Data processing apparatus outputting waveform data for sound signals with precise timings

• US 5,726,371 A
• Filed: 04/06/1994
• Issued: 03/10/1998
• Est. Priority Date: 12/29/1988
• Status: Expired due to Term

• Current Assignee: Casio Computer Company Limited
• Original Assignee: Casio Computer Company Limited
• Inventors: Ogura, Kazuo, Shiba, Kosuke, Daigo, Koichiro, Usami, Ryuji, Hosoda, Jun
• Primary Examiner(s): WITKOWSKI, STANLEY J
• Application Number:
  US08/223,589
• Time in Patent Office: 1,434 Days
• Field of Search: 84/601-608, 84/622-625, 84/659-661, 84/692-700, 84/615-620, 84/626-633, 84/647, 84/649
• US Class Current: 84/603
• CPC Class Codes: G10H 1/04 by additional modulation
• CPC Class Codes: G10H 1/0575 using a data store from which the envelope is synthesized tones synthesized from a data store G10H7/00
• CPC Class Codes: G10H 1/186 Microprocessor-controlled keyboard and assigning means
• CPC Class Codes: G10H 2250/591 DPCM [delta pulse code modulation]
• CPC Class Codes: G10H 2250/621 Waveform interpolation
• CPC Class Codes: G10H 7/004 with one or more auxiliary processor in addition to the main processing unit
• CPC Class Codes: G10H 7/006 using two or more algorithms of different types to generate tones, e.g. according to tone color or to processor workload
• CPC Class Codes: G10H 7/08 by calculating functions or polynomial approximations to evaluate amplitudes at successive sample points of a tone waveform

Abstract

In a musical tone waveform generation apparatus for outputting musical tone signals generated by a software program at predetermined time intervals, sound source methods can be selected in units of tone generation channels. In the musical tone waveform generation apparatus, the sound source method or the tone color of a musical tone signal to be output is determined in accordance with performance data (pitch data, touch data, music part data, and the like). A musical tone signal is generated by CPU upon execution of a sound source processing program, associated with a modulation method stored in a memory. The generated musical tone signal is output at predetermined time intervals. As for sound source processing based on the modulation method, at least one operator processing, and algorithm processing for determining an input/output relationship among the operator processing operations are independently executed.

Claims

1. A musical tone signal outputting apparatus comprising:

a microcomputer for generating a digital musical tone signal under a program control, said microcomputer comprising;

time signal generating means for outputting an accurate sampling time signal with a predetermined sampling period;

computing means for computing a digital musical tone signal at timings which may vary with reference to said sampling time signal;

first latch means for latching the digital musical tone signal computed by said computing means at an ending timing of computation of the digital musical tone signal, which ending timing may vary with reference to said sampling time signal; and

second latch means, provided between an output of said first latch means and an input of a digital-to-analog converting means, for latching an output signal of said first latch means at a timing of the sampling time signal to thereby produce, at an output of said second latch means, an accurately timed digital musical tone signal.

2. An apparatus according to claim 1, wherein said microcomputer is formed on an integrated circuit chip and wherein said integrated circuit chip comprises a digital-to-analog converter for converting said digital musical tone signals into analog signals, and a port for receiving an input to control said tone signal outputting apparatus.

3. An electronic musical instrument for digitally producing musical tone signals, comprising:

a microcomputer for generating a digital musical tone signal under a program control, said microcomputer comprising;

time signal generating means for outputting an accurate sampling time signal with a predetermined sampling period;

computing means for computing a digital musical tone signal at timings which may vary with reference to said sampling time signal;

first latch means for latching the digital musical tone signal computed by said computing means at an ending timing of computation of the digital musical tone signal which ending timing may vary with reference to said sampling time signal; and

second latch means, provided between an output of said first latch means and an input of a digital-to-analog converting means, for latching an output signal of said first latch means at a timing of the sampling time signal to thereby produce, at an output of said second latch means, an accurately timed digital musical tone signal.

4. The electronic musical instrument according to claim 3, wherein said microcomputer is formed on an integrated circuit chip and wherein said integrated circuit chip comprises a digital-to-analog converter for converting said digital musical tone signals into analog signals, and a port for receiving an input to control said tone signal outputting apparatus.

5. A musical tone signal outputting apparatus to be used with several peripheral units, comprising:

a microcomputer for controlling operations of the peripheral units, and for generating a digital musical tone signal under a program control, said microcomputer comprising;

time signal generating means for outputting an accurate sampling time signal with a predetermined sampling period;

computing means for computing a digital musical tone signal at timings which may vary with reference to said sampling time signal;

first latch means for latching the digital musical tone signal computed by said computing means at an ending timing of computation of the digital musical tone signal, which ending timing may vary with reference to said sampling time signal; and

second latch means, provided between an output of said first latch means and an input of a digital-to-analog converting means, for latching an output signal of said first latch means at a timing of the sampling time signal to thereby produce, at an output of said second latch means, an accurately timed digital musical tone signal.

