STANDARD PRODUCT
DATASHEET
PMC-1981125
ISSUE 7
PM8315 TEMUX
HIGH DENSITY T1/E1 FRAMER WITH
INTEGRATED VT/TU MAPPER AND M13 MUX
Figure 40
CTCLK*
- T1/E1 Diagnostic Digital Loopback
TRANSMITTER
T1-XBAS/E1-TRAN
BasicTransmitter:
Frame Generation,
Alarm Insertion,
Signaling
Trunk Conditioning
I
ti
Line Coding
TOPS
Timing Options
TJAT
Digital Jitter
Attenuator
TxCLK[1:28]
TxD[1:28]
ED[1:28]
ECLK[1:28]/EFP[1:28]/
ESIG[1:28]
CEFP*
CECLK*
ESIF
Egress
Interface
Di agn ost i c Loopb ack
CICLK*
CIFP*
ID[1:28]
ICLK[1:28]/ISIG[1:28]
IFP[1:28]
FRAM
Framer/
Slip Buffer
RAM
T1/E1-FRMR
Framer:
Frame
Alignment,
Alarm
Extraction
RJAT
Digital Jitter
Attenuator
RxCLK[1:28]
RxD[1:28]
ELST
Elastic
Store
ISIF
Ingress
Interface
RECEIVER
Per-Channel Loopback
The T1/E1 payload may be looped-back on a per-channel basis through the use
of the TPSC. If all channels are looped-back, the result is very similar to Payload
Loopback on other PMC framers. In order for per-channel loopback to operate
correctly, the Ingress Interface must be in Clock Master mode. The LOOP bit
must be set to logic 1 in the TPSC Internal Registers for each channel desired to
be looped back, and the PCCE bit must be set to logic 1 in the TPSC
Configuration register. When all these configurations have been made, the
ingress DS0s or timeslots selected will overwrite their corresponding egress
channels; the remaining egress channels will pass through intact. Note that
because the egress and ingress streams will not be superframe aligned, that any
robbed-bit signaling in the ingress stream may not fall in the correct frame once
looped-back, and that egress robbed-bit signaling will overwrite the looped-back
channel data if signaling insertion is enabled. PRBS generation and detection is
not available in payload loopback mode. The data flow in per-channel loopback
is illustrated in Figure 41.
PROPRIETARY AND CONFIDENTIAL
206
PMC [ PMC-SIERRA, INC ]
