XRT75VL00_08 Datasheet, PDF (11/50 Pages) Exar Corporation – E3/DS3/STS-1 LINE INTERFACE UNIT WITH JITTER ATTENUATOR

REV. 1.0.6
XRT75VL00
E3/DS3/STS-1 LINE INTERFACE UNIT WITH JITTER ATTENUATOR
OPERATING MODE SELECT
PIN #
SIGNAL NAME
TYPE
21
HOST/(HW)
I
20
E3
I
19
STS-1/DS3
I
22
SR/DR
I
DESCRIPTION
HOST/Hardware Mode Select:
Tie this pin “High” to configure the XRT75VL00 in HOST mode. Tie this “Low” to
configure in Hardware mode.
When the XRT75VL00 is configured in HOST mode, the states of many discrete
input pins are ignored.
NOTE: This pin is internally pulled up.
E3 Mode Select Input
A "High" on this pin configures to operate in the E3 mode.
A "Low" on this pin configures to operate in either STS-1 or DS3 mode depend-
ing on the setting on pin 19.
NOTES:
1. This pin is internally pulled down
2. This pin is ignored and may be tied to GND if the XRT75VL00 is
configured to operate in HOST mode.
STS-1/DS3 Select Input
A “High” on this pin configures to operate in STS-1 mode.
A “Low” on this pin configures to operate in DS3 mode.
This pin is ignored if the E3 pin is set to “High”.
NOTES:
1. This pin is internally pulled down
2. This pin is ignored and may be tied to GND if the XRT75VL00 is
configured to operate in HOST mode.
Single-Rail/Dual-Rail Select:
Setting this “High” configures both the Transmitter and Receiver to operate in
Single-rail mode and also enables the B3ZS/HDB3 Encoder and Decoder. In
Single-rail mode, Transmit input at TNData should be grounded.
Setting this “Low” configures both the Transmitter and Receiver to operate in
Dual-rail mode and disables the B3ZS/HDB3 Encoder and Decoder.
NOTE: This pin is internally pulled down.
CONTROL AND ALARM INTERFACE
42
MRING
I Monitor Ring Input
The bipolar line output signal from TRING is connected to this pin via a 270 Ω
resistor to check for line driver failure.
NOTE: This pin is internally pulled down.
41
MTIP
I Monitor Tip Input
The bipolar line output signal from TTIP is connected to this pin via a 270-ohm
resistor to check for line driver failure.
NOTE: This pin is internally pulled down.
40
DMO
O Drive Monitor Output
If MTIP and MRING has no transition pulse for 128 ± 32 TxClk cycles, DMO
goes “High” to indictae the driver failure. DMO output stays “High” until the next
AMI signal is detected.
9