STANDARD PRODUCT
PM5365 TEMAP
DATASHEET
PMC-1991148
ISSUE 3
HIGH DENSITY VT/TU MAPPER
AND M13 MULTIPLEXER
9.16 Receive Tributary Path Overhead Processor (RTOP)
The tributary path overhead processor (RTOP) monitors the outgoing stream of
the tributary payload processor (VTPP) and processes the tributaries within an
STS-1, AU3, or TUG3. The RTOP can be configured to process all the VT1.5s
or VT2s that can be carried in an STS-1 or all the TU11s or TU12s that can be
carried in an AU3 or TUG3. The number of tributaries managed by each RTOP
ranges from 21 (when configured to process all VT2s or all TU12s) to 28 (when
configured to process all VT1.5s or all TU11s).
The RTOP provides tributary performance monitoring of incoming tributaries. Bit
interleaved parity of the incoming tributaries is computed and compared with the
BIP-2 code encoded in the V5 byte of the tributary. Errors between the
computed and received values are accumulated. RTOP also accumulates far
end block error codes. Incoming path signal label is debounced and compared
with the provisioned value. Path signal label unstable, path signal label
mismatch and change of path signal label event are identified.
9.16.1 Clock Generator
The clock generator derives a 6.48 MHz clock from the 19.44 MHz system clock
and distributes this to the tributary payload processor.
9.16.2 Timing Generator
The timing generator identifies the incoming tributary being processed at any
given point in time. Based on the configuration of the RTOP (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 identification of specific tributaries
allows the error monitor and extract blocks to be time-sliced across the mix of
tributaries present in the incoming data stream.
9.16.3 Error Monitor
The error monitor block is a time-sliced state machine. It relies on the timing
generator block to identify the tributary being processed. The error monitor block
contains a set of 12-bit counters that are used to accumulate tributary path BIP-2
errors, and a set of 11-bit counters to accumulate far end block errors (FEBE).
The contents of the counters may be transferred to a holding RAM, and the
counters reset under microprocessor control.
Proprietary and Confidential to PMC-Sierra, Inc. and for its Customers’ Internal Use
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PMC [ PMC-SIERRA, INC ]
