| 摘要 |
<p>PROBLEM TO BE SOLVED: To make it possible to reduce a current consumption and shorten the time for boosting a voltage of a incorporated boosting means by boosting a boosting means with a 1st clock signal and changing a 1st clock signal over to a 2nd clock signal of a frequency lower than the 1st clock signal. SOLUTION: Relating to a microcomputer incorporating a flash memory, an oscillator 32 oscillates a clock signal CJ3, and a ring oscillator 31 oscillates a clock signal CK4 of a frequency higher than the clock signal CK3. A counter 33 outputs an overflow signal 47 after an elapse of time from a reset signal input until a recharge pump is boosted up to a predetermined voltage by the clock signal. A selector 34 supplies the clock signal CK4 to the charge pump until the overflow signal 47 is inputted to the charge pump from release of a stand-by signal 45, and thereafter supplies the clock signal CK3. Thus, it is possible to shorten a boosting time and reduce a current consumption.</p> |
