XRT75VL00_08 Datasheet, PDF (12/50 Pages) Exar Corporation – E3/DS3/STS-1 LINE INTERFACE UNIT WITH JITTER ATTENUATOR

XRT75VL00
E3/DS3/STS-1 LINE INTERFACE UNIT WITH JITTER ATTENUATOR
REV. 1.0.6
CONTROL AND ALARM INTERFACE
30
RLOS
O Receive Loss of Signal Output Indicator
This output pin toggles "High" if Receiver has detected a Loss of Signal Condi-
tion in the incoming line signal.
The criteria for declaring/clearing an LOS Condition depends upon whether it is
operating in the E3 or STS-1/DS3 Mode and is described in Section 2.04.
29
RLOL
O Receive Loss of Lock Output Indicator:
This output pin toggles "High" if the XRT75VL00 has detected a Loss of Lock
Condition. LOL (Loss of Lock) condition is declared if the recovered clock fre-
quency deviates from the Reference Clock frequency (available at ExClk input
pin) by more than 0.5%.
33
Rext
**** External Bias control Resistor of 3.3 KΩ ±1%.
Should be connected to RefAGND via 3.3 KΩ resistor.
15
TEST
I
Test Mode:
Connect this pin “High” to configure the XRT75VL00 in test mode.
NOTE: This pin is internally pulled Down.
16
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, set this pin
"High".
NOTE: This pin is internally pulled “High".
2
TAOS
I Transmit All Ones Select
A “High" on this pin causes the Transmitter Section to generate and transmit a
continuous AMI all “1’s” pattern onto the line. The frequency of this “1’s” pattern
is determined by TxClk.
NOTES:
1. This input pin is ignored if the XRT75VL00 is operating in the HOST
Mode and should be tied to GND.
2. Analog Loopback and Remote Loopback have priority over request.
3. This pin is internally pulled down.
28
LOSMUT/
INT
I/O MUTE-upon-LOS Enable Input or Interrupt Ouput:
In Hardware Mode, setting this pin “High” configures the XRT75VL00 to Mute
the recovered data on the RPOS and RNEG whenever an LOS condition is
declared. RPOS and RNEG outputs are pulled “Low”.
NOTE: If the XRT75VL00 is configured in HOST mode, this pin functions as
INT pin (please refer to the pin description for the Microprocessor
Interface).
10