PM5362TUPP-PLUS
DATA SHEET
PMC-951010
ISSUE 6
SONET/SDH TRIBUTARY UNIT PAYLOAD PROCESSOR / PERFORMANCE MONITOR
tributary trace buffers (RTTBs). The output bus multiplexer contains a four frame
counter that will flywheel in the absence of an active OTMF input, internally
generating tributary multiframe timing for the outgoing data stream. When
configured for locked output mode, i.e. when OJ1EN is low, the output bus
multiplexer will internally 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. The locked transport and payload
frame boundaries are reported on the LC1J1V1 and LPL outputs. This timing
drives the outputs of the three VTPPs, RTOPs and RTTBs, substituting for the
function otherwise provided by the OC1J1 and OPL 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 VTPP, RTOP and RTTB blocks.
8.3
Tributary Payload Processor
Each tributary payload processor (VTPP) processes the tributaries within an
STS-1, AU3, or TUG3. Each VTPP 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 VTPP ranges from 1 (when configured to
process a single TU3) to 28 (when configured to process all VT1.5s or
equivalently all TU11s).
8.3.1 Clock Generator
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.
8.3.2 IncomingTiming Generator
The incoming timing generator identifies the incoming tributary being processed
at any given point in time. Based on the configuration of the VTPP (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
PROPRIETARY AND CONFIDENTIAL TO PMC-SIERRA, INC., AND FOR ITS CUSTOMERS’ INTERNAL USE
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