in table 4-1). the int pin will be allowed to return high (if no other interrupts are present) when the user reads the alarm bit that caused the interrupt to occur if the alarm is still present, the register bit will remain set. the event caused interrupts will force the int pin low when the event occurs. the int pin will be allowed to return high (if no other interrupts are present) when the user reads the event bit that caused the interrupt to occur.
DS2154 33 of 87 rir: receive information register (address=08 hex) (msb) (lsb) tesf tese jalt resf rese crcrc fasrc casrc symbol position name and description tesf rir.7 transmit side elastic store full. set when the transmit side elastic store buffer fills and a frame is deleted. tese rir.6 transmit side elastic store empty. set when the transmit side elastic store buffer empties and a frame is repeated. jalt rir.5 jitter attenuator limit trip. set when the jitter attenuator fifo reaches to within 4 bits of its limit; useful for debugging jitter attenuation operation. resf rir.4 receive side elastic store full. set when the receive side elastic store buffer fills and a frame is deleted. rese rir.3 receive side elastic store empty. set when the receive side elastic store buffer empties and a frame is repeated. crcrc rir.2 crc resync criteria met. set when 915/1000 code words are received in error. fasrc rir.1 fas resync criteria met. set when 3 consecutive fas words are received in error. casrc rir.0 cas resync criteria met. set when 2 consecutive cas mf alignment words are received in error.
DS2154 34 of 87 ssr: synchronizer status register (address=1e hex) (msb) (lsb) csc5 csc4 csc3 csc2 csc0 fassa cassa crc4sa symbol position name and description csc5 ssr.7 crc4 sync counter bit 5. msb of the 6-bit counter. csc4 ssr.6 crc4 sync counter bit 4. csc3 ssr.5 crc4 sync counter bit 3. csc2 ssr.4 crc4 sync counter bit 2. csc0 ssr.3 crc4 sync counter bit 0. lsb of the 6-bit counter. the next to lsb is not accessible. fassa ssr.2 fas sync active. set while the synchronizer is searching for alignment at the fas level. cassa ssr.1 cas mf sync active. set while the synchronizer is searching for the cas mf alignment word. crc4sa ssr.0 crc4 mf sync active. set while the synchronizer is searching for the crc4 mf alignment word.
DS2154 35 of 87 crc4 sync counter the crc4 sync counter increments each time the 8 ms crc4 multiframe search times out. the counter is cleared when the DS2154 has successfully obtained synchronization at the crc4 level. the counter can also be cleared by disabling the crc4 mode (ccr1.0=0). this counter is useful for determining the amount of time the DS2154 has been searching for synchronization at the crc4 level. itu g.706 suggests that if synchronization at the crc4 level cannot be obtained within 400 ms, then the search should be abandoned and proper action taken. the crc4 sync counter will rollover. sr1: status register 1 (address=06 hex) (msb) (lsb) rsa1 rdma rsa0 rslip rua1 rra rcl rlos symbol position name and description rsa1 sr1.7 receive signaling all 1s / signaling change. set when the contents of timeslot 16 contains less than three 0s over 16 consecutive frames. this alarm is not disabled in the ccs signaling mode. both rsa1 and rsa0 will be set if a change in signaling is detected. rdma sr1.6 receive distant mf alarm. set when bit 6 of timeslot 16 in frame 0 has been set for two consecutive multiframes. this alarm is not disabled in the ccs signaling mode. rsa0 sr1.5 receive signaling all 0s / signaling change. set when over a full mf, timeslot 16 contains all 0s. both rsa1 and rsa0 will be set if a change in signaling is detected. rslip sr1.4 receive side elastic store slip. set when the elastic store has either repeated or deleted a frame of data. rua1 sr1.3 receive unframed all 1s. set when an unframed all 1s code is received at rposi and rnegi. rra sr1.2 receive remote alarm. set when a remote alarm is received at rposi and rnegi. rcl sr1.1 receive carrier loss. set when 255 (or 2048 if ccr3.0=1) consecutive 0s have been detected at rtip and rring. [note: a test mode exists to allow the DS2154 to detect carrier loss at rposi and rnegi in place of detection at rtip and rring]. rlos sr1.0 receive loss of sync. set when the device is not synchronized to the receive e1 stream.
DS2154 36 of 87 alarm criteria table 4-1 alarm set criteria clear criteria itu spec. rsa1 (receive signaling all 1s) over 16 consecutive frames (one full mf) timeslot 16 contains less than three 0s over 16 consecutive frames (one full mf) timeslot 16 contains three or more 0s g.732 4.2 rsa0 (receive signaling all 0s) over 16 consecutive frames (one full mf) timeslot 16 contains all 0s over 16 consecutive frames (one full mf) timeslot 16 contains at least a single 1 g.732 5.2 rdma (receive distant multiframe alarm) bit 6 in timeslot 16 of frame 0 set to 1 for two consecutive mf bit 6 in timeslot 16 of frame 0 set to 0 for a two consecutive mf o.162 2.1.5 rua1 (receive unframed all 1s) less than three 0s in two frames (512 bits) more than two 0s in two frames (512 bits) o.162 1.6.1.2 rra (receive remote alarm) bit 3 of non-align frame set to 1 for three consecutive occasions bit 3 of non-align frame set to 0 for three consecutive occasions o.162 2.1.4 rcl (receive carrier loss) 255 (or 2048) consecutive 0s received in 255-bit times, at least 32 1s are received g.775 / g.962
DS2154 37 of 87 sr2: status register 2 (address=07 hex) (msb) (lsb) rmf raf tmf sec taf lotc rcmf tslip symbol position name and description rmf sr2.7 receive cas multiframe . set every 2 ms (regardless if cas signaling is enabled or not) on receive multiframe boundaries. used to alert the host that signaling data is available. raf sr2.6 receive align frame . set every 250 transmit multiframe . set every 2 ms (regardless if crc4 is enabled) on transmit multiframe boundaries. used to alert the host that signaling data needs to be updated. sec sr2.4 1-second timer . set on increments of 1 second based on rclk. if ccr2.7=1, then this bit will be set every 62.5 ms instead of once a second. taf sr2.3 transmit align frame . set every 250 loss of transmit clock . set when the tclk pin has not transitioned for one channel time (or 3.9 receive crc4 multiframe . set on crc4 multiframe boundaries; will continue to be set every 2 ms on an arbitrary boundary if crc4 is disabled. tslip sr2.0 transmit elastic store slip. set when the elastic store has either repeated or deleted a frame of data.
DS2154 38 of 87 imr1: interrupt mask register 1 (address=16 hex) (msb) (lsb) rsa1 rdma rsa0 rslip rua1 rra rcl rlos symbol position name and description rsa1 imr1.7 receive signaling all 1s / signaling change. 0=interrupt masked 1=interrupt enabled rdma imr1.6 receive distant mf alarm . 0=interrupt masked 1=interrupt enabled rsa0 imr1.5 receive signaling all 0s / signaling change. 0=interrupt masked 1=interrupt enabled rslip imr1.4 receive elastic store slip occurrence . 0=interrupt masked 1=interrupt enabled rua1 imr1.3 receive unframed all 1s . 0=interrupt masked 1=interrupt enabled rra imr1.2 receive remote alarm . 0=interrupt masked 1=interrupt enabled rcl imr1.1 receive carrier loss . 0=interrupt masked 1=interrupt enabled rlos imr1.0 receive loss of sync . 0=interrupt masked 1=interrupt enabled
DS2154 39 of 87 imr2: interrupt mask register 2 (address=17 hex) (msb) (lsb) rmf raf tmf sec taf lotc rcmf tslip symbol position name and description rmf imr2.7 receive cas multiframe. 0=interrupt masked 1=interrupt enabled raf imr2.6 receive align frame. 0=interrupt masked 1=interrupt enabled tmf imr2.5 transmit multiframe. 0=interrupt masked 1=interrupt enabled sec imr2.4 1-second timer. 0=interrupt masked 1=interrupt enabled taf imr2.3 transmit align frame. 0=interrupt masked 1=interrupt enabled lotc imr2.2 loss of transmit clock. 0=interrupt masked 1=interrupt enabled rcmf imr2.1 receive crc4 multifram e. 0=interrupt masked 1=interrupt enabled tslip imr2.0 transmit side elastic store slip occurrence. 0=interrupt masked 1=interrupt enabled
DS2154 40 of 87 5.0 error count registers there are a set of four counters in the DS2154 that record bipolar or code violations, errors in the crc4 smf code words, e bits as reported by the far end, and word errors in the fas. each of these four counters are automatically updated on either 1-second boundaries (ccr2.7=0) or every 62.5 ms (ccr2.7=1) as determined by the timer in status register 2 (sr2.4). hence, these registers contain performance data from either the previous second or the previous 62.5 ms. the user can use the interrupt from the timer to determine when to read these registers. the user has a full second (or 62.5 ms) to read the counters before the data is lost. 5.1 bpv or code violation counter violation count register 1 (vcr1) is the most significant word and vcr2 is the least significant word of a 16-bit counter that records either bipolar violations (bpvs) or code violations (cvs). if ccr2.6=0, then the vcr counts bipolar violations. bipolar violations are defined as consecutive marks of the same polarity. in this mode, if the hdb3 mode is set for the receive side via ccr1.2, then hdb3 code words are not counted as bpvs. if ccr2.6=1, then the vcr counts code violations as defined in itu o.161. code violations are defined as consecutive bipolar violations of the same polarity. in most applications, the DS2154 should be programmed to count bpvs when receiving ami code and to count cvs when receiving hdb3 code. this counter increments at all times and is not disabled by loss of sync conditions. the counter saturates at 65,535 and will not rollover. the bit error rate on an e1 line would have to be greater than 10** -2 before the vcr would saturate. vcr1: upper bipolar violation count register 1 (address=00 hex) vcr2:lower bipolar violation count register 2 (address=01 hex) (msb) (lsb) v15 v14 v13 v12 v11 v10 v9 v8 vcr1 v7 v6 v5 v4 v3 v2 v1 v0 vcr2 symbol position name and description v15 vcr1.7 msb of the 16-bit bipolar or code violation count . v0 vcr2.0 lsb of the 16-bit bipolar or code violation count.
