| 摘要 |
PURPOSE:To reduce difference data to be stored to half and reduce storage capacity, and to speed up waveform generation processing by finding the difference data from differences between intermediate steps of original steps and the original steps. CONSTITUTION:At interpolation points before and behind the interpolation point O of an original point X point of waveform data RD, difference data as to the intermediate point O are the same, so the difference data to be stored are reduced to half. When a sampled value of normal waveform data RD consists of 10 bits, the difference data consists of 10 bits and even if a compression system is used, four bits are required for difference power data, so the data is reduced to only 7 bits by maximum compression. The difference data are reduced to half, so 6-bit difference data is realized and accessed normally by once by 16 bits in total. Waveform data RD and a program are read out of a ROM 20 alternately and even when the frequency of a read of waveform data RD per unit time is reduced to half, that can be coped with sufficiently. |
