JPH0160292U - - Google Patents

Description

[Brief explanation of the drawing]

FIG. 1 is an overall configuration diagram of an electronic musical instrument according to an embodiment of this invention, FIG. 2 is a block diagram of a sound source LSI,
Figure 3 is a time chart showing the allocation of external RAM occupancy by the interface/control unit of the sound source LSI and the envelope/key code generation circuit. FIG. 5 is a time chart showing the low-speed calculation cycle for generating musical tone control signals and the high-speed calculation cycle for waveform generation. FIG. 6 is a time chart for the timing signal generation circuit. The diagram is an envelope/
A block diagram of the key code generation circuit, Fig. 8 is a time chart of counter B, Fig. 9 is a flow chart of the envelope/key code generation circuit, and Fig. 10 is a block diagram of the key code generation circuit.
Figure 11 is a detailed diagram of the calculation timing signal generation circuit, Figure 11 is a detailed diagram of the index conversion control circuit, Figure 12 is a block diagram of the index conversion/phase angle generation circuit, and Figure 13 is a detailed diagram of the index conversion/phase angle generation circuit.
14 is a detailed diagram of the index conversion circuit, FIG. 14 is a time chart of the index conversion circuit, FIG. 15 is a detailed diagram of the envelope register, and FIG. 16 is a detailed diagram of the frequency information register. 12...Envelope/key code generation circuit,
15...Waveform generation circuit, 74...Exponent conversion circuit,
81...Exponent coarse data ROM, 82, 84...Shift register, 83...Exponent fine data ROM, 8
7, 90... Gate circuit, 88... Adder, 89
...Flip flop.

Claims (1)

[Claims for Utility Model Registration] (1) Musical tone control signal generation circuit means 12 that generates a musical tone control signal expressed as linear data, and a waveform that generates a musical sound waveform based on the musical tone control signal expressed as index data. A musical tone synthesis device comprising: a generation circuit means 15; and an index conversion circuit means 74 for converting linear data from the musical tone control signal generation circuit means into index data used by the waveform generation circuit, wherein the index conversion circuit means comprises: , an index coarse data storage means 81 that is addressed with the upper bit data of the linear data and outputs an exponent conversion value of the upper bit data; and an index conversion value of the lower bit data that is addressed with the lower bit data of the linear data. Exponential fine data storage means 83 for outputting , and arithmetic circuit means 82 and 84 for calculating the exponential conversion value of the linear data by multiplying the output of the exponential coarse data storage means and the output of the exponential fine data storage means. ~90, A musical tone synthesis device characterized by having the following. (2) The musical tone synthesis device according to claim 1, wherein the linear data is a linear envelope. (3) The musical tone synthesis device according to claim 1, wherein the linear data is a linear key code. (4) Utility Model Registration The musical tone synthesis device according to claim 1, wherein the arithmetic circuit means includes shift circuit means 82 and 84 for performing multiplication. (5) The musical tone synthesis device according to claim 1 of the utility model registration claim, characterized in that the index conversion circuit means executes index conversion of a linear envelope and index conversion of a linear key code in a time-sharing manner. Synthesizer.