DS2154 41 of 87 5.2 crc4 error counter crc4 count register 1 (crccr1) is the most significant word and crccr2 is the least significant word of a 10-bit counter that records word errors in the cyclic redundancy check 4 (crc4). since the maximum crc4 count in a 1-second period is 1000, this counter cannot saturate. the counter is disabled during loss of sync at either the fas or crc4 level; it will continue to count if loss of multiframe sync occurs at the cas level. crccr1: crc4 count register 1 (address=02 hex) crccr2: crc4 count register 2 (address=03 hex) (msb) (lsb) (note 1) (note 1) (note 1) (note 1) (note 1) (note 1) crc9 crc8 crccr1 crc7 crc6 crc5 crc4 crc3 crc2 crc1 crc0 crccr2 symbol position name and description crc9 crccr1.1 msb of the 10-bit crc4 error count. crc0 crccr2.0 lsb of the 10-bit crc4 error count. note: 1. the upper 6 bits of crccr1 at address 02 are the most significant bits of the 12-bit fas error counter. 5.3 e-bit counter e-bit count register 1 (ebcr1) is the most significant word and ebcr2 is the least significant word of a 10-bit counter that records far end block errors (febe) as reported in the first bit of frames 13 and 15 on e1 lines running with crc4 multiframe. these count registers will increment once each time the received e-bit is set to 0. since the maximum e-bit count in a 1-second period is 1000, this counter cannot saturate. the counter is disabled during loss of sync at either the fas or crc4 level; it will continue to count if loss of multiframe sync occurs at the cas level. ebcr1: e-bit count register 1 (address=04 hex) ebcr2: e-bit count register 2 (address=05 hex) (msb) (lsb) (note 1) (note 1) (note 1) (note 1) (note 1) (note 1) eb9 eb8 ebcr1 eb7 eb6 eb5 eb4 eb3 eb2 eb1 eb0 ebcr2 symbol position name and description eb9 ebcr1.1 msb of the 10-bit e-bit count. eb0 ebcr2.0 lsb of the 10-bit e-bit count. note: the upper 6 bits of ebcr1 at address 04 are the least significant bits of the 12-bit fas error counter.
DS2154 42 of 87 5.4 fas error counter fas count register 1 (fascr1) is the most significant word and fascr2 is the least significant word of a 12-bit counter that records word errors in the frame alignment signal in timeslot 0. this counter is disabled during loss of synchronization conditions, (rlos = 1). since the maximum fas word error count in a 1-second period is 4000, this counter cannot saturate. fascr1: fas bit count register 1 (address=02 hex) fascr2: fas bit count register 2 (address=04 hex) (msb) (lsb) fas11 fas10 fas9 fas8 fas7 fas6 (note 2) (note 2) fascr1 fas5 fas4 fas3 fas2 fas1 fas0 (note 1) (note 1) fascr2 symbol position name and description fas11 fascr1.7 msb of the 12-bit fas error count. fas0 fascr2.2 lsb of the 12-bit fas error count. notes: 1. the lower 2 bits of fascr1 at address 02 are the most significant bits of the 10-bit crc4 error counter. 2. the lower 2 bits of fascr2 at address 04 are the most significant bits of the 10-bit e-bit counter.
DS2154 43 of 87 6.0 ds0 monitoring function the DS2154 has the ability to monitor one ds0 64 kbps channel in the transmit direction and one ds0 channel in the receive direction at the same time. in the transmit direction the user will determine which channel is to be monitored by properly setting the tcm0 to tcm4 bits in the ccr4 register. in the receive direction, the rcm0 to rcm4 bits in the ccr5 register need to be properly set. the ds0 channel pointed to by the tcm0 to tcm4 bits will appear in the transmit ds0 monitor (tds0m) register and the ds0 channel pointed to by the rcm0 to rcm4 bits will appear in the receive (rds0m) register. the tcm4 to tcm0 and rcm4 to rcm0 bits should be programmed with the decimal decode of the appropriate e1 channel. for example, if ds0 channel 6 (timeslot 5) in the transmit direction and ds0 channel 15 (timeslot 14) in the receive direction needed to be monitored, then the following values would be programmed into ccr4 and ccr5: tcm4=0 ........................................................................................ rcm4=0 tcm3=0 ........................................................................................ rcm3=1 tcm2=1 ........................................................................................ rcm2=1 tcm1=0 ........................................................................................ rcm1=1 tcm0=1 ........................................................................................ rcm0=0 ccr4: ds0 monitoring function (address=a8 hex) [repeated here from section 3 for convenience] (msb) (lsb) rlb llb liais tcm4 tcm3 tcm2 tcm1 tcm0 symbol position name and description rlb ccr4.7 remote loopback. see section 3 for details. llb ccr4.6 local loopback. see section 3 for details. liais ccr4.5 line interface ais generation enable. see section 3 for details. tcm4 ccr4.4 transmit channel monitor bit 4. msb of a channel decode that determines which transmit ds0 channel data will appear in the tds0m register. tcm3 ccr4.3 transmit channel monitor bit 3. tcm2 ccr4.2 transmit channel monitor bit 2. tcm1 ccr4.1 transmit channel monitor bit 1. tcm0 ccr4.0 transmit channel monitor bit 0. lsb of the channel decode that determines which transmit ds0 channel data will appear in the tds0m register.
DS2154 44 of 87 tds0m: transmit ds0 monitor register (address=a9 hex) (msb) (lsb) b1 b2 b3 b4 b5 b6 b7 b8 symbol position name and description b1 tds0m.7 transmit ds0 channel bit 8. msb of the ds0 channel (first bit to be transmitted). b2 tds0m.6 transmit ds0 channel bit 7. b3 tds0m.5 transmit ds0 channel bit 6. b4 tds0m.4 transmit ds0 channel bit 5. b5 tds0m.3 transmit ds0 channel bit 4. b6 tds0m.2 transmit ds0 channel bit 3. b7 tds0m.1 transmit ds0 channel bit 2. b8 tds0m.0 transmit ds0 channel bit 1. lsb of the ds0 channel (last bit to be transmitted). ccr5: common control register 5 (address=aa hex) [repeated here from section 3 for convenience] (msb) (lsb) lirst - - rcm4 rcm3 rcm2 rcm1 rcm0 symbol position name and description lirst ccr5.7 line interface reset. see section 3 for details. - ccr5.6 not assigned. should be set to 0 when written. - ccr5.5 not assigned. should be set to 0 when written. rcm4 ccr5.4 receive channel monitor bit 4. msb of a channel decode that determines which receive ds0 channel data will appear in the rds0m register. rcm3 ccr5.3 receive channel monitor bit 3. rcm2 ccr5.2 receive channel monitor bit 2. rcm1 ccr5.1 receive channel monitor bit 1. rcm0 ccr5.0 receive channel monitor bit 0. lsb of the channel decode that determines which receive ds0 channel data will appear in
DS2154 45 of 87 the rds0m register. rds0m: receive ds0 monitor register (address=ab hex) (msb) (lsb) b1 b2 b3 b4 b5 b6 b7 b8 symbol position name and description b1 rds0m.7 receive ds0 channel bit 8. msb of the ds0 channel (first bit to be received). b2 rds0m.6 receive ds0 channel bit 7. b3 rds0m.5 receive ds0 channel bit 6. b4 rds0m.4 receive ds0 channel bit 5. b5 rds0m.3 receive ds0 channel bit 4. b6 rds0m.2 receive ds0 channel bit 3. b7 rds0m.1 receive ds0 channel bit 2. b8 rds0m.0 receive ds0 channel bit 1. lsb of the ds0 channel (last bit to be received).
