XRT72L13 Datasheet, PDF (128/370 Pages) Exar Corporation – M13 MULTIPLEXER/CLEAR CHANNEL DS3 FRAMER IC

XRT72L13 MULTIPLEXER/FRAMER IC
REV. 1.0.6
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M12 DS2 # 4 LOOP-BACK REGISTER (ADDRESS = 0X2B)
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PRELIMINARY
BIT 7
BIT 6
BIT 5
BIT 4
BIT 3
BIT 2
BIT 1
BIT 0
Loop-back Loop-back Loop-back Loop-back Loop-back Loop-back Loop-back Loop-back
Activation Activation Activation Activation
Request
Request
Request
Request
DS1 Channel DS1 Channel DS1 Channel DS1 Channel DS1 Channel DS1 Channel DS1 Channel DS1 Channel
15
14
13
12
15
14
13
12
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
0
0
0
0
0
0
0
0
Bit 7 - Loop-back Activation - DS1 Channel 15
This “Read/Write” bit-field permits the user to config-
ure DS1 Channel 15 into Remote Loop-back Mode.
When this loop-back is configured, then the
“RxDS1Data_15” signal will internally be “looped-
back” into the “TxDS1Data_15” path. Further, the
“RxDS1Clock_15” clock signal will also be internally
looped back into the “RxDS1Clock_15” signal path.
Setting this bit-field to “1” enables this loop-back
mode. Conversely, setting this bit-field to “0” disables
this loop-back mode.
NOTE: This bit-field is ignored if the XRT72L13 has been
configured to operate in the “ITU-T G.747” Mode.
Bit 6 - Loop-back Activation - DS1 Channel 14
This “Read/Write” bit-field permits the user to config-
ure DS1 Channel 14 into Remote Loop-back Mode.
When this loop-back is configured, then the
“RxDS1Data_14” signal will internally be “looped-
back” into the “TxDS1Data_14” path. Further, the
“RxDS1Clock_14” clock signal will also be internally
looped back into the “RxDS1Clock_14” signal path.
Setting this bit-field to “1” enables this loop-back
mode. Conversely, setting this bit-field to “0” disables
this loop-back mode.
Bit 5 - Loop-back Activation - DS1 Channel 13
This “Read/Write” bit-field permits the user to config-
ure DS1 Channel 13 into Remote Loop-back Mode.
When this loop-back is configured, then the
“RxDS1Data_13” signal will internally be “looped-
back” into the “TxDS1Data_13” path. Further, the
“RxDS1Clock_13” clock signal will also be internally
looped back into the “RxDS1Clock_13” signal path.
Setting this bit-field to “1” enables this loop-back
mode. Conversely, setting this bit-field to “0” disables
this loop-back mode.
Bit 4 - Loop-back Activation - DS1 Channel 12
This “Read/Write” bit-field permits the user to config-
ure DS1 Channel 12 into Remote Loop-back Mode.
When this loop-back is configured, then the
“RxDS1Data_12” signal will internally be “looped-
back” into the “TxDS1Data_12” path. Further, the
“RxDS1Clock_12” clock signal will also be internally
looped back into the “RxDS1Clock_12” signal path.
Setting this bit-field to “1” enables this loop-back
mode. Conversely, setting this bit-field to “0” disables
this loop-back mode.
Bit 3 - Loop-back Request - DS1 Channel 15
This “Read/Write” bit-field permits the user to config-
ure the XRT72L13 to transmit a “DS1 Channel 15 -
Loop-back Request” signal to the Remote Terminal
Equipment. When the Remote Terminal Equipment
receives this request, it is expected to respond by
configuring its own DS1 Channel 15 signal into Loop-
back Mode.
NOTE: This bit-field is ignored if the XRT72L13 has been
configured to operate in the “ITU-T G.747” Mode.
Bit 2 - Loop-back Request - DS1 Channel 14
This “Read/Write” bit-field permits the user to config-
ure the XRT72L13 to transmit a “DS1 Channel 14 -
Loop-back Request” signal to the Remote Terminal
Equipment. When the Remote Terminal Equipment
receives this request, it is expected to respond by
configuring its own DS1 Channel 14 signal into Loop-
back Mode.
NOTE: This bit-field is ignored if the XRT72L13 has been
configured to operate in the “ITU-T G.747” Mode.
Bit 1 - Loop-back Request - DS1 Channel 13
This “Read/Write” bit-field permits the user to config-
ure the XRT72L13 to transmit a “DS1 Channel 13 -
Loop-back Request” signal to the Remote Terminal
Equipment. When the Remote Terminal Equipment
receives this request, it is expected to respond by
configuring its own DS1 Channel 13 signal into Loop-
back Mode.
NOTE: This bit-field is ignored if the XRT72L13 has been
configured to operate in the “ITU-T G.747” Mode.
Bit 0 - Loop-back Request - DS1 Channel 12
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