Digital sound generating system permitting a shared use of a hardware

Abstract

A digital sound generating system is provided which is capable of, in addition to generating a tone (first waveform data), recording or reproducing PCM sound data representing a human voice or sound of a music piece lasting for a relatively long time (second waveform data). To this end, in the tone generating process, tone waveform sample data is read out from a waveform RAM on the basis of address data given from an address calculating section and is then output as an analog signal via an interpolating section and D/A converter. In reproduction of PCM sound data, the PCM sound data supplied via a CPU interface is transferred using the waveform RAM as a buffer and is then supplied outside of the system through a same channel as in the tone generating process. In recording of PCM sound data, a high-frequency-component removing process is performed, by a filtering calculating section, on PCM sound data received via an A/D converter so as to prevent unwanted aliasing noise. The resultant filtered PCM sound data is then transferred using the waveform RAM as a buffer and output via the CPU interface.