XRT75L04 Datasheet, PDF (13/57 Pages) Exar Corporation – FOUR CHANNEL E3/DS3/STS-1 LINE INTERFACE UNIT WITH JITTER

REV. 1.0.4
XRT75L04
FOUR CHANNEL E3/DS3/STS-1 LINE INTERFACE UNIT WITH JITTER ATTENUATOR
CONTROL AND ALARM INTERFACE
131
ICT
I In-Circuit Test Input:
Setting this pin "Low" causes all digital and analog outputs to go into a high-
impedance state to allow for in-circuit testing. For normal operation, tie this pin
"High".
NOTE: This pin is internally pulled “High".
132
TEST
**** Factory Test Pin
NOTE: This pin must be connected to GND for normal operation.
84
LOSMUT/
INT
I/O Hardware Mode: MUTE-upon-LOS Enable Input
Host Mode: Interrupt Ouput:
In Hardware Mode, setting pin “High” configures all three channels to Mute the
recovered data on the RPOS_n and RNEG_n whenever one of the channels
declares an LOS condition. RPOS_n and RNEG_n outputs are pulled “Low”.
Muting of the output data can be configured/controlled on a per channel basis
in Host Mode.
NOTE: If the XRT75L04 is configured in HOST mode, this pin functions as INT
pin (please refer to the pin description for the Microprocessor Interface).
94
LLB_0
103
LLB_1
127
LLB_2
118
LLB_3
I Local Loop-back - Channel 0:
Local Loop-back - Channel 1:
Local Loop-back - Channel 2:
Local Loop-back - Channel 3:
This input pin along with RLB_n configures different Loop-Back modes.
A "High" on this pin with RLB_n set to "Low" configures Channel_n to operate
in the Analog Local Loop-back Mode.
A "High" on this pin with RLB_n set to "High" configures Channel_n to operate
in the Digital Local Loop-back Mode.
NOTE: This input pin is ignored and should be connected to GND if the
XRT75L04 is operating in the HOST Mode.
95
RLB_0
104
RLB_1
126
RLB_2
117
RLB_3
I Remote Loop-back - Channel 0:
Remote Loop-back - Channel 1:
Remote Loop-back - Channel 2:
Remote Loop-back - Channel 3:
This input pin along with LLB_n configures different Loop-Back modes.
A "High" on this pin with LLB_n set to “Low" configures Channel_n to operate in
the Remote Loop-back Mode.
A "High" on this pin with LLB_n set to "High" configures Channel_n to operate
in the Digital Local Loop-back Mode.
RLB_n
0
0
1
1
LLB_n
0
1
0
1
Loopback Mode
Normal Operation
Analog Local
Remote
Digital
NOTE: This input pin is ignored and should be connected to GND if the
XRT75L04 is operating in the HOST Mode.
11