DS2154 46 of 87 7.0 signaling operation the DS2154 contains provisions for both processor-based (i.e., software based) signaling bit access and for hardware based access. both the processor-based access and the hardware-based access can be used simultaneously if necessary. the processor-based signaling is covered in section 7.1 and the hardware- based signaling is covered in section 7.2. 7.1 processor-based signaling the channel associated signaling (cas) bits embedded in the e1 stream can be extracted from the receive stream and inserted into the transmit stream by the DS2154. each of the 30 voice channels has four signaling bits (a/b/c/d) associated with it. the numbers in parenthesis () are the voice channel associated with a particular signaling bit. the voice channel numbers have been assigned as described in the itu documents. please note that this is different than the channel numbering scheme (1 to 32) that is used in the rest of the data sheet. for example, voice channel 1 is associated with timeslot 1 (channel 2) and voice channel 30 is associated with timeslot 31 (channel 32). there is a set of 16 registers for the receive side (rs1 to rs16) and 16 registers on the transmit side (ts1 to ts16). the signaling registers are detailed below. rs1 to rs16: receive signaling registers (address=30 to 3f hex) (msb) (lsb) 0000 xyxx rs1 (30) a(1) b(1) c(1) d(1) a(16) b(16) c(16) d(16) rs2 (31) a(2) b(2) c(2) d(2) a(17) b(17) c(17) d(17) rs3 (32) a(3) b(3) c(3) d(3) a(18) b(18) c(18) d(18) rs4 (33) a(4) b(4) c(4) d(4) a(19) b(19) c(19) d(19) rs5 (34) a(5) b(5) c(5) d(5) a(20) b(20) c(20) d(20) rs6 (35) a(6) b(6) c(6) d(6) a(21) b(21) c(21) d(21) rs7 (36) a(7) b(7) c(7) d(7) a(22) b(22) c(22) d(22) rs8 (37) a(8) b(8) c(8) d(8) a(23) b(23) c(23) d(23) rs9 (38) a(9) b(9) c(9) d(9) a(24) b(24) c(24) d(24) rs10 (39) a(10) b(10) c(10) d(10) a(25) b(25) c(25) d(25) rs11 (3a) a(11) b(11) c(11) d(11) a(26) b(26) c(26) d(26) rs12 (3b) a(12) b(12) c(12) d(12) a(27) b(27) c(27) d(27) rs13 (3c) a(13) b(13) c(13) d(13) a(28) b(28) c(28) d(28) rs14 (3d) a(14) b(14) c(14) d(14) a(29) b(29) c(29) d(29) rs15 (3e) a(15) b(15) c(15) d(15) a(30) b(30) c(30) d(30) rs16 (3f) symbol position name and description x rs1.0/1/3 spare bits. y rs1.2 remote alarm bit (integrated and reported in sr1.6). a(1) rs2.7 signaling bit a for channel 1. d(30) rs16.0 signaling bit d for channel 30.
DS2154 47 of 87 each receive signaling register (rs1 to rs16) reports the incoming signaling from two timeslots. the bits in the receive signaling registers are updated on multiframe boundaries so the user can utilize the receive multiframe interrupt in the receive status register 2 (sr2.7) to know when to retrieve the signaling bits. the user has a full 2 ms to retrieve the signaling bits before the data is lost. the rs registers are updated under all conditions. their validity should be qualified by checking for synchronization at the cas level. in ccs signaling mode, rs1 to rs16 can also be used to extract signaling information. via the sr2.7 bit, the user will be informed when the signaling registers have been loaded with data. the user has 2 ms to retrieve the data before it is lost. the signaling data reported in rs1 to rs16 is also available at the rsig and rser pins. a change in the signaling bits from one multiframe to the next will cause the rsa1 (sr1.7) and rsa0 (sr1.5) status bits to be set at the same time. the user can enable the int pin to toggle low upon detection of a change in signaling by setting either the imr1.7 or imr1.5 bit. once a signaling change has been detected, the user has at least 1.75 ms to read the data out of the rs1 to rs16 registers before the data will be lost. s1 to ts16: transmit signaling registers (address=40 to 4f hex) (msb) (lsb) 0000 xyxx ts1 (40) a(1) b(1) c(1) d(1) a(16) b(16) c(16) d(16) ts2 (41) a(2) b(2) c(2) d(2) a(17) b(17) c(17) d(17) ts3 (42) a(3) b(3) c(3) d(3) a(18) b(18) c(18) d(18) ts4 (43) a(4) b(4) c(4) d(4) a(19) b(19) c(19) d(19) ts5 (44) a(5) b(5) c(5) d(5) a(20) b(20) c(20) d(20) ts6 (45) a(6) b(6) c(6) d(6) a(21) b(21) c(21) d(21) ts7 (46) a(7) b(7) c(7) d(7) a(22) b(22) c(22) d(22) ts8 (47) a(8) b(8) c(8) d(8) a(23) b(23) c(23) d(23) ts9 (48) a(9) b(9) c(9) d(9) a(24) b(24) c(24) d(24) ts10 (49) a(10) b(10) c(10) d(10) a(25) b(25) c(25) d(25) ts11 (4a) a(11) b(11) c(11) d(11) a(26) b(26) c(26) d(26) ts12 (4b) a(12) b(12) c(12) d(12) a(27) b(27) c(27) d(27) ts13 (4c) a(13) b(13) c(13) d(13) a(28) b(28) c(28) d(28) ts14 (4d) a(14) b(14) c(14) d(14) a(29) b(29) c(29) d(29) ts15 (4e) a(15) b(15) c(15) d(15) a(30) b(30) c(30) d(30) ts16 (4f) symbol position name and description x ts1.0/1/3 spare bits. y ts1.2 remote alarm bit. a(1) ts2.7 signaling bit a for channel 1. d(30) ts16.0 signaling bit d for channel 30.
DS2154 48 of 87 each transmit signaling register (ts1 to ts16) contains the cas bits for two timeslots that will be inserted into the outgoing stream if enabled to do so via tcr1.5. on multiframe boundaries, the DS2154 will load the values present in the transmit signaling register into an outgoing signaling shift register that is internal to the device. the user can utilize the transmit multiframe bit in status register 2 (sr2.5) to know when to update the signaling bits. the bit will be set every 2 ms and the user has 2 ms to update the tsrs before the old data will be retransmitted. itu specifications recommend that the abcd signaling not be set to all 0s because they will emulate a cas multiframe alignment word. the ts1 register is special because it contains the cas multiframe alignment word in its upper nibble. the upper nibble must always be set to 0000 or else the terminal at the far end will lose multiframe synchronization. if the user wishes to transmit a multiframe alarm to the far end, then the ts1.2 bit should be set to a 1. if no alarm is to be transmitted, then the ts1.2 bit should be cleared. the three remaining bits in ts1 are the spare bits. if they are not used, they should be set to 1. in ccs signaling mode, ts1 to ts16 can also be used to insert signaling information. via the sr2.5 bit, the user will be informed when the signaling registers need to be loaded with data. the user has 2 ms to load the data before the old data will be retransmitted. via the ccr3.6 bit, the user has the option to use the transmit channel blocking registers (tcbrs) to determine, on a channel by channel basis, which signaling bits are to be inserted via the tsrs (the corresponding bit in the tcbrs=1) and which are to be sourced from the tser or tsig pin (the corresponding bit in the tcbrs=0). see the transmit data flow diagram in section 13 for more details.
