| 摘要 |
PROBLEM TO BE SOLVED: To measure a measuring signal outputted from a PLL or the like at low cost with high precision. SOLUTION: An inspection device is provided with a period measuring circuit 9 for measuring the period of the measuring signal outputted from the PLL or the like of a semiconductor device. In the period measuring circuit 9, a phase clock generating circuit 11 generates and outputs four different phase clock signals by using as a reference, a reference clock signal generated by a reference clock generating portion. A phase data storage circuit 12 detects the signal conditions of a phase clock signal, when the waveform of a frequency- divided signal generated by dividing the frequency of the measuring signal outputted from the semiconductor device into (n) by the use of a frequency divider circuit 10, rises/falls, and stores the conditions as phase correcting data. A measuring period computing circuit 14 corrects a measured result counted by a counter 13, based on the phase correction data of the storage circuit 12, and computes a measured period. COPYRIGHT: (C)2004,JPO
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