| 摘要 |
PURPOSE:To eliminate waveform error and to improve the tone color by comparing of a frequency-division output of a pitch ROM in response to the state of a pitch register and a tone name code with an output of an auxiliary counter and counting up the pitch register and resetting the auxiliary counter when they are coincident. CONSTITUTION:The auxiliary counter 33 is counted up at each clock, the pitch ROM32 inputs the present pitch output and outputs a frequency dividing ratio at each address stage. Its output is connected to a coincidence detecting circuit 34 through an adder circuit 36, and when the output of the adder circuit 36 is coincident with the output of the auxiliary counter 33, the pitch register 31 is incremented by ''1'' and the auxiliary counter 33 is reset. The pitch ROM32 outputs a frequency-division in response to the pitch output subject to +1 increment and the change into the address stage. In frequency-dividing the clock by the frequency division, the pitch output is incremented again by ''1'' and the vibrato number is controlled by repeating it. Thus, the waveform error is eliminated and the tone color is improved.
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