PM5380-BI PMC-Sierra, Inc., PM5380-BI Datasheet - Page 384

• Manufacturer Part Number: PM5380-BI
• Description: Network Interface, SATURN User Network Interface (8x155) Telecom Standard Product
• Manufacturer: PMC-Sierra, Inc.

Proprietary and Confidential to PMC-Sierra, Inc., and for its customers’ internal use.
Document No.: PMC- 2010299, Issue 2
13.2 UTOPIA Level 3 ATM Cell Data Structure
B3: The path bit interleaved parity byte provides a path error monitoring function. In the
transmit direction, the S/UNI-8x155 calculates the B3 bytes. The calculated code is then placed
in the next frame. In the receive direction, the S/UNI-8x155 calculates the B3 code and
compares this calculation with the B3 byte received in the next frame. B3 errors are
accumulated in an error event counter.
C2: The path signal label indicator identifies the equipped payload type. For ATM payloads, the
identification code is 0x13. For Packet over SONET/SDH (including X
scrambling), the identification code is 0x16. In the transmit direction, the S/UNI-8x155 inserts
the value 0x13 or 0x16 using the TPOP Path Signal Label register. In the receive direction, the
code is available in the RPOP Path Signal Label register. In addition, the SPTB block also
provides circuitry to detect path signal label mismatch and unstable alarms.
G1: The path status byte provides a path FEBE function, and a path remote defect indication
function. Three bits are allocated for remote defect indications: bit 5 (the path RD I bit), bit 6
(the auxiliary path RDI bit) and bit 7 (Enhanced RDI bit). Taken together these bits provide a
eight state path RDI code that can be used to categorize path defect indications. In the transmit
direction, the S/UNI-8x155 provides register bits to control the path RDI (bit 5) and auxiliary
path RDI (bit 6) states. For path FEBE, the number of B3 errors detected in the previous
interval is inserted either automatically or using a register. This path FEBE code has 9 legal
values, namely 0 to 8 errors. In the receive direction, a legal path FEBE value is accumulated in
the path FEBE event counter. In addition, the path RDI and auxiliary path RDI signal states are
available in internal registers.
H4: The multi-frame indicator byte is a payload specific byte, and is not used for ATM
payloads. This byte is forced to 0x00 in the transmit direction, and is ignored in the receive
direction.
Z3 - Z5: The path growth bytes provide three unused bytes for future use.
ATM cells on the Level 3 interface use either a 52 word, 32-bit UTOPIA Level 3 compliant data
structure or a 56 word, 32-bit UTOPIA Level 3 compliant data structure. The data structures are
shown in Figure 19 and Figure 20.
For the 52 byte ATM cell structure, bit 31 of each word is the most significant bit (which
corresponds to the first bit transmitted). The HCS octet (H5) is not contained in this structure
and is generated by the Transmit Cell Processor (TXCP). The start of cell indications (TSOC
and RSOC) are coincident with word 1 of the structure.
S/UNI®-8x155 ASSP Telecom Standard Product Data Sheet
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+1 payload
Released
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