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Exar Corporation 48720 Kato Road, Fremont CA, 94538 (510) 668-7000 FAX (510) 668-7017 www.exar.com
XRT72L52
TWO CHANNEL DS3/E3 FRAMER IC WITH HDLC CONTROLLER
OCTOBER 2006
REV. 1.0.3
GENERAL DESCRIPTION
The XRT72L52, Two Channel DS3/E3 Framer IC is
designed to accept user data from the Terminal
Equipment and insert this data into the payload bit-
fields within an outbound DS3/E3 Data Stream.
Further, the Framer is also designed to receive an
inbound DS3/E3 Data Stream from the Remote
Terminal Equipment and extract out the user data.
The XRT72L52 DS3/E3 Framer device is designed to
support full-duplex data flow between Terminal
Equipment and an LIU (Line Interface Unit) IC. The
Framer Device will transmit, receive and process data
in the DS3-C-bit Parity, DS3-M13, E3-ITU-T G.751
and E3-ITU-T G.832 Framing Formats.
The XRT72L52 DS3/E3 Framer IC consists of a
Transmit section, Receiver section, Performance
Monitor Section and a Microprocessor interface.
The Transmit Section includes a Transmit Payload
Data Input Interface, a Transmit Overhead data Input
Interface Section, a Transmit HDLC Controller, a
Transmit DS3/E3 Framer block and a Transmit LIU
Interface
Block
which
permits
the
Terminal
Equipment to transmit data to a remote terminal.
The Receive Section consists of a Receive LIU
Interface, a Receive DS3/E3 Framer, a Receive
HDLC Controller, a Receive Payload Data Output
Interface, and a Receive Overhead Data Interface
which allows the local terminal equipment to receive
data from remote terminal equipment.
The Microprocessor Interface is used to configure the
Framer IC in different operating modes and monitor
the performance of the Framer.
The Performance Monitor Sections consist of a large
number
of
Reset-upon-Read
and
Read-Only
registers that contain cumulative and one-second
statistics that reflect the performance/health of the
Framer IC/system.
FEATURES
Transmits, Receives and Processes data in the
DS3-C-bit Parity, DS3-M13, E3-ITU-T G.751 and
E3-ITU-T G.832 Framing Formats.
1 Channel HDLC Controller - Tx and Rx
Interfaces to all Popular Microprocessors
Integrated Framer Performance Monitor
Available in a 160 Pin PQFP package
3.3V Power Supply with 5V Tolerant I/O
Operating Temperature -40°C to +85°C
APPLICATIONS
Network Interface Units
CSU/DSU Equipment.
PCM Test Equipment
Fiber Optic Terminals
DS3/E3 Frame Relay Equipment
FIGURE 1. BLOCK DIAGRAM OF THE XRT72L52
T3/E3 Transmit
Framer
T3 FEAC & Data
Link Controller
T3/E3 Receive
Framer
Performance
Monitor
Interrupt
Controller
TxOHInd[n:0]
TxNibFrame[n:0]
TxFrame[n:0]
TxNibClk[n:0]
TxLnClk[n:0]
TxFrameRef[n:0]
TxNib[n:0]
TxSer[n:0]
T3/E3
transmit
Input
RxClk[n:0]
RxOHind[n:0]
RxFrame[n:0]
RxNib[n:0]
RxSer[n:0]
RxOUTClk[n:0]
T3/E3
Receive
Output
uP
Interface
Typical Channel n
Where n = 0 or 1
TxLineClk[n:0]
TxPOS[n:0]
TxNEG[n:0]
RxLineClk[n:0]
RxPOS[n:0]
RxNEG[n:0]
ExtLOS
LIU
Interface/
Controller
TxOHEnable
TxOHClk
TxOHFrame
TxAISEn
TxOH
TxOHIns
T3/E3
Transmit
Overhead
Interface
RxOHEnable[n:0]
RxOHClk[n:0]
RxOH[n:0]
RxRed[n:0]
RxOHFrame[n:0]
RxOOF[n:0]
T3/E3
Receive
Overhead
Interface
HDLC
controller
HDLC
controller
TRST
TestMode
NibbleIntf
A(11:0)
D(7:0)
ALE_AS
WR_R/W
CS
RDY_DTCK
Reset
INT
MOTO
RD_DS