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PRELIMINARY
DS3 UNI FOR ATM
XRT7245
REV. 1.03
117
For a detailed description of the XRT7300 DS3/E3 LIU’s
operation, during each of these above-mentioned
loop-back modes, please consult the “XRT7300 DS3/
E3/STS-1 LIU IC” Data Sheet.
Note:
If the customer is not using the XRT7300 DS3/E3/
STS-1 LIU IC, then he/she can use this bit-field and the
“LLOOP” output pin for other purposes.
3.3.2.115
Line Interface Scan Register
Bit 2—DMO (Drive Monitor Output)
This “Read-Only” bit-field indicates the logic state of
the DMO input pin of the UNI device. This input pin is
intended to be connected to the DMO output pin of
the XRT7300 DS3/E3 LIU IC. If this bit-field contains
a logic “1”, then the DMO input pin is “high”. The
XRT7300 DS3/E3 LIU IC will set this pin “high” if the
drive monitor circuitry (within the XRT7300 device)
has not detected any bipolar signals at the MTIP and
MRING inputs (of the XRT7300 device) within the
last 128 ± 32 bit periods.
Conversely, if this bit-field contains a logic “0”, then
the DMO input pin is “high”. The XRT7300 DS3/E3
LIU IC will set this pin “l(fā)ow” if bipolar signals are
being detected at the MTIP and MRING input pins.
Note:
If this customer is not using the XRT7300 DS3/E3
LIU IC, then he/she can use this input pin for a variety of
other purposes.
Bit 1—RLOL (Receive Loss of Lock)
This “Read-Only” bit-field indicates the logic state of
the RLOL input pin of the UNI device. This input pin
is intended to be connected to the RLOL output pin of
the XRT7300 DS3/E3 LIU IC. If this bit-field contains
a logic “1”, then the RLOL input pin is “high”. The
XRT7300 DS3/E3 LIU IC will set this pin "high" if the
clock recovery phase-locked-loop circuitry (within the
XRT7300 device) has lost “l(fā)ock” with the incoming
DS3 data-stream and is not properly recovering clock
and data.
Conversely, if this bit-field contains a logic “0”, then
the RLOL input pin is “l(fā)ow”. The XRT7300 DS3/E3
LIU IC will hold this pin “l(fā)ow” as long as this
“phase-locked-loop” circuitry (within the XRT7300
device) is properly “l(fā)ocked” onto the incoming DS3
data-stream, and is properly recovering clock and
data from this data-stream.
For more information on the operation of the XRT7300
DS3/E3 LIU IC, please consult the “XRT7300 DS3/E3/
STS-1 LIU IC” data sheet.
Note:
If the customer is not using the XRT7300 DS3/E3/
STS-1 IC, then he/she can use this bit-field, and the
“RLOL” input pin for other purposes.
Bit 0—RLOS (Receive Loss of Signal)
This “Read-Only” bit-field indicates the logic state of
the RLOS input pin of the UNI device. This input pin
is intended to be connected to the RLOS output pin
of the XRT7300 DS3/E3 LIU IC. If this bit-field con-
tains a logic “1”, then the RLOS input pin is “high”.
The XRT7300 device will toggle this signal “high” if it
(the XRT7300 LIU IC) is currently declaring an LOS
(Loss of Signal) condition.
Conversely, if this bit-field contains a logic “0”, then
the RLOS input pin is “l(fā)ow”. The XRT7300 device will
hold this signal “l(fā)ow” if it is NOT currently declaring
an LOS (Loss of Signal) condition.
For more information on the LOS Declaration and
Clearance criteria of the XRT7300 device, please
consult the “XRT7300 DS3/E3/STS-1 LIU IC” data
sheet.
Note:
Asserting the “RLOS” input pin will cause the
XRT7245 DS3 UNI device to generate the “Change in LOS
Condition” interrupt and declare an “LOS” (Loss of Signal)
condition. Therefore, this input pin should never be used as
a general purpose input.
Address = 73h, Line Interface Scan Register
B
IT
7
B
IT
6
B
IT
5
B
IT
4
B
IT
3
B
IT
2
B
IT
1
B
IT
0
Unused
DMO
RLOL
RLOS
RO
RO
RO
RO
RO
RO
RO
RO
0
0
0
0
0
0
0
0