GENERAL DESCRIPTION
The M3488 is intended for large telephone switching systems, mainly central exchanges,digital line concentrators and private branch exchanges where a distributed microcomputer control approach is extensively used. It consists of a speech memory (SM), a control memory (CM), a serial/parallel and a parallel/serial converter, an internal parallel bus, an interface (8 data lines, 11 control signals) and dedicated control logic.

■ 256 INPUT AND 256 OUTPUT CHANNEL CMOS DIGITAL SWITCHING MATRIX COMPATIBLE WITH M088
■ BUILDING BLOCK DESIGNED FOR LARGE CAPACITY ELECTRONIC EXCHANGES, SUBSYSTEMS AND PABX
■ NO EXTRA PIN NEEDED FOR NOT-BLOCKING SINGLE STAGE AND HIGHER CAPACITY SYNTHESIS BLOCKS (512 or 1024 channels)
■ EUROPEAN TELEPHONE STANDARD COMPATIBLE (32 serial channels per frame)
■ PCM INPUTS AND OUTPUTS MUTUALLY COMPATIBLE
■ ACTUAL INPUT-OUTPUT CHANNEL CONNECTIONS STORED AND MODIFIED VIA AN ON CHIP 8-BIT PARALLEL MICROPROCESSOR INTERFACE
■ TYPICAL BIT RATE : 2Mbit/s
■ TYPICAL SYNCHRONIZATION RATE : 8KHz (time frame is 125µs)
■ 5V P0WER SUPPLY
■ CMOS & TTL INPUT/OUTPUT LEVELS COMPATIBLE
■ HIGH DENSITY ADVANCED 1.2µm HCMOS3 PROCESS

Main instructions controlled by the microprocessor interface
■ CHANNEL CONNECTION/DISCONNECTION
■ OUTPUT CHANNEL DISCONNECTION
■ INSERTION OF A BYTE ON A PCM OUTPUT CHANNEL/DISCONNECTION
■ TRANSFER TO THE MICROPROCESSOR OF A SINGLE PCM OUTPUT CHANNEL SAMPLE
■ TRANSFER TO THE MICROPROCESSOR OF A SINGLE OUTPUT CHANNEL CONTROL WORD
■ TRANSFER TO THE MICROPROCESSOR OF A SELECTED 0 CHANNEL PCM INPUT DATA