PEF24911HV22XP Lantiq, PEF24911HV22XP Datasheet - Page 105

• Manufacturer Part Number: PEF24911HV22XP
• Manufacturer: Lantiq

Specifications of PEF24911HV22XP

• Control Interface: HDLC
• Lead Free Status / Rohs Status: Supplier Unconfirmed

PEF 24911
Operational Description
4.4.1.5
Local Loopbacks Featured By Register LOOP
Besides the standardized remote loopbacks the DFE-Q V2.1 features additional local
loopbacks for enhanced test and debugging facilities. The local loopbacks that are
featured by the internal register LOOP are shown in
Figure
39. They are closed in the
DFE-Q V2.1 itself.
By register LOOP it can be configured whether the digital local looback is closed only for
the B1 and/or B2 or for all ISDN-BA channels and whether the loopback is closed
®
towards the IOM
-2 interface or towards the U-Interface.
The bit TRANS in the LOOP register allows for selection of transparent or non-
transparent loopback 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).
Note: The digital framer/deframer loopback (DLB) is always transparent.
Besides the loopbacks in the system interface a further digital loopback, the Framer/
Deframer loopback, is provided. It allows to test all digital functions of the 2B1Q U-
transceiver besides the signal processing blocks. However, an activation procedure is
not possible by closing the Framer/Deframer Loopback. Therefore, before loop DLB may
be closed, the DFE-Q V2.1 must be in a transparent state, e.g. by applying C/I-command
’Data Through DT’. If DLB is set to ’1’ in state ’Deactivated’, then a subsequent activation
fails.
Data Sheet
95
2001-07-16