PM7344 S/UNI-MPH
DATA SHEET
PMC-950449
ISSUE 6
MULTI-PHY USER NETWORK INTERFACE
User-programmable Cell Pattern Registers, and their associated Cell Mask
Registers, are passed through the FIFO.
HCK:
The HCK bit controls a FIFO data path integrity check. The integrity check
consists of inserting either an alternating AAH/55H pattern, or a fixed 55H
pattern, in the HCS octet location as selected by the FIXPAT bit in the RXCP
Framing Control register. The AA/55H pattern alternates with each cell
written to the FIFO. An external device reading cells from the receive FIFO
verifies that either the alternating or the fixed pattern is present in the cell
stream. Any pattern discrepancy indicates a failure in the receive data path.
When a logic 1 is written to HCK, the data path integrity check is enabled,
and the HCS octet location is overwritten with the alternating pattern. When
a logic 0 is written to HCK, the received HCS value is passed unaltered
through the FIFO.
HCSADD:
The HCSADD bit enables the addition of the coset polynomial x6 + x4 + x2 + 1
to the received HCS octet before comparison with the calculated result as
required by the ATM Forum UNI specification. When a logic 1 is written to
HCSADD, the coset polynomial is added to the HCS. When a logic 0 is
written to HCSADD, the unmodified HCS value is compared with the
calculated result.
HCSDQDB:
The HCSDQDB bit controls the cell header octets included in the HCS
calculation. When a logic 1 is written to HCSDQDB, header octets two, three,
and four are used in the HCS calculation as required by the IEEE-802.6
DQDB specification. When a logic 0 is written to HCSDQDB, all four header
octets are used in the HCS calculation as required by the ATM Forum UNI
specification, and the ITU-T Recommendation I.432.
HCSPASS:
The HCSPASS bit enables cells containing HCS errors to be passed through
the receive FIFO. When a logic 1 is written to HCSPASS, cells containing
detectable HCS errors are written to the receive FIFO. When a logic 0 is
written to HCSPASS, cells containing detectable HCS errors are dropped.
Note that all cells are dropped while an out of cell delineation defect is
detected.
PROPRIETARY AND CONFIDENTIAL TO PMC-SIERRA, INC., AND FOR ITS CUSTOMERS’ INTERNAL USE
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PMC [ PMC-SIERRA, INC ]
