XRT75L04D Datasheet, PDF (12/98 Pages) Exar Corporation – FOUR CHANNEL E3/DS3/STS-1 LINE INTERFACE UNIT WITH SONET DESYNCHRONIZER

XRT75L04D
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FOUR CHANNEL E3/DS3/STS-1 LINE INTERFACE UNIT WITH SONET DESYNCHRONIZER REV. 1.0.1
RECEIVE INTERFACE
PIN #
SIGNAL NAME
TYPE
DESCRIPTION
91
REQEN_0
100
REQEN_1
130
REQEN_2
121
REQEN_3
I Receive Equalizer On/Off - Channel 0:
Receive Equalizer On/Off- Channel 1:
Receive Equalizer On/Off - Channel 2:
Receive Equalier On/Off- Channel 3:
Tie these pins “High” to enable the receive equalizer.
NOTES:
1. This input pin is ignored and should be connected to GND if the
XRT75L04D is operating in the HOST Mode
2. This pin is internally pulled down.
87
RxON/
SDI
I
Hardware Mode: Receiver Turn ON Input
Host Mode: Serial Data Input:
Function of this pin depends on whether the XRT75L04D is configured to oper-
ate in Hardware mode or Host mode.
In Hardware mode, setting this input pin “High” turns on and enables the
Receivers of all three channels.
NOTES:
1. If the XRT75L04D is configured in HOST mode, this pin functions as
SDI input pin (please refer to the pin description for Microprocessor
Interface)
2. This pin is internally pulled down.
86
RxClkINV/
CS
I
Hardware Mode: RxClk INVERT
Host Mode: Chip Select:
Function of this pin depends on whether the XRT75L04D is configured to oper-
ate in Hardware mode or Host mode.
In Hardware mode, setting this input pin “High” configures the Receiver Sec-
tion of all channels to invert the RxClk_n output signals and outputs the recov-
ered data via RPOS_n and RNEG_n on the falling edge of RxClk_n.
NOTE: If the XRT75L04D is configured in HOST mode, this pin functions as CS
input pin (please refer to the pin description for Microprocessor
Interface).
85
RxMON/
SDO
I
Hardware Mode: Receive Monitoring Mode
Host Mode: Serial Data Output:
In Hardware mode, when this pin is tied “High” all 4 channels configure into
monitoring channels. In the monitoring mode, the Receiver is capable of moni-
toring the signals with 20 dB flat loss plus 6 dB cable attenuation. This allows
monitoring very weak signal before declaring LOS.
In HOST Mode each channel can be independently configured to be a monitor-
ing channel by setting the bits in the channel control registers.
NOTE: If the XRT75L04D is configured in HOST mode, this pin functions as
SDO pin (please refer to the pin description for the Microprocessor
Interface).
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