STC5425 Datasheet, PDF (19/48 Pages) Connor-Winfield Corporation – Line Card Clock

STC5425
Line Card Clock
Data sheet
be set from 1 to 16ms, where any hit of signal abnor-
mality (or multiple hits) during the window increments
the bucket count by one. The leak observation win-
dow is 1 to 16 times the fill observation window. The
leaky bucket accumulator decrements by one for
each leak observation window that passes with no
signal abnormality. Both windows operate in a con-
secutive, non-overlapping manner. The bucket accu-
mulator has alarm assert and alarm de-assert
thresholds that can each be programmed from 1 to
64.
Fill Observa-
tion Window,
1ms ~ 16ms
Input Qualification
A selected referenc^Fe^uiⁿs ^c“q^tiu^oaⁿlif^aie^ld^S” ^pif^ei^ct ⁱp^fia^cs^as^teⁱs^onthe
activity evaluation and its frequency offset is within
the programmed qualification range for over a pre-
programmed soaking time.
A reference qualification range may be programmed
up to 102.3 ppm by writing to register Qualification
Range, and a disqualification range set up to 102.3
ppm, by writing to register Disqualification Range.
The qualification range must be set less than the dis-
qualification range. Additionally, qualification soaking
time may be programmed from 0 to 63 seconds by
writing to register Qualification Soaking Time. The
pull-in range is the same as the disqualification range.
Frequency
Ref
Detector
Pulse
Monitor
Leaky
Bucket
Accumulator
Alarm Assert
Alarm De-Assert
Activity
Not Good
Leak Observation
Window, 1~16 x Fill
Observation Window
Activity Alarm
Asserted
Activity Alarm
De-Asserted
Activity Alarm
Asserted
Figure 2: Activity Monitor
Applications can write to the following registers to
configure the activity monitor: Fill Obs Window,
Leak Obs Window, Bucket Size, Assert Threshold,
and De Assert Threshold.
Continuously
Within Offset Qualification
Range for more than
Qualification soaking Time
Activity
Good
Qualified
The activity monitor can be bypassed by setting the
bucket size to 0. This operation de-asserts the activity
alarms of all the references. A non-zero bucket size
must be greater than or equal to the alarm assert
threshold value. The alarm assert threshold value
must be greater than the alarm de-assert threshold
value and less than or equal to the bucket size value.
Attempted writes of invalid values will be ignored.
Therefore, user must carefully plan an appropriate
sequence of writes when re-configure the activity
monitor. See register Bucket Size, Assert Thresh-
old and De Assert Threshold for details.
Alarms appear in the Refs Activity register. A “1”
indicates activity, and a “0” indicates an alarm, no
activity. Note that if a reference is detected as a differ-
ent frequency, the leaky bucket accumulator is set to
the bucket size value and the reference will become
inactive immediately.
Out of Disqualification Range
Figure 3: Reference Qualification Scheme
The frequency offset of each reference is relative to
the internal freerun clock may be read by selecting
the reference in the Ref Info Selector register and
then reading the offset value from register Ref Info.
Figure 3 shows the reference qualification scheme. A
reference is qualified if it has no activity alarm and is
continuous within the qualification range for more
than the qualification soaking time. An activity alarm
or frequency offset beyond the disqualification range
will disqualify the reference. It may then be re-quali-
fied if the activity alarm is off and the reference is
within the qualification range for more than the qualifi-
cation time.
The reference qualification status of each reference
Preliminary
Page 19 of 48 TM113 Rev: P1.3
Date: September 20, 2011
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