摘要 |
<P>PROBLEM TO BE SOLVED: To reduce the influence of a power supply noise to be imposed on a clock of an electric circuit. <P>SOLUTION: A noise frequency measuring circuit 12 measures data about the frequency of generation of specific frequency component of the power supply noise propagated from a global clock to a local clock. Upon receiving the generation frequency data, a state machine 14 outputs a state value corresponding to the generation frequency data to a frequency variable clock driver 16. The frequency variable clock driver 16 varies the frequency of the local clock depending on the above state value. <P>COPYRIGHT: (C)2008,JPO&INPIT |