![](http://datasheet.mmic.net.cn/Exar-Corporation/XRT94L33IB-L_datasheet_100163/XRT94L33IB-L_395.png)
xr
XRT94L33
3-CHANNEL DS3/E3/STS-1 TO STS-3/STM-1 MAPPER IC DATA SHEET
Rev.1.2.0.
395
2.3.3.1.1
Handling Incrementing Pointer Adjustment Events
2.3.3.1.2
Handling Decrementing Pointer Adjustment Events
2.3.3.1.3
Handling NDF (New Data Flag) Events
2.3.3.1.4
LOP-P DECLARATION AND CLEARANCE CRITERIA
2.3.3.1.5
AIS-P DECLARATION AND CLEARANCE CRITERIA
2.3.3.2
PROCESSING/HANDLING THE G1 BYTE
2.3.3.2.1
RDI-P DETECTION AND CLEARANCE CRITERIA
2.3.3.2.2
DETECTING/FLAGGING REI-P EVENTS
The Receive SONET POH Processor block is capable of detecting the REI-P indicator, within the incoming
STS-1 SPE data-stream. As the Receive SONET POH Processor block receives a given STS-1 SPE data-
stream, it will monitor the contents within Bits _ through _ in the G1 byte. The bit-format of the G1 byte is
Figure 93 Bit format of the G1 Byte
Figure 93 indicates that Bits _ through _, within the G1 byte are allocated for the REI-P function.
The role of the REI-P bit-fields was described in some detail, in Section _. This section indicates that the
remote PTE will set the “REI-P” value (within the G1 byte) to “0” during “un-erred” conditions. However, the
remote PTE will typically set the “REI-P” value to a value (ranging from “1” to “8”) during “erred” conditions.
If the Receive SONET POH Processor block receives an STS-1 SPE, that contains a “non-zero” value of REI-
P, then it will do the following.
1. It will generate the “Detection of REI-P Event” Interrupt.
Note:
The Receive SONET POH Processor block will indicate this by, pulling the “INT*” output pin “LOW” and by
setting Bit 6 (Detection of REI-P Event Interrupt Status), within the “Receive SONET Path – SONET Receive
Path Interrupt Status – Byte 1” to “1” as depicted below.
Receive SONET Path – SONET Receive Path Interrupt Status – Byte 1 (Address = 0xN18A)
BIT 7
BIT 6
BIT 5
BIT 4
BIT 3
BIT 2
BIT 1
BIT 0
Unused
Detection of
REI-P Event
Interrupt
Status
Change in
UNEQ-P
Defect
Condition
Interrupt
Status
Change in
PLM-P
Defect
Condition
Interrupt
Status
New C2
Byte
Interrupt
Status
Change in
C2 Byte
Unstable
Defect
Condition
Interrupt
Status
Change in
RDI-P
Unstable
Defect
Condition
Interrupt
Status
New
RDI-P Value
Interrupt
Status
R/O
RUR
0
1
0
2. It will increment the “Receive SONET Path – REI-P Error Count” Registers
Note:
These registers are actually 32-bit registers, which are located at Direct Address locations 0xNA9C through
0xNA9F. The bit-format of these registers is presented below.