XRT79L71 Datasheet, PDF (248/441 Pages) Exar Corporation – 1 - CHANNEL DS3/E3 ATM UNI/PPP COMBO IC

XRT79L71
REV. P1.0.3
PRELIMINARY
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1 - CHANNEL DS3/E3 ATM UNI/PPP COMBO IC
GENERAL PURPOSE I/O PIN CONTROL REGISTERS
LINE INTERFACE DRIVE REGISTER (DIRECT ADDRESS = 0X1180)
BIT 7
BIT 6
BIT 5
BIT 4
BIT 3
BIT 2
Internal
Remote
Loop-back
Unused
REQB
Output Pin
TAOS
Output Pin
ENCODIS
Output Pin
TxLEV
Output Pin
R/W
R/O
R/W
R/W
R/W
R/W
0
0
0
0
1
0
BIT 1
RLOOP
Output Pin
R/W
0
BIT 0
LLOOP
Output Pin
R/W
0
BIT NUMBER
NAME
7
Internal Remote
Loop-back
6
Unused
5
REQB Output Pin
4
TAOS Output Pin
3
ENCODIS Output Pin
2
TxLEV Output Pin
TYPE
R/W
R/O
R/W
R/W
R/W
R/W
DESCRIPTION
Internal Remote Loop-back Mode:
This READ/WRITE bit-field permits the user to configure the
DS3/E3 Framer block to operate in the "Remote Loop-back"
Mode.
If the user enables this feature, then the Receive Input of the Pri-
mary Frame Synchronizer block will automatically be routed to
the Transmit Output of the Frame Generator block.
0 - Disables the Remote Loop-back Mode.
1 - Enables the Remote Loop-back Mode.
NOTE: This feature is only available if both the Frame Generator
and the Primary Frame Synchronizer blocks are
enabled.
REQB Output Pin control:
This READ/WRITE bit-field permits the user to control the state
of the "REQB" output pin. This output pin can be used to func-
tion as a General Purpose Output pin.
0 - Commands this output pin to toggle and stay "LOW".
1 - Commands this output pin to toggle and stay "HIGH".
TAOS Output Pin control:
This READ/WRITE bit-field permits the user to control the state
of the "TAOS" output pin. This output pin can be used to function
as a General Purpose Output pin.
0 - Commands this output pin to toggle and stay "LOW".
1 - Commands this output pin to toggle and stay "HIGH".
ENCODIS Output Pin control:
This READ/WRITE bit-field permits the user to control the state
of the "ENCODIS" output pin. This output pin can be used to
function as a General Purpose Output pin.
0 - Commands this output pin to toggle and stay "LOW".
1 - Commands this output pin to toggle and stay "HIGH".
TxLEV Output Pin control:
This READ/WRITE bit-field permits the user to control the state
of the "TxLEV" output pin. This output pin can be used to func-
tion as a General Purpose Output pin.
0 - Commands this output pin to toggle and stay "LOW".
1 - Commands this output pin to toggle and stay "HIGH".
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