| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide a semiconductor device which prevents malfunction due to drop of operation voltage with rapid increase of a clock frequency. <P>SOLUTION: A determination part 10 determines the frequency region of an operation clock and outputs a warning signal to a CPU part 6 when the frequency region is changed from "low frequency region" to "high frequency region". Receiving the warning signal from the determination part 10, a control part 30 stops counting up by a program counter in an arithmetic part 28, and gives a prescribed operation command to a peripheral function circuit 8 also during receiving the warning signal. After the lapse of a sufficient period for stabilizing output voltage by a regulator 12, the determination part 10 finishes the output of the warning command. The control part 30 starts counting up by the program counter in the arithmetic part 28 again according to the finish of the warning signal. Then, the arithmetic part 28 starts execution of instruction again. <P>COPYRIGHT: (C)2006,JPO&NCIPI</p> |
