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CHAPTER 24 STANDBY FUNCTION
User’s Manual U12697EJ3V0UM
(1) Releasing the STOP mode by NMI input
When the valid edge specified in external interrupt edge enable registers 0 (EGP0, EGN0) is input by the NMI
input, the oscillator starts oscillating again. Then the STOP mode is released after the oscillation stabilization
time set by the oscillation stabilization time specification register (OSTS).
When the STOP mode is released and non-maskable interrupts from the NMI pin input can be acknowledged,
execution branches to the NMI interrupt service program. If acknowledgement is not possible (such as when
set in the STOP mode in the NMI interrupt service program), execution starts again from the instruction following
the instruction that set the STOP mode. When acknowledgement is enabled, execution branches to the NMI
interrupt service program (by executing the RETI instruction).
For details about NMI interrupt acceptance, refer to
22.6 Non-Maskable Interrupt Acknowledgment Operation
.
Figure 24-7. Releasing STOP Mode by NMI Input
Oscillator
f
XX
/2
STP F/F1
NMI input
when the rising
edge is set
STP F/F2
Oscillator stops
Time until clock starts oscillating
STOP
Timer count time for
oscillation stabilization
