xrt94l33 Exar Corporation, xrt94l33 Datasheet - Page 266

• Manufacturer Part Number: xrt94l33
• Description: Multi-channel, Multi-function Device Aggregates 3 Ds3/e3/sts-1 Into Oc3/stm-1
• Manufacturer: Exar Corporation

XRT94L33
Rev.1.2.0.
2.2.8.3.3
The Transmit SONET POH Processor block can be configured to transmit the REI-P indicator either (1)
automatically, (2) upon software command or (3) via the “TxPOH_n” input port as described below.
2.2.8.3.3.1
The user can configure the Transmit SONET POH Processor block to automatically transmit the REI-P
indicator whenever the corresponding Receive SONET POH Processor block detects at least one B3 byte
error within its incoming STS-1 SPE data-stream.
The user can configure the Transmit SONET POH Processor block to automatically transmit the REI-P
indicator, in response to detection of B3 byte errors, by executing the following steps.
STEP 1 – Write the value [0, 0] into Bits 5 and 6 (REI-P Insertion Type[1, 0]) within the “Transmit
SONET Path – SONET Control Register – Byte 0” as depicted below.
Transmit SONET Path – SONET Control Register – Byte 0 (Address = 0xN983)
This step configures the “Transmit SONET POH Processor” block to automatically set bits 1 through 4 (of the
G1 byte) within the “outbound” STS-1 SPE to the appropriate REI-P value, based upon receive conditions as
detected by the corresponding Receive SONET POH Processor block.
STEP 2 – Indicate whether the REI-P value (transmitted to the remote PTE) reflects the number of bits
(within the B3 byte) that are in error, or the number of erred STS-1 SPE that have been detected by the
corresponding Receive SONET POH Processor block.
The XRT94L33 permits the user to (1) flag B3 byte errors, and (2) to transmit the resulting REI-P value (back
out to the remote PTE) by the following means.
• By flagging and reporting the number of bits (within the B3 byte) that have be determined to be in error,
within a given STS-1 SPE.
• By flagging and reporting whether or not the corresponding Receive SONET POH Processor block is
currently receiving erred STS-1 SPE.
The user can choose between these two options by writing the appropriate value into Bit 0 (B3 Error Type)
within the Receive SONET Path – Control Register – Byte 0”; as illustrated below.
Receive SONET Path – Control Register – Byte 0 (Address = 0x1183)
F2 Insertion
B
Type
B
R/W
R/O
IT
IT
0
0
7
7
TRANSMISSION OF THE REI-P INDICATOR
REI-P Insertion Type[1:0]
Configuring the Transmit SONET POH Processor block to automatically transmit the
REI-P indicator
B
B
R/W
R/O
IT
IT
0
0
6
6
Unused
B
B
R/W
R/O
IT
IT
0
0
3-CHANNEL DS3/E3/STS-1 TO STS-3/STM-1 MAPPER IC DATA SHEET
5
5
RDI-P Insertion Type[1:0]
B
B
R/W
R/O
IT
IT
0
0
4
4
266
Check Stuff
B
B
R/W
R/W
IT
IT
0
0
3
3
RDI-P Type
Insertion
C2 Byte
B
Type
B
R/W
R/W
IT
IT
0
0
2
2
REI-P Error
Auto Insert
C2 Byte
Enable
Mode
B
B
Type
R/W
R/W
IT
IT
0
0
1
1
xr
Transmit
B3 Error
Enable
AIS-P
Type
B
B
R/W
R/W
IT
IT
X
0
0
0