Functional Description
2.5
Layer-1 Functions for the S/T Interface
The common functions in all operating modes are:
– line transceiver functions for the S/T interface according to the electrical specifications of
CCITT I.430;
– conversion of the frame structure between IOM and S/T interface;
– conversion from/to binary to/from pseudo-ternary code;
– level detect.
Mode specific functions are:
– receive timing recovery for point-to-point, passive bus and extended passive bus
configuration;
– S/T timing generation using IOM timing synchronous to system, or vice versa;
– D-channel access control and priority handling;
– D-channel echo bit generation by handling of the global echo bit;
– activation/deactivation procedures, triggered by primitives received over the IOM C/I
channel or by INFO's received from the line;
– execution of test loops.
For a block diagram, see figure 10.
The wiring configurations in user premises, in which the ISAC-S can be used are illustrated in
figure 41.
Semiconductor Group
79
INFINEON [ Infineon ]
