HARDWARE MANUAL
The XRT79L72 is a two channel, ATM UNI/PPP Physical Layer Processor with integrated DS3/E3 framing controllers and Line Interface Units with Jitter Attenuators that are designed to support ATM direct mapping and cell delineation as well as PPP mapping and Frame processing. For ATM UNI applications, this device provides the ATM Physical Layer (Physical Medium Dependent and Transmission Convergence sub-layers) interface for the public and private networks at DS3/E3 rates. For Clear-Channel Framer applications, this device supports the transmission and reception of “user data” via the DS3/E3 payload.

GENERAL FEATURES:
• Integrated T3/E3 Line Interface Unit
• Integrated Jitter Attenuator that can be selected either in Receive or Transmit path
• Flexible integrated Clock Multiplier that takes single frequency clock and generates either DS3 or E3 frequency.
• 8/16 bit UTOPIA Level I and II and PPP Multi-PHY Interface operating at 25, 33 or 50 MHz.
• HDLC Controller that provides the mapping/extraction of either bit or byte mapped encapsulated packet from DS3/E3 Frame.
• Contains on-chip 16 cell FIFO (configurable in depths of 4, 8, 12 or 16 cells), in both the Transmit (TxFIFO) and Receive Directions (RxFIFO)
• Contains on-chip 54 byte Transmit and Receive OAM Cell Buffer for transmission, reception and processing of OAM Cells
• Supports ATM cell or PPP Packet Mapping
• Supports M13 and C-Bit Parity Framing Formats
• Supports DS3/E3 Clear-Channel Framing.
• Includes PRBS Generator and Receiver
• Supports Line, Cell, and PLCP Loop-backs
• Interfaces to 8 Bit wide Intel, Motorola or PowerPC
• Low power 3.3V, 5V Input Tolerant, CMOS
• Available in 456 Lead PBGA Package
• JTAG Interface

APPLICATIONS
• Digital Access and Cross Connect Systems
• 3G Base Stations
• DSLAMs
• Digital, ATM, WAN and LAN Switches