JP3106530B2 - Musical instrument 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 a musical tone generator for an electronic musical instrument which calculates and generates musical tone data at a constant speed irrespective of the musical tone pitch and mixes and outputs a plurality of musical tones whose pitches are not always the same. It concerns the device.

[0002]

2. Description of the Related Art In recent years, a musical tone is generated by storing data obtained by converting a musical tone from analog to digital into a waveform memory, reading out the data, and digitally performing an envelope addition or a filtering process on the data. So-called PCM (PulseCode Modula)
) method is being generated.

A conventional tone generator for an electronic musical instrument which calculates and generates musical tone data at a constant speed regardless of the pitch of musical tones and mixes and outputs a plurality of musical tones whose pitches are not always the same will be described below. .

FIG. 4 shows a configuration of a conventional tone generator for an electronic musical instrument. In FIG. 4, reference numeral 410 denotes tone data generating means, 420 denotes tone data mixing means, and 421 and 4
Reference numerals 22 and 423 denote tone mixing units, 424 denotes a selector, and 430
Is a digital-analog converter (hereinafter abbreviated as DAC), 441, 442 and 443 are sample-hold circuits (hereinafter abbreviated as S / H circuits), 451, 452 and 4
53 is a low-pass filter (hereinafter abbreviated as LPF), 46
0 is an amplitude adjusting means, 461, 462, and 463 are voltage-controlled amplifiers (hereinafter abbreviated as VCA), 470 is an amplitude specifying section, 480 is a mixing specifying section, and 490 is a volume setting operator.

FIG. 5 shows a tone mixing section (42) shown in FIG.
1, 422 and 423 are the same. FIG. In FIG. 5, reference numeral 501 denotes a selector, 502 denotes an adder, 503 denotes a latch with reset, 504 denotes a latch, and 505 denotes a shifter.

The operation of the tone generator for an electronic musical instrument constructed as described above will be described below with reference to the operation timing chart of FIG. 3 (the operation timing is the same for both the conventional example and the embodiment of the present invention). .

The tone data generator 410 generates tone data for eight tones (having a data length of 16 bits and a maximum value of 327).
67), and the musical sound data mixing means 420
Sound and sound data for one sound are mixed,
0 indicates that the maximum value of the input data is 32767 (2's complement 16
It is assumed that the DAC has a resolution of 16 bits which is the maximum value of the bit data.

First, tone data for eight tones is generated in time division by the tone data generating means 410, and the tone data W
i (W0 to W7). Here, W0 is 0th
The channel tone data, W1 is called the first channel tone data, and similarly, W7 is called the seventh channel tone data.

Next, the tone mixing units 421, 422, 423
In, music data is mixed. Mixed designation section 480
The channels to be mixed are specified by the mixing specifying signals S1, S2, and S3 output from. That is, the tone data of the channel when the mixing designation signals S1 to S3 are 1 are mixed. In the example shown in FIG. 3, the mixed designation signal S1 is such that the time-division tone data Wi is W0, W1, W
Since it is 1 at 3, W4, and W7, the tone mixing unit 421
, The tone data of a total of five tones of channels 0, 1, 3, 4, and 7 are mixed. Similarly, the tone mixing unit 4
At 22, the tone data of a total of two tones of the second and fifth channels are mixed, and the tone mixing unit 423 mixes only the tone data of one tone of the sixth channel.

The mixing operation will be described in more detail. The operations of the tone mixing units 421, 422, and 423 are the same except that the mixing designation signals are S1, S2, and S3, respectively.

First, the reset signal R1 becomes 1, and the accumulated value MW1 stored in the latch 503 is reset to 0. When the input S is 0, the selector 501 outputs the value of the input A (that is, 0). When the input S is 1, the selector 501 outputs the value of the input B (that is, the tone data Wi). The output of the selector 501 is input to the input B of the adder 502,
The output of the latch 503 (that is, the accumulated value MW1) is
02 is input to input A. Therefore, the mixing designation signal S1
Is 1, the tone data Wi and the accumulated value MW1 are added. When the mixed designation signal S1 is 0, the value 0 and the accumulated value MW1 are added. The result of the addition is stored in the latch 503 at the rise of the clock signal CK1. Thus, the tone data from the 0th channel to the 7th channel are accumulated, that is, mixed, in accordance with the mixing designation signal S1. The maximum value of the musical tone data is 32767 (the data length is 1
6 bits), and the musical tone data for 5 tones is accumulated, so the maximum value of the accumulated value MW1 is mathematically 32767 * 5 = 16
3835 (the data length is 19 bits). Further, since the musical sound data generating means 410 generates musical sound data for eight sounds, it is possible to mix up to eight musical sounds, and the maximum value when mixing musical sound data for eight sounds is 32767 *
8 = 262136 (data length is 19 bits).

