
PMC-Sierra,Inc.
Quad T1 Framer
PM4344
TQUAD
FEATURES
• Monolithic single-chip device that 
integrates four full-f eatured T1 framer s 
and transmitters for term inatin g duple x 
DS1 signals.
• Supports SF, ESF, T1DM (DDS), and 
SLC®96 format DS1 signals.
• Supports unframed mode. Supports  
B8ZS or AMI line codes.
• Supports transfer of PCM and 
signalling data to/from 1.544 Mbit/s, 
2.048 Mbit/s, 12.352 Mbit/s, or 
16.384 Mbit/s backplane buses.
• Supports n x DS0 backplane interface 
for fractional T1.
• Provides robbed-bit signalling 
extraction/insertion , programmable idle 
and digital milliwatt code substitution, 
and two superframes of signalling 
debounce on a per-channel basis.
• Provides trunk conditioning which 
forces programmable trouble code 
substitution and s ignal ling c ondit ioning  
on all/selected channels.
• Provides ESF bit-oriented code 
detection/generation, and an HDLC 
ANSI specifications. Accum ula tors are 
provided for counting, ESF CRC-6 
errors, Framing bit errors, Line Code 
Violations (LCVs), and Loss Of Frame 
(LOF) or change of frame alignment 
events.
• Extracts the data link in ESF, T1DM 
(DDS), or SLC®96 modes. Extracts 
selected channels.
• Provides a 2-frame elastic store buffer 
for jitter and wander attenuation.
TRANSMIT SECTION
• Optionally accepts/provides dual-rail 
digital PCM inputs/outputs.
• Provides per-channel minimum ones 
density through Bell (bit 7), GTE, DDS, 
or “jammed bit 8" (56 Kbit/s) zero code 
suppression.
• Detects violations of the ANSI T1.403 
12.5% pulse density rule over a 
moving 192-bit window.
• Allows insertion of framed or unframed in-band loopback code 
sequences.
• Allows insertion of a data link in ESF, 
T1DM (DDS) or SLC
®
96 modes.
• Allows insertion of selected channels 
through a serial port.
• Supports transmission of the AIS or 
the yellow alarm signal in all formats.
• Provides a digital PL L for generat ion of 
a low jitter transmit clock.
• Provides a FIFO buffer for jitter 
attenuation and transmit rate 
conversion. FIFO full or empty 
indication allows for bit-stuffing in 
higher rate multiplexing applications.
APPLICATIONS
• T1/T3 Multiplexers and Digi tal Private  
Branch Exchanges (PBXs)
• T1 Frame Relay Interfaces
• T1 ATM Interfaces
• Fractional T1 Interfaces
• Digital Access and Cross-Connect 
Systems (DACS) and Electronic DSX 
Cross-Connect Systems (EDSXs)
• Digital Loop Carriers (DLCs)
• T1 Channel Service Units (CSUs) and 
Data Service Units (DSUs)
• ISDN Primary Rate Interfaces (PRIs)
• SONET Add/Drop Multiplexers (ADMs)
interface for terminating/g enerating the 
ESF data link.
• Software and functionally compatible 
with the PM4341A T1XC Single T1 
Transceiver. Pin-compatible with the 
PM6344 EQUAD Quad E1 Framer.
• Provides an 8-bit microprocessor bus 
interface for config uration , contro l, a nd 
status monitoring.
• Low power 5 V CMOS technology.
• Available in a rectangular 128-pin 
PQFP (14 by 20 mm) package.
RECEIVE SECTION
• Recovers clock an d data usi ng a digital 
PLL for high jitter tolerance.
• Accepts/provides dual- or single-rail 
digital PCM inputs/output s. Acc epts 
gapped data stream s to supp ort higher 
rate demultiplexing.
• Provides Loss Of Signal (LOS) 
detection, and red, yellow, and Alarm 
Indication Signal (AIS) alarm detection.
• Detects violations of the ANSI T1.403 
12.5% pulse density rule over a 
moving 192-bit window.
• Provides programmable in-band 
loopback code detecti on .
