PM5366-PI PMC-Sierra, Inc., PM5366-PI Datasheet - Page 106

• 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
9.21 E3 Trail Trace Buffer
9.22 Tributary Payload Processor (VTPP)
PROPRIETARY AND CONFIDENTIAL
In each case, the E3 transmitter drives the selected E3 clock source onto the
TCLK output pins of the DS3/E3 line side interface.
The Trail Trace Buffer (TTB) extracts and sources the trail trace message carried
in the TR byte of the G.832 E3 stream. The message is used by the OS
(operating system) to prevent delivery of traffic from the wrong source and is 16
bytes in length. The 16-byte message is framed by the PTI Multiframe Alignment
Signal (TMFAS = 'b10000000 00000000). One bit of the TMFAS is placed in the
most significant bit of each message byte. In the receive direction, the extracted
message is stored in the internal RAM for review by an external microprocessor.
By default, the byte of a 16-byte message with its most significant bit set high will
be written to the first location in the RAM. The extracted trail trace message is
checked for consistency between consecutive multiframes. A message received
unchanged three or five times (programmable) is accepted for comparison with
the copy previously written into the internal RAM by the external microprocessor.
Alarms are raised to indicate reception of unstable and mismatched messages.
In the transmit direction, the trail trace message is sourced from the internal
RAM for insertion into the TR byte by the E3-TRAN.
The Payload Type label carried in the MA byte of the G.832 E3 stream is also
extracted. The label is used to ensure that the adaptation function at the trail
termination sink is compatible with the adaptation function at the trail termination
source. The Payload Type label is check for consistency between consecutive
multiframes. A Payload Type label received unchanged for five frames is
accepted for comparison with the copy previously written into the TTB by the
external microprocessor. Alarms are raised to indicate reception of unstable and
mismatched Payload Type label bits.
Each of of three tributary payload processors (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.
ISSUE 1
94
HIGH DENSITY 84/63 CHANNEL VT/TU MAPPER
AND M13 MULTIPLEXER
PM5366 TEMAP-84