PEB20550 Datasheet, PDF (362/407 Pages) Infineon Technologies AG – ICs for Communications

PEB 20550
PEF 20550
Application Notes
6.1.4 Line Activation by Subscriber A
When subscriber A takes the receiver off the hook, the layer-1 device (e.g. the
ISAC-P TE) of terminal A activates the physical layer between itself and the line card.
Digital Line Card
Switching
Network
Subscriber A ^UPN
IOM ^R -2 (LC)
PCM
ELIC ^R
Subscriber B ^{UPN OCTAT R -P +}
Transceivers
SACCOB
µP
HDLC Group
Controller
ITS08106
Figure 126
Call-up by Subscriber A
The ELIC reports this activation by signalling an interrupt. To allow the D-channel arbiter
to monitor subscriber A, the line activation must be confirmed and the D-channel arbiter
of the ELIC enabled for the subscriber. With D-channel communications between the
subscriber and the ELIC established, the ETSI / E-DSS1 protocol can be followed to
build up layers 2 and 3.
6.1.4.1 Handling of C/I Interrupt
When subscriber A hooks OFF, the ELIC signals an interrupt:
Read ISTA_E= 40_H
Read CIFIFO = 88_H
at least one valid entry in C/I FIFO
change in C/I value at port 0, time slot 2 (IOM-2 channel 0)
If the µP responds slowly, the ELIC continues signalling an interrupt:
Read CIFIFO = 88_H second change in C/I value at port 0, time slot 2
If the µP responds slowly, the ELIC continues signalling an interrupt:
Read CIFIFO = 88_H third change in C/I value at port 0, time slot 2
Interrupt no longer signalled by the ELIC: when subscriber A hooks OFF, the ELIC
reports three changes of the C/I code from the OCTAT-P.
Reading the current upstream C/I value of IOM-2 channel 0:
Write
Write
Read
MAAR = 88_H
MACR = C8_H
MADR = F3_H
upstream CM address where C/I value changed
read data from the CM data field
upstream C/I code ‘1100’ (active indication) → the subscriber
of IOM-2 channel 0 has activated his line
Semiconductor Group
362
01.96