6. An electronic musical instrument having a keyboard, for digitally producing musical tone signals, the electronic musical instrument comprising:

a microcomputer for controlling operations of the keyboard, and for generating a musical tone signal under a program control, said microcomputer comprising;

time signal generating means for outputting an accurate sampling time signal with a predetermined sampling period;

computing means for computing a digital musical tone signal at timings which may vary with reference to said sampling time signal;

first latch means for latching the digital musical tone signal computed by said computing means at an ending timing of computation of the digital musical tone signal, which ending timing may vary with reference to said sampling time signal; and

second latch means, provided between an output of said first latch means and an input of a digital-to-analog converting means, for latching an output signal of said first latch means at a timing of the sampling time signal to thereby produce, at an output of said second latch means, an accurately timed digital musical tone signal.

7. A musical tone signal outputting apparatus comprising:

a microcomputer for generating a digital musical tone signal under a program control, said microcomputer comprising;

time signal generating means for outputting an accurate sampling time signal with a predetermined sampling period;

computing means for computing a digital musical tone signal at timings which may vary with reference to said sampling time signal;

first latch means for latching the digital musical tone signal computed by said computing means at an ending timing of computation of the digital musical tone signal, which ending timing may vary with reference to said sampling time signal; and

second latch means, coupled to said first latch means, for latching an output signal of said first latch means at a timing of the sampling time signal to thereby produce, at an output of said second latch means, an accurately timed digital musical tone signal.

8. A musical tone waveform generation apparatus, comprising:

storage means for storing a plurality of sound source processing programs corresponding to a plurality of types of sound source methods;

a microcomputer for generating musical tone signals in arbitrary sound source methods in tone generation channels by executing the plurality of sound source programs stored in said storage means; and

musical tone signal output means for outputting the musical tone signals generated by said microcomputer at predetermined constant output time intervals, said musical tone signal output means comprising;

timing signal generating means for generating a timing signal for each predetermined sampling period;

first latch means for latching a digital musical tone signal generated by said microcomputer at an outputting timing of the digital musical tone signal from said microcomputer; and

second latch means for outputting the digital musical tone signal by latching an output signal of said first latch means when the timing signal is generated from said timing signal generating means.

9. An apparatus according to claim 8, further comprising tone color designation means for designating a tone color of a musical tone signal to be generated by said microcomputer, and wherein said microcomputer generates a musical tone signal having the tone color designated by a said sound source method according to the tone color designated by said tone color designation means in units of tone generation channels.

10. An apparatus according to claim 8, further comprising designation means for designating a sound source method in units of tone generation channels in said microcomputer, and wherein said microcomputer generates a musical tone signal by the sound source method designated by said designation means in units of tone generation channels.

11. An apparatus according to claim 8, further comprising pitch designation means for designating a pitch of a musical tone signal to be generated by said microcomputer, and wherein said microcomputer generates a musical tone signal at a pitch designated by said designation means by a said sound source method according to the designated pitch in units of tone generation channels.

12. An apparatus according to claim 8, further comprising a performance operation member for instructing said microcomputer to generate a musical tone signal, and wherein said microcomputer generates a musical tone signal by a said sound source method according to an operation speed of said performance operation member in units of tone generation channels.

13. An apparatus according to claim 8, further comprising output means for outputting performance data of a plurality of parts constituting a music piece, and wherein said microcomputer generates a musical tone signal by said sound source method in accordance with a part to which the performance data output from said output means belongs.

14. A musical tone waveform generation apparatus, comprising:

a plurality of musical tone waveform generation means, each comprising storage means for storing a plurality of sound source processing programs corresponding to a plurality of sound source methods, and a microcomputer for generating musical tone signals in arbitrary sound source methods in units of tone generation channels by executing at least one of the plurality of sound source programs stored in said storage means;

control means for controlling said plurality of musical tone waveform generation means to be operated substantially in parallel;

accumulation means for accumulating musical tone signals generated by said plurality of musical tone waveform generation means; and

musical tone signal output means for outputting an accumulation result from said accumulation means at predetermined constant output time intervals, said musical tone signal output means comprising;

timing signal generating means for generating a timing signal for each predetermined sampling period;

first latch means for latching a digital musical tone signal generated by said accumulation means at an outputting timing of the digital musical tone signal from said accumulation means; and

second latch means for outputting the digital musical tone signal by latching an output signal of said first latch means when the timing signal is generated from said timing signal generating means.

