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Chapter 18 Timebase Counter
7.Q&A
7. Q&A
7.1 How do I setup the oscillation stabilization wait time that is generated automatically?
Use the oscillation stabilization wait time selection bits (STCR.OS[1:0]). (The following lists likely scenarios
and the required settings.)
Scenario
To not halt the main PLL or oscillator during stop mode
(No oscillation stabilization wait time required)
To not stop the oscillator during external clock input or
stop mode
(Main PLL lock wait time)
When using an oscillator with a fast stabilization time
such as a ceramic resonator
(Oscillation stabilization wait time (medium))
When using a standard quartz oscillator
(Oscillation stabilization wait time (long))
• F2: Main clock divided by 2, or subclock
• In the case of an INIT pin input, operation defaults to "00" (F2 x 2
• For other resets and when recovering from stop mode, the operation is in accordance with the specified
clock (main or sub) and oscillation stabilization wait time (OS[1:0]) setting.
• The count is performed by the timebase counter.
• Once the time is selected, it is not initialized except by a settings initialization triggered by the external
INIT pin.
260
Example oscillation stabilization wait time
Oscillation
stabilization wait
Oscillation
time selection bits
stabiliza-
(OS[1:0])
tion
wait time
Φ2 × 2
Set "00".
Φ2 × 2
Set "01".
Φ2 × 2
Set to "10".
Φ2 × 2
Set to "11".
1
=main clock divided by 4).
after a reset (INIT) or on
recovering from stop mode
4.0MHz
Main clock
running
1
1.00µs
11
1.0ms
16
32ms
22
2s
32.768kHz
Subclock
running
61µs
62.5ms
2.0s
128s
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