mt8981de1 Zarlink Semiconductor, mt8981de1 Datasheet - Page 9

• Manufacturer Part Number: mt8981de1
• Description: Digital Switch
• Manufacturer: Zarlink Semiconductor

Fig. 8 shows how a simple digital switching system may be designed using the ST-BUS architecture. This is a
private telephone network with 128 extensions which uses a single MT8981 as a speech switch and a second
MT8981 for communication with the line interface circuits.
A larger digital switching system may be designed by cascading a number of MT8981s. Fig. 9 shows how four
MT8981s may be arranged in a non-blocking configuration which can switch any channel on any of the ST-BUS
inputs to any channel on the ST-BUS outputs.
Controlling
Processor
Micro-
IN 0/3
IN 4/7
Figure 9 - Four 8981s Arranged in a Non-Blocking 8 x 8 Configuration
Figure 8 - Example Architecture of a Simple Digital Switching System
Signalling
Control &
Speech
Switch
8981
8981
-
-
STo0-3
Zarlink Semiconductor Inc.
STi0/3 STo0/3
STi0/3 STo0/3
STi0/3 STo0/3
STi0/3 STo0/3
4
STi0-3
MT8981D
8981
8981
8981
8981
#4
4
#1
#2
#3
STo0-3
4
STi0-3
9
4
with Codec (e.g. 8964)
with Codec (e.g. 8964)
Line Interface Circuit
Line Interface Circuit
Repeated for Lines
2 to 127
•
•
•
OUT 0/3
OUT 4/7
Line 128
Line 1
Repeated for Lines
2 to 127
Data Sheet
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