
XRT79L71
PRELIMINARY
379
1-CHANNEL DS3/E3 CLEAR-CHANNEL FRAMERLIU COMBO - CC/HDLC ARCHITECTURE
REV. P2.0.0
Generating the "Change in LOF Defect Condition" Interrupt
The Receive E3 Framer block will indicate that it is declaring the "Change in LOF Defect Condition" Interrupt by
doing all of the following.
a. Asserting the Interrupt Request output pin (INT*), by pulling it "low".
b. Setting Bit 2 (Change in LOF Defect Condition Interrupt Status), within the "Receive E3 Interrupt Status
Register # 1", to "1" as depicted below
5.3.2.2
THE FRAME-MAINTENANCE MODE - THE OOF AND LOF DECLARATION CRITERIA
Once the Receive E3 Framer block has entered the "In-Frame" state, then it is considered to be operating in
the "Frame Maintenance" Mode. As the Receive E3 Framer block transitions into the "In-Frame" state, it will
notify the Microprocessor/Microcontroller of this fact by doing all of the following.
Clearing the "OOF" (Out-of-Frame) and "LOF" (Loss of Frame) Defect Conditions
The Receive E3 Framer block will indicate that it is clearing both the "OOF" and "LOF Defect Conditions" by
setting Bit 5 (OOF Defect Condition Declared) and 6 (LOF Defect Condition Declared) within the "Receive E3
Configuration and Status Register # 2" to "0" as depicted below.
Receive E3 Configuration and Status Register # 2 - G.751 (Address = 0x1111)
BIT 7
BIT 6
BIT 5
BIT 4
BIT 3
BIT 2
BIT 1
BIT 0
RxLOF
Algo
LOF
Defect
Condition
Declared
OOF
Defect
Condition
Declared
LOS
Defect
Condition
Declared
AIS
Defect
Condition
Declared
Unused
FERF/RDI
Defect
Condition
Declared
R/W
R/O
X
1
0
1
Receive E3 Interrupt Status Register # 1 - G.751 (Address = 0x1114)
BIT 7
BIT 6
BIT 5
BIT 4
BIT 3
BIT 2
BIT 1
BIT 0
Unused
COFA
Interrupt
Status
Change in
OOF Defect
Condition
Interrupt
Status
Change in
LOF Defect
Condition
Interrupt
Status
Change in
LOS Defect
Condition
Interrupt
Status
Change in
AIS Defect
Condition
Interrupt
Status
R/O
RUR
0
1
0
Receive E3 Configuration and Status Register # 2 - G.751 (Address = 0x1111)
BIT 7
BIT 6
BIT 5
BIT 4
BIT 3
BIT 2
BIT 1
BIT 0
Receive
LOF
Algo
LOF
Defect
Condition
Declared
OOF
Defect
Condition
Declared
LOS
Defect
Condition
Declared
AIS Defect
Condition
Declared
Unused
FERF/RDI
Defect
Condition
Declared
R/W
R/O
X
0
1