HD404356 查看數據表（PDF） - Hitachi -> Renesas Electronics

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HD404356

4-bit HMCS400-series microcomputer

Hitachi -> Renesas Electronics 


,
HD404358Series

Stop mode

Oscillator

Internal

clock

RESET

or STOPC

STOP instruction execution

tres

tres ≥ tRC (stabilization period)

Figure 13 Timing of Stop Mode Cancellation

Stop Mode Cancellation by STOPC: The MCU enters active mode from stop mode by inputting STOPC

as well as by RESET. In either case, the MCU starts instruction execution from the starting address

(address 0) of the program. However, the value of the RAM enable flag (RAME: $021, bit 3) differs

between cancellation by STOPC and by RESET. When stop mode is cancelled by RESET, RAME = 0;

when cancelled by STOPC, RAME = 1. RESET can cancel all modes, but STOPC is valid only in stop

mode; STOPC input is ignored in other modes. Therefore, when the program requires to confirm that stop

mode has been cancelled by STOPC (for example, when the RAM contents before entering stop mode is

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 figure 15. It is reset by an

asynchronous RESET input, regardless of its status.

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 Operating Sequence (Power On)

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