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PMC-Sierra, Inc.
PM5349 S/UNI-QUAD
DATASHEET
PMC-971239 ISSUE 6 SATURN USER NETWORK INTERFACE (155-QUAD)
Proprietary and Confidential to PMC-Sierra, Inc., and for its Customers’ Internal Use
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The pointer value is used to insert the path overhead into the transmit stream.
The current pointer value may be read via internal registers.
10.10.2
BIP-8 Calculate
The BIP-8 Calculate Block performs a path bit interleaved parity calculation on
the SPE of the transmit stream. Details are provided in the references. The
resulting parity byte is inserted in the path BIP-8 (B3) byte position of the
subsequent frame. BIP-8 errors may be continuously inserted under register
control for diagnostic purposes.
10.10.3
FEBE Calculate
The FEBE Calculate Block accumulates far end block errors on a per frame
basis, and inserts the accumulated value (up to maximum value of eight) in the
FEBE bit positions of the path status (G1) byte. The FEBE information is derived
from path BIP-8 errors detected by the receive path overhead processor, RPOP.
Far end block errors may be inserted under register control for diagnostic
purposes.
10.11
Transmit ATM Cell Processor (TXCP)
The Transmit ATM Cell Processor (TXCP) provides rate adaptation via
idle/unassigned cell insertion, provides HCS generation and insertion, and
performs ATM cell scrambling. The TXCP contains a four cell transmit FIFO. An
idle or unassigned cell is transmitted if a complete ATM cell has not been written
into the FIFO.
10.11.1
Idle/Unassigned Cell Generator
The Idle/Unassigned Cell Generator inserts idle or unassigned cells into the cell
stream when enabled. Registers are provided to program the GFC, PTI, and
CLP fields of the idle cell header and the idle cell payload. The idle cell HCS is
automatically calculated and inserted.
10.11.2
Scrambler
The Scrambler scrambles the 48 octet information field. Scrambling is performed
using a parallel implementation of the self synchronous scrambler (x
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+ 1
polynomial) described in the references. The cell headers are transmitted
unscrambled, and the scrambler may optionally be disabled.