| 摘要 |
PURPOSE:To partially expand a periodic waveform with high accuracy without depending upon the frequency of an input periodic waveform by a partial expanding function and an averaging function which enables high-accuracy waveform data to be fetched irrelevantly to an input signal frequency. CONSTITUTION:Assuming that the input signal frequency fin of a waveform 13 to be measured is already known, the clock frequency fclk of a clock generator 8 is set as NXfin from the number (n) of data fetched in each cycle of the waveform 13. Then the clock fclk and the number N of data as preset data are supplied to a data quantity counter 11, which outputs a data quantity count-over signal 18 every time the clock fclk is counted up to N. Its output frequency is equal to the frequency fin, so the trimming of data fetch at the time of averaging is performed with high accuracy. The waveform 13 can be expanded partially by an address comparator 6 which counts in synchronism with the counter 11 which counts the number N of data and then the waveform 13 is expanded partially and averaged with high accuracy.
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