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PRELIMINARY
XRT79L71
528
REV. P2.0.0
1-CHANNEL DS3/E3 CLEAR-CHANNEL FRAMERLIU COMBO - CC/HDLC ARCHITECTURE
will generate the FERF/RDI indicator. In this Section, we will describe how a given Terminal that contains the
XRT79L71 will respond to receiving the FERF/RDI indicator from the remote terminal equipment.
The FERF/RDI Defect Declaration Criteria
The Receive E3 Framer block will declare the FERF/RDI defect condition, if it receives a user-selectable
number of consecutive E3 frames, in which the FERF/RDI bit-field is set to "1".
The user can select the appropriate number of consecutive incoming E3 frames in which the FERF/RDI bit-
field are set to "1" prior to the Receive E3 Framer block declaring the FERF/RDI Defect condition by writing the
appropriate value into Bit 4 (RxFERF Algo) within the Receive E3 Configuration and Status Register # 1 as
depicted below.
Setting this bit-field to "0" configures the Receive E3 Framer block to declare the FERF/RDI defect condition, if
it has received at least three (3) consecutive E3 frames, in which the FERF/RDI bit-field has been set to "1".
Conversely, setting this bit-field to "1" configures the Receive E3 Framer block to declare the FERF/RDI defect
condition, if it has received at least five (5) consecutive E3 frames, in which the FERF/RDI bit-field has been
set to "1".
When the Receive E3 Framer block declares the FERF or RDI defect condition in the incoming E3 frame, then
it will then do the following.
It will set Bit 0 (FERF/RDI Defect Declared), within the Receive E3 Configuration and Status Register # 2, to
"1" as depicted below.
This bit-field will remain asserted for the duration that the Receive E3 Framer block declares the FERF/RDI
defect condition.
The Receive E3 Framer block will also generate the Change in FERF/RDI Defect Condition Interrupt
request, by asserting the Interrupt Output pin (e.g., by pulling it "Low") and setting Bit 3 (Change in FERF/
RDI Defect Condition Interrupt Status), within the Receive E3 Interrupt Status Register # 2 to "1" as depicted
below.
Receive E3 Configuration and Status Register # 1 - G.832 (Direct Address = 0x1110)
BIT 7
BIT 6
BIT 5
BIT 4
BIT 3
BIT 2
BIT 1
BIT 0
RxPLDType[2:0]
RxFERF
Algo.
RxTMark
Algo
RxPLDTypeExp[2:0]
R/O
R/W
0
1
0
X
0
1
0
Receive E3 Configuration and Status Register # 2 - G.832 (Address = 0x1111)
BIT 7
BIT 6
BIT 5
BIT 4
BIT 3
BIT 2
BIT 1
BIT 0
Receive LOF
Algo
LOF Defect
Declared
OOF Defect
Declared
LOS Defect
Declared
AIS Defect
Declared
RxPLD
Unstab
RxTMark
FERF/RDI
Defect
Declared
R/W
R/O
0
1