CHAPTER 15 STANDBY FUNCTION
Preliminary User’s Manual U16846EJ1V0UD
303
(b) Release by RESET input
When the RESET signal is input, STOP mode is released and a reset operation is performed after the
oscillation stabilization time has elapsed.
Figure 15-7. STOP Mode Release by RESET Input
(1) When high-speed system clock is used as CPU clock
STOP
instruction
RESET signal
High-speed system clock
Operating mode
STOP mode
Reset
period
Operation
stopped
Operating mode
Oscillates
Oscillation
stopped
Oscillates
Status of CPU
(High-speed
system clock)
Oscillation stabilization time (2
11
/f
XP
to 2
16
/f
XP
)
Note
(Ring-OSC clock)
(17/f
R
)
Oscillation stopped
Note Waiting for the oscillation stabilization time is not required when the external RC oscillation clock is
selected as the high-speed system clock by the option byte. Therefore, the CPU clock can be
switched without reading the OSTC value.
(2) When Ring-OSC clock is used as CPU clock
STOP
instruction
RESET signal
Ring-OSC clock
Operating mode
STOP mode
Reset
period
Operation
stopped
Operating mode
Oscillates
Oscillation
stopped
Oscillates
Status of CPU
(Ring-OSC clock)
(17/f
R
)
(Ring-OSC clock)
Remarks 1. f
XP
: High-speed system clock oscillation frequency
2. f
R
: Ring-OSC clock oscillation frequency
Table 15-5. Operation in Response to Interrupt Request in STOP Mode
Release Source
MK
××
PR
××
IE ISP
Operation
0 0 0
×
Next address instruction execution
0 0 1
×
Interrupt servicing execution
0 1 0 1
0 1
×
0
Next address instruction execution
0 1 1 1
Interrupt
servicing
execution
Maskable interrupt request
1
×
×
×
STOP mode held
RESET input
−
−
×
×
Reset processing
×
: Don't care