CHAPTER 15 STANDBY FUNCTION
Preliminary User’s Manual U16846EJ1V0UD
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The STOP mode can be released by the following two sources.
(a) Release by unmasked interrupt request
When an unmasked interrupt request is generated, the STOP mode is released. After the oscillation
stabilization time has elapsed, if interrupt acknowledgment is enabled, vectored interrupt servicing is carried
out. If interrupt acknowledgment is disabled, the next address instruction is executed.
Figure 15-6. STOP Mode Release by Interrupt Request Generation
(1) When high-speed system clock is used as CPU clock
Operating mode
Operating mode
Oscillates
Oscillates
STOP
instruction
STOP mode
Wait
(set by OSTS)
Standby release signal
Oscillation stabilization
wait status
Oscillation stopped
High-speed system clock
Status of CPU
Oscillation stabilization time (set by OSTS)
(High-speed system clock)
(High-speed
system clock)
(2) When Ring-OSC clock is used as CPU clock
Operating mode
Operating mode
Oscillates
STOP
instruction
STOP mode
Standby release signal
Ring-OSC clock
Status of CPU
(Ring-OSC clock)
Operation
stopped
(17/f
R
)
(Ring-OSC clock)
Remarks 1. The broken lines indicate the case when the interrupt request that has released the standby
mode is acknowledged.
2.
f
R
: Ring-OSC clock oscillation frequency