| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide a clock changer which executes the control for gradually increasing the frequency of a clock applied a high current consumption type semiconductor device and the control for gradually decreasing the clock frequency in testing the semiconductor device which has a high clock frequency in a regular operation and consumes a high current in the regular operation. SOLUTION: The clock changer is composed of a clock generator for generating clocks covering all frequencies required for a semiconductor device and a selector circuit for selecting and outputting the clock generated by the clock generator. Further, the clock changer comprises a synchronizing circuit for generating a switching control signal synchronized with each clock, and a gate circuit constituting the selector circuit is controlled according to the switching control signal synchronized with each clock obtained by the synchronizing circuit.</p> |