When the accumulation up to the seventh channel is completed,
The rising of the clock signal CK2 causes the latch 50
3 is stored in the latch 504. Further, the data is shifted leftward by 3 bits in the shifter 505, and is output as mixed data M1 (the data length is 16 bits). Shifting to the left by 3 bits means that the maximum value when mixing 8 tone data is mathematically 327
Since 67 * 8 = 262136, the maximum value is 3276
In order to input to the DAC 430 of FIG.
This is because it must be reduced to one part. Thus, the mixed data M1 is output from the musical sound mixing section.

The tone data are similarly mixed in the tone mixing units 422 and 423. Since only two notes and one note are mixed respectively, the maximum values of the accumulated values MW2 and MW3 are 65534 (the data length is 17 bits) and 32767.
(The data length is 16 bits). However, unless the amplitude of the musical tone data per tone is made the same as that of the musical tone mixing unit 421, the amplitude of the analog musical tone signal differs for each musical tone output when converted into an analog musical tone signal by the DAC. , 423, the mixed data is shifted to the left by 3 bits by the shifter 505.

The mixed data M1, M2 and M3 are supplied to the selector 4
24, and output to the DAC 430 as mixed tone data in a time-division manner. The mixed tone data is DAC430
Is converted to an analog tone signal by the sample and hold signals SH1, SH2, SH3.
/ H circuits 441, 442, 443 sample and hold. The sampled and held tone signal is an LPF
After unnecessary sampling noise is removed by 451, 452, and 453, the volume level of each output is adjusted by the VCAs 461, 462, and 463, and output as tone outputs 1, 2, and 3. The volume level for each output is controlled by the amplitude specifying section 470 based on the settings on the volume setting operator 490.

In this way, the tone data generating means 41
The tone data generated in a time division manner at 0 is mixed by the tone data mixing means 420 based on the designation of the mixing designation section 480, and a tone output of a plurality of analog signals can be obtained.

The maximum value of the input to the DAC per sound is:
The 16-bit tone data is shifted 3
Since the data is shifted by bits, the tone data becomes 13 bits, and its maximum value is 4095. Since up to eight sounds can be mixed, 4095 * 8 = 32760, and D
The maximum value of the AC input data is 32767 or less.

[0017]

However, in the above-described conventional configuration, the maximum value of data input to the DAC per sound is only 4095 (data length is 13 bits), and the S / N ratio (signal and noise) is small. Ratio) is not good. Further, even when only one sound is mixed, there is a problem that the maximum value per sound input to the DAC is reduced to match with the others, thereby deteriorating the S / N ratio.

An object of the present invention is to solve the above-mentioned conventional problems, and an object of the present invention is to provide a tone generator for an electronic musical instrument having a good S / N ratio.

[0019]

In order to achieve the above object, a musical sound generation control device for an electronic musical instrument according to the present invention comprises a musical sound data generating means for generating a plurality of musical sound data, and the musical sound data being mixed into a plurality of groups. Means to specify that the tone data after mixing should be as large as possible.
Amplitude designation means for designating the amplitude at the time of mixing for each group so that the tone data designated by the mixture designation means are mixed based on the amplitude designated by the amplitude designation means and output as mixed tone data. the grayed corrected for each of the groups according the musical sound data mixing means, the amplitude of the generated musical tone signal based on the mixed musical tone data to the amplitude at the time of mixing
Amplitude adjusting means for adjusting the volume balance between loops .

[0020]

With this configuration, the effective arithmetic bit length can be increased, thereby reducing the arithmetic error and obtaining a tone signal with less noise even when converting the digital signal to an analog signal.

