HD404618 Datasheet, PDF (34/91 Pages) Hitachi Semiconductor – 4-Bit Single-Chip Microcomputer

HD404618 Series
MCU operation
cycle
IF = 1 ?
No
Yes
No
Instruction
execution
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 17 MCU Operating Sequence (MCU operation cycle)
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