HD404618 Datasheet, PDF (33/89 Pages) Hitachi Semiconductor – 4-Bit Single-Chip Microcomputer

Low-power mode
operation cycle
IF = 1
No
IM = 0 ?
Yes
Standby/watch
mode
Hardware NOP
execution
No
IF = 1
IM = 0 ?
Yes
Hardware NOP
execution
HD404618 Series
Stop mode
PC ← next
Iocation
PC ← next
Iocation
Instruction
execution
MCU operation
cycle
For IF and IM operation, refer to figure 12.
Figure 18 MCU Operating Sequence (low-power mode operation)
Notes on Use:
• In subactive mode, the timer A interrupt request or the external interrupt request (INT₀) occurs in
synchronism with the interrupt strobe.
If the STOP or SBY instruction is executed at the same time with the interrupt strobe, these interrupt
requests will be cancelled and the corresponding interrupt request flags (IFTA, IF0) will not be set.
In subactive mode, do not use the STOP or SBY instruction at the time of the interrupt strobe.
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