Electronic musical instrument with waveform memory for storing waveform data based on external sound

• US 4,667,556 A
• Filed: 07/29/1985
• Issued: 05/26/1987
• Est. Priority Date: 08/09/1984
• Status: Expired due to Term

• Current Assignee: Casio Computer Company Limited
• Original Assignee: Casio Computer Company Limited
• Inventors: Sasaki, Hiroyuki, Morikawa, Shigenori, Morokuma, Hiroshi, Hanzawa, Kohtaro
• Primary Examiner(s): Witkowski, S. J.
• Assistant Examiner(s): Warren, David
• Application Number:
  US06/760,291
• Time in Patent Office: 666 Days
• Field of Search: 84/1.01, 84/1.28, 84/1.03, 84/462, 84/DIG. 21
• US Class Current: 84/603
• CPC Class Codes: G10H 1/0033 Recording/reproducing or transmission of music for electrophonic musical instruments
• CPC Class Codes: G10H 2250/621 Waveform interpolation
• CPC Class Codes: G10H 2250/631 Waveform resampling, i.e. sample rate conversion or sample depth conversion
• CPC Class Codes: G10H 7/02 in which amplitudes at successive sample points of a tone waveform are stored in one or more memories

Abstract

A CPU supplies data write and read commands to only an address control section, and the address control section then designates, for the purpose of writing and reading data, addresses of a waveform memory in which external sound waveform data is stored.

Claims

1. An electronic musical instrument, comprising:

analog-to-digital converting means for converting an analog external sound signal into a digital waveform signal which represents a waveform corresponding to the waveform of said analog external sound signal;

memory means for storing the digital waveform signal output from said analog-to-digital converting means;

digital-to-analog converting means for converting the digital waveform signal output from said memory means into an analog sound signal having a waveform determined by said digital waveform signal;

pitch designating means for designating a pitch of the sound produced based on the analog sound signal derived from said digital-to-analog converting means;

address control logic circuit means coupled to said memory means for designating memory addresses for writing and reading the digital waveform signal; and

control means coupled to said address control logic circuit means and to said pitch designating means for supplying to said address control logic circuit means record and reproduce commands for writing and reading said digital waveform signal in and from the memory means, and for instructing said address control logic circuit means to designate a memory address with a speed determined by said pitch designating means when the digital waveform signal is read out from said memory means, so that a sound having a waveform determined by the read out digital waveform signal and a frequency determined by said pitch designating means can be reproduced.

2. The electronic musical instrument according to claim 1, wherein said address control logic circuit means includes:

a temporary storage register means for storing addresses of said memory means;

renewal means for renewing the content of said temporary storage register means;

a pitch register means for storing pitch data designated by said pitch designating means for determining the renewal speed of said renewal means;

an end register means for storing the end address of said renewed content;

comparing means for comparing the content of said temporary storage register means and the content of said end register means and providing an end signal to said renewal means when the content of said temporary storage register means coincides with or exceeds the content of said end register; and

control register means for controlling the continuation and termination of the renewal operation of said renewal means according to commands from said control means.

3. The electronic musical instrument according to claim 2, wherein each of the temporary storage register means, end register means, pitch register means and control register means in said address control logic circuit means has a plurality of memory stages arranged to be operative on a time division basis.

4. The electronic musical instrument according to claim 2, wherein said address control logic circuit means includes providing means for providing a complement of pitch data stored in said pitch register means to said renewal means to cause said renewal means to complement update the content of said temporary storage register means.

5. The electronic musical instrument according to claim 2, wherein said control means includes a CPU, a command control circuit for providing a plurality of commands according to commands from said CPU, and supplying means for supplying said plurality of commands to said address control logic circuit means.

6. The electronic musical instrument according to claim 1, wherein said control means includes a CPU, and said address control logic circuit means includes a temporary storage register means for storing addresses of said memory means, a renewal means for renewing the content of said temporary storage register means, a pitch register means for storing the pitch data for determining the renewal speed of said renewal means, an end register means for storing the end address of said renewed content, a flip-flop for controlling loop designation of the address of said memory means, a loop end register means for storing the end address of the loop designation, first comparing means for comparing the content of said temporary storage register means and the content of said loop end register means and providing a loop end signal to cause transfer of the content of said loop start register means to said temporary storage register means when the content of said temporary storage register means coincides with or exceeds the content of said loop end register means, second comparing means for comparing the content of said temporary storage register means and the content of said end register means and providing an end signal to said renewal means when the content of said temporary storage register means coincides with or exceeds the content of said end register means, and renewal operation control means having a flip-flop for controlling the continuation and termination of the renewal operation of said renewal means according to commands from said CPU.

7. An electronic musical instrument, comprising:

waveform memory means for storing tone waveform data;

sampling means for sampling external sound and writing sampled data as digital waveform data in said waveform memory means, said sampling means including analog-to-digital converting means for converting an analog external sound signal representing said external sound, into digital waveform data corresponding to the waveform of said external sound analog signal;

digital-to-analog converting means for converting the digital waveform data output from said waveform memory means into an analog sound signal having a waveform determined by said digital waveform data;

pitch designating means for designating a pitch of the sound produced based on the analog sound signal derived from said digital-to-analog converting means;

first reading means for reading out the tone waveform data stored in said waveform memory means at a rate according to the pitch designated by said pitch designating means;

control means; and

address control logic circuit means for designating addresses of said waveform memory means according to commands from said control means,

first designating means for repeatedly designating a predetermined address area of said waveform memory means as write addresses according to a preliminary record command from said control means; and

second designating means for designating a different address area of said waveform memory means as write addresses according to a regular record command from said control means.

