7477 datasheet(184/354 Pages) RENESAS

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7470/7471/7477/7478 GROUP USER’S MANUAL

HARDWARE

1.17 Low-power dissipation function

(2) Releasion of wait mode

The wait mode is released by inputting a reset signal or generating an interrupt request. There is a

difference in restore processing from the wait mode between the use of reset input and the use of

interrupt.

s Recovery by reset input

________________

The microcomputer is reset by applying the “L” level to the RESET pin for 2

s or more in the wait

mode, thereby releasing the wait mode.

After the wait mode is released by inputting the reset signal, the supply of internal clock

φ to the

CPU is started.

The reset state is released after 32768 counts of the XIN pin input signal after the “H” level is

________________

applied to the RESET pin.

For the details of the reset, refer to “1.15 Reset.”

Note: When the wait mode is released, the contents of the RAM before reset are held. However,

the contents of the CPU register and the SFR cannot be held but are reset.

Figure 1.17.5 shows the reset input time.

Fig. 1.17.5 Reset input time

RESET

XIN

VCC

Execute WIT instruction

Recovered by reset input

Wait mode

µs or more

(Note)

Note: No waveform may be input to X

(in low-speed mode).

Oscillation stabilizing wait time : 32768 counts of XIN pin input signal

7477 Datasheet(PDF) 184 Page - Renesas Technology Corp