NEC PD750004 User Manual page 242

µPD750008 USER'S MANUAL
(2) Application of the HALT mode (at f
<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>
V
Voltage on V
0 V
P00/INT4
CPU operation
222
X
DD
DD
(HALT mode + low-speed operation)
Operating mode
INT4
= 4.19 MHz)
Intermittent operation
Operating mode Operating mode
(low-speed) (high-speed)
250 ms
INT4