摘要 |
A phase adjustment unit adjusts the phases of a plurality of external clocks successively shifted in phase, thereby generating a plurality of internal clocks having an equal phase difference between every adjacent transition edges thereof. The internal clocks are synthesized to generate a composite clock having equal pulse intervals. Thus, even when the semiconductor integrated circuit is supplied with external clocks of lower frequencies, it is possible to operate the semiconductor integrated circuit at high speed. For example, the internal circuit can be operated and tested at high speed by using a low-cost LSI tester having a low clock frequency. This can reduce the testing cost of the semiconductor integrated circuit, allowing a reduction in chip cost.
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