• Supports line and path performan ce  
monitoring according to AT&T and 
PMC-941030 (R7)   1998 PMC-Sierra, Inc. October, 1998
BLOCK DIAGRAM 
TCLK1[1:4]
BTPCM/
BTDP[1:4]/MTD*
BTSIG/BTDN[1:4] 
BTFP[1:4]/MTFP*
BTCLK[1:4]/
MTCLK*
BRCLK*/MRCLK*
BRFPI*/MRFPI*
MENB*
XCLK/VCLK*
RCLK[1:4]
RDP/RDD[1:4]
RDN/RLCV[1:4]
A[9:0]*
RDB*
WRB*
CSB*
ALE*
INTB*
RSTB*
D[7:0]*
Internal
Bus
BTIF 
Backplane 
Transmit 
Interface
Enforcer
DRIF
DS-1
Receive 
Interface
MPIF 
Micro-
processor
Interface
XPDE 
Pulse
Density 
XBAS
Basic Transmitter: 
Frame Generation, 
Alarm Insertion, 
Trunk Conditioning, 
Line Coding
TPSC
Per-channel 
Controller: 
Signal, Idle, 
Zero Control
XBOC
Bit-oriented 
Code 
Generator
CDRC
Clock and 
Data
Recovery
IBCD
In-band
Loopback 
Code
Detector
PDVD
Pulse
Density
Violation 
Detector
* These signals are shared between all four framers.
XIBC
In-band 
Loopback 
Code 
Generator
XFDL 
HDLC
Transmitter
PMON
Performance
Monitor 
Counters
FRMR
Framer: 
Frame 
Alignment, 
Alarm
Extraction
ALMI
Alarm
Integrator
RBOC
Bit-oriented 
Code
Detector
DJAT
Digital Jitt e r
Attenuator
ELST
Elastic
Store
FRAM 
Framer/Slip 
Buffer RAM
RFDL
HDLC 
Receiver
Transmitter
TOPS
Timing
Options
SIGX
Signalling 
Extractor
RPSC
Per-channel 
Controller: Trunk 
Conditioning
DTIF
Digital 
Transmit 
Interface
Receiver
BRIF
Backplane 
Receive
Interface
TCLKO[1:4] 
TDP/TDD[1:4] 
TDN/TFLG[1:4]
TDLCLK/TDLUDR[1:4] 
TDLSIG/TDLINT[1:4]
BRPCM/BRDP[1:4] 
BRSIG/BRDN[1:4]
BRFPO[1:4] 
MRD* 
RCLKO[1:4]
RFP[1:4]
RDLSIG/ 
RDLINT[1:4]
RDLCLK/ 
RDLEOM[1:4]

Quad T1 Framer
TYPICAL APPLICATIONS
FULLY CHANNELIZED HDLC APPLICATION
 PM4344 TQUAD
Processor
PM4314
4
QDSX 
Quad 
T1/E1 LIU
PM4344
TQUAD
Quad 
T1 Framer
PM6344
EQUAD
Quad
E1 Framer
STRUCTURED/UNSTRUCTURED T1 AAL1 OCTAL PORT CARD
PM4314
4
4
QDSX 
Quad 
T1/E1 LIU
PM4314
QDSX 
Quad 
T1/E1 LIU
PM4344
TQUAD
Quad 
T1 Framer
PM4344
TQUAD
Quad 
T1 Framer
PM7366
FREEDM-8™ 
Frame Engine and Datalink 
Manager
PM73121
AAL1gator II™
AAL1 
SAR Processor
PCI Bus
Packet 
Memory
Head Office: 
PMC-Sierra, Inc. 
#105 - 8555 Baxter Place 
Burnaby, B.C. V5A 4V7 
Canada 
Tel: 604.415.6000 
Fax: 604.415.6200
To order documentation, 
send email to: 
document@pmc-sierra.com 
or contact the head office, 
Attn: Document Coordinator
All product documentation is 
available on our web site at: 
http://www.pmc-sierra.com 
For corpo rate information, 
send email to: 
info@pmc-sierra.com
UTOPIA Bus
PMC-941030 (R7) 
 1998 PMC-Sierra, Inc. 
October, 1998 
AAL1gator II and FREEDM-8 are 
trademarks of PMC-Sierra, Inc.
®
96 is a registered trademark 
SLC 
of AT&T.