JPH0715636B2 - Musical tone phase control device for electronic musical instruments - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electronic musical instrument using a waveform reading method capable of simultaneously producing a plurality of musical tone signals, when two or more musical tones having the same note name are simultaneously produced.
The present invention relates to a musical tone phase control device for an electronic musical instrument, which is adapted to generate a new musical tone signal in the same phase as a musical tone signal which is already being sounded.

[0002]

2. Description of the Related Art When two or more tones having the same note name are pronounced at the same time, a certain tone color and volume cannot be obtained unless the tones already pronounced and the newly pronounced tones are in phase, which is the worst case. In this case, it is well known among the parties that there is a problem that the phases are opposite to each other and the sounds cancel each other.

To address this problem, Japanese Patent Publication No. 54-41
The invention described in Japanese Patent No. 499 publication selects a phase matching signal that is set first and indicates the cycle of the musical tone signal generated from the musical tone waveform generator, and the phase of the musical tone signal that is set later is selected by the phase matching signal. , Has proposed an electronic musical instrument provided with a phase matching circuit for matching a predetermined phase relationship with the musical tone signal previously generated.

However, the above-mentioned phase matching circuit has a drawback that it is not general because it becomes very complicated even if the solution to the above-mentioned problem is given and it is expensive.

On the other hand, in the invention described in Japanese Patent Publication No. 63-29751, in order to avoid the above-mentioned complication, the pitch name frequency number corresponding to the pitch of the standard pitch and the auxiliary frequency whose value is slightly different. A frequency number with one set of numbers is provided for each note name, and when it is detected that the two keys pressed have the same note name, one key is the note name frequency number and the other key is the auxiliary frequency. By selecting a number, you can prevent problems due to phase differences, and if you do not detect the same note name, select both note name frequency numbers and prevent musical sounds other than the standard pitch from mixing. Are taking.

However, in the case of the above invention, when two or more tones having the same pitch name are to be sounded, there is a problem that the tone always accompanies a beat due to a difference in frequency. Further, the means and method of the present invention do not provide a fundamental solution to the problem of phase mismatch.

[0007]

SUMMARY OF THE INVENTION The present invention has been made in view of the above points, and it is an object of the present invention to require a complicated circuit structure when simultaneously producing two or more tones having the same note name. It is to make it possible to easily match the phases of those musical sounds without doing so.

[0008]

In order to solve the above-mentioned problems, the present invention is an electronic musical instrument using a waveform reading method capable of simultaneously producing a plurality of musical tone signals, and the number of waveform data in one cycle is 2n (2). (n power) times the waveform memory in which the waveform data limited to have at least one cycle is stored, and whether the newly sounded tone signal and the already sounded tone signal have the same note name. And a waveform read address register for obtaining the current waveform read address value of the specified channel number, when the determination is made and the same note name is determined. , A bit shifter for shifting the address value up or down based on the octave difference of the musical tones of the same pitch and the multiplication factor of the number of waveform data, and the bit shifter. By providing a read start address selector that obtains the address value obtained by designating the shift value to the shifter as the waveform read start address of the tone signal to be newly generated, phase matching when a plurality of tones are simultaneously pronounced Is a means for realizing arbitrary channel numbers by CPU control.

The above-mentioned waveform memory limits the number of pieces of waveform data, thereby making it possible to use the lower n bits of the read-out address of a musical tone that has already been pronounced as a read-out address of a musical tone that is newly pronounced. It is a means.

Such means eliminates the need for a complicated circuit configuration for phase management, and facilitates phase matching in combination with the use of a CPU or the like.

[0011]

The present invention will be described in detail with reference to the following examples. FIG. 1 illustrates a phase control device according to the present invention, which is composed of a waveform reading device 1 of a sound source section using a waveform reading method and a circuit associated therewith.

The waveform reading device 1 forms the central part of the electronic musical instrument according to the present invention, and has a counter area consisting of N channel numbers and a waveform reading address register 2 storing the read address of the channel.

The waveform memory 3 stores waveform data for at least one cycle for each arbitrary note name.
The number of waveform data is limited and stored so that the number of waveform data of one cycle is all 2n (2 to the nth power) times the number of waveform data of one cycle as a reference. The limited number of data in one cycle limits the number of lower addresses necessary to read one cycle.

For example, if the number of waveform data of one cycle as a reference is 512, each data is stored by an address of 9 bits, but this address value divides one cycle of the waveform into 512. Since the present phase is shown, the present position of the phase can be easily grasped by obtaining the address counter value.

