
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
112
The THPP calculates the path BIP-8 error detection code on the transmit data stream. The path
BIP-8 byte is calculated on all the payload bytes. The path BIP-8 byte is based on a bit
interleaved parity calculation using even parity. The calculated BIP-8 error detection code is
optionaly inserted in the B3 byte of the following frame. The path trace byte (J1) can be
optionally sourced from the Transmit Path Trace Buffer.
The THPP accumulates the path BIP-8 errors detected by the RHPP during the last receive
frame. The path BIP-8 errors are optionally returned to the far end as path remote error
indication (REI-P : G1 Bytes) during the next transmit frame. Because the RHPP and the THPP
are in two different clock domains, two, one or no path BIP-8 errors can be accumulated per
transmit frame. The minimum value between the maximum REI-P and the accumulator count is
returned as the path REI in the G1 byte. Optionally, block BIP-8 errors can be accumulated. T
gives the source priority for each overhead byte.
Table 12 Path Overhead Byte Source Priority
Byte
Highest
Priority
Lowest
Priority
J1
UNEQV
(UNEQ=1)
J1 pass through
(TDIS=1
OR
PAIS=1)
Path trace buffer
(PTBJ1=1)
J1 ind. reg.
(SRCJ1=1)
J1 pass
through
B3
UNEQV
(UNEQ=1)
B3 pass through
(TDIS=1
OR
PAIS=1)
Calculated B3
Calculated
B3
XOR
B3MASK
C2
UNEQV
(UNEQ=1)
C2 pass through
(TDIS=1
OR
PAIS=1)
C2 ind. reg.
(SRCC2=1)
C2 pass
through
G1
UNEQV
(UNEQ=1)
G1 pass through
(TDIS=1
OR
PAIS=1
OR
IBER=1)
PRDI[2:0] and
PREI[3:0]
(ENG1REC=1)
G1 ind. reg.
(SRCG1=1)
G1 pass
through
F2
UNEQV
(UNEQ=1)
F2 pass through
(TDIS=1
OR
PAIS=1)
F2 ind. reg.
(SRCF2=1)
F2 pass
through
H4
UNEQV
(UNEQ=1)
H4 pass through
(TDIS=1
OR
PAIS=1)
H4 pass through
XOR H4 ind. reg.
(SRCH4=1
AND
H4 ind. reg.
(SRCH4=1)
H4 pass through
H4 pass
through