PEB3086 Infineon Technologies, PEB3086 Datasheet - Page 48

• Manufacturer Part Number: PEB3086
• Description: ISDN Subscriber Access Controller
• Manufacturer: Infineon Technologies

ISAC-SX
PEB 3086
Description of Functional Blocks
3.3.1
S/T-Interface Coding
Transmission over the S/T-interface is performed at a rate of 192 kbit/s. 144 kbit/s are
used for user data (B1+B2+D), 48 kbit/s are used for framing and maintenance
information.
Line Coding
The following figure illustrates the line code. A binary ONE is represented by no line
signal. Binary ZEROs are coded with alternating positive and negative pulses with two
exceptions:
For the required frame structure a code violation is indicated by two consecutive pulses
of the same polarity. These two pulses can be adjacent or separated by binary ONEs.
In bus configurations a binary ZERO always overwrites a binary ONE.
0 1 1
code violation
Figure 16
S/T -Interface Line Code
Frame Structure
Each S/T frame consists of 48 bits at a nominal bit rate of 192 kbit/s. For user data
(B1+B2+D) the frame structure applies to a data rate of 144 kbit/s (see
Figure
17).
In the direction TE ® NT the frame is transmitted with a two bit offset. For details on the
framing rules please refer to ITU I.430 section 6.3. The following figure illustrates the
standard frame structure for both directions (NT ® TE and TE ® NT) with all framing
and maintenance bits.
Data Sheet
48
2003-01-30