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CHAPTER 6 EXTERNAL INTERRUPT AND NMI CONTROLLER
■ Return Operation from STOP State
The following operation is performed when using an external interrupt to allow the current circuit to return
from the STOP state.
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Processing procedure before the device enters the STOP state
Setting external interrupts
You must enable the interrupt input pass for the STOP state before the device enters the STOP state.
This can be done by setting the PFR register (Port Function Register). Nevertheless, the interrupt input
pass is already enabled in normal states (those other than STOP state); therefore, you do not have to be
conscious to set the register. In the STOP state, on the other hand, the input pass is controlled by the
PFR register.
P62/INT5/PPG0
Inputting external interrupts
When allowing the device to return from the STOP state, external interrupt signals are in such a state
that they send input signals asynchronously. As soon as this interrupt input is asserted, the internal
STOP signal is caused to fall. At the same time, the external interrupt circuit switches its mode to
synchronize the interrupt input of other levels.
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Regulator stabilization wait time
When the internal STOP signal falls, the device starts switching from the STOP regulator to the RUN
regulator. If internal operation starts before the output of RUN regulator voltage stabilizes, the operation
will become unstable. For this reason, a regulator stabilization wait time of approximately 12µs is
secured as the stabilization wait time for the internal output voltage. The clock is stopped during this
period.
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Oscillation time of oscillator
The clock starts oscillation upon the completion of the regulator stabilization wait time. The oscillation
time of the oscillator varies depending on the oscillator used.
138
Pin name
P63/INT9
P62/INT8
P26/INT7
P27/INT6
P60/INT4/CKI
P57/INT3
P56/INT2
P55/INT1
P54/INT0
Setting for returning from STOP state by external interrupt
Set bit 3 in PCR6 to "0".
Set bit 2 in PCR6 to "0".
Set bit 7 in PCR2 to "0".
Set bit 6 in PCR2 to "0".
Set bit 1 in PCR6 to "0".
Set bit 0 in PCR6 to "0".
Set bit 7 in PFR5 to "0".
Set bit 6 in PFR5 to "0".
Set bit 5 in PFR5 to "0".
Set bit 4 in PFR5 to "0".
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