XRT79L71_07 Datasheet, PDF (55/109 Pages) Exar Corporation – 1-CHANNEL DS3/E3 ATM UNI/PPP/CLEAR-CHANNEL FRAMER IC - HARDWARE

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PIN #
P10
P11
NAME
MTIP
MRING
XRT79L71
1-CHANNEL DS3/E3 ATM UNI/PPP/CLEAR-CHANNEL FRAMER IC - HARDWARE
TYPE
DESCRIPTION
I Transmit Drive Monitor Input pin - Positive Polarity Input:
This input pin along with MRING functions as the Transmit Drive Monitor Output
(DMO) input monitoring pins.
If the user wishes to (1) monitor the Transmit Output line signal and (2) to perform
this monitoring externally, then the user MUST connect this particular pin to the
TTIP output pin via a 274 ohm series resistor. Similarly, the user MUST also con-
nect the MRING input pin to the TRING output pin via a 274 ohm series resistor.
The MTIP and MRING input pins will continuously monitor the Transmit Output
line signal via the TTIP and TRING output pins for bipolar activity. If these pins do
not detect any bipolar activity for 128 bit periods, then the Transmit Drive Monitor
circuit will drive the DMO output pin "High" in order to denote a possible fault con-
dition in the Transmit Output Line signal path.
NOTES:
1. This input pin is inactive if the user choose to internally monitor the
Transmit Output line signal.
2. Internal Monitoring is only available as an option if the user is operating
the XRT79L71 in the Host Mode.
I Transmit Drive Monitor Input pin - Negative Polarity Input:
This input pin along with MTIP functions as the Transmit Drive Monitor Output
(DMO) input monitoring pins.
If the user wishes to (1) monitor the Transmit Output line signal and (2) to perform
this monitoring externally, then the user MUST connect this particular input pin to
the TRING output pin via a 274 ohm series resistor. Similarly, the user MUST also
connect the MTIP input pin to the TTIP output pin via a 274 ohm series resistor.
The MTIP and MRING input pins will continuously monitor the Transmit Output
line signal via the TTIP and TRING output pins for bipolar activity. If these pins do
not detect any bipolar activity for 128 bit periods, then the Transmit Drive Monitor
circuit will drive the DMO output pin "High" in order to denote a possible fault con-
dition in the Transmit Output Line signal path.
NOTES:
1. This input pin is inactive if the user chooses to internally monitor the
Transmit Output line signal.
2. Internal Monitoring is only available as an option if the user is operating
the XRT79L71 in the Host Mode.
PIN #
NAME
TYPE
RECEIVE LINE SIDE SIGNALS
R14
RTIP
I
DESCRIPTION
Receive Input - Positive Polarity Signal:
This input pin, along with the RRING input pin, functions as the Receive DS3/E3
Line Signal input for the XRT79L71.
The user is expected to connect this signal and the RRING input signal to a 1:1
transformer.
Whenever the RTIP/RRING input pins are receiving a positive-polarity pulse
within the incoming DS3 or E3 line signal, this input pin will be pulsed to a higher-
voltage than that of the RRING input pin.
Conversely, whenever the RTIP/RRING input pins are receiving a negative-
polarity pulse within the incoming DS3 or E3 line signal, this input pin will be
pulsed to a lower-voltage than that of the RRING input pin.
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