XRT75L03D Datasheet, PDF (78/134 Pages) Exar Corporation – THREE CHANNEL E3/DS3/STS-1 LINE INTERFACE UNIT WITH SONET DESYNCHRONIZER

XRT75L03D
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REV. 1.0.0 THREE CHANNEL E3/DS3/STS-1 LINE INTERFACE UNIT WITH SONET DESYNCHRONIZER
BIT NUMBER
NAME
3
FL Alarm Declared
2
Receive LOL Con-
dition Declared
TYPE
R/O
R/O
DEFAULT
VALUE
DESCRIPTION
0
FL (FIFO Limit) Alarm Declared:
This READ-ONLY bit-field indicates whether or not the Jit-
ter Attenuator block (within Channel_n) is currently declar-
ing the FIFO Limit Alarm.
The Jitter Attenuator block will declare the FIFO Limit
Alarm anytime the Jitter Attenuator FIFO comes within two
bit-periods of either overflowing or under-running.
Conversely, the Jitter Attenuator block will clear the FIFO
Limit Alarm anytime the Jitter Attenuator FIFO is NO
longer within two bit-periods of either overflowing or under-
running.
Typically, this Alarm will only be declared whenever there is
a very serious problem with timing or jitter in the system.
0 - Indicates that the Jitter Attenuator block (within
Channel_n) is NOT currently declaring the FIFO Limit
Alarm condition.
1 - Indicates that the Jitter Attenuator block (within
Channel_n) is currently declaring the FIFO Limit Alarm
condition.
NOTE: This bit-field is only active if the Jitter Attenuator
(within Channel_n) has been enabled.
0
Receive LOL (Loss of Lock) Condition Declared:
This READ-ONLY bit-field indicates whether or not the
Receive Section (within Channel_n) is currently declaring
the LOL (Loss of Lock) condition.
The Receive Section (of Channel_n) will declare the LOL
Condition, if any one of the following conditions are met.
• If the frequency of the Recovered Clock signal differs
from that of the signal provided to the E3CLK input (for
E3 applications), the DS3CLK input (for DS3
applications) or the STS-1CLK input (for STS-1
applications) by 0.5% (or 5000ppm) or more.
• If the frequency of the Recovered Clock signal differs
from the line-rate clock signal (for Channel_n) that has
been generated by the SFM Clock Synthesizer PLL (for
SFM Mode Operation) by 0.5% (or 5000ppm) or more.
0 - Indicates that the Receive Section of Channel_n is NOT
currently declaring the LOL Condition.
1 - Indicates that the Receive Section of Channel_n is cur-
rently declaring the LOL Condition.
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