XRT73LC00A_08 Datasheet, PDF (56/63 Pages) Exar Corporation – E3/DS3/STS-1 LINE INTERFACE UNIT

REV. 1.0.1
XRT73LC00A
E3/DS3/STS-1 LINE INTERFACE UNIT
This bit-field is set to “0” if the Clock Recovery PLL is in lock with the incoming line signal. This bit-field is set
to “1” if the Clock Recovery PLL is out of lock with the incoming line signal.
Bit D3 - RLOS (Receive Loss of Signal Status)
This Read-Only bit-field indicates whether or not the Receiver in the XRT73LC00A is currently declaring an
LOS (Loss of Signal) Condition.
This bit-field is set to “0” if the XRT73LC00A is not currently declaring the LOS Condition. This bit-field is set to
“1” if the XRT73LC00A is declaring an LOS Condition.
Bit D2 - ALOS (Analog Loss of Signal Status)
This Read-Only bit-field indicates whether or not the Analog LOS Detector in the XRT73LC00A is currently
declaring an LOS condition.
This bit-field is set to “0” if the Analog LOS Detector in the XRT73LC00A is NOT currently declaring an LOS
condition. Conversely, this bit-field is set to “1” if the Analog LOS Detector is currently declaring an LOS
condition.
The purpose of this feature is to isolate either the Analog LOS or the Digital LOS detector that is declaring the
LOS condition. This feature may be useful for troubleshooting/debugging purposes.
Bit D1 - DLOS (Digital Loss of Signal Status)
This Read-Only bit-field indicates whether or not the Digital LOS Detector in the XRT73LC00A is currently
declaring an LOS condition.
This bit-field is set to “0” if the Digital LOS Detector in the XRT73LC00A is NOT currently declaring an LOS
condition. Conversely, this bit-field is set to “1” if the Digital LOS Detector is currently declaring an LOS
condition.
NOTE: The purpose of this feature is to isolate the Detector (e.g., either the Analog LOS or the Digital LOS detector) that is
declaring the LOS condition. This feature may be useful for troubleshooting/debugging purposes.
Bit D0 - DMO (Drive Monitor Output Status)
This Read-Only bit-field reflects the status of the DMO output pin.
5.1.2 Command Register - CR1
Bit D4 - TXOFF (Transmitter OFF)
This Read/Write bit-field is used to turn off the Transmitter in the XRT73LC00A.
Writing a “1” to this bit-field turns off the Transmitter and tri-states the Transmit Output. Writing a “0” to this bit-
field turns on the Transmitter.
Bit D3 - TAOS (Transmit All OneS)
This Read/Write bit-field is used to command the XRT73LC00A Transmitter to generate and transmit an all
“1’s” pattern onto the line.
Writing a “1” to this bit-field commands the Transmitter to transmit an all “1’s” pattern onto the line. Writing a “0”
to this bit-field commands normal operation.
Bit D2 - TXCLKINV (Transmit Clock Invert)
This Read/Write bit-field is used to configure the XRT73LC00A Transmitter to sample the signal at the TPDATA
and TNDATA pins on the rising or falling edge of TCLK (the Transmit Line Clock signal).
Writing a “1” to this bit-field configures the Transmitter to sample the TPDATA and TNDATA input pins on the
rising edge of TCLK. Writing a “0” to this bit-field configures the Transmitter to sample the TPDATA and
TNDATA input pins on the falling edge of TCLK.
Bit D1 - TXLEV (Transmit Level Select)
This Read/Write bit-field is used to enable or disable the XRT73LC00A Transmit Line Build-Out circuit.
Setting this bit-field "High" disables the Line Build-Out circuit of the XRT73LC00A. In this mode, the
XRT73LC00A outputs partially-shaped pulses onto the line via the TTIP and TRING output pins. Setting this
bit-field "Low" enables the Line Build-Out circuit of the XRT73LC00A. In this mode the XRT73LC00A outputs
shaped pulses onto the line via the TTIP and TRING output pins.
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