JPH0514918B2 - - Google Patents

Description

Detailed Description of the Invention Technical Field The present invention relates to a musical tone forming device that synthesizes musical waveform signals using modulation calculations such as frequency modulation calculations or amplitude modulation calculations, and in particular, relates to a musical tone forming device that synthesizes musical waveform signals using modulation calculations such as frequency modulation calculations or amplitude modulation calculations. This invention relates to being able to control the ingredients.

Prior Art When a musical tone signal having a desired spectral structure is synthesized by frequency modulation calculation in the audio frequency range, a waveform memory is incorporated into the calculation circuit to generate a modulated wave or a modulated wave. Conventional frequency modulation (hereinafter abbreviated as FM) calculation circuits use a memory that permanently stores a sine wave or a predetermined waveform as a waveform memory, so the timbre of the musical tone to be synthesized is determined solely by the calculation parameters and equations. It had come to be controlled according to the structure. Therefore, in order to synthesize a musical tone with a satisfactory timbre having sufficient overtone components, a simple mononomial FM operation is insufficient, and a multiple or polynomial FM operation has to be performed. As a result, the structure of the arithmetic circuit becomes complicated and large, and in the case of a method in which each arithmetic term is computed in a time-sharing manner, the control clock has to be made faster, which tends to increase costs. Similar problems exist not only in the FM calculation type, but also in musical tone forming apparatuses in the amplitude modulation (hereinafter abbreviated as AM) calculation type in the audible frequency range.

Purpose of the invention This invention has been made in view of the above points,
It is an object of the present invention to enable temporal change in timbre and complex timbre control with a relatively simple configuration in a device that forms musical waveform signals through predetermined modulation calculations.

Summary of the Invention A musical tone forming device according to the present invention includes: a readable/writable waveform storage means; a tone selection means for selecting a desired tone from among a plurality of tones; As the waveform data, for each of the plurality of tones, a waveform change data memory that stores the waveform data in advance, and data of different waveforms from the waveform change data memory according to the selection contents of the tone color selection means and a predetermined time sequence. a stored waveform rewriting means for sequentially reading out the waveforms stored in the waveform storage means and rewriting the stored waveforms in the waveform storage means according to the read waveform data; and an address signal for reading out the stored data in the waveform storage means in accordance with a desired pitch. and address signal modulation means for modulating the address signal supplied from the address signal supply means to the waveform storage means in accordance with the waveform data read from the waveform storage means. It is equipped with

As a result, the read address signal of the waveform storage means is modulated in accordance with the waveform data read from the waveform storage means, and a frequency modulation calculation is performed. Furthermore, since the waveforms stored in the waveform storage means are sequentially rewritten into different waveforms according to the selection contents of the timbre selection means and a predetermined time sequence, the waveforms of the modulated wave and carrier wave used in frequency modulation calculations change at any time. Become. Thereby, the synthesized waveform can be changed over time without changing the parameters in the frequency modulation calculation. Furthermore, since frequency modulation calculations are performed using only one waveform storage means, the configuration is simple, and furthermore, it is possible to correspond to many types of tones and realize temporal changes in the tones. A variety of timbre controls can be performed. Therefore, it is possible to change the timbre over time and perform complex timbre control without using complex arithmetic expressions such as multiple or polynomial equations, and without particularly controlling complicated arithmetic parameters.

