XRT72L50 Datasheet, PDF (1/471 Pages) Exar Corporation – SINGLE CHANNEL DS3/E3 FRAMER IC WITH HDLC CONTROLLER

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XRT72L50
OCTOBER 2003
SINGLE CHANNEL DS3/E3 FRAMER IC WITH HDLC CONTROLLER
REV. 1.2.1
GENERAL DESCRIPTION
The XRT72L50, single 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 IC 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 XRT72L50 DS3/E3 Framer device is designed to
support full-duplex data flow between Terminal Equip-
ment 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 XRT72L50 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 In-
terface Block which permits the Terminal Equipment
to transmit data to a remote terminal.
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
the local terminal equipment to receive data from re-
mote 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 regis-
ters 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 100 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 XRT72L50
TRST
T es tM ode
NibIntf
T xO H E n able
T xO H C lk
T xO H F ra m e
T xA I S E n
T xO H
T xO H Ins
T xL ine C l k
T xP O S
T xN E G
RxLineClk
RxPOS
RxNEG
E xtLO S
RxOHEnable
R xO H C lk
RxOH
RxRed
RxOHFram e
RxOOF
T3/E3
Transm it
Overhead
Interface
LIU
Interface/
Controller
T3/E3
Receive
Overhead
Interface
T3/E3 Transmit
Fram er
T3/E3
transm it
Input
T3 FEAC & Data
Link Controller
Perform ance
Monitor
Interrupt
Controller
T3/E3 Receive
Fram er
T3/E3
Receive
Output
HDLC
controller
µP
Interface
HDLC
controller
T xO H Ind
T xN ibF ra m e
TxFram e
T xN ibC lk
T xL nC lk
TxFram eRef
T xN ib
T xS e r
A[8:0]
D[7:0]
ALE_AS
W R_R/W
CS
RDY_DTCK
Reset
Int
MOTO
RD_DS
R xC lk
RxOHind
RxFram e
R xN ib
RxSer
R xO utC lk
Exar Corporation 48720 Kato Road, Fremont CA, 94538 • [phone] • FAX [phone] • www.exar.com