XRT73LC04A_08 Datasheet, PDF (46/64 Pages) Exar Corporation – 4 CHANNEL DS3/E3/STS-1 LINE INTERFACE UNIT

XRT73LC04A
4 CHANNEL DS3/E3/STS-1 LINE INTERFACE UNIT
REV. 1.0.2
clearing ALOS_(n) in order to prevent chattering in
the RLOS_(n) output signal.
Monitoring the State of ALOS_(n)
If the XRT73LC04A is operating in the HOST Mode,
the state of ALOS_(n) of Channel(n) can be polled or
monitored by reading in the contents of Command
Register CR0. .
COMMAND REGISTER CR0-(n)
D4
D3
D2
D1
D0
RLOL_(n)
RLOS_(n)
ALOS_(n)
DLOS_(n)
DMO_(n)
Read Only
Read Only
Read Only
Read Only
Read Only
If the ALOS_(n) bit-field contains a "1", then the cor-
responding Channel(n) is currently declaring an
ALOS condition. Conversely, if the ALOS_(n) bit-field
contains a "0", then the channel is not currently de-
claring an ALOS condition.
For debugging purposes, it may be useful to disable
the ALOS Detector. If the XRT73LC04A is operating
in the HOST Mode, disable the Channel(n) ALOS De-
tector by writing a "1" into the ALOSDIS_(n) bit-field
in Command Register CR2.
Disabling the ALOS Detector
COMMAND REGISTER CR2-(n)
D4
D3
D2
D1
D0
Reserved
Reserved
ALOSDIS_(n)
DLOSDIS_(n)
REQEN_(n)
X
X
1
X
X
2. The Digital LOS (DLOS) Declaration/Clearance
Criteria
A given channel(n) declares a Digital LOS
(DLOS_(n)) condition if the XRT73LC04A detects
160±32 or more consecutive "0’s" in the incoming da-
ta.
The channel clears DLOS if it detects four consecu-
tive sets of 32 bit-periods, each of which contains at
least 10 "1’s" (e.g., average pulse density of greater
than 33%).
Monitoring the State of DLOS
If the XRT73LC04A is operating in the HOST Mode
the state of DLOS_(n) of Channel(n) can be polled or
monitored by reading in the contents of Command
Register CR0.
COMMAND REGISTER CR0-(n)
D4
D3
D2
D1
D0
RLOL_(n) RLOS_(n) ALOS_(n) DLOS_(n) DMO_(n)
Read Only Read Only Read Only Read Only Read Only
If the DLOS_(n) bit-field contains a “1”, then the cor-
responding channel(n) is currently declaring a DLOS
condition. If the DLOS_(n) bit-field contains a “0”,
then the channel(n) is currently declaring the DLOS
condition.
Disabling the DLOS Detector
For debugging purposes, it is useful to disable the
DLOS_(n) detector. If the XRT73LC04A is operating
in the HOST Mode, the DLOS Detector can be dis-
abled by writing a “1” into the DLOSDIS_(n) bit-field in
Command Register CR2.
COMMAND REGISTER CR2-(n)
D4
D3
D2
D1
D0
Reserved
Reserved
ALOSDIS_(n)
DLOSDIS_(n)
REQEN_(n)
X
X
X
1
X
NOTE: Setting both the ALOSDIS_(n) and DLOSDIS_(n)
bit-fields to "1" disables LOS Declaration by Channel(n).
3.5.3 Muting the Recovered Data while the LOS
is being Declared
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