STANDARD PRODUCT
PM8315 TEMUX
DATASHEET
PMC-1981125
ISSUE 7
HIGH DENSITY T1/E1 FRAMER WITH
INTEGRATED VT/TU MAPPER AND M13 MUX
4. Read the requested channel data from the TPSC (RPSC) Channel Indirect
Data Buffer register.
5. If there is more data to be read, go back to step 1.
12.8 T1/E1 Framer Loopback Modes
The TEMUX provides three loopback modes for T1/E1 links to aid in network and
system diagnostics. The internal T1/E1 line loopback can be initiated at any time
via the µP interface, but is usually initiated once an inband loopback activate
code is detected. The system Diagnostic Digital loopback can be initiated at any
time by the system via the µP interface to check the path of system data through
the framer. The payload can also be looped-back on a per-DS0 basis to allow
network testing without taking an entire DS1 off-line.
T1/E1 Line Loopback
T1/E1 Line loopback is initiated by setting the LLOOP bit to a 1 in the T1/E1
Diagnostics register (000DH + N*80H, N=1 to 28). When in line loopback mode
the appropriate T1/E1 framer in the TEMUX is configured to internally connect
the jitter-attenuated clock and data from the RJAT to the transmit clock and data
(shown as TxD[x] and TxCLK[x] in the lineloopback diagram) going to the M13
mux and SONET/SDH mapper. The RJAT may be bypassed if desired.
Conceptually, the data flow through a single T1/E1 framer in this loopback
condition is illustrated in Figure 39.
PROPRIETARY AND CONFIDENTIAL
204
PMC [ PMC-SIERRA, INC ]
