![](http://datasheet.mmic.net.cn/Exar-Corporation/XRT94L33IB-L_datasheet_100163/XRT94L33IB-L_335.png)
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XRT94L33
3-CHANNEL DS3/E3/STS-1 TO STS-3/STM-1 MAPPER IC DATA SHEET
Rev.1.2.0.
335
Receive STS-3 Transport Status Register – Byte 0 (Address = 0x1107)
BIT 7
BIT 6
BIT 5
BIT 4
BIT 3
BIT 2
BIT 1
BIT 0
RDI-L
Defect
Declared
S1 Byte
Unstable
Defect
Declared
K1, K2 Byte
Unstable
Defect
Declared
SF Defect
Declared
SD Defect
Declared
LOF Defect
Declared
SEF Defect
Declared
LOS Defect
Declared
R/O
0
1
It will generate the “Change of LOS Defect Condition” Interrupt, by toggling the “INT*” output pin “LOW”,
and by setting Bit 0 (Change of LOS Defect Condition Interrupt Status), within the “Receive STS-3 Transport
Interrupt Status Register – Byte 0” to “1”, as illustrated below.
Receive STS-3 Transport Interrupt Status Register – Byte 0 (Address = 0x110B)
BIT 7
BIT 6
BIT 5
BIT 4
BIT 3
BIT 2
BIT 1
BIT 0
Change of
SF Defect
Condition
Interrupt
Status
Change of
SD Defect
Condition
Interrupt
Status
Detection of
REI-L Error
Interrupt
Status
Detection of
B2 Byte
Error
Interrupt
Status
Detection of
B1 Byte
Error
Interrupt
Status
Change of
LOF Defect
Condition
Interrupt
Status
Change of
SEF Defect
Condition
Interrupt
Status
Change of
LOS Defect
Condition
Interrupt
Status
RUR
0
1
2.3.1.2.2
How the Receive STS-3 TOH Processor Block Clears the LOS Defect
The Receive STS-3 TOH Processor block will clear the LOS defect once both of the following conditions have
been met.
That the Receive STS-3 TOH Processor block detects proper A1 and A2 bytes in two consecutive STS-3
frames, and
That, in between the detection of the two sets of A1/A2 bytes, the Receive STS-3 TOH Processor block does
not detect the “LOS_THRESHOLD[15:0]” number of “All Zero” bytes, within the incoming STS-3 data-stream.
Once the Receive STS-3 TOH Processor block clears the LOS defect, it will notify the system of this fact by
doing the following.
It will set Bit 1 (LOS Detected) within the Receive STS-3c Transport Status Register – Byte 0” to “0” as
illustrated below.
Receive STS-3 Transport Status Register – Byte 0 (Address = 0x1107)
BIT 7
BIT 6
BIT 5
BIT 4
BIT 3
BIT 2
BIT 1
BIT 0
RDI-L
Defect
Declared
S1 Byte
Unstable
Defect
Declared
K1, K2 Byte
Unstable
Defect
Declared
SF Defect
Declared
SD Defect
Declared
LOF Defect
Declared
SEF Defect
Declared
LOS Defect
Declared
R/O
0
It will generate the “Change of LOS Defect Condition” Interrupt by toggling the “INT*” output pin “LOW”, and
by setting Bit 0 (Change of LOS Defect Condition Interrupt Status), within the “Receive STS-3 Transport
Interrupt Status Register – Byte 0” to “1”, as illustrated below.