Description
This VLSI CMOS device is designed for switching PCM-encoded voice or data, under microprocessor control, in a modern digital exchange, PBX or Central Office. It provides simultaneous connections for up to 256 64 kbit/s channels. Each of the eight serial inputs and outputs consist of 32 64 kbit/s channels multiplexed to form a 2048 kbit/s ST-BUS stream. In addition, the MT89L80 provides microprocessor read and write access to individual ST-BUS channels.

FEATUREs
• 3.3 volt supply
• 5 V tolerant inputs and TTL compatible outputs.
• 256 x 256 channel non-blocking switch
• Accepts serial streams at 2.048 Mb/s
• Per-channel three-state control
• Patented per channel message mode
• Non-multiplexed microprocessor interface
• Zarlink ST-BUS compatible
• Low power consumption: typical 15 mW
• Pin compatible with the MT8980DP

APPLICATIONs
• Key telephone systems
• PBX systems
• Small and medium voice switching systems