XRT79L71_1 Datasheet, PDF (90/434 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
Receive DS3 Sync Detect Register (Address = 0x1114)
BIT 7
BIT 6
BIT 5
BIT 4
BIT 3
Unused
R/O
R/O
R/O
R/O
R/O
0
0
0
0
0
BIT 2
BIT 1
P-Bit Correct F Algorithm
R/W
R/W
0
0
BIT 0
One and
Only
R/W
0
BIT NUMBER
NAME
7-3
Reserved
2
P-Bit Correct
1
F Algorithm
0
One and Only
TYPE
R/O
R/W
R/W
R/W
DESCRIPTION
P-Bit Correct:
This READ/WRITE bit-field permits the user to enable or disable
the P-Bit Correct feature within the Receive DS3/E3 Framer
block. If the user enables this feature, then the Receive DS3/E3
Framer block will automatically invert the state of any P-bits,
whenever it detects P-bit errors within the incoming DS3 data-
stream.
0 - Disables the P-Bit Correct feature.
1 - Enables the P-Bit Correct feature
F-Bit Search Algorithm Select:
This READ/WRITE bit-field permits the user to select the F-bit
acquisition criteria that the Receive DS3/E3 Framer block will
use whenever it is operating in the F-Bit Search state.
0 - Configures the Receive DS3/E3 Framer block to move on to
the M-Bit Search state whenever it has properly located 10 con-
secutive F-bits within the incoming DS3 data-stream.
1 -Configures the DS3/E3 Framer block to move on to the M-Bit
Search state whenever it has properly located 16 consecutive F-
bits within the incoming DS3 data-stream.
NOTE: This bit-field is only active if the user has configured the
XRT79L71 to operate in the DS3 Mode.
F-Bit Search/Mimic-Handling Algorithm Select:
This READ/WRITE bit-field permits the user to select the F-bit
acquisition criteria that the Receive DS3/E3 Framer block will
use whenever it is operating in the F-Bit Search state.
0 - Configures the Receive DS3/E3 Framer block to move on to
the M-Bit Search state whenever it has properly located 10 (or
16) consecutive F-bits (as configured in Bit 1 of this register).
1 - Configures the Receive DS3/E3 Framer block to move on to
the M-Bit Search state, when (1) it has properly located 10 (or
16) consecutive F-bits and (2) when it has located and identified
only one viable F-Bit Alignment candidate.
NOTE: If this bit is set to "1", then the Receive DS3/E3 Framer
block will NOT transition into the M-Bit Search state, as
long as at least two viable candidate set of bits appear to
function as the F-bits.
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