PM4314 QDSX
DATA SHEET
PMC-950857
ISSUE 5
QUAD T1/E1 LINE INTERFACE DEVICE
reference clock. When an 8X reference is provided, the CLKO1X output is active,
and carries the internal 8X reference clock divided by 8.
9.7
Pseudo-Random Bit Sequence Generator (PRSG)
The Pseudo-Random Bit Sequence Generator (PRSG) generates an unframed
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2 -1 test sequence as defined in Recommendation O.151. The PRSG can be
enabled to overwrite the unipolar input transmit data when configured to be in the
transmit data stream or the recovered unipolar receive data when configured to
be in the receive data stream. The microprocessor can force the PRSG to insert
single bit errors in the pseudorandom data for diagnostic purposes.
The PRSG can be configured to generate either an inverted or a noninverted
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15
2 -1 pseudorandom bit sequence (PRBS). An inverted 2 -1 PRBS will
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contain at most 15 consecutive zeroes, while a non-inverted 2 -1 PRBS will
contain at most 14 consecutive zeroes.
9.8
Inband Loopback Code Generator (XIBC)
The Inband Loopback Code Generator function is provided by the XIBC block.
This block generates a stream of inband loopback codes to be inserted into a
DS-1 data stream.The stream consists of continuous repetitions of a specific
code. The contents of the code and its length are programmable from 3 to 8 bits.
The XIBC can be enabled to overwrite the unipolar input transmit data when
configured to be in the transmit data stream or the recovered unipolar receive
data when configured to be in the receive data stream.
9.9
B8ZS/HDB3/AMI Line Encoder (LCODE)
The B8ZS/HDB3/AMI line encoding function is provided by the LCODE block.
This block will encode single-rail data inputs into bipolar B8ZS, HDB3, or AMI
format. For DSX-1 applications, B8ZS line encoding is selected by default. For
E1 applications, HDB3 line encoding is selected by default. The microprocessor
may instruct the LCODE block to insert line code violations for diagnostic
purposes.
9.10 Digital Jitter Attenuator (DJAT)
The Digital Jitter Attenuator (DJAT) function is used to attenuate jitter in the
transmit clock when required. The DJAT block receives jittered data and stores
PROPRIETARY AND CONFIDENTIAL TO PMC-SIERRA, INC., AND FOR ITS CUSTOMERS’ INTERNAL USE
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PMC [ PMC-SIERRA, INC ]
