Datasheet

78K0/Ix2 CHAPTER 5 CLOCK GENERATOR
R01UH0010EJ0500 Rev.5.00 179
Feb 28, 2012
5.6.3 Example of controlling internal low-speed oscillation clock
The internal low-speed oscillation clock cannot be used as the CPU clock.
Only the following peripheral hardware can operate with this clock.
Watchdog timer
8-bit timer H1 (if f
IL is selected as the count clock)
In addition, the following operation modes can be selected by the option byte.
Internal low-speed oscillator cannot be stopped
Internal low-speed oscillator can be stopped by software
The internal low-speed oscillator automatically starts oscillation after a reset release, and the watchdog timer is driven
(30 kHz (TYP.)) if the watchdog timer operation has been enabled by the option byte.
(1) Example of setting procedure when stopping the internal low-speed oscillation clock
<1> Setting LSRSTOP to 1 (RCM register)
When LSRSTOP is set to 1, the internal low-speed oscillation clock is stopped.
(2) Example of setting procedure when restarting oscillation of the internal low-speed oscillation clock
<1> Clearing LSRSTOP to 0 (RCM register)
When LSRSTOP is cleared to 0, the internal low-speed oscillation clock is restarted.
Caution If “Internal low-speed oscillator cannot be stopped” is selected by the option byte, oscillation of the
internal low-speed oscillation clock cannot be controlled.