PEB22554 SIEMENS [Siemens Semiconductor Group], PEB22554 Datasheet - Page 80

• Manufacturer Part Number: PEB22554
• Description: ICs for Communications
• Manufacturer: SIEMENS [Siemens Semiconductor Group]

Single Channel Loop Back
Each of the 32 time-slots may be selected for loopback from the system PCM input (XDI)
to the system PCM output (RDO). This loopback is programmed for one time-slot at a
time selected by register LOOP. During loopback, an idle channel code programmed in
register IDLE is transmitted to the remote end in the corresponding PCM route time-slot.
For the time-slot test, sending sequences of test patterns like a 1 kHz check signal
should be avoided. Otherwise, an increased occurrence of slips in the tested time-slot
will disturb testing. These slips do not influence the other time-slots and the function of
the receive memory. The usage of a quasi-static test pattern is recommended.
Figure 25
Single Channel Loopback
Semiconductor Group
RL1
RL2
XL1
XL2
Clock +
Data
Recovery
Trans.
Framer
RCLK
Rec.
Framer
MUX
80
IDLE Code
MUX
Functional Description E1
Elast.
Store
Elast.
Store
PEB 22554
ITS09747
RDO
XDI
09.98