PM5366-PI PMC-Sierra, Inc., PM5366-PI Datasheet - Page 108

• Manufacturer Part Number: PM5366-PI
• Description: HIGH DENSITY 84/63 CHANNEL VT/TU MAPPER AND M13 MULTIPLEXER
• Manufacturer: PMC-Sierra, Inc.

PRELIMINARY
DATASHEET
PMC-2010672
9.22.4 Pointer Generator
9.23 Receive Tributary Path Overhead Processor (RTOP)
PROPRIETARY AND CONFIDENTIAL
1. The pointer generator block generates the tributary pointers (V1/V2) as
The pointer generator is a time-sliced state machine that can process up to 28
independent tributaries. The state vector is saved in RAM at the address
associated with the current tributary. The pointer generator fills the outgoing
tributary synchronous payload envelopes with bytes read from the associated
FIFO in the payload buffer for the current tributary. The pointer generator
creates pointers in the V1-V3 bytes of the outgoing data stream. The marker
that tags the V5 byte that is passed through the payload buffer is used to align
the pointer. The outgoing timing generator directs the pointer generator to the
FIFO in the payload buffer that is associated with the tributary being processed.
The pointer generator monitors the fill levels of the payload buffers and inserts
outgoing pointer justifications as necessary to avoid FIFO spillage. Normally, the
pointer generator has a FIFO dead band of two bytes. The dead band can be
collapse to one so that any incoming pointer justifications will be reflected by a
corresponding outgoing justification with no attenuation. Signals are output by
the pointer generator that identify outgoing V5 bytes and the tributary
synchronous payload envelopes. On a per tributary basis, tributary path AIS and
tributary idle (unequipped) can be inserted as controlled by microprocessor
accessible registers. The idle code is selectable globally for the entire VC3 or
TUG3 to be all-zeros or all-ones. It is also possible to force an inverted new data
flag on individual tributaries for the purpose of diagnosing downstream pointer
processors. Tributary path AIS is automatically inserted into outgoing tributaries
if the pointer interpreter detects tributary path AIS on the corresponding incoming
tributary.
Each one of three tributary path overhead processors (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
specified in the references. The pointer value is used to determine the
location of the tributary path overhead byte (V5) on the outgoing stream.
ISSUE 1
96
HIGH DENSITY 84/63 CHANNEL VT/TU MAPPER
AND M13 MULTIPLEXER
PM5366 TEMAP-84