STANDARD PRODUCT
PM5365 TEMAP
DATASHEET
PMC-1991148
ISSUE 3
HIGH DENSITY VT/TU MAPPER
AND M13 MULTIPLEXER
When demultiplexing three 2048 kbit/s streams from a G.747 formatted 6312
kbit/s stream, the MX12 performs bit destuffing via interpretation of the C-bits.
Tributary payload loopback can be activated or deactivated under software
control. Although no remote loopback request has been defined for G.747,
inversion of the third C-bit triggers a loopback request detection indication in
anticipation of Recommendation G.747 refinement. All three demultiplexed 2048
kbit/s streams can be replaced with AIS on an individual basis.
9.15 Tributary Payload Processor (VTPP)
The tributary payload processor (VTPP) processes the virtual tributaries within
an STS-1, AU3, or TUG3. The VTPP can be configured to process either VT1.5s
or VT2s within an STS-1 or either TU11s or TU12s within an AU3 or TUG3. The
number of tributaries managed by each VTPP ranges from 21 (when configured
to process all VT2s or equivalently all TU12s) to 28 (when configured to process
all VT1.5s or equivalently all TU11s).
The Tributary payload processor is used in both the ingress and egress data
paths. In the egress direction the pointer interpreter section of the VTPP can be
bypassed on a per tributary basis to allow for pointer generator in the absence of
valid pointers which is necessary when mapping floating transparent virtual
tributaries from the SBI bus.
9.15.1 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.
9.15.2 Incoming Timing 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
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 allows the
pointer interpreter to function.
Proprietary and Confidential to PMC-Sierra, Inc. and for its Customers’ Internal Use
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PMC [ PMC-SIERRA, INC ]
