| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide a frequency control circuit capable of controlling the power consumption of the system to be optimal according to activity by automatically changing the frequency of a clock to be supplied to a system according to the rate of the operating state of the system. SOLUTION: This frequency control circuit is provided with a clock supplying circuit 15 capable of supplying system clocks SYSCLK with a plurality of clock frequencies to a CPU 11 for executing processing synchronously with the system clock SYSCLK, and for supplying the system clock with the clock frequency corresponding to a control signal, a timer 12 and a counter 13 for observing the operating state of the CPU 11 in each fixed time, and a control circuit 14 for deciding the frequency of the system clock SYSCLK based on the observed operating state of the CPU 11, and for outputting a control signal S142 to the clock supplying circuit 15 to instruct the supply of the system clock with the decided clock frequency.</p> |