8. The electronic musical instrument according to claim 7, which further comprises:

stopping means for stopping the address renewal according to said preliminary record command when said regular record command is provided from said control means;

rearranging means for rearranging, into a correct sequence, the waveform data in said waveform memory means at the instant of the termination of said address renewal; and

second reading means for successively and continuously reading out rearranged preliminary and regular record data.

9. The electronic musical instrument according to claim 7, wherein said first reading means for reading tone waveform data includes interpolation means for interpolating the tone waveform data read out from said waveform memory means by said second reading means.

10. The electronic musical instrument according to claim 7, wherein said address control logic circuit means includes addressing means for generating address data consisting of an integer number portion and a decimal fraction portion, effecting means for effecting the writing and reading of waveform data by designating addresses of said waveform memory means according to the integer number portion of said address data, first forming means for forming interpolated data with respect to the waveform data read out from said waveform memory means according to the integer number portion of said address data, and second forming means for forming a tone signal by combining said read out waveform data and interpolated data.

11. The electronic musical instrument according to claim 7, wherein said control means includes a CPU.

12. An electronic musical instrument, comprising:

analog-to-digital converting means for converting an external sound signal into a digital waveform signal;

memory means for storing said digital waveform signal;

address control logic circuit means for designating memory addresses for writing and reading the digital waveform signal; and

control means for supplying to said address control logic circuit means record and reproduce commands for writing and reading said digital waveform signal in and from said memory means;

wherein said address control logic circuit means includes;

temporary storage register means for storing addresses of said memory means;

renewal means for renewing the content of said temporary storage register means;

pitch register means for storing pitch data for determining the renewal speed of said renewal means;

end register means for storing the end address of said renewed content;

comparing means for comparing the content of said temporary storage register means and the content of said end register means, and for providing an end signal to said renewal means when the content of said temporary storage register means coincides with or exceeds the content of said end register;

control register means for controlling the continuation and termination of the renewal operation of said renewal means according to commands from said control means; and

providing means for providing a complement of pitch data stored in said pitch register means to said renewal means, for causing renewal means to complement update the content of said temporary storage register means.

13. The electronic musical instrument according to claim 12, wherein the temporary storage register means, end register means, pitch register means and control register means in said address control logic circuit means each include a plurality of stages arranged to be operative in response to a designation signal on a time division basis.

14. The electronic musical instrument according to claim 12, wherein said control means includes a CPU, a command control circuit for providing a plurality of commands according to commands from said CPU, and supplying means for supplying said plurality of commands to said address control logic circuit means.

15. An electronic musical instrument, comprising:

analog-to-digital converting means for converting an external sound signal into a digital waveform signal;

memory means for storing said digital waveform signal;

address control logic circuit means for designating memory addresses for writing and reading the digital waveform signal; and

control means for supplying to said address control logic circuit means record and reproduce commands for writing and reading said digital waveform signal in and from said memory means;

wherein said control means includes a CPU, and said address control logic circuit means includes temporary storage register means for storing addresses of said memory means, renewal means for renewing the content of said temporary storage register means, pitch register means for storing the pitch data for determining the renewal speed of said renewal means, end register means for storing the end address of said renewed content, a flip-flop for controlling loop designation of the address of said memory means, loop end register means for storing the end address of the loop designation, first comparing means for comparing the content of said temporary storage register means and the content of said loop end register means, and for providing a loop end signal to cause transfer of the content of said loop start register means to said temporary storage register means when the content of said temporary storage register means coincides with or exceeds the content of said loop end register means, second comparing means for comparing the content of said temporary storage register means and the content of said end register means, and for providing an end signal to said renewal means when the content of said temporary storage register means coincides with or exceeds the content of said end register means, and renewal operation control means including a flip-flop for controlling the continuation and termination of the renewal operation of said renewal means according to commands from said CPU.

16. An electronic musical instrument, comprising:

waveform memory means for storing tone waveform data;

sampling means for sampling external sound and writing sampled data as waveform data in said waveform memory means;

first reading means for reading out the tone waveform data stored in said waveform memory means;

control means; and

address control logic circuit means for designating addresses of said waveform memory means according to commands from said control means,

said address control logic circuit means including;

first designating means for repeatedly designating a predetermined address area of said waveform memory means as write addresses according to a preliminary record command from said control means, and

second designating means for designating a different address area of said waveform memory means as write addresses according to a regular record command from said control means;

addressing means for generating address data comprised of an integer number portion and a decimal fraction portion, effecting means for effecting the writing and reading of waveform data by designating addresses of said waveform memory means according to the integer number portion of said address data, and

wherein said first reading means includes first forming means for forming interpolated data according to the decimal fraction portion of said address data with respect to the waveform data read out from said waveform memory means according to the integer number portion of said address data, and second forming means for forming a tone signal by combining said read out waveform data and said interpolated data.

17. The electronic musical instrument according to claim 16, which comprises:

stopping means for stopping the address renewal operation according to said preliminary record command when said regular record command is provided from said control means;

rearranging means for rearranging, into a correct sequence, the waveform data in said waveform memory means at an instant of termination of said address renewal; and

second reading means for successively and continuously reading out rearranged preliminary and regular record data.