XRT5997 Datasheet, PDF (6/37 Pages) Exar Corporation – Seven-Channel E1 Line Interface Unit

XRT5997
PIN DESCRIPTION (CONT'D)
Pin#
26
Symbol
TxNEG3
27
TxPOS3
28
LOS3
29
RxPOS3
Type
I
I
O
O
Description
Transmitter - Negative Data Input – Channel 3:
The exact signal that should be applied to this input pin depends upon
whether the user intends to operate the “Transmit Section” (of Channel 3) in
the “Clocked” or “Clockless” Mode.
Clocked Mode:
The Terminal Equipment should apply bit-wide NRZ pulses on this input
pin, whenever the Terminal Equipment needs to transmit a “negative-
polarity” pulse onto the line via TTIP3 and TRing3 output pins. The
XRT5997 device will sample this input pin upon the falling edge of the
TClk3 signal.
Clockless Mode:
The Terminal Equipment should apply RZ pulses to this input pin, anytime
the Terminal Equipment needs to transmit a “negative-polarity” pulse onto
the line viaTTIP3 and TRing3 output pins.
Transmitter - Positive Data Input – Channel 3:
The exact signal that should be applied to this input pin depends upon
whether the user intends to operate the “Transmit Section” (of Channel 3) in
the “Clocked” or “Clockless” Mode.
Clocked Mode:
The Terminal Equipment should apply bit-wide NRZ pulses on this input
pin, whenever the Terminal Equipment needs to transmit a “positive-
polarity” pulse onto the line via TTIP1 and TRing1 output pins. The
XRT5997 device will sample this input pin upon the falling edge of the
TClk1 signal.
Clockless Mode:
The Terminal Equipment should apply RZ pulses to this input pin, anytime
the Terminal Equipment needs to transmit a “positive-polarity” pulse onto the
line via TTIP1 and TRing1 output pins).
Receiver 3 – Loss of Signal Output Indicator:
This output pin toggles “high” if Channel 3, within the XRT5997 device has
detected a “Loss of Signal” condition in the incoming line signal.
Receiver 3 Positive Data Out:
This output pin will pulse “high” whenever Channel 3, within the XRT5997
device has received a “Positive Polarity” pulse, in the incoming line signal, at
RTIP3/RRing3 inputs.
Rev. 1.0.0
6