[0021]

(Embodiment 1) An embodiment of the present invention will be described below with reference to the drawings.

In FIG. 1, reference numeral 110 denotes tone data generating means, 120 denotes tone data mixing means, 121, 122 and 1
23 is a tone mixing section, 124 is a selector, 130 is DA
C, 141, 142 and 143 are S / H circuits, 151 and 1
52 and 153 are LPFs, 160 is an amplitude adjusting means, 161
, 162 and 163 are VCA, and 170 is an amplitude designation section (amplitude
Corresponds to the designating means), 180 is mixed designating unit (mixing specifying means
The equivalent), 190 is a volume setting operator.

FIG. 2 is a diagram showing the tone mixing unit (12) shown in FIG.
1, 122 and 123 are the same. FIG. In FIG. 2, 201 is a selector, 202 is an adder, 203 is a latch with reset, 204 is a latch, 205 is a multiplier, 206 is an overflow / underflow detector, and 207 is a selector.

The operation of the tone generator of the electronic musical instrument constructed as described above will now be described with reference to the operation timing chart of FIG. 3 (the operation timing is the same in both the conventional example and the embodiment of the present invention). .

The musical sound data generating means 110 generates musical sound data for eight sounds (the data length is 16 bits and the maximum value is 327
67), and the musical sound data mixing means 120
Sound and sound data for one sound are mixed,
0 indicates that the maximum value of the input data is 32767 (2's complement 16
It is assumed that the DAC has a resolution of 16 bits which is the maximum value of the bit data.

First, the musical sound data generating means 110 generates musical sound data for eight sounds in a time-division manner.
i (W0 to W7). Here, W0 is 0th
The channel tone data, W1 is called the first channel tone data, and similarly, W7 is called the seventh channel tone data.

Next, the tone mixing sections 121, 122, 123
In, music data is mixed. Mixed designation section 180
The channels to be mixed are specified by the mixing specifying signals S1, S2, and S3 output from. That is, the tone data of the channel when the mixing designation signals S1 to S3 are 1 are mixed. In the example shown in FIG. 3, the mixed designation signal S1 is such that the time-division tone data Wi is W0, W1, W
Since it is 1 at 3, W4 and W7, the tone mixing unit 121
, The tone data of a total of five tones of channels 0, 1, 3, 4, and 7 are mixed. Similarly, the tone mixing unit 1
At 22, the tone data of a total of two tones of the second and fifth channels are mixed, and the tone mixing unit 123 mixes only one tone data of the sixth channel.

The mixing operation will be described in more detail. The operation of the tone mixing units 121, 122, and 123 is such that the mixing designation signals are S1, S2, and S3, respectively, and the amplitude control data is G1, G2, and G, respectively.
Since it is the same except that it is 3, the case of the tone mixing unit 121 will be described.

First, the reset signal R1 becomes 1, and the accumulated value MW1 stored in the latch 203 is reset to 0. When the input S is 0, the selector 201 outputs the value of the input A (ie, 0), and when the input S is 1, the selector 201 outputs the value of the input B (ie, the tone data Wi). The output of the selector 201 is input to the input B of the adder 202,
The output of the latch 203 (that is, the accumulated value MW1) is
02 is input to input A. Therefore, the mixing designation signal S1
Is 1, the tone data Wi and the accumulated value MW1 are added. When the mixed designation signal S1 is 0, the value 0 and the accumulated value MW1 are added. The result of the addition is stored in the latch 203 at the rise of the clock signal CK1. Thus, the tone data from the 0th channel to the 7th channel are accumulated, that is, mixed, in accordance with the mixing designation signal S1. The maximum value of the musical tone data is 32767 (the data length is 1
6 bits), and the musical tone data for 5 tones is accumulated, so the maximum value of the accumulated value MW1 is mathematically 32767 * 5 = 16
3835 (the data length is 19 bits).

