| 摘要 |
<p>PURPOSE:To realize data processing at an optimum working speed with no malfunction and to increase greatly the back-up time, by varying the frequency of the clock signal in response to the power supply voltage which is supplied to a data processor. CONSTITUTION:A central processing part 4 can work while varying the frequency of its own clock signal by executing an instruction in accordance with the state of the power supply voltage and controlling a clock generating part 3. Now a commercial power supply is interrupted, and the power supply is switched to a battery or a large-capacity capacitor to keep the working until the power supply is recovered. In such a back-up mode, if the power supply voltage of a data processor drops, this state of the voltage drop is detected at a detecting part 7. Then the part 4 lowers the frequency of its own clock signal by a program process and continues the normal working.</p> |
