XRT75L03D Datasheet, PDF (11/134 Pages) Exar Corporation – THREE CHANNEL E3/DS3/STS-1 LINE INTERFACE UNIT WITH SONET DESYNCHRONIZER

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XRT75L03D
THREE CHANNEL E3/DS3/STS-1 LINE INTERFACE UNIT WITH SONET DESYNCHRONIZER REV. 1.0.0
SYSTEM-SIDE TRANSMIT INPUT AND TRANSMIT CONTROL PINS
PIN #
SIGNAL NAME
TYPE
DESCRIPTION
37
TAOS_0
7
TAOS_1
8
TAOS_2
I Transmit "All Ones" Input - Channel 0:
Transmit "All Ones" Input - Channel 1:
Transmit "All Ones" Input - Channel 2:
These input pin are used to configure the Transmit Section of the corre-
sponding channel to generate and transmit an unframed "All Ones" pattern
via the DS3, E3 or STS-1 line signal to the remote terminal equipment.
When this configuration is implemented the Transmit Section will ignore the
data that it is accepting from the System-side equipment and will overwrite
this data will the "All Ones" Pattern.
"Low" - Does not configure the channel to transmit an unframed "All Ones"
Pattern to the remote terminal equipment. In this mode, the Transmit Sec-
tion of the Channel will output data based upon the signals that are applied
to the TxPOS_n and TxNEG_n input pins.
"High" - Configures the Channel to transmit an unframed "All Ones" Pattern
to the remote terminal equipment. In this mode, the Transmit Section will
override the data that is applied to the TxPOS_n and TxNEG_n input pins,
and will proceed to generate and transmit an unframed "All Ones" pattern.
4. This input pin is ignored if the XRT75L03D is operating in the
HOST Mode and should be tied to GND.
5. These input pins are internally pulled down.
36
TxLEV_0
9
TxLEV_1
10
TxLEV_2
I
Transmit Line Build-Out Enable/Disable Select - Channel 0:
Transmit Line Build-Out Enable/Disable Select - Channel 1:
Transmit Line Build-Out Enable/Disable Select - Channel 2:
These input pins are used to enable or disable the Transmit Line Build-Out
(e.g., pulse-shaping) circuit within the corresponding channel. The user
should set these input pins either "High" or "Low" based upon the following
guidelines.
"Low" - If the cable length between the Transmit Output of the correspond-
ing Channel and the DSX-3/STSX-1 location is 225 feet or less.
"High" - If the cable length between the Transmit Output of the correspond-
ing Channel and the DSX-3/STSX-1 location is 225 feet or more.
NOTES:
1. These guidelines must be followed in order to insure that the
Transmit Section of Channel_n will always generate a DS3 pulse
that complies with the Isolated Pulse Template requirements per
Bellcore GR-499-CORE, or an STS-1 pulse that complies with the
Pulse Template requirements per Telcordia GR-253-CORE.
2. This input pin is inactive if the XRT75L03D has been configured to
operate in the Host Mode, or if the corresponding channel has
been configured to operate in the E3 Mode. If either of these
cases are true, then tie this input pin to GND.
3. These input pins are internally pulled "Low".
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