| 摘要 |
PURPOSE:To obtain an envelope of high quality whose characteristic is not restricted by performing the musical sound waveform generating operation and the musical sound envelope generating operation practically synchronously with each other. CONSTITUTION:A ROM address control part 39 sends a control signal at intervals of a certain time by an interrupt control part 40 having a timer. The control part 39 sets the start address of an interrupt service program (processing program) by which musical sounds are generated. This processing program includes routines where waveforms of musical sounds of respective channels are operated and the routine where the envelope of musical sounds is operated, and the waveform and the envelope are generated with the sampling period of musical sounds. Since routines to operate the waveform of musical sounds and the routine to operate the envelope are provided in the interrupt service program, conventional sound source circuit hardware is unnecessary, and the envelope of high quality whose characteristic is not restricted is generated and is given to the waveform of musical sounds. |