Embodiment FIG. 1 shows the basic structure of an electronic musical instrument implementing a musical tone forming apparatus according to the present invention, in which a musical tone forming operator 10 and a control signal generating circuit 11 correspond to the main parts of the present invention. First, to briefly explain FIG. 1, the key press detection circuit 13 detects the press or release of each key on the keyboard 12, and based on this detection output, the single note priority circuit 14 selects a single pressed key. The key code KC of the selected pressed key and the key-on signal KON (a signal that becomes "1" when the key is pressed and "0" when the key is released) are selected according to predetermined priority criteria. The phase data generator 15 has a key code KC.
Based on this, phase data P(t) (instantaneous phase angle information) that changes at a rate corresponding to the pitch of the pressed key is generated.
The musical tone forming operator 10 forms a musical waveform signal according to a predetermined modulation calculation formula (eg, FM calculation formula) using the phase data P(t) as a phase parameter. The control signal generation circuit 11 supplies calculation parameters and other control signals to the operator 10, and generates predetermined modulation index data IDX according to the timbre information TC given from the timbre selection circuit 16, and also generates an initial waveform at a predetermined timing. Generates write signal and memory switching signal M1/2. Envelope generator 17 is a key-on signal
It generates an envelope waveform signal EV in response to KON, and the envelope waveform to be generated is selected by tone information TC. Furthermore, as described later,
When the initial waveform write signal is "0", the tone synthesis calculation by the operator 10 has not started, so an AND circuit 18 is provided to delay the rise of the envelope waveform signal EV by that amount. That is, the key-on signal KON and the initial waveform write signal are input to the AND circuit 18, and when KON is "0", the key-on signal KON is prohibited from being applied to the envelope generator 17. The multiplier 19 is for multiplying the musical waveform signal outputted from the operator 10 by the envelope waveform signal EV to give an amplitude envelope. The output of the multiplier 19 finally reaches the sound system 20 via a D/A converter (not shown) or the like.

FIG. 2 is a diagram showing an example of the musical tone forming operator 10, which includes two readable and writable waveform memories 21, 2 consisting of RAM (abbreviation for random access memory).
It is equipped with 2. Two FM operators 10 that synthesize musical waveform signals using cyclic FM calculations
A and 10B are provided, which correspond to musical sound waveform synthesis means. Each waveform memory 21, 22
It is built into the FM operators 10A and 10B. Each FM operator 10A, 10B includes a waveform memory 21, 22, a multiplier 23, 24 that multiplies the read output by modulation index data IDX, and adds the output of the multiplier 23, 24 to the phase data P(t). Adders 25 and 26 are provided for performing phase modulation. The outputs of the adders 25 and 26 are applied to the phase address inputs AD of the corresponding waveform memories 21 and 22.

The waveform function stored in the waveform memory 21 is f _n (θ)
If the instantaneous value of the phase address input signal is θ, and the output of the multiplier 23 is IDX・f _n (θ ₁ ), then θ ₁ is the phase address value one sample point before the current θ. , adder 25, waveform memory 2
1. It is assumed that a delay of one sample time is set in the loop of the multiplier 23), waveform memory 2
The output of FM operator 10A is f _n (θ)=f _n {P(t)+IDX·f _n (θ ₁ )} (1), which is the modulation calculation formula for musical tone synthesis in the FM operator 10A. The same goes for the other FM operator 10B.

The waveform change data memory 27 stores data of a plurality of mutually different waveforms in advance, and a predetermined combination of the plurality of waveforms is selected according to the timbre information TC, and each of the selected plurality of waveforms is stored in the counter. The selected waveforms are sequentially selected according to the output of 28, and the selected waveforms are read out according to the phase data P(t). The read output of this waveform modification data memory 27 is applied to data inputs D _IN of the waveform memories 21 and 22.
The counter 28 is reset by the initial waveform write signal and counted up in response to the memory switching signal M1/2. That is, a signal obtained by inverting the initial waveform write signal by the inverter 29 is applied to the reset input R of the counter 28 via the rising differentiation circuit 30. In addition, the initial waveform write signal
INT and memory switching signal M1/2 are AND circuit 3
1, and its output is applied to the read/write control input R/ of the waveform memory 21, and is also applied to the counter 2 via the rising differential circuit 32 and the OR circuit 33.
8 is applied to the count input C. Further, a signal obtained by inverting the memory switching signal M1/2 by the inverter 34 is applied to the read/write control input R/ of the waveform memory 22, and is also applied to the count input C of the counter 28 via the rising differentiation circuit 35 and the OR circuit 33.
given to.

The read outputs of the waveform memories 21 and 22 are separately given to the A and B inputs of the selector 36. A memory switching signal is input to the control input A/ of the selector 36.
M1/2 is given, and when the signal M1/2 is "1", select the output of the waveform memory 21 (that is, the output of the FM operator 10A) that is added to the A input,
When it is "0", the output of the waveform memory 22 (that is, the output of the FM operator 10B) that is added to the B input is selected.

