XRT73L03 View Datasheet(PDF) - Exar Corporation
Part Name
Description
MFG CO.
'XRT73L03' PDF : 62 Pages View PDF
XRT73L03 3 CHANNEL E3/DS3/STS-1 LINE INTERFACE UNIT
REV. P1.0.13
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PRELIMINARY
This Read/Write bit-field is used to configure the
Transmitter in the XRT73L03 to sample the signal at
the TPData and TNData pins on the rising edge or
falling edge of TxClk (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 TxClk. Writing a "0" to this bit-field con-
figures the Transmitter to sample the TPData and
TNData input pins on the falling edge of TxClk.
Bit D1 - TxLEV(n) (Transmit Line Build-Out En-
able/Disable Select - Channel(n))
This Read/Write bit-field is used to enable or disable
the Channel(n) Transmit Line Build-Out circuit in the
XRT73L03.
Setting this bit-field "High” disables the Channel(n)
Line Build-Out circuit. In this mode, Channel(n) out-
puts partially-shaped pulses onto the line via the
TTIP(n) and TRing(n) output pins.
Setting this bit-field "Low" enables the Channel(n)
Line Build-Out circuit. In this mode, Channel(n) out-
puts shaped pulses onto the line via the TTIP(n) and
TRing(n) output pins.
In order to comply with the Isolated DSX-3/STSX-1
Pulse Template Requirements (per Bellcore GR-499-
CORE or GR-253-CORE):
a. Set this bit-field to "1" if the cable length between
the Cross-Connect and the transmit output of Chan-
nel(n) is greater than 225 feet.
b. Set this bit-field to "0" if the cable length between
the Cross-Connect and the transmit output of Chan-
nel(n) is less than 225 feet.
NOTE: This bit-field is active only if the XRT73L03 is config-
ured to operate in the DS3 or SONET STS-1 Modes.
If the cable length is greater than 225 feet, set this bit-
field to "1" in order to increase the amplitude of the
Transmit Output Signal. If the cable length is less
than 225 feet, set this bit-field to "0".
NOTE: This option is only available when the XRT73L03 is
operating in the DS3 or STS-1 Mode.
Bit D0 - TxBIN(n) (Transmit Binary Data - Chan-
nel(n))
This Read/Write bit-field is used to configure the
Channel(n) Transmitter to accept an un-encoded bi-
nary data stream via the TPData input and convert
this data into the appropriate bipolar signal for the
line.
Writing a "1" configures the Transmitter to accept a bi-
nary data stream via the TPData input. The TNData
input is ignored.
This form of data acceptance is sometimes referred
to as Single-Rail mode operation. The Transmitter
then encodes this data into the appropriate line code
(e.g., B3ZS or HDB3) prior to its transmission over
the line.
Writing a "0" configures the Transmitter to accept data
in a Dual-Rail manner (e.g., via both the TPData and
TNData inputs).
5.2.3 Command Register CR2-(n)
The bit-format and default values for Command Reg-
ister CR2-(n) are listed below followed by the function
of each of these bit-fields.
COMMAND REGISTER CR2-(N)
D4
D3
D2
D1
D0
Reserved ENDECDIS ALOSDIS DLOSDIS REQEN
X
0
0
0
0
Bit D4 - Reserved
Bit D3 - ENDECDIS (B3ZS/HDB3 Encoder/Decod-
er-Disable - Channel(n))
This Read/Write bit-field is used to enable or disable
the Channel(n) B3ZS/HDB3 Encoder and Decoder
blocks.
Writing a "1" to this bit-field disables the B3ZS/HDB3
Encoder and Decoder blocks. Writing a "0" to this bit-
field enables the B3ZS/HDB3 Encoder and Decoder
blocks.
NOTE: This Encoder/Decoder performs HDB3 Encoding/
Decoding if the XRT73L03 is operating in the E3 Mode.
Otherwise it performs B3ZS Encoding/Decoding.
Bit D2 - ALOSDIS (Analog LOS Disable - Chan-
nel(n))
This Read/Write bit-field is used to enable or disable
the Channel(n) Analog LOS Detector.
Writing a "0" to this bit-field enables the Analog LOS
Detector. Writing a "1" to this bit-field disables the
Analog LOS Detector.
NOTE: If the Analog LOS Detector is disabled, then the
RLOS input pin is only asserted by the DLOS (Digital LOS
Detector).
Bit D1 - DLOSDIS (Digital LOS Disable - Chan-
nel(n))
This Read/Write bit-field to used to enable or disable
the Channel(n) Digital LOS Detector .
Writing a "0" to this bit-field enables the Digital LOS
Detector. Writing a "1" to this bit-field disables the
Digital LOS Detector.
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