RELEASED
PM4354 COMET-QUAD
DATASHEET
PMC-1990315
ISSUE 6
FOUR CHANNEL COMBINED E1/T1/J1
TRANSCEIVER / FRAMER
PROPRIETARY AND CONFIDENTIAL TO PMC-SIERRA, INC. AND FOR ITS CUSTOMERS’ INTERNAL USE
211
Table 32
- TPSC Transmit Data Conditioning
INVERT
SIGNINV
Effect on PCM Channel Data
0
0
PCM Channel data is unchanged
1
0
All 8 bits of the PCM channel data are inverted
0
1
Only the MSB of the PCM channel data is inverted (SIGN bit
inversion)
1
1
All bits EXCEPT the MSB of the PCM channel data is inverted
(Magnitude inversion)
DMW:
When the DMW bit is set to a logic 1, the digital milliwatt pattern replaces the BTPCM[x] or
MVBTD data stream of the quadrant for the duration of that channel.
The DMW bit only has effect in T1 mode.
TEST:
When the TEST bit is set to a logic 1, channel data from the BTPCM[x] or MVBTD data
stream of the quadrant is either overwritten with a test pattern from the PRBS generator block
or is routed to the PRBS checker block and compared against an expected test pattern. The
RXPATGEN bit in the T1/E1 PRBS Positioning and HDLC Control register determines
whether the transmit data is overwritten or compared as shown in the following table:
Table 33
- Transmit Test Pattern Modes
TEST
RXPATGEN
Description
0
X
Channel data is not included in test pattern
1
1
Channel data is routed to PRBS Checker and compared against
expected test pattern
1
0
Channel data is overwritten with PRBS test pattern
All the channels that are routed to the PRBS generator/checker are concatenated and treated
as a continuous stream in which PRBS patterns are searched for. Similarly, all channels set
to be overwritten with PRBS test pattern data are treated such that if the channels are
subsequently extracted and concatenated, the PRBS appears in the concatenated stream.
PRBS generation/detection can be enabled to work on only the first 7 bits of a channel (for
Nx56Kbit/s fractional T1) using the Nx56K_DET and Nx56K_GEN bits in the T1/E1 PRBS
Positioning and HDLC Control register. The PRBS generator/checker can also be enabled to
work on the entire DS1, including framing bits, using the UNF_GEN and UNF_DET bits in the
PRBS Positioning/Control and HDLC Control register.