PM5361-RI PMC-Sierra, Inc., PM5361-RI Datasheet - Page 31

• Manufacturer Part Number: PM5361-RI
• Description: SONET/SDH TRIBUTARY UNIT PAYLOAD PROCESSOR
• Manufacturer: PMC-Sierra, Inc.

DATA SHEET
PMC-920526
9.3
9.3.1 Clock Generator
9.3.2 Incoming Timing Generator
generate J1 and SPE timing for the outgoing data stream that corresponds to the
J1 bytes following the C1 bytes and no pointer justifications at the STS-1 (AU3)
or AU4 level. This timing drives the outputs of the three tributary payload
processors, substituting for the function otherwise provided by the OC1J1 and
OSPE inputs.
When configured for AU4 mode, the output bus multiplexer provides the
necessary timing coordination between the three tributary payload processors.
This consists of deriving VC4 framing from the single J1 byte marker input on
OC1J1 and distributing this to each tributary payload processor.
Tributary Payload Processor
Each tributary payload processor processes the tributaries within an STS-1, AU3,
or TUG3. Each TPP can be configured to process any legal mix of VT1.5s, VT2s,
VT3s, or VT6s that can be carried in an STS-1 or any legal mix of TU11s, TU12s,
TU2s, or TU3s, that can be carried in an AU3 or TUG3. The number of tributaries
managed by each TPP ranges from 1 (when configured to process a single TU3)
to 28 (when configured to process all VT1.5s or all TU11s).
The clock generator derives various clocks from the 19.44 MHz system clock and
distributes them to other blocks within the tributary payload processor. The
overall design is totally synchronous, with processing occurring at a 6.48 MHz
rate in each tributary payload processor.
The incoming timing generator identifies the incoming tributary being processed
at any given point in time. Based on the configuration of the TPP (it can process
various mixes of tributary types), the incoming timing generator extracts the STS-
1 SPE, VC3, or a single TUG3 from a VC4, and identifies the bytes within these
envelopes that correspond to various types of overhead and those that carry
specific tributaries to be processed. The H4 byte is identified for the incoming
multiframe detector so that it can determine the incoming tributary multiframe
boundaries. The identification of specific tributaries allows the pointer interpreter
to be time-sliced across the mix of tributaries present in the incoming data
stream. The identification of the V1-V3 bytes of VTs, or TUs (or H1-H3 bytes in
the case of TU3s) allows the pointer interpreter to function.
PROPRIETARY AND CONFIDENTIAL TO PMC-SIERRA, INC., AND FOR ITS CUSTOMERS’ INTERNAL USE
ISSUE 8
TRIBUTARY UNIT PAYLOAD PROCESSOR
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PM5361 TUPP