US 4,537,110 A · Envelope control apparatus

Abstract

Under the presence of an internally generated mandolin clock (MDN) or an externally generated mandolin clock (MDN'), an envelope clock (ENV-CLK) obtained in accordance with a lower bit output having three-bit signals (including the LSB) is supplied through AND gates to an envelope counter. The counter is set in an up count state in response to an output from a flip-flop set in response to a key on pulse. When a carry signal is generated by the envelope counter, the counter is set in a down count state. In the latter case, the fourth-bit signal from the LSB of the output from the binary counter is gated through the AND gate. The envelope counter counts down the envelope clock (ENV-CLK) having a period twice that of the envelope clock (ENV-CLK) in the up count state.

Claims13

Dependent claims

An envelope control apparatus comprising:

clock pulse generating means for generating clock pulses of a predetermined cycle in response to continued operation of a key;
envelope clock pulse counting means for counting clock pulses generated by said clock pulse generating means;
means for forming envelope waveform data defining a complete envelope waveform which varies in accordance with the count of said envelope clock pulse counting means;
and
changing means for changing the state of said envelope clock pulse counting means to a counting state corresponding to an attack state of the envelope waveform when the clock pulses of said predetermined cycle are supplied from said clock pulse generating means to said changing means;
wherein new envelope waveform data defining a new complete envelope waveform is generated by said envelope waveform data forming means prior to formation of one envelope waveform.

3 more elements

An envelope control apparatus, comprising:

clock pulse generating means for generating clock pulses of a predetermined cycle in response to continued operation of a key;
envelope clock pulse counting means for counting clock pulses generated by said clock pulse generating means;
means for forming envelope waveform data defining a complete envelope waveform which varies in accordance with the count of said envelope clock pulse counting means;
changing means for changing the state of said envelope clock pulse counting means to a counting state corresponding to an attack state of the envelope waveform when said clock pulses of said predetermined cycle are supplied from said clock pulse generating means to said changing means so that new envelope waveform data defining a new complete envelope waveform is generated prior to formation of one envelope waveform;
and
means for receiving another clock pulse of another predetermined cycle from an external circuit and for supplying said other clock pulse to said changing means in substitution of the clock pulse generated by said clock pulse generating means.

3 more elements

Dependencies are inferred from the claim text.

Envelope control apparatus

Life of this patent

Envelope control apparatus

Life of this patent

Abstract

Claims13