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S/UNI-ATLAS-3200 Telecom Standard Product Data Sheet
Preliminary
Proprietary and Confidential to PMC-Sierra, Inc., and for its Customers’ Internal Use
Document ID: PMC-1990553, Issue 4
171
CRC10
The CRC10 bit forces the generation of the Error Detection Code (EDC) for cells written into
the insert FIFO. If CRC10 is set to logic 1 prior to assembling the cell in the buffer, the last
10-bits of the cell are overwritten with the CRC-10 value calculated over the information
field (payload) of the cell. When CRC10 is logic 1, the last 16 bits of the cell are typically
written to zero, and the CRC-10 replaces the 10 least significant bits.
PROC_CELL
The Cell Process Enable (PROC_CELL) bit controls the processing of the current cell written
into the insert FIFO. If PROC_CELL was set to logic 1 prior to writing the cell in the buffer,
the current is subject to all cell processing functions, just as if the cell had been inserted
through the Input Cell Interface. Therefore, the header information and PHYID must
correspond to a provisioned VC, or the cell will be discarded.
If PROC_CELL is logic 0, the current cell is passed to the output cell interface without
modification, with the exception that appended bytes may be added or stripped off to ensure a
correct cell length for the selected interface. The cell need not belong to a provisioned
connection. The cell is not processed.
PHYID[5:0]
The PHY identification bits determine the PHY association of the current cell being written
by the microprocessor. The state of the PHY[5:0] when the WRSOC is set selects the PHY
device for that cell:
PHY[5:0] = 000000, PHY #1/Single PHY.
PHY[5:0] = 000001, PHY #2
PHY[5:0] = 000010, PHY #3
…
PHY[5:0] = 101111, PHY #48.
WRSOC
The write start of cell (WRSOC) bit must identify the first word of the current cell that the
microprocessor is writing. If WRSOC is logic 1, the next word written into the
Microprocessor Cell Data register becomes the first word of the cell. Subsequent writes to
the Microprocessor Cell Data register fill the remainder of the cell sequentially, to a total of
16 writes. If WRSOC is set again before a complete cell is written, the existing contents will
be overwritten without transmission.
WRSOC is not readable.