GENERAL DESCRIPTION
The DS21Q59 E1 quad transceiver contains all the necessary functions for connecting to four E1 lines. The DS21Q59 is a direct replacement for the DS21Q50, with the addition of signaling access and improved interrupt handling. It is composed of a line interface unit (LIU), framer, and a TDM backplane interface, and is controlled through an 8-bit parallel port configured for Intel or Motorola bus operations or serial port operation.

FEATURES
■ Four Complete E1 (CEPT) PCM-30/ISDN-PRI Transceivers
■ Pin Compatible with the DS21Q50
■ Long-Haul and Short-Haul Line Interfaces
■ 32-Bit or 128-Bit Crystal-Less Jitter Attenuator
■ Frames to FAS, CAS, and CRC4 Formats
■ CAS/CCS Signaling Support
■ 4MHz/8MHz/16MHz Clock Synthesizer
■ Flexible System Clock with Automatic Source Switching on Loss-of-Clock Source
■ Two-Frame Elastic-Store Slip Buffer on the Receive Side
■ Interleaving PCM Bus Operation Up to 16.384MHz
■ Configurable Parallel and Serial Port Operation
■ Detects and Generates Remote and AIS Alarms
■ Fully Independent Transmit and Receive Functionality
■ Four Separate Loopback Functions
■ PRBS Generation/Detection/Error Counting
■ 3.3V Low-Power CMOS
■ Large Counters for Bipolar and Code Violations, CRC4 Codeword Errors, FAS Word Errors, and E Bits
■ Eight Additional User-Configurable Output Pins
■ 100-Pin (14mm) LQFP Package

APPLICATIONS
    DSLAMs
    Routers
    IMA and WAN Equipment