When the accumulation up to the seventh channel is completed,
The rising edge of the clock signal CK2 causes the latch 20
3 is stored in the latch 204. The output of the latch 204 is input to the multiplier 205 and multiplied by the amplitude control data G1 output from the amplitude controller 170. When the amplitude control data G1 is equal to 0.125, it becomes equivalent to a 3-bit left shift in the conventional shifter 505. Since the tone mixing unit 121 mixes tone data of five tones, the multiplication result does not overflow or underflow even if the amplitude control data G1 is increased to 0.2 (that is, 16-bit data). The maximum value does not exceed 32767). In practice, it is almost impossible for all five tone data to take the maximum value or the minimum value (sign negative maximum value) at the same time. Therefore, even if the amplitude control data G1 is larger than 0.2, there is a practical problem. Absent.

In the case of an attenuated sound such as a piano, the amplitude is large at the first rising portion of the musical tone, but is attenuated immediately and the amplitude becomes small.
Even if it is increased to about 5, there is no practical problem. However, since there is a possibility that the multiplication result overflows or underflows, it is better not to generate a large spike noise due to the overflow or underflow.

That is, as shown in FIG. 2, an overflow / underflow detector 206 and a selector 207 are provided. The overflow / underflow detector 206
When neither overflow nor underflow is detected, the selector 207 selects the input A, that is, the multiplication result. If an overflow is detected, input B,
That is, when the maximum tone value (32767) is selected and an underflow is detected, the input C, that is, the minimum tone value (-
32768) is selected. Since the overflow and the underflow occur only for a moment, the distortion of the mixed musical tone data due to the countermeasure for the overflow and the underflow does not cause a problem in hearing. However, the amplitude control data G
If 1 is made extremely large (approximately 1 or 1 or more), an overflow or an underflow frequently occurs, and it goes without saying that the distortion of the mixed musical tone data is sensed.

In the tone mixing section 122, two tone data are mixed, so that even if the amplitude control data G2 is set to 0.5, overflow and underflow never occur. Since tone data for two sounds rarely take the maximum value or the minimum value at the same time, in the case of an attenuated sound such as a piano, there is no practical problem even if the amplitude control data G2 is increased to about 0.7.

Since only one tone data is mixed in the tone mixing section 123, the amplitude control data G3 may be set to 1.

Thus, the mixed data M1, M2, M3
(The data length is 16 bits each) is output. The amplitude control data G1, G2, G3 are respectively 0.5, 0.7,
When set to 1, the maximum value per tone input to the DAC is 16384 (data length is 15 bits) for mixed data M1, and 22937 for mixed data M2.
(Data length is equivalent to 15.4 bits) and 3 for M3
This is 2767 (the data length is 16 bits), which is 4 to 8 times that of the conventional example, so that the quantization noise is reduced and the S / N ratio is improved.

The mixed data M1, M2 and M3 are stored in the selector 1
24, and output to the DAC 130 as mixed tone data in a time-division manner. The mixed tone data is stored in the DAC 130
Is converted to an analog tone signal by the sample and hold signals SH1, SH2, SH3.
/ H circuits 141, 142, 143 sample and hold. The sampled and held tone signal is an LPF
After unnecessary sampling noise is removed by 151, 152, and 153, the volume level of each output is adjusted in the VCAs 161, 162, and 163, and output as musical tone outputs 1, 2, and 3. The volume level of each output is set by the volume setting operator 490 and the amplitude control data G
It is controlled by the amplitude designation unit 170 based on both of the items 1-3.

That is, if the settings of the tone output 1, 2, and 3 on the volume setting operator 490 are the same, the VCAs 161 and 16
The amplification factors at 2, 163 are set by the reciprocal ratios of the amplitude control data G1 to G3. Amplitude control data G1 = 0.5,
Assuming that G2 = 0.7 and G3 = 1, VCAs 161 and 16
2, 163 volume adjustment signals V1 = 2, V2 = 1.43,
V3 may be set to 1. To make the amplitudes of the musical tone outputs 1, 2, and 3 the same as in the conventional example, V1 = 0.25 and V2 =
It is sufficient to set 0.18 and V3 = 0.125. (However, V
The amplification factor in CA is the same as the value of the amplitude control signal. Therefore, the noise caused by the cause after the DAC is reduced in the present embodiment by the amount corresponding to the decrease in the amplitude in the VCA, and the S / N ratio is further improved as compared with the conventional example.

