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XRT7250
DS3/E3 FRAMER IC
REV. 1.1.1
431
the RxE3 Interrupt Enable Register - 1, as indicated
below.
Setting this bit-field to “1” enables this interrupt. Con-
versely, setting this bit-field to “0” disables this inter-
rupt.
Servicing the Change in Receive OOF Condition
Interrupt
Whenever the XRT7250 Framer IC detects this inter-
rupt, it will do all of the following.
It will assert the Interrupt Request output pin (INT),
by driving it “Low”.
It will set Bit 3 (OOF Interrupt Status), within the Rx
E3 Interrupt Status Register - 1 to “1”, as indicated
below.
Whenever the user’s system encounters the Change
in Receive OOF Condition Interrupt, then it should do
the following.
1. It should determine the current state of the OOF
condition. Recall, that this interrupt can be gen-
erated, whenever the XRT7250 Framer IC
declares or clears the OOF defect. Hence, the
user can determine the current state of the LOS
defect by reading the state of Bit 5 (RxOOF)
within the Rx E3 Configuration and Status Regis-
ter - 2, as illustrated below.
If the OOF state is TRUE
1. It should transmit a FERF (Far-End-Receive Fail-
ure) indicator to the Remote Terminal Equipment.
The XRT7250 Framer IC automatically supports
this action via the FERF-upon-OOF feature.
If the OOF state is FALSE
1. It should cease transmitting the FERF indication
to the Remote Terminal Equipment. The
XRT7250 Framer IC automatically supports this
action via the FERF-upon-OOF feature.
6.3.6.2.3
The Change in Receive LOF Condi-
tion Interrupt
If the Change in Receive LOF Condition Interrupt is
enabled, then the XRT7250 Framer IC will generate
an interrupt in response to either of the following con-
ditions.
RXE3 INTERRUPT ENABLE REGISTER - 1 (ADDRESS = 0X12)
BIT 7BIT 6BIT 5BIT 4BIT 3BIT 2BIT 1BIT 0
Not Used
COFA
Interrupt
Enable
OOF
Interrupt
Enable
LOF
Interrupt
Enable
LOS
Interrupt
Enable
AIS
Interrupt
Enable
RO
R/W
0
0000
0
X
0
RXE3 INTERRUPT STATUS REGISTER - 1 (ADDRESS = 0X14)
BIT 7BIT 6BIT 5BIT 4BIT 3BIT 2BIT 1BIT 0
Not Used
COFA
Interrupt
Status
OOF
Interrupt
Status
LOF
Interrupt
Status
LOS
Interrupt
Status
AIS
Interrupt
Status
RO
RUR
0
0000
010
RXE3 CONFIGURATION & STATUS REGISTER 2 (ADDRESS = 0X11)
BIT 7BIT 6BIT 5BIT 4BIT 3BIT 2BIT 1BIT 0
Rx LOF Algo
RxLOF
RxOOF
RxLOS
RxAIS
RxPld Unstab
Rx
TMark
RxFERF
R/W
RORO
RO
RORORORO
XX
XXXX
XX