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Exar Corporation 48720 Kato Road, Fremont CA, 94538 (510) 668-7000 FAX (510) 668-7017 www.exar.com
PRELIMINARY
XRT79L71
1-CHANNEL DS3/E3 CLEAR-CHANNEL FRAMERLIU COMBO - CC/HDLC ARCHITECTURE
OCTOBER 2010
REV. P2.0.0
GENERAL DESCRIPTION
The XRT79L71 is a single channel, integrated DS3/
E3 framing controller and Line Interface Unit with Jit-
ter Attenuator that is designed to support Frame pro-
cessing. For Clear-Channel Framer applications, this
device supports the transmission and reception of
“user data” via the DS3/E3 payload.
The
XRT79L71
includes
DS3/E3
Framing,
Line
Interface Unit with Jitter Attenuator that supports
mapping of HDLC framed data. A flexible parallel
microprocessor interface is provided for configuration
and control.
GENERAL FEATURES:
Integrated T3/E3 Line Interface Unit
Integrated Jitter Attenuator that can be selected
either in Receive or Transmit path
HDLC Controller that provides the mapping/
extraction
of
either
bit
or
byte
mapped
encapsulated packet from DS3/E3 Frame.
Contains on-chip 16 cell FIFO (configurable in
depths of 4, 8, 12 or 16 cells), in both the Transmit
(TxFIFO) and Receive Directions (RxFIFO)
Contains on-chip 54 byte Transmit and Receive
OAM Cell Buffer for transmission, reception and
processing of OAM Cells
Supports M13 and C-Bit Parity Framing Formats
Supports DS3/E3 Clear-Channel Framing.
Includes PRBS Generator and Receiver
Supports Line, Cell, and PLCP Loop-backs
Interfaces to 8 Bit wide Intel, Motorola, PowerPC,
and Mips Ps
Low power 3.3V, 5V Input Tolerant, CMOS
Available in 208 STBGA Package
JTAG Interface
LINE INTERFACE UNIT
On chip Clock and Data Recovery circuit for high
input jitter tolerance
Meets E3/DS3 Jitter Tolerance Requirements
Detects and Clears LOS as per G.775.
Receiver Monitor mode handles up to 20 dB flat
loss with 6 dB cable attenuation
Compliant with jitter transfer template outlined in
ITU G.751, G.752, G.755 and GR-499-CORE,1995
standards
Meets ETSI TBR 24 and GR-499 Jitter Transfer
Requirements
On chip B3ZS/HDB3 encoder and decoder that can
be either enabled or disabled
On-chip clock synthesizer provides the appropriate
rate clock from a single 12.288 MHz Clock
On chip advanced crystal-less Jitter Attenuator
Jitter Attenuator can be selected in Receive or
Transmit paths
16 or 32 bits selectable FIFO size
Meets the Jitter and Wander specifications
described in T1.105.03b,ETSI TBR-24, Bellcore
GR-253 and GR-499 standards
Jitter Attenuator can be disabled
Typical power consumption 1.3W
DS3/E3 FRAMER
DS3 framer supports both M13 and C-bit parity.
DS3 framer meets ANSI T1.107 and T1.404
standards.
Detects OOF,LOF,AIS,RDI/FERF alarms.
Generation and Insertion of FEBE on received
parity errors supported.
Automatic insertion of RDI/FERF on alarm status.
E3 framer meets G.832,G.751 standards.
Framers can be bypassed.
Maps HDLC data stream directly into DS3 or E3
frame
Extracts in-band messaging packets
Supports CRC-16/32, HDLC flag and Idle
sequence generation
RECEIVE PACKET PROCESSING
Extracts HDLC data stream from DS3 or E3 frame
Inserts in-band messaging packets
Detects and removes HDLC flags
SERIAL INTERFACE
Serial clock and data interface for accessing DS3/
E3 framer