222
µPD750008 USER'S MANUAL
(2) Application of the HALT mode (at fX = 4.19 MHz)
<Intermittent operation under the following conditions>
The main system clock is switched to the subsystem clock on the falling edge of INT4.
The oscillation of the main system clock is stopped, and HALT mode is set.
In the standby mode, intermittent operation is performed at intervals of 0.5 s.
The subsystem clock is switched back to the main system clock on the rising edge of INT4.
INTBT is not used.
<Timing chart>
INT4
INT4
250 ms
Operating mode
(low-speed)
Intermittent operation
(HALT mode + low-speed operation)
Operating mode
V
DD
0 V
P00/INT4
CPU operation
Voltage on V
DD
Operating mode
(high-speed)