7470_M Datasheet, PDF (174/361 Pages) Renesas Technology Corp – 8-BIT SINGLE-CHIP MICROCOMPUTER 740 FAMILY / 7470 SERIES

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.
2 Recovery by reset input
The microcomputer is reset by applying the “L” level to the RESET pin for 2 ms 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.
Wait mode
VCC
RESET
XIN
(Note)
Execute WIT instruction
2 µs or more Oscillation stabilizing wait time : 32768 counts of XIN pin input signal
Recovered by reset input
Note: No waveform may be input to XIN (in low-speed mode).
Fig. 1.17.5 Reset input time
7470/7471/7477/7478 GROUP USER’S MANUAL
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