15. A musical tone waveform generation apparatus comprising:

storage means for storing a sound source processing program;

a microcomputer for executing the sound source processing program stored in said storage means to generate a musical tone signal;

output means for outputting performance data of a plurality of parts constituting a music piece;

tone color determination means for determining a tone color of the musical tone signal to be generated by said microcomputer in accordance with one of the plurality of parts to which the performance data output from said output means belongs;

control means for controlling said microcomputer to generate the musical tone signal having the tone color determined by said tone color determination means; and

musical tone signal output means for outputting the musical tone signal generated by said microcomputer at predetermined constant output time intervals, said musical tone signal output means comprising;

timing signal generating means for generating a timing signal for each predetermined sampling period;

first latch means for latching a digital musical tone signal generated by said microcomputer at an outputting timing of the digital musical tone signal from said microcomputer; and

second latch means for outputting the digital musical tone signal by latching an output signal of said first latch means when the timing signal is generated from said timing signal generating means.

16. A musical tone waveform generation apparatus comprising:

storage means for storing a sound source processing program based on a predetermined modulation method;

a microcomputer for generating a musical tone signal on the basis of a process of the modulation method by executing the sound source processing program stored in said storage means; and

musical tone signal output means for outputting the musical tone signal generated by said microcomputer at predetermined constant output time intervals, said musical tone signal output means comprising;

timing signal generating means for generating a timing signal for each predetermined sampling period;

first latch means for latching a digital musical tone signal generated by said microcomputer at an outputting timing of the digital musical tone signal from said microcomputer; and

second latch means for outputting the digital musical tone signal by latching an output signal of said first latch means when the timing signal is generated from said timing signal generating means.

17. An apparatus according to claim 16, wherein the modulation method is a method of receiving a mixed signal obtained by mixing a carrier signal and a modulation signal as an input and outputting a modulated musical tone signal as an output.

18. An apparatus according to claim 17, wherein a functional relationship between the input and the output is expressed by neither of sine and cosine function relationships, and the carrier signal is a signal for making the output to be a sine or cosine wave at a single frequency when the carrier signal is directly used as the input.

19. An apparatus according to claim 17, wherein a functional relationship between the input and the output is expressed by a sine function, and the carrier signal is defined by a sine wave.

20. A musical tone waveform generation apparatus comprising:

storage means for storing a sound source processing program associated with a modulation method, having an operator processing program for executing operator processings, and an algorithm processing program for executing algorithm processing for determining an input/output relationship among operator processings;

a microcomputer for generating a musical tone signal by executing the operator processings based on the operator processing program at a time, and executing the algorithm processing at a time based on the algorithm processing program independently of the operator processing program; and

musical tone signal output means for outputting the musical tone signal generated by said microcomputer at predetermined constant output time intervals, said musical tone signal output means comprising;

timing signal generating means for generating a timing signal for each predetermined sampling period;

first latch means for latching a digital musical tone signal generated by said microcomputer at an outputting timing of the digital musical tone signal from said microcomputer; and

second latch means for outputting the digital musical tone signal by latching an output signal of said first latch means when the timing signal is generated from said timing signal generating means.

21. An apparatus according to claim 20, wherein the modulation method is a method of receiving a mixed signal obtained by mixing a carrier signal and a modulation signal as an input and outputting a modulated musical tone signal as an output.

22. An apparatus according to claim 21, wherein a functional relationship between the input and the output is expressed by neither of sine and cosine function relationships, and the carrier signal is a signal for making the output to be a sine or cosine wave at a single frequency when the carrier signal is directly used as the input.

23. An apparatus according to claim 21, wherein a functional relationship between the input and the output is expressed by a sine function, and the carrier signal is defined by a sine wave.

24. A sound signal outputting apparatus comprising a microcomputer for generating a digital sound signal under a program control, said microcomputer comprising:

a timing signal generator for outputting an accurate sampling time signal with a predetermined sampling period;

a computing device for computing a digital sound signal under a program control at timings which may vary with reference to said sampling time signal, to generate a digital sound signal;

a first latch for latching the digital sound signal computed by said computing device at an ending timing of computation of the digital sound signal, which ending timing may vary with reference to said sampling time signal; and

a second latch for latching an output signal of said first latch at a timing of the sampling time signal to thereby produce, at an output of said second latch, an accurately timed digital sound signal at a timing of the sampling time signal.

25. A sound signal outputting method comprising the following steps which are implemented using a microcomputer:

outputting an accurate sampling time signal with a predetermined sampling period;

computing, in said microcomputer, a digital sound signal under a program control at timings which may vary with reference to said sampling time signal, to generate a digital sound signal;

a first latching step of latching the digital sound signal computed by said computing step at an ending timing of computation of the digital sound signal, which may vary with reference to said sampling time signal; and

a second latching step of latching the digital sound signal latched by said first latching step at a timing of the sampling time signal, to thereby produce an accurately timed digital sound signal.