As described above, according to the present embodiment, the mixing specifying means for specifying that the musical sound data is to be mixed into a plurality of groups, and the amplitude of the mixed musical sound data is as large as possible.
Amplitude specifying means for specifying the amplitude at the time of mixing for each of the groups so that the tone data specified by the mixing specifying means are mixed based on the amplitude specified by the amplitude specifying means and output as mixed tone data Mixing means for correcting the amplitude of the mixed musical tones for each group , and
By providing amplitude adjustment means for adjusting the volume balance between loops, the volume
Ignoring the balance and increasing the effective bit length
Reduce the difference, and sound between groups at the end of the calculation.
Mixed tone data with increased amplitude to properly restore volume balance
The amplitude of the data relative to the other groups
As a result, a mixed tone signal with less noise can be obtained.

[0039]

In this embodiment, the tone mixing section is set to 1
Although three sets 21, 122 and 123 are provided, it goes without saying that time-division calculation may be performed using only one tone mixing unit. However, even in this case, only three sets of accumulated values must be stored.

In the volume control means 160, VCA
However, it is needless to say that any device that can adjust the amplitude of the analog signal may be used.

In the tone mixing section, the latch 204
Is multiplied by the amplitude control data. The multiplier 205 is provided before the input of the adder 202, and the tone data is multiplied by the amplitude control data. It is needless to say that is also equivalent.

Although the tone data is mixed in only one of the plurality of tone mixing units, it is mixed in two or more tone mixing units, and one tone data is output to a plurality of tone outputs. Needless to say, it is good.

[0044]

As described above, according to the present invention, there are provided tone data generating means for generating a plurality of tone data, mixing designating means for designating that the tone data is to be mixed into a plurality of groups, and tone data after mixing. The amplitude of
Amplitude specifying means for specifying the amplitude at the time of mixing for each group as described above, and tone data for mixing the tone data specified by the mixing specifying means based on the amplitude specified by the amplitude specifying means and outputting as mixed tone data Mixing means;
The group is corrected for each of the groups according to the amplitude of the mixed musical tone data generated musical tone signal based on the amplitude during mixing
By providing amplitude adjustment means for adjusting the volume balance between groups , the volume balance between groups can be
Ignoring calculation errors and increasing the effective bit length
At the end of the calculation,
Of mixed tone data with increased amplitude to return the
Since the width is restored, an excellent tone generator for an electronic musical instrument that can generate a mixed tone signal with less noise can be realized.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of a musical sound generating device for an electronic musical instrument according to an embodiment of the present invention.

FIG. 2 is a configuration diagram of a tone mixing unit of the tone generator of the electronic musical instrument according to the embodiment of the present invention.

FIG. 3 is an operation timing chart of a musical sound generator of an electronic musical instrument according to an embodiment of the present invention and a conventional example.

FIG. 4 is a block diagram of a conventional musical sound generator for an electronic musical instrument.

FIG. 5 is a configuration diagram of a tone mixing unit of a conventional tone generator for an electronic musical instrument.

[Explanation of symbols]

 110 Musical Sound Data Generation Means 120 Musical Sound Data Mixing Means 130 Digital-to-Analog Converter 160 Amplitude Adjusting Means

Claims (3)

(57) [Claims] 1. A musical sound data generating means for generating a plurality of musical sound data, a mixing specifying means for specifying that the musical sound data is to be mixed into a plurality of groups, and the musical sound data after mixing
Amplitude specifying means for specifying the amplitude at the time of mixing for each of the groups so that the amplitude of the sound is as large as possible, and mixing and mixing the tone data specified by the mixing specifying means based on the amplitude specified by the amplitude specifying means. Tone data mixing means for outputting as tone data; and correcting the amplitude of the tone signal generated based on the mixed tone data for each of the groups according to the amplitude at the time of mixing to adjust the volume balance between the groups.
Musical tone generating apparatus for an electronic musical instrument provided with an amplitude adjustment means for settling. 2. The apparatus according to claim 1, wherein said amplitude designating means changes the amplitude at the time of mixing according to the number of musical sound data to be mixed and the form of musical sound such as continuous or attenuated. Musical instrument for electronic musical instruments. 3. The amplitude adjusting means converts the mixed musical tone data into an analog signal, and then corrects the amplitude in accordance with the amplitude at the time of mixing to adjust the volume balance between the groups. The musical sound generator for an electronic musical instrument according to claim 1, wherein