
XRT86SH221
PRELIMINARY
123
SDH-TO-PDH FRAMER/MAPPER WITH INTEGRATED 21-CHANNEL E1 SH LIU
REV. P1.0.5
determined that the number of B2 byte errors (measured over a user-selected period of time) exceeds a certain user-
specified B2 Byte Error threshold.
0 - Indicates that the SD Defect condition is NOT currently being declared.
This bit is set to 0 when the number of B2 errors (accumulated over a given interval of time) does not exceed the SD
Declaration threshold.
1 - Indicates that the SD Defect condition is currently being declared.This bit is set to 1 when the number of B2 errors
(accumulated over a given interval of time) does exceed the SD Defect Declaration threshold.
BIT 2 - LOF (Loss of Frame) Defect Declared
This READ-ONLY bit-field indicates whether or not the Receive STM-0 TOH Processor block is currently declaring the
LOF defect condition. The Receive STM-0 TOH Processor block will declare the LOF defect condition if it has been
declaring the SEF condition for 24 consecutive STM-0 frame periods. Once the LOF defect is declared, then the
Receive STM-0 TOH Processor block will clear the LOF defect if it has not been declaring the SEF condition for 3ms
(or 24 consecutive STM-0 frame periods).
0 - Indicates that the Receive STM-0 TOH Processor block is NOT currently declaring the LOF defect condition.
1 - Indicates that the Receive STM-0 TOH Processor block is currently declaring the LOF defect condition.
BIT 1 - SEF (Severely Errored Frame) Defect Declared
This READ-ONLY bit-field indicates whether or not the Receive STM-0 TOH Processor block is currently declaring the
SEF defect condition. The Receive STM-0 TOH Processor block will declare the SEF defect condition if it detects
Framing Alignment byte errors in four consecutive STM-0 frames. Once the Receive TOH Processor block declares
the SEF defect condition, the Receive STM-0 TOH Processor block will then clear the SEF defect condition if it detects
two consecutive STM-0 frames with un-erred framing alignment bytes. If the Receive TOH Processor block declares
the SEF defect condition for 24 consecutive STM-0 frame periods, then it will declare the LOF defect condition.
0 - Indicates that the Receive STM-0 TOH Processor block is NOT currently declaring the SEF defect condition.
1 - Indicates that the Receive STM-0 TOH Processor block is currently declaring the SEF defect condition.
BIT 0 - LOS (Loss of Signal) Defect Declared
This READ-ONLY bit-field indicates whether or not the Receive STM-0 TOH Processor block is currently declaring the
LOS (Loss of Signal) defect condition. The Receive STM-0 TOH Processor block will declare the LOS defect condition
if it detects LOS_THRESHOLD[15:0] consecutive All Zero bytes in the incoming STM-0 data stream.
N
OTE
:
The user can set the LOS_THRESHOLD[15:0] value by writing the appropriate data into the Receive STM-0
Transport - LOS Threshold Value Register (Address Location= 0x022E and 0x022F).
0 - Indicates that the Receive STM-0 TOH Processor block is NOT currently declaring the LOS defect condition.
1 - Indicates that the Receive STM-0 TOH Processor block is currently declaring the LOS defect condition.