CMOS ST-BUS™ FAMILY
MT89L80
Digital Switch
Advance Information
Features
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3.3 volt supply
5V tolerant inputs and TTL compatible outputs.
256 x 256 channel non-blocking switch
Accepts serial streams at 2.048Mb/s
Per-channel three-state control
Patented per channel message mode
Non-multiplexed microprocessor interface
Mitel ST-BUS compatible
Low power consumption: typical 15mW
Pin compatible with the MT8980DP
DS5196
ISSUE 2
September 1999
Ordering Information
MT89L80AP
MT89L80AN
44 Pin PLCC
48 Pin SSOP
-40°C to +85°C
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.
Applications
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Key telephone systems
PBX systems
Small and medium voice switching systems
C4i
F0i RESET V
DD
V
SS
**
ODE
STi0
STi1
STi2
STi3
STi4
STi5
STi6
STi7
Serial
to
Parallel
Converter
Data
Memory
Frame
Counter
Output
MUX
Parallel
to
Serial
Converter
STo0
STo1
STo2
STo3
STo4
STo5
STo6
STo7
Control Register
Connection
Memory
Control Interface
DS CS R/W A5/
A0
** for 48-pin SSOP only
DTA D7/
D0
CSTo
Figure 1 - Functional Block Diagram
2-3