MTC-20172-PC AMI Semiconductor, Inc., MTC-20172-PC Datasheet - Page 33

• Manufacturer Part Number: MTC-20172-PC
• Description: S Interface Circuit for ISDN (SIC)
• Manufacturer: AMI Semiconductor, Inc.

5. Detailed Operational Description
Fig. 5.1 : S Frame Structure
of The S-Bus Interface
Introduction
An overview of the functional environ-
ment is given in chapter 4. In this chap-
ter we give external and internal opera-
tional details of the S-bus interface.
Detailed interface timing and electrical
specifications are given in chapter 9.
5.1 General
The S-interface realizes full-duplex
transmission of two B-channels
(64 kbit/s each) and one D-channel
(16 kbit/s). In addition, the S-interface
allows controlled access to the com-
mon D-channel and the activation/
deactivation of each connected
device.
Characteristics
23
MTC-20172
Data Sheet & Reference Manual
Rev. 1.1 February 1997
5.1.1 Transmission Rate
The nominal transmission rate is 192
kbit/s in each direction. There is no
requirement for special bit sequences
in the B-channels.
5.1.2 Frame Structure
Data is transmitted within a frame of
48 bits in each direction. The nominal
frame period is 250 µs, which gives a
frequency of 4 kHz. The frame
structure is not dependant on 'bus' or
'point-to-point' configuration. The
frame structure is shown in Figure 5.1.