HD404358 Datasheet, PDF (29/102 Pages) Renesas Technology Corp – microcomputer has an A/D converter,


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^{HD404358Series}
Stop mode
Oscillator
Internal
clock
RESET
or STOPC
STOP instruction execution
t_res
t_res ≥ t_RC (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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