DS2154 49 of 87 7.2 hardware based signaling 7.2.1 receive side in the receive side of the hardware based signaling, there are two operating modes for the signaling buffer: signaling extraction and signaling reinsertion. signaling extraction involves pulling the signaling bits from the receive data stream and buffering them over a 2-multiframe buffer and outputting them in a serial pcm fashion on a channel-by-channel basis at the rsig output pin. this mode is always enabled. in this mode, the receive elastic store may be enabled or disabled. if the receive elastic store is enabled, then the backplane clock (rsysclk) must be 2.048 mhz. the abcd signaling bits are output on rsig in the lower nibble of each channel. see the timing diagrams in section 13 for an example. the rsig data is updated once a multiframe (2 ms) unless a freeze is in effect. the other hardware based signaling operating mode called signaling re-insertion can be invoked by setting the rsre control bit high (ccr3.3=1). in this mode, the user will provide a multiframe sync at the rsync pin and the signaling data will be re-aligned in the pcm data stream provided at the rser output pin according to this applied multiframe boundary. in this mode, the elastic store must be enabled and the backplane clock (rsysclk) must be 2.048 mhz. the signaling data in the 2-multiframe buffer will be frozen in a known good state upon either a loss of synchronization (oof event), carrier loss, or frame slip. to allow this freeze action to occur, the rfe control bit (ccr2.0) should be set high. the user can force a freeze by setting the rff control bit (ccr2.1) high. setting the rff bit high causes the same freezing action as if a loss of synchronization, carrier loss, or slip has occurred. the rsigf output pin provides a hardware indication that a freeze is in effect. the rsigf pin will go high immediately upon detection of any of the events that can cause a freeze to occur. the rsigf pin will return low 3 ms to 5 ms after the event subsides. the rsigf pin action cannot be disabled. the 2-multiframe buffer provides an approximate 1-multiframe delay in the signaling bits provided at the rsig pin (and at the rser pin if rsre=1 via ccr3.3). when freezing is enabled (rfe=1), the signaling data will be held in the last known good state until the corrupting error condition subsides. when the error condition subsides, the signaling data will be held in the old state for an additional 3 ms to 5 ms before being allowed to be updated with new signaling data. 7.2.2 transmit side via the thse control bit (ccr3.2), the DS2154 can be set up to take the signaling data presented at the tsig pin and insert the signaling data into the pcm data stream that is being input at the tser pin. the hardware signaling insertion capabilities of the DS2154 are available whether the transmit side elastic store is enabled or disabled. if the transmit side elastic store is enabled, the backplane clock (tsysclk) must be 2.048 mhz. when hardware signaling insertion is enabled on the DS2154 (tsre=1), then the user must enable the transmit channel blocking register function select (tcbfs) control bit (ccr3.6=1). this is needed so that the cas multiframe alignment word, multiframe remote alarm, and spare bits can be added to timeslot 16 in frame 0 of the multiframe. the ts1 register should be programmed with the proper information. if ccr3.6=1, then a 0 in the tcbrs implies that signaling data is to be sourced from tser (or tsig if ccr3.2=1) and a 1 implies that signaling data for that channel is to be sourced from the transmit signaling (ts) registers. see definition below.
DS2154 50 of 87 tcbr1/tcbr2/tcbr3/tcbr4: definition when ccr3.6=1 (msb) (l sb) ch20 ch4 ch19 ch3 ch18 ch2 ch17* ch1* tcbr1(22) ch24 ch8 ch23 ch7 ch22 ch6 ch21 ch5 tcbr2(23) ch28 ch12 ch27 ch11 ch26 ch10 ch25 ch9 tcbr3(24) ch32 ch16 ch31 ch15 ch30 ch14 ch29 ch13 tcbr4(25) *=ch1 and ch17 should be set to 1 to allow the internal ts1 register to create the cas multiframe alignment word and spare/remote alarm bits. the user can also take advantage of this functionality to intermix signaling data from the tsig pin and from the internal transmit signaling registers (ts1 to ts16). as an example, assume that the user wishes to source all the signaling data except for voice channels 5 and 10 from the tsig pin. in this application, the following bits and registers would be programmed as follows: control bits .................................................................................................. register values tsre=1 (ccr3.2) ............................................................................................................... ........................ .......................................................................... ts1=0bh (mf alignment word, remote alarm etc.) tcbfs=1 (ccr3.6) .............................................................................................................. ....................... ................................................................................tcbr1=03h (source timeslot 16, frame 1 data) t16s=1 (tcr1.5) ............................................................................................................... ......................... ......................................................tcbr2=01h (source voice channel 5 signaling data from ts6) tcbr3=04h (source voice channel 10 signaling data from ts11) tcbr4=00h
DS2154 51 of 87 8.0 per-channel code generation the DS2154 can replace data on a channel-by-channel basis in both the transmit and receive directions. the transmit direction is from the backplane to the e1 line and is covered in section 8.1. the receive direction is from the e1 line to the backplane and is covered in section 8.2. 8.1 transmit side code generation in the transmit direction there are two methods by which channel data from the backplane can be overwritten with data generated by the DS2154. the first method which is covered in section 8.1.1 was a feature contained in the original ds2153 while the second method which is covered in section 8.1.2 is a new feature of the DS2154. 8.1.1 simple idle code insertion and per-channel loopback the first method involves using the transmit idle registers (tir1/2/3/4) to determine which of the 32 e1 channels should be overwritten with the code placed in the transmit idle definition register (tidr). this method allows the same 8-bit code to be placed into any of the 32 e1 channels. if this method is used, then the ccr3.5 control bit must be set to 0. the transmit idle registers (tirs) have an alternate function that allow them to define a per-channel loopback (pclb). if the ccr3.5 control bit is set to 1, then the tirs will determine which channels (if any) from the backplane should be replaced with the data from the receive side or in other words, off of the e1 line. see figure 1-1. if this mode is enabled, then transmit and receive clocks and frame syncs must be synchronized. one method to accomplish this would be to tie rclk to tclk and rfsync to tsync. there are no restrictions on which channels can be loopback or on how many channels can be looped back.
DS2154 52 of 87 tir1/tir2/tir3/tir4: transmit idle registers (address=26 to 29 hex) [also used for per-channel loopback] (msb) (l sb) ch8 ch7 ch6 ch5 ch4 ch3 ch2 ch1 tir1 (26) ch16 ch15 ch14 ch13 ch12 ch11 ch10 ch9 tir2 (27) ch24 ch23 ch22 ch21 ch20 ch19 ch18 ch17 tir3 (28) ch32 ch31 ch30 ch29 ch28 ch27 ch26 ch25 tir4 (29) symbol position name and description ch32 tir4.7 transmit idle registers . 0=do not insert the idle code in the tidr into this channel ch1 tir1.0 1=insert the idle code in the tidr into this channel note: if ccr3.5=1, then a 0 in the tirs implies that channel data is to be sourced from tser and a 1 implies that channel data is to be sourced from the output of the receive side framer (i.e., per-channel loopback; see figure 1-1). tidr: transmit idle definition register (address=2a hex) (msb) (lsb) tidr7 tidr6 tidr5 tidr4 tidr3 tidr2 tidr1 tidr0 symbol position name and description tidr7 tidr.7 msb of the idle code (this bit is transmitted first) tidr0 tidr.0 lsb of the idle code (this bit is transmitted last) 8.1.2 per-channel code insertion the second method involves using the transmit channel control registers (tcc1/2/3/4) to determine which of the 32 e1 channels should be overwritten with the code placed in the transmit channel registers (tc1 to tc32). this method is more flexible than the first in that it allows a different 8-bit code to be placed into each of the 32 e1 channels. tc1 to tc32: transmit channel registers (address=60 to 7f hex) (for brevity, only channel 1 is shown; see table 1-3 for other register address) (msb) (lsb) c7 c6 c5 c4 c3 c2 c1 c0 symbol position name and description c7 tc1.7 msb of the code (this bit is transmitted first)
DS2154 53 of 87 c0 tc1.0 lsb of the code (this bit is transmitted last) tcc1/tcc2/tcc3/tcc4: transmit channel control register (address=a0 to a3 hex) (msb) (l sb) ch8 ch7 ch6 ch5 ch4 ch3 ch2 ch1 tcc1 (a0) ch16 ch15 ch14 ch13 ch12 ch11 ch10 ch9 tcc2 (a1) ch24 ch23 ch22 ch21 ch20 ch19 ch18 ch17 tcc3 (a2) ch32 ch31 ch30 ch29 ch28 ch27 ch26 ch25 tcc4 (a3) symbol position name and description ch1 tcc1.0 transmit channel 1 code insertion control bit 0=do not insert data from the tc1 register into the transmit data stream 1=insert data from the tc1 register into the transmit data stream ch32 tcc4.7 transmit channel 32 code insertion control bit 0=do not insert data from the tc32 register into the transmit data stream 1=insert data from the tc32 register into the transmit data stream 8.2 receive side code generation on the receive side, the receive channel control registers (rcc1/2/3/4) are used to determine which of the 32 e1 channels off of the e1 line and going to the backplane should be overwritten with the code placed in the receive channel registers (rc1 to rc32). rc1 to rc32: receive channel registers (address=80 to 9f hex) (for brevity, only channel 1 is shown; see table 1-3 for other register addresses) (msb) (ls b) c7 c6 c5 c4 c3 c2 c1 c0 rc1 (80) symbol position name and description c7 rc1.7 msb of the code (this bit is sent first to the backplane) c0 rc1.0 lsb of the code (this bit is sent last to the backplane)
DS2154 54 of 87 rcc1/rcc2/rcc3/rcc4: receive channel control register (address=a4 to a7 hex) (msb) (l sb) ch8 ch7 ch6 ch5 ch4 ch3 ch2 ch1 rcc1 (a4) ch16 ch15 ch14 ch13 ch12 ch11 ch10 ch9 rcc2 (a5) ch24 ch23 ch22 ch21 ch20 ch19 ch18 ch17 rcc3 (a6) ch32 ch31 ch30 ch29 ch28 ch27 ch26 ch25 rcc4 (a7) symbol position name and description ch1 rcc1.0 receive channel 1 code insertion control bit 0=do not insert data from the rc1 register into the receive data stream 1=insert data from the rc1 register into the receive data stream ch32 rcc4.7 receive channel 32 code insertion control bit 0=do not insert data from the rc32 register into the receive data stream 1=insert data from the rc32 register into the receive data stream 9.0 clock blocking registers the receive channel blocking registers (rcbr1 / rcbr2 / rcbr3 / rcbr4) and the transmit channel blocking registers (tcbr1 / tcbr2 / tcbr3 / tcbr4) control rchblk and tchblk pins respectively. (the rchblk and tchblk pins are user programmable outputs that can be forced either high or low during individual channels). these outputs can be used to block clocks to a usart or lapd controller in isdn-pri applications. when the appropriate bits are set to a 1, the rchblk and tchblk pin will be held high during the entire corresponding channel time. see the timing in section 13 for an example. the tcbrs have alternate mode of use. via the ccr3.6 bit, the user has the option to use the tcbrs to determine, on a channel by channel basis, which signaling bits are to be inserted via the tsrs (the corresponding bit in the tcbrs=1) and which are to be sourced from the tser or tsig pins (the corresponding bit in the tcbr=0). see section 7 for more details about this mode of operation.
