Tone generation method with envelope computation separate from waveform synthesis

An electronic musical apparatus utilizing a central processing unit for working various modules to generate music tones, while controlling a work load of the central processing unit, the apparatus comprising:

• a player module that provides a sequence of event data indicating an event of a music tone and timing data indicating an occurrence time of the event;
• a driver module that is intermittently triggered to process the event data for creating control parameters reserved for use in generation of the music tone corresponding to the event data, and for determining an envelope of the music tone according to the control parameters, the envelope being also reserved for use in generation of the music tone;
• a sound source module that is routinely triggered to load therein the reserved control parameters and the envelope for generating the music tone according to the timing data;
• and
• a timing module that issues a synchronous trigger signal effective to routinely trigger the sound source module, and that issues an asynchronous trigger signal independently of the timing data for intermittently triggering the driver module so as to avoid concentration of the work load of the central processing unit.

An apparatus of generating a music tone by means of a sound source and buffer memories, comprising:

• first means for writing a sequence of event data together with timing data in a first buffer memory, each event data indicating a music event of a music tone, and each timing data indicating an occurrence timing of each music event;
• second means for retrieving each event data from the first buffer memory to create control parameters prepared to control the sound source in production of a waveform of the music tone, and storing the control parameters together with the corresponding timing data in a second buffer memory;
• third means for determining an envelope of the music tone according to the control parameters and the timing data stored in the second buffer memory, and storing the envelope in the third buffer memory;
• fourth means for operating the sound source based on the control parameters and the timing data stored in the second buffer memory and based on the envelope stored in the third buffer memory to effect the production of the waveform of the music tone, and storing the waveform in a fourth buffer memory;
• fifth means for sequentially retrieving the waveform from the fourth buffer memory to reproduce the music tone of each music event;
• sixth means for regulating a first timing along with progression of the reproduction of the music tone to trigger the fourth means at the first timing such that the production of the waveform is regulated along with the occurrence timing of each music event;
• and
• seventh means for regulating a second timing independently of the occurrence timing of the music event to trigger either of the second means and the third means at the second timing such that the creation of the control parameters and the determination of the envelope are conducted separately from the occurrence timing of each music event.

A machine readable medium used in an electronic musical apparatus having a central processing unit for operating various modules to generate music tones while controlling a work load of the central processing unit, the medium containing program instructions executable by the central processing unit for causing the electronic music apparatus to perform the method comprising the steps of:

• operating a player module that provides a sequence of event data indicating an event of a music tone and timing data indicating an occurrence time of the event;
• operating a driver module that is intermittently triggered to process the event data for creating control parameters reserved for use in generation of the music tone corresponding to the event data, and for determining an envelope of the music tone according to the control parameters, the envelope being also reserved for use in generation of the music tone;
• operating a sound source module that is routinely triggered to load therein the reserved control parameters and the envelope for generating the music tone according to the timing data;
• and
• operating a timing module that issues a synchronous trigger signal effective to routinely trigger the sound source module, and that issues an asynchronous trigger signal independently of the timing data for intermittently triggering the driver module so as to avoid concentration of the work load of the central processing unit.