XRT75L00 Datasheet, PDF (9/50 Pages) Exar Corporation – E3/DS3/STS-1 LINE INTERFACE UNIT WITH JITTER ATTENUATOR

REV. 1.0.2
RECEIVE INTERFACE
PIN #
SIGNAL NAME
37
RNEG/LCV
11
RRING
12
RTIP
27
RxMON/
SDO
XRT75L00
E3/DS3/STS-1 LINE INTERFACE UNIT WITH JITTER ATTENUATOR
TYPE
O
I
I
I
DESCRIPTION
Receive Negative Data Output/Line Code Violation Indicator
Function of these pins depends on whether the XRT75L00 is configured in
Single Rail or Dual Rail mode.
If the XRT75L00 is configured in Dual Rail mode, a negative pulse is output
through RNEG.
In Hardware mode: Tie the pin SR/DR (pin 22) “High” to configure the
XRT75L00 in Single Rail mode and tie “Low” to configure in Dual Rail mode.
In HOST mode: XRT75L00 can be configured in Single Rail or Dual Rail by set-
ting or clearing the bit in the block control register.
Line Code Violation Indicator
If the XRT75L00 is configured in Single Rail mode then:
Whenever the Receiver Section detects a Line Code violation, it pulses this
output pin “High”. This output pin remains “Low” at all other times. It is
advisable to sample this output pin using the RxClk output signal.
Receive Ring Input
This input pin along with RTIP is used to receive the bipolar line signal from the
Remote DS3/E3/STS-1 Terminal.
Receive TIP Input
This input pin along with RRNG is used to receive the bipolar line signal from
the Remote DS3/E3/STS-1 Terminal.
Receive Monitoring Mode or Serial Data Output:
In Hardware mode, when this pin is tied “High” XRT75L00 configures into mon-
itoring channel. In the monitoring mode, the Receiver is capable of monitoring
the signals with 20 dB flat loss plus 6 dB cable attenuation. This allows to moni-
tor very weak signal before declaring LOS.
In HOST Mode, XRT75L00 can be configured to be a monitoring channel by
setting the bits in the receive control register.
NOTE: If the XRT75L00 is configured in HOST mode, this pin functions as SDO
pin (please refer to the pin description for the Microprocessor Interface).
7