pef80913 Infineon Technologies Corporation, pef80913 Datasheet - Page 142

• Manufacturer Part Number: pef80913
• Description: 2b1q Second Gen. Modular Isdn Nt
• Manufacturer: Infineon Technologies Corporation

3.2.3.2
Single channel loopbacks are always performed directly in the U-Transceiver. No
difference between the B1-channel and the B2-channel loopback control procedure
exists.
3.2.4
Besides the standardized remote loopbacks the U-transceiver features additional local
loopbacks for enhanced test and debugging facilities. The local loopbacks that are
featured by register LOOP are shown in
itself and can be activated regardless of the current operational status.
By the LOOP register it can be configured whether the loopback is closed only for the B1
and/or B2 or for 2B+D channels and whether the loopback is closed towards the internal
IOM -2 interface or towards the U-Interface.
By default the loopbacks are set to transparent mode. In transparent mode the data is
both passed on and looped back. In non-transparent mode the data is not forwarded but
substituted by 1s (idle code).
Besides the loopbacks in the system interface an additional digital loopback (DLB), the
Framer/ Deframer loopback, is featured. It allows to test most digital functions of the U-
transceiver besides the signal processing blocks.
Data Sheet
Loopback No.2 - Single Channel Loopbacks
Local Loopbacks Featured By the LOOP Register
Figure
128
66. They are closed in the U-transceiver
Operational Description
PEF 82912/82913
2001-03-30