Musical tone generation apparatus using high-speed bus for data transfer

Abstract

A musical tone generation apparatus creates musical-tone-waveform samples based on waveform samples stored in a waveform memory by each sampling period. Herein, a high-speed bus such as a PCI bus is provided for data transfer with regard to the waveform memory. A waveform buffer is provided to temporarily and selectively store the waveform samples which are read from the waveform memory. A sound source operates in accordance with time-division-channel timings which are provided by dividing a sampling period by a number of channels. The sound source performs interpolation calculations on the waveform samples of the waveform buffer to create a musical-tone-waveform sample in accordance with each time-division-channel timing with respect to each channel. The apparatus generates a read address whose value is changed in response to a pitch of a musical tone. When the waveform buffer does not store the waveform samples which are necessary to create the musical-tone-waveform sample, the apparatus accesses the waveform memory in accordance with the read address to read out the waveform samples, which are then transferred to the waveform buffer via the high-speed bus. Herein, burst reading operations are performed on the waveform memory, regardless of the time-division-channel timing. Thus, it is possible to reduce an occupancy time of the high-speed bus by the sound source as well as a number of times to access the waveform memory.