
PRELIMINARY
XRT86SH221
58
REV. P1.0.5
SDH-TO-PDH FRAMER/MAPPER WITH INTEGRATED 21-CHANNEL E1 SH LIU
I
STS PTE that supports ERDI-P shall terminate a particular type of RDI-P defect (one-bit or enhanced)
when a code other than the code corresponding to that defect is received for 5 to 10 consecutive frames
The rxspoh_stat block allows software to specify the type of RDI-P error to monitor. The software also
programs the number of consecutive consistent RDI-P codes that must be observed before it is accepted as
valid. When a new valid RDI-P is detected, a flag is set for software and the RDI-P code that caused the
condition is captured in a register. The rxspoh_stat block also implements a RDI-P unstable counter. The RDI-
P unstable counter is incremented for each byte that differs from the previously received byte. An invalid RDI-P
condition is declared when the RDI-P unstable counter reaches the software specified threshold. The RDI-P
unstable counter is cleared to 0 when a valid RDI-P code is accepted.
REI-P MONITOR
Bits 1 through 4 (most significant 4 bits) of the G1 byte are allocated to convey the path REI (REI-P) function
and are defined in the SDH standard as:
I
STS PTE shall set bits 1 through 4 of the G1 byte to indicate (to the upstream STS PTE) the count of
interleaved-bit block errors that it has detected based on the STS Path BIP-8 byte (B3). The error count
shall be a binary number from zero to 8. The remaining seven values shall not be transmitted and shall
be interpreted by receiving STS PTE as zero errors.
The rxspoh_stat accumulates the REI-P counts in a 16 bit saturation counter. The count is transferred to a
holding register and reset by software request. The rxspoh_stat also flags any non zero REI-L counts. The
software can configure the rxstoh_stat block to accumulate either bit errors or error events. An error event is
defined as any non-zero REI-P count.
SIGNAL LABEL (C2) MONITOR
The C2 byte is allocated to indicate the contents of the STS SPE and is treated as a signal label. The
rxspoh_stat block monitors the C2 byte for several conditions according to the SDH standard.
I
STS PTE shall detect an STS Payload Label Mismatch (PLM-P) defect within 250ms of the onset of at
least five consecutive samples (which may or may not be consecutive frames) of mismatched STS
Signal Labels (C2 byte), as specified in
Table 5
.
I
STS PTE should detect a PLM-P defect immediately upon receipt of five contiguous frames with
mismatched STS Signal Labels, as specified in
Table 5
.
I
STS PTE shall terminate a PLM-P defect within 250ms of detecting the onset of at least five consecutive
samples (which may or may not be consecutive frames) of matched STS Signal Labels.
I
STS PTE should terminate a PLM-P defect immediately upon receipt of five contiguous frames with
matched STS Signal Labels, as specified in
Table 5
.
I
STS PTE shall terminate a PLM-P defect upon detecting an UNEQ-P defect.
T
ABLE
4: RDI-P S
ETTINGS
AND
I
NTERPRETATION
G1 B
ITS
5, 6
AND
7
P
RIORITY
OF
ERDI-P
CODES
T
RIGGER
I
NTERPRETATION
0xx
not applicable (for SRDI-P only, bits 6 and 7
should be '00')
No defects
No RDI-P defect
1xx
not applicable (for SRDI-P only, bits 6 and 7
should be '00')
AIS-P, LOP-P
one-bit RDI-P defect
001
4
No defects
No RDI-P defect
010
3
PLM-P, LCD-P
ERDI-P Payload Defect
101
2
AIS-P, LOP-P
ERDI-P Server Defect
110
1
UNEQ-P, TIM-P
ERDI-P Connectivity
defect