HD4074344 Datasheet, PDF (36/100 Pages) Hitachi Semiconductor – 4-bit microcomputers

HD404344R Series/HD404394 Series
MCU Operation Sequence: The MCU operates according to the flowcharts shown in figures 14 to 16.
Since RESET is asynchronous input, the MCU will be reset in any mode that the MCU is operating in.
The low-power mode operation sequence is shown in figure 16. 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 = 0?
No
Yes
RAME = 0
Reset MCU
MCU
operation
cycle
Figure 14 MCU Operation Sequence (Power On)
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