In other words, when the number of data for one cycle of the reference wave is 256, this means data for 256 addresses, which can be read by an 8-bit address line. Even in a waveform memory in which two or more waveforms each having 256 data for one cycle are continuously stored, one cycle ends every 256 addresses, and the lower 8 bits of the read address counter value are 1
The current phase in the 256 divided cycles is shown.

When the waveform data is continuously stored, it is natural that the phase mismatch does not occur even if the number of waveform data in one cycle is slightly before or after the 256 data as long as the desired frequency is generated. is there. As described above, the present invention is characterized in that the lower n bits of the read address counter value are used to perform the phase matching.

The CPU (information processing device) 4 judges whether or not the newly sounded tone signal has the same note name as that of the tone signal which is already sounded, and when it judges that it has the same note name, it already determines The channel number of the tone signal being sounded is given from the waveform reading device to the read start address selector 5.

A bit shifter 6 is provided to shift up or down the current waveform read address value based on the octave difference between musical tones having the same pitch name and the multiplication factor of the number of waveform data. The CPU 4 is also used to give a correction value to the bit shifter 6.

That is, when the number of data for one cycle of a newly generated musical tone signal is the same as the number of data for one period of a musical tone signal that has already been generated and the musical tones to be generated have an octave relationship. The correction is made in accordance with the octave difference, but in order to make this correction, the CPU 4 gives a correction value (shift value) to the bit shifter 6 and sets the waveform read address.

In the apparatus of the present invention thus constructed, two musical tones having the same pitch name can be simultaneously played by the key operation of the electronic musical instrument.
When it is necessary to produce more than one note, the CPU 4 outputs the channel number having the same note name as the tone signal already produced.
Is supplied from the waveform reading device 1 to the read start address selector 5, whereby the address counter value of the lower n bits indicating the current phase of the musical tone is selected.

Next, when the number of data in one cycle is the same and there is an octave difference, there is a case in which phase matching cannot be obtained as shown in FIG. The bit shifter 6 works to avoid this case. With reference to FIG. 3 as an example, in the case of generating a tone signal having the same pitch name one octave higher than a tone signal that is already sounded, the lower 8 bits of the read address counter value of the tone signal that is already sounded. Is set to the 1-bit start address.

By setting the shift-up and shift-down in the bit shifter 6 by the CPU as described above, the phase can be surely matched in any case.
The flow of processing in the musical tone phase control device of the present invention operated by key operation is as shown in FIG.

[0023]

Since the present invention is constructed and operates as described above, when two or more musical tones having the same pitch name are simultaneously pronounced, the phases of those musical tones can be perfectly matched. There is an effect that can be done.

In particular, according to the present invention, by limiting the number of waveform data in one cycle, the lower n bits of the read address of the musical tone which is already sounded are utilized as the read start address of the newly generated musical sound. The bit shifter in the configuration can be realized by a simple circuit without requiring a complicated device such as a circuit for managing a phase or a circuit for newly generating a control signal. There is a feature that the phase can be reliably matched with an inexpensive circuit.

[Brief description of drawings]

FIG. 1 is a block diagram showing an embodiment of a musical tone phase control device according to the present invention.

FIG. 2 is a graph showing the phase relationship of a plurality of tone signals.

FIG. 3 is a graph similarly showing a phase relationship.

FIG. 4 is a flowchart showing a flow of processing by the device according to the present invention.

Claims (1)

[Claims] 1. An electronic musical instrument using a waveform reading method capable of simultaneously producing a plurality of tone signals, wherein at least one period of waveform data is limited so that the number of waveform data in one period is all 2n times. It is judged whether the stored waveform memory and the newly pronounced tone signal and the already pronounced tone signal have the same note name, and when it is decided that they have the same note name, the tone signal already pronounced From the CPU for designating the channel number of, the waveform read address register for obtaining the current waveform read address value of the designated channel number, the octave difference of the tones having the same note name, and the multiplication factor of each waveform data, A bit shifter that shifts up or down an address value and an address value obtained by designating the shift value to the bit shifter are newly generated. And a read start address selector which is obtained as a waveform read start address of a musical tone signal. When two or more musical tones having the same note name are simultaneously pronounced, the phases of the respective tones can be adjusted by software under the control of the CPU. A musical tone phase control device for an electronic musical instrument, characterized in that it is configured to be performed for channel numbers.