![](http://datasheet.mmic.net.cn/Exar-Corporation/XRT94L33IB-L_datasheet_100163/XRT94L33IB-L_390.png)
XRT94L33
xr
Rev.1.2.0.
3-CHANNEL DS3/E3/STS-1 TO STS-3/STM-1 MAPPER IC DATA SHEET
390
Configuring the Receive STS-3c POH Processor block to increment the “Receive STS-3c Path – REI-P
Error Count” Register on an “REI-P Value” basis.
The user can configure the Receive STS-3c TOH Processor block to increment the “Receive STS-3c Path –
REI-P Error Count” Register by the contents within the “REI-P” nibbles, within each incoming STS-3c SPE.
Therefore, in this mode, it is possible for the Receive STS-3c POH Processor block to increment this register
by as much as the value “8” per STS-3c SPE.
The user can accomplish this by setting Bit 1 (REI-P Error Type) within the “Receive STS-3c Path – Control
Register – Byte 0” to “0”, as illustrated below.
Receive STS-3c Path – Control Register – Byte 0 (Address = 0x1183)
BIT 7
BIT 6
BIT 5
BIT 4
BIT 3
BIT 2
BIT 1
BIT 0
Unused
Check
Stuff
RDI-P
Type
REI-P
Error Type
B3 Error
Type
R/O
R/W
0
2.3.2.3
PATH BIP-8 (B3) BYTE VERIFICATION
Configuring the Receive STS-3c POH Processor block to increment the “Receive STS-3c Path – B3
Error Count” Register on a “per-SPE” basis.
The Receive STS-3c POH Processor block has the responsibility for computing and verifying the Path BIP-8
(e.g., B3) byte within each incoming STS-3c SPE. When the Receive STS-3c POH Processor block executes
this function, it will do the following.
It will read in the contents of a given “newly received” STS-3c SPE.
It will compute the BIP-8 value over the SPE.
This resulting BIP-8 value will be compared with the contents of the B3 byte, within the very next STS-3c
SPE.
The user can configure the Receive STS-3c POH Processor block to increment the “Receive STS-3c Path –
B3 Error Count” Register, by the value “1” for each STS-3c SPE that it determined to have a bit-error.
The user can accomplish this by setting Bit 0 (B3 Error Type), within the “Receive STS-3c Path – Control
Register – Byte 0” to “1”, as illustrated below.
Receive STS-3c Path – Control Register – Byte 0 (Address = 0x1183)
BIT 7
BIT 6
BIT 5
BIT 4
BIT 3
BIT 2
BIT 1
BIT 0
Unused
Check Stuff
RDI-P Type
REI-P Error
Type
B3 Error
Type
R/O
R/W
0
1
Note:
This the user implements this setting, then the corresponding Transmit STS-3c POH Processor block will set the
REI-P nibble value (within the G1 byte) to the number of erred SPE that have been detected. In this case, the
maximum value that the REI-P nibble (within an STS-3c SPE) will contain will be “1”.
If the Receive STS-3c POH Processor block detects any B3 byte errors, then it will do the following.
a. It will generate the “Detection of B3 Error” Interrupt, by toggling the “INT*” output pin “LOW” and by
setting Bit 7 (Detection of B3 Byte Error Interrupt Status) to “1” as indicated below.