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XRT72L52
TWO CHANNEL DS3/E3 FRAMER IC WITH HDLC CONTROLLER
FEBRUARY 2005
REV. 1.0.1
the local terminal equipment to receive data from re-
mote terminal equipment.
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. Fur-
ther, the Framer is also designed to receive an in-
bound DS3/E3 Data Stream from the Remote Termi-
nal Equipment and extract out the user data.
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 regis-
ters that contain cumulative and one-second statistics
that reflect the performance/health of the Framer IC/
The XRT72L52 DS3/E3 Framer device is designed to
support full-duplex data flow between Terminal Equip- system.
ment and an LIU (Line Interface Unit) IC. The Framer
FEATURES
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.
• 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.
The XRT72L52 DS3/E3 Framer IC consists of a
Transmit section, Receiver section, Performance
Monitor Section and a Microprocessor interface.
• 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
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 Equip-
ment to transmit data to a remote terminal.
APPLICATIONS
• Network Interface Units
• CSU/DSU Equipment.
• PCM Test Equipment
• Fiber Optic Terminals
• DS3/E3 Frame Relay Equipment
The Receive Section consists of a Receive LIU Inter-
face, a Receive DS3/E3 Framer, a Receive HDLC
Controller, a Receive Payload Data Output Interface,
and a Receive Overhead Data Interface which allows
FIGURE 1. BLOCK DIAGRAM OF THE XRT72L52
TRST
TestMode
NibbleIntf
Typical Channel n
Where n = 0 or 1
TxOHInd[n:0]
TxNibFrame[n:0]
TxFrame[n:0]
TxNibClk[n:0]
TxLnClk[n:0]
TxFrameRef[n:0]
TxNib[n:0]
TxOHEnable
TxOHClk
TxOHFrame
TxAISEn
TxOH
T3/E3
Transmit
Overhead
Interface
T3/E3
transmit
Input
HDLC
controller
T3/E3 Transmit
Framer
TxOHIns
TxSer[n:0]
TxLineClk[n:0]
TxPOS[n:0]
TxNEG[n:0]
A(11:0)
D(7:0)
ALE_AS
WR_R/W
CS
RDY_DTCK
Reset
INT
LIU
Interface/
Controller
T3 FEAC & Data
Link Controller
Performance
Monitor
Interrupt
Controller
uP
Interface
RxLineClk[n:0]
RxPOS[n:0]
RxNEG[n:0]
ExtLOS
MOTO
RD_DS
RxClk[n:0]
RxOHEnable[n:0]
RxOHClk[n:0]
RxOH[n:0]
RxRed[n:0]
RxOHFrame[n:0]
RxOOF[n:0]
RxOHind[n:0]
RxFrame[n:0]
RxNib[n:0]
RxSer[n:0]
RxOUTClk[n:0]
T3/E3 Receive
Framer
T3/E3
Receive
Output
T3/E3
Receive
Overhead
Interface
HDLC
controller
Exar Corporation 48720 Kato Road, Fremont CA, 94538 • (510) 668-7000 • FAX (510) 668-7017 • www.exar.com