BAT32G1x9 user manual | Chapter 4 Clock generation circuit
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Rev.1.02
4.7.3.2
Operation setup process
The Operation mode start/stop process is shown in the following figure when the high-speed internal
oscillating clock frequency correction function is used.
Figure 4-28 Operation mode setting process (example).
Note: Before stopping the high-speed internal oscillating clock frequency correction function, the high-speed
internal oscillating clock frequency correction operation is performed repeatedly.
4.7.4
Precautions for use
4.7.4.1
SFR access
Regarding the control of the FCST bit in the interval mode, when writing 1 to the FCST bit, you must first
confirm that the value of the current FCST bit is 0 and then write 1 to it. Due to the priority of hardware clearance,
when the FCST bit is written to 1 immediately after the interval operation is completed (when the high-speed
internal vibration frequency correction completes the interrupt generation), the operation should be performed
at least 1 cycle after the high-speed internal vibration frequency correction is completed after the interrupt is
generated.
4.7.4.2
Action during reset
Before entering deep sleep, the high-speed internal oscillating clock frequency correction function must be
stopped.
Processing
execution
note
CRCTL=40H
Does the high speed internal
frequency correction
completion interrupt occur?
High speed internal frequency correction
continuous action mode setting
Allow high-speed internal frequency correction
completion interrupt
CRCTL=41H
Allow high-speed internal frequency
correction action
No
CRCTL=01H
High speed internal frequency correction
completion interrupt is prohibited
Yes
Action Start Process
CRCTL=00H
High speed internal vibration
frequency correction action stops
Action stop process
CRCTL=C0H
Does the high speed internal
frequency correction
completion interrupt occur?
High speed internal frequency correction interval
action mode setting
Allow high-speed internal frequency correction
completion interrupt
CRCTL=C1H
Allow high-speed internal frequency
correction action
No
High speed internal vibration
frequency correction completed
Yes
Does the high speed internal
frequency correction
completion interrupt occur?
CRCTL=C1H
Allow high-speed internal frequency
correction action
No
Yes
Action Start Process
(
2
)
Timer interrupt, etc
<
Continuous action mode
>
Action Start Process
(
1
)
<
Interval action mode
>
High speed internal vibration
frequency correction completed