DS2154 55 of 87 rcbr1/rcbr2/rcbr3/rcbr4: receive channel blocking registers (address=2b to 2e hex) (msb) (l sb) ch8 ch7 ch6 ch5 ch4 ch3 ch2 ch1 rcbr1 (2b) ch16 ch15 ch14 ch13 ch12 ch11 ch10 ch9 rcbr2 (2c) ch24 ch23 ch22 ch21 ch20 ch19 ch18 ch17 rcbr3 (2d) ch32 ch31 ch30 ch29 ch28 ch27 ch26 ch25 rcbr4 (2e) symbol position name and description ch32 rcbr4.7 receive channel blocking registers. 0=force the rchblk pin to remain low during this channel time ch1 rcbr1.0 1=force the rchblk pin high during this channel time tcbr1/tcbr2/tcbr3/tcbr4: transmit channel blocking registers (address=22 to 25 hex) (msb) (l sb) ch8 ch7 ch6 ch5 ch4 ch3 ch2 ch1 tcbr1 (22) ch16 ch15 ch14 ch13 ch12 ch11 ch10 ch9 tcbr2 (23) ch24 ch23 ch22 ch21 ch20 ch19 ch18 ch17 tcbr3 (24) ch32 ch31 ch30 ch29 ch28 ch27 ch26 ch25 tcbr4 (25) symbol position name and description ch32 tcbr4.7 transmit channel blocking registers. 0=force the tchblk pin to remain low during this channel time ch1 tcbr1.0 1=force the tchblk pin high during this channel time note: if ccr3.6=1, then a 0 in the tcbrs implies that signaling data is to be sourced from tser (or tsig if ccr3.2=1) and a 1 implies that signaling data for that channel is to be sourced from the transmit signaling (ts) registers. see definition below. tcbr1/tcbr2/tcbr3/tcbr4: definition when ccr3.6=1 (msb) (ls b) ch20 ch4 ch19 ch3 ch18 ch2 ch17* ch1* tcbr1 (22) ch24 ch8 ch23 ch7 ch22 ch6 ch21 ch5 tcbr2 (23) ch28 ch12 ch27 ch11 ch26 ch10 ch25 ch9 tcbr3 (24) ch32 ch16 ch31 ch15 ch30 ch14 ch29 ch13 tcbr4 (25) *=ch1 and ch17 should be set to 1 to allow the internal ts1 register to create the cas multiframe alignment word and spare/remote alarm bits.
DS2154 56 of 87 10.0 elastic stores operation the DS2154 contains dual two-frame (512 bits) elastic stores, one for the receive direction, and one for the transmit direction. these elastic stores have two main purposes. first, they can be used to rate-convert the e1 data stream to 1.544 mbps (or a multiple of 1.544 mbps) which is the t1 rate. secondly, they can be used to absorb the differences in frequency and phase between the e1 data stream and an asynchronous (i.e., not frequency locked) backplane clock which can be 1.544 mhz or 2.048 mhz. the backplane clock can burst at rates up to 8.192 mhz. both elastic stores contain full controlled slip capability which is necessary for this second purpose. the elastic stores can be forced to a known depth via the elastic store reset bit (ccr3.4). toggling the ccr3.4 bit forces the read and write pointers into opposite frames. both elastic stores within the DS2154 are fully independent and no restrictions apply to the sourcing of the various clocks that are applied to them. the transmit side elastic store can be enabled whether the receive elastic store is enabled or disabled and vice versa. also, each elastic store can interface to either a 1.544 mhz or 2.048 mhz backplane without regard to the backplane rate the other elastic store is interfacing. 10.1 receive side if the receive side elastic store is enabled (rcr2.1=1), then the user must provide either a 1.544 mhz (rcr2.2 =0) or 2.048 mhz (rcr2.2=1) clock at the rsysclk pin. the user has the option of either providing a frame/multiframe sync at the rsync pin (rcr1.5=1) or having the rsync pin provide a pulse on frame/multiframe boundaries (rcr1.5=0). if the user wishes to obtain pulses at the frame boundary, then rcr1.6 must be set to 0; if the user wishes to have pulses occur at the multiframe boundary, then rcr1.6 must be set to 1. the DS2154 will always indicate frame boundaries via the rfsync output whether the elastic store is enabled or not. if the elastic store is enabled, then either cas (rcr1.7=0) or crc4 (rcr1.7=1) multiframe boundaries will be indicated via the rmsync output. if the user selects to apply a 1.544 mhz clock to the rsysclk pin, then every fourth channel of the received e1 data will be deleted and an f-bit position (which will be forced to 1) will be inserted. hence channels 1, 5, 9, 13, 17, 21, 25, and 29 (timeslots 0, 4, 8, 12, 16, 20, 24, and 28) will be deleted from the received e1 data stream. also, in 1.544 mhz applications, the rchblk output will not be active in channels 25 through 32 (or in other words, rcbr4 is not active). see section 13 for timing details. if the 512-bit elastic buffer either fills or empties, a controlled slip will occur. if the buffer empties, then a full frame of data (256-bits) will be repeated at rser and the sr1.4 and rir.3 bits will be set to a 1. if the buffer fills, then a full frame of data will be deleted and the sr1.4 and rir.4 bits will be set to a 1. 10.2 transmit side the operation of the transmit elastic store is very similar to the receive side. the transmit side elastic store is enabled via ccr3.7. a 1.544 mhz (ccr3.1=0) or 2.048 mhz (ccr3.1=1) clock can be applied to the tsysclk input. the tsysclk can be a bursty clock with rates up to 8.192 mhz. if the user selects to apply a 1.544 mhz clock to the tsysclk pin, then the data sampled at tser will be stuffed with 8 empty channels. the user must supply an 8 khz frame sync pulse to the tssync input. see section 13 for timing details. controlled slips in the transmit elastic store are reported in the sr2.0 bit and the direction of the slip is reported in the rir.6 and rir.7 bits.
