
PM5317 SPECTRA-9953 Telecom Standard Product Data Sheet
Release
Proprietary and Confidential to PMC-Sierra, Inc., and for its customers’ internal use.
Document No.: PMC-2000741, Issue 5
111
The TRMP calculates the line BIP-8 error detection codes on the transmit data stream. One line
BIP-8 error detection code is calculated for each of the constituent STS-1 (STM-0). The line
BIP-8 byte is calculated on the unscrambled bytes of the STS-1 (STM-0) except for the 9 SOH
bytes. The line BIP-8 byte is based on a bit interleaved parity calculation using even parity. For
each STS-1 (STM-0), the calculated BIP-8 error detection code is inserted in the B2 byte of the
following frame before scrambling.
The TRMP optionally scrambles the transmit data stream.
The TRMP calculates the section BIP-8 error detection code on the transmit data stream. The
section BIP-8 byte is calculated on the scrambled bytes of the complete frame. The section
BIP-8 byte is based on a bit interleaved parity calculation using even parity. The calculated
BIP-8 error detection code is inserted in the B1 byte of STS-1 (STM-0) #1 of the following
frame before scrambling.
14.12 Transmit Trail trace Processor (TTTP)
The Transmit Trail trace Processor (TTTP) block generates the trail trace messages to be
transmitted. The TTTP can generate a 16 or 64-byte trail trace message. The message is
sourced from an internal RAM and must have been previously written by an external
microprocessor. Optionally, the trail trace message can be reduced to a single continuous trail
trace byte.
The trail trace message must include synchronization because the TTTP does not add
synchronization. The synchronization mechanism is different for a 16-byte message and for a
64- byte message. When the message is 16 bytes, the synchronization is based on the MSB of
the trail trace byte. Only for one of the 16 bytes is MSB set high. The byte with its MSB set
high is considered the first byte of the message. When the message is 64 bytes, the
synchronization is based on the CR/LF (CR = 0Dh, LF = 0Ah) characters of trail trace message.
The byte following the CR/LF bytes is considered the first byte of the message.
To avoid generating an unstable/mismatch message, the TTTP forces the message to all zeros
while the microprocessor updates the internal RAM.
14.13 Transmit High Order Path Processor (THPP)
The Transmit High Order Path Processor (THPP) block inserts the path overhead bytes in the
transmit data stream. Path overhead bytes can be sourced from different possible sources. All
overhead bytes may optionally be passed-through the THPP.
The path overhead bytes can be sourced from internal registers. There are 8 bits in the THPP
Source & Pointer Control Register (TSPCR) that are used in determining the origin of path
overhead bytes. They are SRCJ1, SRCC2, SRCG1, SRCF2, SRCH4, SRCZ3, SRCZ4, and
SRCZ5.