
XRT86SH221
PRELIMINARY
59
SDH-TO-PDH FRAMER/MAPPER WITH INTEGRATED 21-CHANNEL E1 SH LIU
REV. P1.0.5
I
STS PTE shall detect an STS Path Unequipped (UNEQ-P) defect within 10ms of the onset of at least 5
consecutive samples (which may or may not be consecutive frames) of unequipped STS Signal Labels
(C2 byte = 00hex)
I
STS PTE should detect an UNEQ-P defect immediately upon receipt of five contiguous frames with
unequipped STS Signal Labels, as specified in
Table 5
.
I
STS PTE shall terminate an UNEQ-P defect within 10ms of the onset of at least five consecutive
samples (which may or may not be consecutive frames) of STS Signal Labels that are not unequipped.
I
STS PTE should terminate an UNEQ-P defect immediately upon receipt of five contiguous frames with
STS Signal Labels that are not unequipped, as specified in
Table 5
.
The rxspoh_stat block allows software to specify the expected signal label and compares it with the observed
value. If the values mismatch, then a path label mismatch (PLM) error is declared. If the observed value is
00hex, then a path unequipped (UNEQ) error is declared (and PLM cleared). If the observed value matches
the expected value, then PLM is cleared. If the observed value changes, then a flag is set for software. For a
C2 label to be considered valid, it must be received in 5 consecutive frames. The rxspoh_stat blocks also
implements a C2 unstable counter. The C2 unstable counter is incremented for each byte that differs from the
previously received byte. An invalid C2 condition is declared when the C2 unstable counter reaches 5. The C2
unstable counter is cleared to 0 when 5 consecutive identical C2 bytes are received. The rxspoh_stat block
implements a mismatch mechanism that can be summarised in
Table 6
.
T
ABLE
5: STS S
IGNAL
L
ABEL
M
ISMATCH
D
EFECT
C
ONDITIONS
P
ROVISIONED
STS PTE
F
UNCTIONALITY
R
ECEIVED
P
AYLOAD
L
ABEL
(C2 B
YTE
,
IN
HEX
FORMAT
)
D
EFECT
Any Equipped functionality (C2 =
anything except H00)
Unequipped (00)
UNEQ-P
Any Equipped functionality
Equipped - Non Specific (01)
none (Matched)
Equipped - Non Specific (C2 = H01) A value corresponding to any Payload Specific functionality
none (Matched)
Any Payload Specific functionality
(C2 = anything except H00 or H01)
A value corresponding to the same payload specific functional-
ity as the provisioned functionality
none (Matched)
Any Payload Specific functionality
A value corresponding to a different payload specific functional-
ity as the provisioned functionality
PLM
T
ABLE
6: T
RUTH
T
ABLE
FOR
P
ATH
L
ABEL
E
RROR
C
ONDITIONS
E
XPECTED
V
ALUE
R
ECEIVED
V
ALUE
A
CTION
00
00
match
00
01
mismatch
00
XX
mismatch
01
00
UNEQ-P
01
01
match
01
XX
match
XX
00
UNEQ-P
XX
01
match
XX
XX
match
XX
YY
mismatch