S/UNI®-JET Data Sheet
Released
Figure 19 8-bit Wide, 53-byte Word Structure
Bit 7 Bit 0
W ord 1
W ord 2
W ord 3
W ord 4
W ord 5
W ord 6
H1
H2
H3
H4
H5
PAYLOAD1
W ord 53
PAYLOAD48
The 8-bit SCI-PHYTM compliant data structure is selected when the ATM8 input is tied high. Bit 7
of each word is the most significant bit, which corresponds to the first bit transmitted or received.
Selection between the 52-byte and 53-byte word data structures is done by the DS27_53 register
bit in the S/UNI-JET Configuration 1 Register. The 52-byte word structure is chosen when
DS27_53 is set to logic zero. The 53-byte word structure is chosen when DS27_53 is set to logic
one. The start of cell indication input and output (TSOC and RSOC) are coincident with Word 1
(containing the first cell header octet). The header check sequence octet (HCS) is passed through
the 53-byte word structure. Word 5 of this structure contains the HCS octet.
In the receive direction, cells containing "detected and uncorrected" header errors are dropped
when the HCSPASS bit in the RXCP-50 Configuration 2 Register is set to logic zero. No HCS
status information is passed within this data structure. Cells with error free headers and "detected
and corrected" headers are passed when HCSPASS and DISCOR are logic zero. Cells containing
uncorrectable HCS errors are dropped while the HCSPASS bit is set to logic zero. Error free
headers, "detected and corrected" headers, and "detected and uncorrected" headers are passed
when HCSPASS is a logic one.
In the receive direction, idle cells are dropped when the IDLEPASS bit in the RXCP-50
Configuration 2 Register is set to a logic zero. No cells are passed when the S/UNI-JET is in the
PLCP LOF defect state (for PLCP based transmission), or when the S/UNI-JET is in the out of
cell delineation defect state (for non-PLCP based transmission).
Proprietary and Confidential to PMC-Sierra, Inc., and for its Customers’ Internal Use
Document ID: PMC-1990267, Issue 3
276
PMC [ PMC-SIERRA, INC ]
