XRT7250 Datasheet, PDF (104/463 Pages) Exar Corporation – DS3/E3 FRAMER IC

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DS3/E3 FRAMER IC
XRT7250
REV. 1.1.1
Writing a "1" to this bit-field invokes this command.
Writing a "0" allows the Transmit DS3 Framer to func-
tion normally (e.g., the Transmit DS3 Framer will
transmit its payload and internally generated over-
head bits).
NOTE: For more information on this feature, please see
Section 3.2.4.2.1.3.
NOTE: This bit-setting is ignored if Bits 3 or 4 (within this
register) are set to "1".
Bit 4 - Tx AIS (Pattern)
This Read/Write bit-field permits the user to com-
mand the Transmit DS3 Framer to transmit an AIS
pattern. If the user invokes this command, then the
Transmit DS3 Framer will force the outbound DS3
frames to have the following patterns.
• Valid M-bits, F-bits, and P-bits
• All C-bits are set to '0'
• All X-bits are set to '1'
• A repeating '1010...' pattern is written into the pay-
load of the DS3 Frames.
Writing a "1' to this bit-field invokes this command.
Writing a "0" allows the Transmit DS3 Framer to func-
tion normally (e.g., the Transmit DS3 Framer will
transmit its payload and internally generated over-
head bits).
NOTE: For more information on this feature, please see
Section 3.2.4.2.1.4.
Bit 3 - Tx LOS (Loss of Signal)
This Read/Write bit-field permits the user to com-
mand the Transmit DS3 Framer to simulate an LOS
Condition. If the user invokes this command, then the
Transmit DS3 Framer will stop sending mark pulses
out on the line and will transmit an all-zero pattern.
Writing a '0' to this bit-field disables (or shuts off) this
feature, thereby allowing internally generated DS3
Frames to be generated and transmitted over the line.
Writing a '1' to this bit-field invokes this command,
causing the Transmit DS3 Framing to generate an all
'0' pattern.
NOTE: For more information on this feature, please see
Section 3.2.4.2.1.5.
Bit 2 - FERF on LOS
This Read/Write bit-field allows the user to configure
the Transmit DS3 Framer to generate a Yellow Alarm
if the Near-End Receive DS3 Framer detects a LOS
(Loss of Signal) Condition.
Writing a "1" to this bit-field enables this feature. Writ-
ing a "0" to this bit-field disables this feature.
NOTE: For more information on this feature, please see
Section 3.2.4.2.1.6.
Bit 1 - FERF on OOF
This Read/Write bit-field allows the user to configure
the Transmit DS3 Framer to generate a Yellow Alarm
if the Near-End Receive DS3 Framer detects an OOF
(Out-of-Frame) Condition.
Writing a "1" to this bit-field enables this feature. Writ-
ing a "0" to this bit-field disables this feature.
NOTE: For more information on this feature, please see
Section 3.2.4.2.1.7.
Bit 0 - FERF on AIS
This Read/Write bit-field allows the user to configure
the Transmit DS3 Framer to generate a Yellow Alarm
if the Near-End Receive DS3 Framer detects an AIS
(Alarm Indication Signal) Condition.
Writing a "1" to this bit-field enables this feature. Writ-
ing a "0" to this bit-field disables this feature.
NOTE: For more information on this feature, please see
Section 3.2.4.2.1.8.
2.3.5.2 Transmit DS3 FEAC Configuration &
Status Register (DS3 Applications)
TRANSMIT DS3 FEAC CONFIGURATION & STATUS REGISTER (ADDRESS = 0X31)
BIT 7
BIT 6
BIT 5
BIT 4
BIT 3
BIT 2
BIT 1
BIT 0
Not Used
Tx FEAC
Interrupt
Enable
TxFEAC
Interrupt
Status
TxFEAC
Enable
TxFEAC
GO
TxFEAC
Busy
RO
RO
RO
R/W
RUR
R/W
R/W
RO
0
0
0
0
0
0
0
0
Bit 4 - Tx FEAC Interrupt Enable
This Read-Write bit-field permits the user to enable or
disable the Transmit FEAC Interrupt.
Setting this bit-field to “0” disables this interrupt.
Conversely, setting this bit-field to “1” enables this in-
terrupt.
Bit 3 - TxFEAC Interrupt Status
85