®
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
ISSUE 6
May 1995
Ordering Information
MT8981DC
40 Pin Ceramic DIP
MT8981DE
40 Pin Plastic DIP
MT8981DP
44 PLCC
MT8981DL
44 Pin QFP
-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
STo0
STo1
STo2
STo3
Control Register
Connection
Memory
Control Interface
Converter
AAA
A A
AAA
A A
DS CS R/W A5/
A0
DTA D7/
D0
Figure 1 - Functional Block Diagram
2-17
MITEL [ MITEL NETWORKS CORPORATION ]
