M38203M4 Datasheet, PDF (268/344 Pages) Mitsubishi Electric Semiconductor – 8-BIT SINGLE-CHIP MICROCOMPUTER

APPLICATION
2.9 Standby function
(2) Release of wait mode
The wait mode is released by reset input or by the occurrence of an interrupt request.
There is a difference in restore processing from the wait mode by use of reset input and by use of
an interrupt request.
In the wait mode, oscillation is continued, so an instruction can be executed immediately after the wait
mode is released.
sRestoration by reset input
The reset state is provided by holding the input level of the RESET pin at “L” for 2 µs or more in the
wait mode. As a result, the wait mode is released.
At the time when the wait mode is released, the supplying the internal clock φ to the CPU is started.
The reset state is released in approximately 8,000 cycles of the XIN input after the input of the RESET
pin is returned to the “H” level.
At release of the wait mode, the contents of the internal RAM previous to the reset are held. However,
the contents of the CPU mode register and SFR are not held.
Figure 2.9.3 shows the reset input time.
For reset, refer to “2.10 Reset.”
Wait mode
Time to hole internal reset state =
approximately 8000 cycles of XIN
input
Oscillation stabilizing time
VCC
RESET
2 µs or more
XIN
(Note)
Execute WIT instruction
Restored by reset input
Note: No waveform may be input to XIN (in low-speed mode)
Fig. 2.9.3 Reset input time
2–182
3820 GROUP USER’S MANUAL