ACS8582 Semtech Corporation, ACS8582 Datasheet - Page 69

• Manufacturer Part Number: ACS8582
• Manufacturer: Semtech Corporation

Address (hex):
Address (hex):
Revision 1.00/March 2008 ©Semtech Corp.
ADVANCED COMMS & SENSING
Register Name
freq_mon_clk
Register Name
Bit No.
Bit No.
Bit 7
Bit 7
[7:4]
[3:0]
2
1
0
48
49
cnfg_monitors
los_flag_on_
TDO
Description
PBO_en
Bit to enable Phase Build-out events on source
switching. When enabled a Phase Build-out event is
triggered every time the T0 DPLL selects a new
source. This includes exiting the Holdover or Free-
run states.
freq_monitor_soft_enable
Control to enable frequency monitoring of input
reference sources using soft frequency alarms.
freq_monitor_hard_enable
Control to enable frequency monitoring of input
reference sources using hard frequency alarms.
cnfg_freq_mon_threshold
Description
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.
soft_frequency_alarm_threshold
Bit 6
Bit 6
ultra_fast_
switch
Bit 5
Bit 5
Description
ext_switch
Description
CONFIDENTIAL
Bit 4
Bit 4
FINAL
Page 69
(R/W) Configuration register
controlling several input
monitoring and switching options.
PBO_freeze
(R/W) Register to set both the
hard and soft frequency alarm
limits for the monitors on the
input reference sources.
Bit Value
Bit Value
Bit 3
Bit 3
0
1
0
1
0
1
-
PBO_en
Value Description
Phase Build-out not enabled. T0 DPLL locks to zero
degrees phase.
Phase Build-out enabled on source switching.
Soft frequency monitor alarms disabled.
Soft frequency monitor alarms enabled.
Hard frequency monitor alarms disabled.
Hard frequency monitor alarms enabled.
Value Description
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.
hard_frequency_alarm_threshold
Bit 2
Bit 2
Default Value
freq_monitor_
soft_enable
Default Value
Bit 1
Bit 1
ACS8582
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0000 0101*
freq_monitor_
hard_enable
0010 0011
Bit 0
Bit 0