HD4074344 Datasheet, PDF (37/100 Pages) Hitachi Semiconductor – 4-bit microcomputers

HD404344R Series/HD404394 Series
MCU operation
cycle
IF = 1?
Yes
No
Instruction
execution
No
IM = 0 and
IE = 1?
Yes
Yes _SBY/STOP
instruction?
No
Low-power mode
operation cycle
PC ← Next
location
IE ← 0
Stack ← (PC),
(CA),
(ST)
PC ←Vector
address
IF: Interrupt request flag
IM: Interrupt mask
IE: Interrupt enable flag
PC: Program counter
CA: Carry flag
ST: Status flag
Figure 15 MCU Operation Sequence (MCU Operation Cycle)
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