ACS8520 View Datasheet(PDF) - Semtech Corporation
Part Name
Description
MFG CO.
'ACS8520' PDF : 150 Pages View PDF
ACS8520 SETS
ADVANCED COMMUNICATIONS
Address (hex): 49
Register Name cnfg_freq_mon_threshold
FINAL
Description
(R/W) Register to set both the
hard and soft frequency alarm
limits for the monitors on the
input reference sources.
DATASHEET
Default Value 0010 0011
Bit 7
Bit 6
Bit 5
soft_frequency_alarm_threshold
Bit 4
Bit 3
Bit 2
Bit 1
hard_frequency_alarm_threshold
Bit 0
Bit No.
Description
Bit Value Value Description
[7:4]
[3:0]
soft_frequency_alarm_threshold
Threshold to trigger the soft frequency alarms in the
sts_reference_sources registers.
This is only used for monitoring.
hard_frequency_alarm_threshold
Threshold to trigger the hard frequency alarms in
the sts_reference_sources registers, which can
cause a reference source rejection.
-
To calculate the limit in ppm, add one to the 4-bit
value in the register, and multiply by 3.81 ppm. The
limit is symmetrical about zero. A value of 0010 bin
corresponds to an alarm limit of ±11.43 ppm.
To calculate the limit in ppm, add one to the 4-bit
value in the register, and multiply by 3.81 ppm. The
limit is symmetrical about zero. A value of 0011 bin
corresponds to an alarm limit of ±15.24 ppm.
Address (hex): 4A
Register Name cnfg_current_freq_mon_
threshold
Description
(R/W) Register to set both the
hard and soft frequency alarm
limits for the monitors on the
currently selected reference
source.
Default Value 0010 0011
Bit 7
Bit 6
Bit 5
current_soft_frequency_alarm_threshold
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
current_hard_frequency_alarm_threshold
Bit No.
Description
Bit Value Value Description
[7:4]
[3:0]
current_soft_frequency_alarm_threshold
Threshold to trigger the soft frequency alarm in the
sts_reference_sources register applying to the
currently selected source.The currently selected
source can be monitored for frequency using
different limits to all other sources.
current_hard_frequency_alarm_threshold
Threshold to trigger the hard frequency alarm in the
sts_reference_sources register applying to the
currently selected source.
-
To calculate the limit in ppm, add one to the 4-bit
value in the register, and multiply by 3.81 ppm. The
limit is symmetrical about zero. A value of 0010 bin
corresponds to an alarm limit of ±11.43 ppm.
To calculate the limit in ppm, add one to the 4-bit
value in the register, and multiply by 3.81 ppm. The
limit is symmetrical about zero. A value of 0011 bin
corresponds to an alarm limit of ±15.24 ppm.
Revision 3.02/October 2005 © Semtech Corp.
Page 98
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