
HD404318 Series
20
MCU Operation Sequence:
The MCU operates in the sequence shown in figure 13 and figure 14.
The low-power mode operation sequence is shown in figure 14. With the IE flag cleared and an interrupt
flag set together with its interrupt mask cleared, if a STOP/SBY instruction is executed, the instruction is
cancelled (regarded as an NOP) and the following instruction is executed. Before executing a STOP/SBY
instruction, make sure all interrupt flags are cleared or all interrupts are masked.
Power ON
Reset MCU
RAME = 0
IE
←
0
Stack
←
(PC),
(CA), (ST)
No
Yes
IF = 1
RESET
= 0
SBY/STOP
instruction
IM = 0
IE = 1
RAME = 1
execution
Reset input
PC
←
vector
address
No
No
No
Yes
Yes
MCU operation cycle
PC
←
(PC)+1
Low-power mode
operation cycle
(figure 15)
Figure 13 MCU Operating Sequence (Power ON)