
PRELIMINARY
XRT86SH221
208
REV. P1.0.5
SDH-TO-PDH FRAMER/MAPPER WITH INTEGRATED 21-CHANNEL E1 SH LIU
BIT [7:6] - Unused
BITt 5 - Pointer Force
This READ/WRITE bit-field is used to load the values contained within the Transmit STM-0 POH Arbitrary H1 Pointer
and Transmit STM-0 POH Arbitrary H2 Pointer registers (Address Location= 0x07BF and 0x07C3) into the H1 and H2
bytes (within the outbound STM-0 data stream).
The actual location of the VC-3 will NOT be adjusted, per the value of H1 and H2 bytes. Hence, this feature should
cause the remote terminal to declare an Invalid Pointer condition.
0 - Configures the Transmit STM-0 POH and TOH Processors to Transmit STM-0 data will normal and correct H1 and
H2 bytes.
1 - Configures the Transmit STM-0 POH and TOH Processor Blocks to overwrite the values of the H1 and H2 bytes
(in the outbound STM-0 data-stream) with the values in the Transmit STM-0 POH Arbitrary H1 and H2 Pointer registers.
BITt 4 - Check Stuff Monitoring
This READ/WRITE bit-field is used to configure the Transmit STM-0 POH and TOH Processor Blocks to only execute
a Positive, Negative or NDF event (via the Insert Positive Stuff, Insert Negative Stuff, Insert Continuous or Single NDF
options, via software command) if no pointer adjustment (NDF or otherwise) has occurred during the last 3 STM-0 frame
periods.
0 - Disables this feature.In this mode, the Transmit STM-0 POH and TOH Processor Block will execute a software-
commanded pointer adjustment event, independent of whether a pointer adjustment event has occurred in the last 3
STM-0 frame periods.
1 - Enables this feature.In this mode, the Transmit STM-0 POH and TOH Processor Block will ONLY execute a
software-commanded pointer adjustment event, if no pointer adjustment event has occurred during the last 3 STM-0
frame periods.
BITt 3 - Insert Negative Stuf
This READ/WRITE bit-field is used to configure the Transmit STM-0 POH and TOH Processor Blocks to insert a
negative-stuff into the outbound STM-0 data stream. This command, in-turn will cause a Pointer Decrementing event
at the remote terminal.
Writing a 0 to 1 transition into this bit-field causes the following to happen.
A negative-stuff will occur (e.g., a single payload byte will be inserted into the H3 byte position within the
outbound STM-0 data stream).
The D bits, within the H1 and H2 bytes will be inverted (to denote a Decrementing Pointer Adjustment event).
The contents of the H1 and H2 bytes will be decremented by 1, and will be used as the new pointer from this
point on.
N
OTE
:
Once the user writes a 1 into this bit-field, the XRT86SH328 will automatically clear this bit-field. Hence, there
is no need to subsequently reset this bit-field to 0.
BITt 2 - Insert Positive Stuff
This READ/WRITE bit-field is used to configure the Transmit STM-0 POH and TOH Processor Blocks to insert a
positive-stuff into the outbound STM-0 data stream. This command, in-turn will cause a Pointer Incrementing event at
the remote terminal.
Writing a 0 to 1 transition into this bit-field causes the following to happen.
T
ABLE
179: T
RANSMIT
STM-0 P
ATH
P
OINTER
C
ONTROL
R
EGISTER
(TPPCR 0
X
07B7)
BIT 7
BIT 6
BIT 5
BIT 4
BIT 3
BIT 2
BIT 1
BIT 0
Unused
Pointer
Force
Check Stuff
Insert
Negative
Stuff
Insert
Positive Stuff
Insert
Continuous
NDF Events
Insert
Single NDF
Event
R/O
R/O
R/W
R/W
W
W
R/W
R/W
0
0
0
0
0
0
0
0