TAN-042
Designing the XRT71D00 and the XRT73L00 Devices to
operate in the Host Mode, and to be accessed via a single Chip
Select pin.
Preliminary
July 19, 2001
Revision 1.03
32
Command Register CR1
Bit D0 – TXBIN (Transmitter - Single Rail Enable/Disable)
This “Read/Write” bit-field permits the user to configure the Transmit Section of the LIU
IC to operate in either the Single-Rail or Dual-Rail Mode.
If the Transmit Section is configured to operate in the “Single-Rail” Mode, then it will
only accept and latch data that is applied to the LIU IC via the “TPDATA” input pin.
Data, which is applied to the “TNDATA”, input pin is ignored.
If the Transmit Section is configured to operate in the “Dual-Rail” Mode, then it will
accept and latch data that is applied to the LIU IC via both the “TPDATA” and
“TNDATA” input pins. In this case the state of the “TNDATA” input pin will NOT be
ignored.
NOTE:
If the user configures the Transmit Section of the LIU to operate in the “Single-Rail”
Mode, then is imperative that the user to enable both the B3ZS/HDB3 Encoder and
Decoder blocks by setting the “ENDECDIS” bit-field to “0”.
Bit D1 – TXLEV (Transmit Line Build-Out Enable/Disable)
This “Read/Write” bit-field permits the user to enable or disable the “Transmit Line
Build-Out” circuit within the Transmit Section of the LIU IC.
The “Transmit Line Build-Out” circuit should be enabled if the cable length between the
Line Card (containing the XRT73L00 device) and the DSX-3/STSX-1 location is less
than 225 feet.
Conversely, the “Transmit Line Build-Out” circuit should be disabled if the cable length
between the Line Card (containing the XRT73L00 device) and the DSX-3/STSX-1
location is greater than 225 feet.
Setting this bit-field to “0” enables the “Transmit Line Build-Out” circuit. Conversely,
setting this bit-field to “1” disables the “Transmit Line Build-Out” circuit.
NOTE:
This bit-field is ignored if the XRT73L00 device has been configured to operate
in the E3 Mode.