DS2154 57 of 87 11.0 additional (sa) and international (si) bit operation the DS2154 provides for access to both the sa and the si bits via three different methods. the first is via a hardware scheme using the rlink/rlclk and tlink/ tlclk pins. the first method is discussed in section 11.1. the second involves using the internal raf/rnaf and taf/tnaf registers and is discussed in section 11.2 the third method which is covered in section 11.3 involves an expanded version of the second method and is one of the features added to the DS2154 from the original ds2153 definition. 11.1 hardware scheme on the receive side, all of the received data is reported at the rlink pin. via rcr2, the user can control the rlclk pin to pulse during any combination of sa bits. this allows the user to create a clock that can be used to capture the needed sa bits. if rsync is programmed to output a frame boundary, it will identify the si bits. see section 13 for detailed timing. on the transmit side, the individual sa bits can be either sourced from the internal tnaf register (see section 11.2 for details) or from the external tlink pin. via tcr2, the DS2154 can be programmed to source any combination of the additional bits from the tlink pin. if the user wishes to pass the sa bits through the DS2154 without them being altered, then the device should be set up to source all five sa bits via the tlink pin and the tlink pin should be tied to the tser pin. si bits can be inserted through the tser pin via the clearing of the tcr1.3 bit. please see the timing diagrams and the transmit data flow diagram in section 13 for examples. 11.2 internal register scheme based on double-frame on the receive side, the raf and rnaf registers will always report the data as it received in the additional and international bit locations. the raf and rnaf registers are updated with the setting of the receive align frame bit in status register 2 (sr2.6). the host can use the sr2.6 bit to know when to read the raf and rnaf registers. it has 250 us to retrieve the data before it is lost. on the transmit side, data is sampled from the taf and tnaf registers with the setting of the transmit align frame bit in status register 2 (sr2.3). the host can use the sr2.3 bit to know when to update the taf and tnaf registers. it has 250 us to update the data or else the old data will be retransmitted. data in the si bit position will be overwritten if either the DS2154 is programmed: (1) to source the si bits from the tser pin, (2) in the crc4 mode, or (3) have automatic e-bit insertion enabled. data in the sa bit position will be overwritten if any of the tcr2.3 to tcr2.7 bits are set to 1 (please see section 11.1 for details). please see the register descriptions for tcr1 and tcr2 and the transmit data flow diagram in section 13 for more details.
DS2154 58 of 87 raf: receive align frame register (address=2f hex) (msb) (lsb) si001101 1 symbol position name and description si raf.7 international bit. 0raf.6 frame alignment signal bit. 0raf.5 frame alignment signal bit. 1raf.4 frame alignment signal bit. 1raf.3 frame alignment signal bit. 0raf.2 frame alignment signal bit. 1raf.1 frame alignment signal bit. 1raf.0 frame alignment signal bit. rnaf: receive non-align frame register (address=1f hex) (msb) (lsb) si 1 a sa4 sa5 sa6 sa7 sa8 symbol position name and description si rnaf.7 international bit. 1 rnaf.6 frame non-alignment signal bit. a rnaf.5 remote alarm. sa4 rnaf.4 additional bit 4. sa5 rnaf.3 additional bit 5. sa6 rnaf.2 additional bit 6. sa7 rnaf.1 additional bit 7. sa8 rnaf.0 additional bit 8.
DS2154 59 of 87 taf: transmit align frame register (address=20 hex) (msb) (lsb) si001101 1 [must be programmed with the 7-bit fas word; the DS2154 does not automatically set these bits] symbol position name and description si taf.7 international bit. 0taf.6 frame alignment signal bit. 0taf.5 frame alignment signal bit. 1taf.4 frame alignment signal bit. 1taf.3 frame alignment signal bit. 0taf.2 frame alignment signal bit. 1taf.1 frame alignment signal bit. 1taf.0 frame alignment signal bit. tnaf: transmit non-align frame register (address=21 hex) (msb) (lsb) si 1 a sa4 sa5 sa6 sa7 sa8 [bit 2 must be programmed to 1; the DS2154 does not automatically set this bit] symbol position name and description si tnaf.7 international bit. 1 tnaf.6 frame non-alignment signal bit. a tnaf.5 remote alarm (used to transmit the alarm). sa4 tnaf.4 additional bit 4. sa5 tnaf.3 additional bit 5. sa6 tnaf.2 additional bit 6. sa7 tnaf.1 additional bit 7. sa8 tnaf.0 additional bit 8.
DS2154 60 of 87 11.3 internal register scheme based on crc4 multiframe on the receive side, there is a set of eight registers (rsiaf, rsinaf, rra, rsa4 to rsa8) that report the si and sa bits as they are received. these registers are updated with the setting of the receive crc4 multiframe bit in status register 2 (sr2.1). the host can use the sr2.1 bit to know when to read these registers. the user has 2 ms to retrieve the data before it is lost. the msb of each register is the first received. please see the register descriptions below and the transmit data flow diagram in section 13 for more details. on the transmit side, there is also a set of eight registers (tsiaf, tsinaf, tra, tsa4 to tsa8) that can be programmed to insert both si and sa data via the transmit sa bit control register (tsacr). data is sampled from these registers with the setting of the transmit multiframe bit in status register 2 (sr2.5). the host can use the sr2.5 bit to know when to update these registers. it has 2 ms to update the data or else the old data will be retransmitted. the msb of each register is the first bit transmitted. please see the register descriptions below and the transmit data flow diagram in section 13 for more details. register name address (hex) function rsiaf 58 the 8 si bits in the align frame rsinaf 59 the 8 si bits in the non-align frame rra 5a the 8 reportings of the receive remote alarm (ra) rsa4 5b the 8 sa4 reported in each crc4 multiframe rsa5 5c the 8 sa5 reported in each crc4 multiframe rsa6 5d the 8 sa6 reported in each crc4 multiframe rsa7 5e the 8 sa7 reported in each crc4 multiframe rsa8 5f the eight sa8 reported in each crc4 multiframe tsiaf 50 the 8 si bits to be inserted into the align frame tsinaf 51 the 8 si bits to be inserted into the non-align frame tra 52 the 8 settings of remote alarm (ra) tsa4 53 the 8 sa4 settings in each crc4 multiframe tsa5 54 the 8 sa5 settings in each crc4 multiframe tsa6 55 the 8 sa6 settings in each crc4 multiframe tsa7 56 the 8 sa7 settings in each crc4 multiframe tsa8 57 the 8 sa8 settings in each crc4 multiframe
DS2154 61 of 87 tsacr: transmit sa bit control register (address=1c hex) (msb) (lsb) siaf sinaf ra sa4 sa5 sa6 sa7 sa8 symbol position name and description siaf tsacr.7 international bit in align frame insertion control bit. 0=do not insert data from the tsiaf register into the transmit data stream 1=insert data from the tsiaf register into the transmit data stream sinaf tsacr.6 international bit in non-align frame insertion control bit. 0=do not insert data from the tsinaf register into the transmit data stream 1=insert data from the tsinaf register into the transmit data stream ra tsacr.5 remote alarm insertion control bit. 0=do not insert data from the tra register into the transmit data stream 1=insert data from the tra register into the transmit data stream sa4 tsacr.4 additional bit 4 insertion control bit. 0=do not insert data from the tsa4 register into the transmit data stream 1=insert data from the tsa4 register into the transmit data stream sa5 tsacr.3 additional bit 5 insertion control bit. 0=do not insert data from the tsa5 register into the transmit data stream 1=insert data from the tsa5 register into the transmit data stream sa6 tsacr.2 additional bit 6 insertion control bit. 0=do not insert data from the tsa6 register into the transmit data stream 1=insert data from the tsa6 register into the transmit data stream sa7 tsacr.1 additional bit 7 insertion control bit. 0=do not insert data from the tsa7 register into the transmit data stream 1=insert data from the tsa7 register into the transmit data stream sa8 tsacr.0 additional bit 8 insertion control bit. 0=do not insert data from the tsa8 register into the transmit data stream 1=insert data from the tsa8 register into the transmit data stream
DS2154 62 of 87 12.0 line interface functions the line interface function in the DS2154 contains three sections: (1) the receiver which handles clock and data recovery; (2) the transmitter which waveshapes and drives the e1 line; and (3) the jitter attenuator. each of these three sections is controlled by the line interface control register (licr) which is described below. licr: line interface control register (address=18 hex) (msb) (lsb) l2 l1 l0 egl jas jabds dja tpd licr symbol position name and description l2 licr.7 line build out bit 2. transmit waveshape setting; see table 12-2. l1 licr.6 line build out bit 1. transmit waveshape setting; see table 12-2. l0 licr.5 line build out bit 0. transmit waveshape setting; see table 12-2. egl licr.4 receive equalizer gain limit. 0=-12 db 1=-43 db jas licr.3 jitter attenuator select. 0=place the jitter attenuator on the receive side 1=place the jitter attenuator on the transmit side jabds licr.2 jitter attenuator buffer depth select 0=128-bits 1=32-bits (use for delay sensitive applications) dja licr.1 disable jitter attenuator. 0=jitter attenuator enabled 1=jitter attenuator disabled tpd licr.0 transmit power down. 0=normal transmitter operation 1=powers down the transmitter and 3-states the ttip and tring pins 12.1 receive clock and data recovery the DS2154 contains a digital clock recovery system. see the DS2154 block diagram in section 1 and figure 12-1 for more details. the DS2154 couples to the receive e1 shielded twisted pair or coax via a 1:1 transformer. see table 12-3 for transformer details. the 2.048 mhz clock attached at the mclk pin is internally multiplied by 16 via an internal pll and fed to the clock recovery system. the clock recovery system uses the clock from the pll circuit to form a 16 times oversampler which is used to
DS2154 63 of 87 recover the clock and data. this oversampling technique offers outstanding jitter tolerance (see figure 12- 2).
