XRT79L71_1 Datasheet, PDF (84/434 Pages) Exar Corporation – 1-CHANNEL DS3/E3 ATM UNI/PPP/CLEAR-CHANNEL FRAMER IC -

XRT79L71
1-CHANNEL DS3/E3 ATM UNI/PPP/CLEAR-CHANNEL FRAMER IC - REGISTER/MAP DESCRIPTION
REV. 1.0.0
BIT NUMBER
NAME
4
OOF Defect Condition
Declared
3
Unused
2
Framing with Valid P Bits
1
F-Sync Algo
0
M-Sync Algo
TYPE
R/O
R/O
R/W
R/W
R/W
DESCRIPTION
OOF (Out of Frame) Defect Condition Declared Indicator:
This READ-ONLY bit-field indicates whether or not the Receive
DS3/E3 Framer block is currently declaring the OOF (Out of
Frame) defect condition.
0 - Indicates that the Receive DS3/E3 Framer block is NOT cur-
rently declaring the OOF defect condition.
1 - Indicates that the Receive DS3/E3 Framer block is currently
declaring the OOF defect condition.
Framing with Valid P-Bit Select:
This READ/WRITE bit-field permits the user to choose between
two different sets of DS3 Frame Acquisition/Maintenance criteria
that the Receive DS3/E3 Framer block will use to (1) acquire and
declare Frame Synchronization, and (2) to declare the OOF
Defect condition
.0 - Normal Framing Acquisition/Maintenance Criteria (without P-
bit Checking)
In this mode, the Receive DS3/E3 Framer block will declare the
In-frame state, one it has successfully completed both the F-Bit
Search and the M-Bit Search states
1 - Framing Acquisition/Maintenance with P-bit CheckingIn this
mode, the Receive DS3/E3 Framer block will (in addition to
passing through the F-Bit Search and M-Bit Search states) also
verify valid P-bits, prior to declaring the In-Frame state.
NOTE: This bit-field is ignored if the XRT79L71 has been
configured to operate in the E3 Mode.
F-Bit Search State Criteria Select:
This READ/WRITE bit-field permits the user to choose between
two different sets of DS3 Out of Frame (OOF) Defect Declaration
criteria.
0 - The OOF defect condition will be declared when 6 out of 15
F-bits are erred.
1 - The OOF defect condition will be declared when 3 out of 15
F-bits are erred.
NOTE: This bit-field is ignored if the XRT79L71 has been
configured to operate in the E3 Mode.
M-Bit Search State Criteria Select:
This READ/WRITE bit-field permits the user to choose between
two different sets of DS3 Out of Frame (OOF) Defect Declaration
criteria.
0 - M-bit Errors do not result in the Receive DS3/E3 Framer
block declaring the OOF defect condition.
1 - The OOF defect condition will be declared when all M-bits,
within 3 out of 4 consecutive DS3 frames are in error.
NOTE: This bit-field is ignored if the XRT79L71 has been
configured to operate in the E3 Mode.
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