Datasheet

CHAPTER 19 STANDBY FUNCTION
User’s Manual U18698EJ1V0UD
467
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 19-6. STOP Mode Release by Interrupt Request Generation (1/2)
(1) When high-speed system clock (X1 oscillation) is used as CPU clock
Normal operation
(high-speed
system clock)
Normal operation
(high-speed
system clock)
OscillatesOscillates
STOP
instruction
STOP mode
Wait
(set by OSTS)
Standby release signal
Oscillation stabilization wait
(HALT mode status)
Oscillation stopped
High-speed
system clock
(X1 oscillation)
Status of CPU
Oscillation stabilization time (set by OSTS)
Interrupt
request
(2) When high-speed system clock (external clock input) is used as CPU clock
Interrupt
request
STOP
instruction
Standby release signal
Status of CPU
High-speed
system clock
(external clock input)
Normal operation
(high-speed
system clock)
Oscillates
STOP mode
Oscillation stopped
Wait
Note
Normal operation
(high-speed
system clock)
Oscillates
Note The wait time is as follows:
• When vectored interrupt servicing is carried out: 8 or 9 clocks
• When vectored interrupt servicing is not carried out: 2 or 3 clocks
Remark The broken lines indicate the case when the interrupt request that has released the standby mode
is acknowledged.