DS2154 64 of 87 normally, the clock that is output at the rclko pin is the recovered clock from the e1 ami/hdb3 waveform presented at the rtip and rring inputs. when no ami signal is present at rtip and rring, a receive carrier loss (rcl) condition will occur and the rclko will be sourced from the clock applied at the mclk pin. if the jitter attenuator is either placed in the transmit path or is disabled, the rclko output can exhibit slightly shorter high cycles of the clock. this is due to the highly oversampled digital clock recovery circuitry. if the jitter attenuator is placed in the receive path (as is the case in most applications), the jitter attenuator restores the rclk to being close to 50% duty cycle. please see the receive ac timing characteristics in section 14 for more details. 12.2 transmit waveshaping and line driving the DS2154 uses a set of laser-trimmed delay lines along with a precision digital-to-analog converter (dac) to create the waveforms that are transmitted onto the e1 line. the waveforms created by the DS2154 meet the itu g.703 specifications. see figure 12-3. the user will select which waveform is to be generated by properly programming the l2/l1/l0 bits in the line interface control register (licr). the DS2154 can be set up in a number of various configurations depending on the application. see table 12-2 and figure 12-1. line build out select in licr table 12-2 lll 210 application transformer return loss rt (see figure 12-1) 000 75 ohms normal (see note 1) 1:1.15 step-up nm 0 ohms 001 120 ohms normal 1:1.15 step-up nm 0 ohms 010 75 ohms w/ protection resistors 1:1.15 step-up nm 8.2 ohms 011 120 ohms w/ protection resistors 1:1.15 step-up nm 8.2 ohms 100 75 ohms w/ high return loss 1:1.15 step-up 21db 27 ohms 110 75 ohms w/ high return loss 1:1.36 step-up 21db 18 ohms 100 120 ohms w/ high return loss 1:1.36 step-up 21db 27 ohms note: 1. this lbo is not recommended for use in the a2 revision of the DS2154. due to the nature of the design of the transmitter in the DS2154, very little jitter (less then 0.005 uipp broadband from 10 hz to 100 khz) is added to the jitter present on tclk. also, the waveforms that they create are independent of the duty cycle of tclk. the transmitter in the DS2154 couples to the e1 transmit shielded twisted pair or coax via a 1:1.15 or 1:1.36 step up transformer as shown in figure 12- 1. in order for the devices to create the proper waveforms, this transformer used must meet the specifications listed in table 12-3 the line driver in the DS2154 contains a current limiter that will prevent more than 50 ma (rms) from being sourced in a 1 ohm load. transformer specifications table 12-3 specification recommended value turns ratio 1:1 (receive) and 1:1.15 or 1:1.36 (transmit) 5% primary inductance 600 uh minimum leakage inductance 1.0 uh maximum intertwining capacitance 40 pf maximum dc resistance 1.2 ohms maximum
DS2154 65 of 87 12.3 jitter attenuator the DS2154 contains an onboard jitter attenuator that can be set to a depth of either 32 or 128 bits via the jabds bit in the line interface control register (licr). the 128-bit mode is used in applications where large excursions of wander are expected. the 32-bit mode is used in delay sensitive applications. the characteristics of the attenuation are shown in figure 12-4. the jitter attenuator can be placed in either the receive path or the transmit path by appropriately setting or clearing the jas bit in the licr. also, the jitter attenuator can be disabled (in effect, removed) by setting the dja bit in the licr. in order for the jitter attenuator to operate properly, a 2.048 mhz clock ( 50 ppm) must be applied at the mclk pin or a crystal with similar characteristics must be applied across the mclk and xtald pins. if a crystal is applied across the mclk and xtald pins, then capacitors should be placed from each leg of the crystal to ground as shown in figure 12-1. onboard circuitry adjusts either the recovered clock from the clock/data recovery block or the clock applied at the tclki pin to create a smooth jitter-free clock which is used to clock data out of the jitter attenuator fifo. it is acceptable to provide a gapped/bursty clock at the tclki pin if the jitter attenuator is placed on the transmit side. if the incoming jitter exceeds either 120 uipp (buffer depth is 128 bits) or 28 uipp (buffer depth is 32 bits), then the DS2154 will divide the internal nominal 32.768 mhz clock by either 15 or 17 instead of the normal 16 to keep the buffer from overflowing. when the device divides by either 15 or 17, it also sets the jitter attenuator limit trip (jalt) bit in the receive information register (rir.5). DS2154 external analog connections figure 12-1 notes: 1. all resistor values are 1%. 2. the rt resistors are used to increase the transmitter return loss or to protect the device from over? voltage. 3. the rr resistors are used to terminate the receive e1 line. 4. for 75-ohm termination, rr=37.5 ohms; for 120-ohm termination rr=60 ohm. 5. see the separate application note for details on how to construct a protected interface. 6. either a crystal can be applied across the mclk and xtald pins or a ttl level clock can be applied to just mclk. 7. c1 and c2 should be 5 pf lower than two times the nominal loading capacitance of the crystal to adjust for the input capacitance of the DS2154.
DS2154 66 of 87 DS2154 jitter tolerance figure 12-2 DS2154 transmit waveform template figure 12-3
DS2154 67 of 87 DS2154 jitter attenuation figure 12-4
DS2154 68 of 87 13.0 timing diagrams/sync flowchart/transmit data flow diagram receive side timing figure 13-1 notes: 1. rsync in the frame mode (rcr1.6=0). 2. rsync in the multiframe mode (rcr1.6=1). 3. rlclk is programmed to pulse high during the sa4 bit position. 4. rlink will always output all 5 sa bits as well as the rest of the receive data stream. 5. this diagram assumes the cas mf begins with the fas word.
DS2154 69 of 87 receive side boundary timing (with elastic store disabled) figure 13-2 notes: 1. rchblk is programmed to block channel 2. 2. rlclk is programmed to pulse high during the sa4 bits position. 3. shown is a non-align frame boundary. 4. rsig normally contains the cas multiframe alignment nibble (0000) in channel 1. receive side 1.544 mhz boundary timing (with elastic store enabled) figure 13-3 notes: 1. data from the e1 channels 1, 5, 9, 13, 17, 21, 25, and 29 is dropped (channel 2 from the e1 link is mapped to channel 1 of the t1 link, etc.) and the f-bit position is added (forced to 1). 2. rsync is in the output mode (rcr1.5=0). 3. rsync is in the input mode (rcr1.5=1). 4. rchblk is programmed to block channel 24.
DS2154 70 of 87 receive side 2.048 mhz boundary timing (with elastic store enabled) figure 13-4 notes: 1. rsync is in the output mode (rcr1.5=0). 2. rsync is in the input mode (rcr1.5=1). 3. rchblk is programmed to block channel 1. 4. rsig normally contains the cas multiframe alignment nibble (0000) in channel 1. transmit side timing figure 13-5 notes: 1. tsync in the frame mode (tcr1.1=0). 2. tsync in the multiframe mode (tcr1.1=1). 3. tlink is programmed to source only the sa4 bit. 4. this diagram assumes both the cas mf and the crc4 begin with the align frame.
DS2154 71 of 87 transmit side boundary timing figure 13-6 notes: 1. tsync is in the input mode (tcr1.0=0). 2. tsync is in the output mode (tcr1.0=1). 3. tchblk is programmed to block channel 2. 4. tlink is programmed to source the sa4 bits. 5. the signaling data at tsig during channel 1 is normally overwritten in the transmit formatter with the cas multiframe alignment nibble (0000). 6. shown is a non-align frame boundary. transmit side 1.544 mhz boundary timing (with elastic store enabled) figure 13-7 notes: 1. tchblk is programmed to block channel 23. 2. the f-bit position is ignored by the DS2154.
DS2154 72 of 87 transmit side 2.048 mhz (with elastic store enabled) figure 13-8 note: 1. tchblk is programmed to block channel 31. g.802 timing figure 13-9 note: 1. rchblk or tchblk is programmed to pulse high during timeslots 1 to 15, 17 to 25, and during bit 1 of timeslot 26.
DS2154 73 of 87 DS2154 synchronization flowchart figure 13-10
DS2154 74 of 87 DS2154 transmit data flow figure 13-11 notes: 1. tclk should be tied to rclk and tsync should be tied to rfsync for data to be properly sourced from rser. 2. auto remote alarm if enabled will only overwrite bit 3 of timeslot 0 in the non align frames if the alarm needs to be sent.
