![](http://datasheet.mmic.net.cn/260000/PSB2115F_datasheet_15948207/PSB2115F_139.png)
PSB 2115
PSF 2115
Functional Description
Semiconductor Group
139
11.97
2.7.5
The Command/Indication channel carries real-time status information between the IPAC
and another device connected to the IOM.
C/I-Channel Handling
1) One C/I channel (called C/I0) conveys the commands and indications between the
layer-1 and the layer-2 parts of the IPAC. This channel is available in all timing modes
(TE and non-TE). It can be accessed by an external layer-2 device e.g. to control the
layer-1 activation/deactivation procedures. C/I0 channel access may be arbitrated via
the TIC bus access protocol in the IOM-2 terminal timing mode (pin MODE0=0). In this
case the arbitration is done in C/I channel 2 (
see figure 53
).
The C/I0 channel is accessed via register CIR0 (in receive direction, layer-1 to layer-2)
and register CIX0 (in transmit direction, layer-2 to layer-1). The C/I0 code is four bits
long.
A listing and explanation of the layer-1 C/I codes can be found in
chapter 3.6.2
.
In the receive direction, the code from layer-1 is continuously monitored, with an interrupt
being generated anytime a change occurs (ISTAD:CIC). A new code must be found in
two consecutive IOM frames to be considered valid and to trigger a C/I code change
interrupt status (double last look criterion).
In the transmit direction, the code written in CIX0 is continuously transmitted in C/I0.
2) A second C/I channel (called C/I1) can be used to convey real time status information
between the IPAC and various non-layer-1 peripheral devices e.g. PSB 2163 ARCOFI-
SP. The channel consists of six bits in each direction. It is available only in the IOM-2 TE
timing mode (
see figure 53
).
The C/I1 channel is accessed via registers CIR1 and CIX1. A change in the received
C/I1 code is indicated by an interrupt status without double last look criterion.