DESCRIPTION
The DS2143 is a comprehensive, software-driven E1 framer. It is meant to act as a slave or coprocessor to a microcontroller or microprocessor. Quick access via the parallel control port allows a single micro to handle many E1 lines. The DS2143 is very flexible and can be configured into numerous orientations via software. The software orientation of the device allows the user to modify their design to conform to future E1 specification changes.

FEATURES
■ E1/ISDN-PRI framing transceiver
■ Frames to CAS, CCS, and CRC4 formats
■ Parallel control port
■ Onboard two frame elastic store slip buffer
■ Extracts and inserts CAS signaling bits
■ Programmable output clocks for fractional E1 links, DS0 loopbacks, and drop and insert applications
■ Onboard Sa data link support circuitry
■ FEBE E-Bit detection, counting and generation
■ Pin-compatible with DS2141A T1 Controller
■ 5V supply; low power (50 mW) CMOS
■ Available in 40-pin DIP and 44-pin PLCC (DS2143Q)