DS2154 75 of 87 14.0 a. c. and d. c. characteristics absolute maximum ratings* voltage on any pin relative to ground ......................................................................................... ............. ............................................................................................................................... ............................ -1.0v to +7.0v operating temperature for DS2154l ............................................................................................. ............. ............................................................................................................................... ............................ 0c to 70c operating temperature for DS2154ln ............................................................................................ ........... ............................................................................................................................... ............................ -40c to +85c storage temperature ........................................................................................................... ......................... ............................................................................................................................... ............................ ............................................................................................................................... ............................ ............................................................................................................................... . -55c to +125c soldering temperature ......................................................................................................... ........................ ............................................................................................................................... ............................ ............................................................................................................................... ............................ 260c for 10 seconds * this is a stress rating only and functional operation of the device at these or any other conditions above those indicated in the operation sections of this specification is not implied. exposure to absolute maximum rating conditions for extended periods of time may affect reliability. recommended dc (0 c to 70 c for DS2154l; operating conditions -40 c to +85 c for DS2154ln) parameter symbol min typ max units notes logic 1 v ih 2.0 v dd +0.3 v logic 0 v il -0.3 +0.8 v supply v dd 4.75 5.25 v 1 capacitance (t a =25 c) parameter symbol min typ max units notes input capacitance c in 5pf output capacitance c out 7pf (0 c to 70 c; v dd =5v = 5% for DS2154l; dc characteristics -40 c to +85 c; v dd =5v = 5% for DS2154ln) parameter symbol min typ max units notes supply current @ 5v i dd 75 ma 2 input leakage i il -1.0 +1.0 a 3 output leakage i lo 1.0 a 4 output current (2.4v) i oh -1.0 ma
DS2154 76 of 87 output current (0.4v) i ol +4.0 ma notes: 1. applies to rvdd, tvdd, and dvdd. 2. tclk=rclk=tsysclk=rsysclk=2.048 mhz; outputs open circuited. 3. 0.0v < v in < v dd . 4. applied to int when 3-stated.
DS2154 77 of 87 ac characteristics - multiplexed parallel (0 c to 70 c; v dd =5v = 5% for DS2154l; port (mux=1) -40 c to +85 c; v dd =5v = 5% for DS2154ln) parameter symbol min typ max units notes cycle time t cyc 200 ns pulse width, ds low or rd high pw el 100 ns pulse width, ds high or rd low pw eh 100 ns input rise/fall times t r , t f 20 ns r/ w hold times t rwh 10 ns r/ w set up time before ds high t rws 50 ns cs set up time before ds, wr , or rd active t cs 20 ns cs hold time t ch 0ns read data hold time t dhr 10 50 ns write data hold time t dhw 0ns muxed address valid to as or ale fall t asl 15 ns muxed address hold time t ahl 10 ns delay time ds, wr or rd to as or ale rise t asd 20 ns pulse width as or ale high pw ash 30 ns delay time, as or ale to ds, wr or rd t ased 10 ns output data delay time from ds or rd t ddr 20 80 ns data set up time t dsw 50 ns see figures 14-1 to 14-3 for details.
DS2154 78 of 87 ac characteristics - (0 c to 70 c; v dd =5v = 5% for DS2154l; receive side -40 c to +85 c; v dd =5v = 5% for DS2154ln) parameter symbol min typ max units notes rclko period t lp 488 ns rclko pulse width t lh t ll 200 200 244 244 ns ns 1 1 rclko pulse width t lh t cl 150 150 244 244 ns ns 2 2 rclki period t cp 488 ns rclki pulse width t ch t cl 75 75 ns ns rsysclk period t sp t sp 122 122 648 488 ns ns 3 4 rsysclk pulse width t sh t sl 50 50 ns ns rsync set up to rsysclk falling t su 20 t sh -5 ns rsync pulse width t pw 50 ns rposi/rnegi set up to rclki falling t su 20 ns rposi/rnegi hold from rclki falling t hd 20 ns rsysclk/rclki rise and fall times t r , t f 25 ns delay rclko to rposo, rnego valid t dd 50 ns delay rclk to rser, rdata, rsig, rlink valid t d1 50 ns delay rclk to rchclk, rsync, rchblk, rfsync, rlclk t d2 50 ns delay rsysclk to rser, rsig valid t d3 50 ns delay rsysclk to rchclk, rchblk, rmsync, rsync t d4 50 ns see figures 14-4 to 14-6 for details. notes: 1. jitter attenuator enabled in the receive path. 2. jitter attenuator disabled or enabled in the transmit path. 3. rsysclk=1.544 mhz. 4. rsysclk=2.048 mhz.
DS2154 79 of 87 intel bus read ac timing (bts=0/mux=1) figure 14-1 intel bus write ac timing (bts=0/mux=1) figure 14-2
DS2154 80 of 87 motorola bus ac timing (bts=1/mux=1) figure 14-3 receive side ac timing figure 14-4 notes: 1. rsync is in the output mode (rcr1.5=0). 2. rlclk will only pulse high during sa bit locations as defined in rcr2; no relationship between rlclk and rsync or rfsync is implied.
DS2154 81 of 87 ac characteristics - (0 c to 70 c; v dd =5v = 5% for DS2154l; transmit side -40 c to +85 c; v dd =5v = 5% for DS2154ln) parameter symbol min typ max units notes tclk period t cp 488 ns tclk pulse width t ch t cl 75 75 ns ns tclki period t lp 488 ns tclki pulse width t lh t ll 75 75 ns tsysclk period t sp t sp 122 122 648 448 ns ns 1 2 tsysclk pulse width t sh t sl 50 50 ns ns tsync or tssync set up totclk or tsysclk falling t su 20 t ch -5 or t sh -5 ns tsync or tssync pulse width t pw 50 ns tser, tsig, tdata, tlink, tposi, tnegi set up to tclk, tsysclk, tclki falling t su 20 ns tser, tsig, tdata, tlink, tposi, tnegi hold from tclk, tsysclk, tclki falling t hd 20 ns tclk, tclki, or tsysclk rise and fall times t r , t f 25 ns delay tclko to tposo, tnego valid t dd 50 ns delay tclk to teso valid t d1 50 ns delay tclk to tchblk, tchblk, tsync, tlclk t d2 50 ns delay tsysclk to tchclk, tchblk t d3 75 ns see figures 14-7 to 14-9 for details. notes: 1. tsysclk=1.544 mhz. 2. tsysclk=2.048 mhz.
DS2154 82 of 87 receive system side ac timing figure 14-5 notes: 1. rsync is in the output mode (rcr1.5=0). 2. rsync is in the input mode (rcr1.5=1). receive line interface ac timing figure 14-6
DS2154 83 of 87 transmit side ac timing figure 14-7 notes: 1. tsync is in the output mode (tcr1.0=1). 2. tsync is in the input mode (tcr1.0=0). 3. tser is sampled on the falling edge of tclk when the transmit side elastic store is disabled. 4. tchclk and tchblk are synchronous with tclk when the transmit side elastic store is disabled. 5. tlink is only sampled during sa bit locations as defined in tcr2; no relationship between tlclk/tlink and tsync is implied.
DS2154 84 of 87 transmit system side ac timing figure 14-8 notes: 1. tser is only sampled on the falling edge of tsysclk when the transmit side elastic store is enabled. 2. tchclk and tchblk are synchronous with tsysclk when the transmit side elastic store is enabled. transmit line interface side ac timing figure 14-9
DS2154 85 of 87 ac characteristics - non-multiplexed parallel (0 c to 70 c; v dd =5v = 5% for DS2154t; port (mux=0) -40 c to +85 c; v dd =5v = 5% for DS2154tn) parameter symbol min typ max units notes set up time for a0 to a7 valid to cs active t1 0 ns set up time for cs active to either rd , wr , or ds active t2 0 ns delay time from either rd or ds active to data valid t3 75 ns hold time from either rd , wr , or ds inactive to cs inactive t4 0 ns hold time from cs inactive to data bus 3-state t5 5 20 ns wait time from either wr or ds active to latch data t6 75 ns data set up time to either wr or ds inactive t7 10 ns data hold time from either wr or ds inactive t8 10 ns address hold from either wr or ds inactive t 9 10 ns see figures 14-10 to 14-13 for details. intel bus read ac timing (bts=0/mux=0) figure 14-10
DS2154 86 of 87 intel bus write ac timing (bts=0/mux=0) figure 14-11 motorola bus read ac timing (bts=1/mux=0) figure 14-12 motorola bus write ac timing (bts=1/mux=0) figure 14-13
DS2154 87 of 87 DS2154 100-pin lqfp pkg 100-pin dim min max a -1.60 a1 0.05 - a2 1.35 1.45 b 0.17 0.27 c 0.09 0.20 d 15.80 16.20 d1 14.00 bsc e 15.80 16.20 e1 14.00 bsc e 0.50 bsc l 0.45 0.75 detail a

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