XRT72L71 Datasheet, PDF (1/102 Pages) Exar Corporation – DS3 ATM UNI/CLEAR CHANNEL FRAMER

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XRT72L71
AUGUST 2002
GENERAL DESCRIPTION
The XRT72L71 DS3 ATM User Network Interface
(UNI)/Clear-Channel Framer is designed to function
as either a DS3 ATM UNI or Clear channel framer.
For ATM UNI applications, this device provides the
ATM Physical Layer (Physical Medium Dependent
and Transmission Convergence sub-layers) interface
for both the public and private networks at DS3 rates.
For Clear-Channel framer applications, this device
supports the transmission and reception of “user da-
ta” via the DS3 payload bits.
The XRT72L71incorporates Receive, Transmit, Micro-
processor Interface, Performance Monitor, Test and Di-
agnostic and Line Interface Unit Scan Drive sections.
APPLICATIONS
• Private User Network Interfaces
• ATM Switches
• ATM Concentrators
• DSLAM Equipment
• DS3 Frame Relay Equipment
DS3 ATM UNI/CLEAR CHANNEL FRAMER
REV. 1.1.0
FEATURES
• Compliant with UTOPIA Level 1 and 2 with 8 or 16
Bit Interface Specification and supports UTOPIA
Bus speeds of up to 50 MHz
• Contains on-chip 16 cell FIFO in both the Transmit
(TxFIFO) and Receive Directions (RxFIFO)
• Contains on-chip 54 byte Transmit OAM Cell buffer
and a 108 byte Receive OAM cell buffer, for trans-
mission, reception and processing of OAM cells.
• Supports PLCP or ATM Direct Mapping modes
• Supports M13 and C-Bit Parity Framing Formats
• Supports DS3 Clear Channel Framing Applications
• Includes PRBS Generator and Receiver
• Supports Local, Remote-Line, Cell, and PLCP
Loop-backs
• Interfaces to 8 or 16 Bit wide Motorola and Intel µPs
• Low power 3.3V, 5V input tolerant, CMOS
• 160 pin PQFP Package
• 3 and 4 Channel Version also Available
FIGURE 1. XRT72L71 SIMPLIFIED BLOCK DIAGRAM WITH SYSTEM INTERFACES
UTOPIA BUS
Level 1 or 2
ATM
Layer
Processor
TxUClav
16
Address ⁵
XRT72L71
Tx
UTOPIA
Interface
Tx
Cell
Processor
Tx
PLCP
Processor
Performance
Monitor
FEAC
Processor
LAPD
Transceiver
Microprocessor
Interface
Tx
DS3
Framer
LIU
Interface
Drive
and
Scan
Address ₅
16
RxUClav
Rx
UTOPIA
Interface
Rx
Cell
Processor
Rx
PLCP
Processor
Rx
DS3
Framer
ATM Switch
25, 33 or 50 MHz
D[15:0]
D[7:0]
A[8:0]
WR_RW
4 ALE_AS
RD_DS
RDY_DTCK
Intel/Motorola µP
Configuration, Control and Status Monitor
TxPOS
TxNEG
TCK
DMO
RLOS
RLOL
XRT73L00
TPDATA
TNDATA Tx
TCK
DMO
RLOS
RLOL
LLOOP
RLOOP
TAOS
TxLEV
EncoDis
Req
LLB
RLB
TAOS
TxLEV
ENCODIS
ReQDIS
RxPOS
RxNEG
RxLineClk
RPOS
RNEG Rx
RCLK1
DS3/E3 LIU
75Ω coax
DS3
44.736 MHz
75Ω coax
Exar Corporation 48720 Kato Road, Fremont CA, 94538 • [phone] • FAX [phone] • www.exar.com