HD404369 Datasheet, PDF (36/117 Pages) Hitachi Semiconductor – 4-bit HMCS400-Series microcomputer

HD404369 Series
used after transition to active mode), execute the TEST instruction to the RAM enable flag (RAME) at the
beginning of the program.
MCU Operation Sequence: The MCU operates in the sequence shown in figures 17 to 19. It is reset by an
asynchronous RESET input, regardless of its status.
The low-power mode operation sequence is shown in figure 19. 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/SBYinstruction, make sure all interrupt flags are cleared or all interrupts are masked.
Power on
No
RESET = 0 ?
Yes
RAME = 0
Reset MCU
MCU
operation
cycle
Figure 17 MCU Operating Sequence (Power On)
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