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 data” via the DS3 payload bits.

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 transmission, 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

APPLICATIONS
• Private User Network Interfaces
• ATM Switches
• ATM Concentrators
• DSLAM Equipment
• DS3 Frame Relay Equipment