®
ISO-CMOS ST-BUS™ FAMILY
MT8981D
Digital Switch
Features
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Mitel ST-BUS compatible
4-line x 32-channel inputs
4-line x 32-channel outputs
128 ports non-blocking switch
Single power supply (+5 V)
Low power consumption: 30 mW Typ.
Microprocessor-control interface
Three-state serial outputs
MT8981DE
MT8981DP
ISSUE8
March 1997
Ordering Information
40 Pin Plastic DIP
44 PLCC
-40°C to +85°C
Description
This VLSI ISO-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 128 64 kbit/s
channels. Each of the four serial inputs and outputs
consist of 32 64 kbit/s channels multiplexed to form a
2048 kbit/s ST-BUS stream. In addition, the MT8981
provides microprocessor read and write access to
individual ST-BUS channels.
C4i
F0i
V
DD
V
SS
ODE
STi0
STi1
STi2
STi3
Serial
to
Parallel
Converter
Data
Memory
Frame
Counter
Output
MUX
Parallel
to
Serial
Converter
STo0
STo1
STo2
STo3
Control Register
Connection
Memory
Control Interface
DS CS R/W A5/
A0
DTA D7/
D0
Figure 1 - Functional Block Diagram
2-17
MITEL [ MITEL NETWORKS CORPORATION ]