Each control signal, M1/2, is waveform memory 21,
22 is rewritten according to a predetermined time sequence, and an example of its occurrence is shown in FIG. That is, the control signal generation circuit 11 (first
In Figure), the key-on signal KON and phase data P(t) are input, and when the key-on signal KON rises to "1", the time corresponding to one waveform period is detected based on the phase data P(t), and during this period Set the initial waveform write signal to “0”. Also, initially the memory switching signal M1/
M2 is set to "1", and thereafter, the signal M1/2 is inverted to "0" or "1" in a predetermined time sequence depending on the selected timbre. Initial waveform write signal
When INT falls to "0", a pulse is output from the differentiating circuit 30 and the counter 28 is reset. With the output "0" of the counter 28, the waveform change data memory 27 selects the first waveform from the waveform combination (waveform change sequence) selected by the timbre information TC, and selects the first waveform according to the phase data P(t). and read it out. Also, while the signal is "0", the output of the AND circuit 31 is "0", and the waveform memory 21 is in write mode by "0" of the R/input.
(W) (see the mode column of memory 21 in FIG. 3). Therefore, the first sequence of waveform data read from memory 27 is written to waveform memory 21. At this time, the output of the multiplier 23 is "0", and the write address is the phase data P(t).
specified by.

When the initial waveform write signal rises to “1”,
The AND circuit 31 is enabled and the waveform memory 21 is set to read mode (R). Therefore, the waveform data stored in the waveform memory 21 is input to the address.
It is read out in accordance with the phase address signal θ applied to the AD, and the tone synthesis calculation according to the above-mentioned equation (1) is performed in the operator 10A. At this time, the function f _n (θ) corresponds to the waveform of the first sequence read from the memory 27. In addition, during this time, the output of the waveform memory 21 (the output of the operator 10A) is selected by the selector 36 due to the memory switching signal M1/2 being "1", and is output as the musical waveform signal formed by the musical tone forming operator 10.
On the other hand, as the signal rises, AND circuit 3
When the output of 1 rises to "1", a pulse is output from the differentiating circuit 32, and the counter 28 is counted up by 1. When the output of the counter 28 changes to "1" in this way, the waveform change data memory 27
selects the second waveform from the waveform combination (waveform change sequence) selected by the timbre information TC and reads it out according to the phase data P(t).
During this time, the other waveform memory 22 is
is set to write mode (W) (“Memory 22” in Figure 3).
(see column ``Mode''), the second waveform data read from the memory 27 is written to the waveform memory 22. At this time, the output of the multiplier 24 is "0" (because the memory 22 has not been read),
The write address of the waveform memory 22 is the phase data P.
(t).

Eventually, when the memory switching signal M1/2 falls to "0", the read/write mode (R, W) of the waveform memories 21, 22 is reversed, and the selector 36 outputs the readout (R, W) of the waveform memory 22 via the B input. In other words, the musical tone waveform signal synthesized by the operator 10B is selected. The waveform stored in the waveform memory 22 at this time is a second waveform different from the first waveform that had been stored in the waveform memory 21 and used for tone synthesis calculations. Therefore,
The calculation formula of FM operator 10B is basically the above
It is the same as equation (1), but the function f _n (θ) is the previous FM
This is different from that of the operator 10A, and as a result, the overtone composition of the musical waveform signal to be synthesized is also different from the previous one. On the other hand, when the signal M1/2 falls to "0", a pulse is output from the differentiating circuit 35, and the counter 28 is counted up by one. When the output of the counter 28 changes to "2" in this way, the waveform change data memory 27 selects the third waveform in the waveform change sequence, and this is read out. During this period, the output of the AND circuit 31 is “0” and the waveform memory 21 is in write mode (W).
The third waveform data read from the memory 27 is written into the waveform memory 21.

Eventually, the memory switching signal M1/2 becomes “1” again.
When the voltage rises, the reading and writing modes of the waveform memories 21 and 22 are reversed again, and the selector 36 selects the output of the waveform memory 21 via the A input. The waveform stored in the waveform memory 21 at this time is a third waveform that is different from the second waveform that has been stored in the waveform memory 22 and used for tone synthesis calculations. Therefore, the function f _n (θ) in equation (1) is further different from the previous one, and the overtone composition of the musical waveform signal to be synthesized is also different.

In this way, the count value of the counter 28 changes according to the temporal generation sequence of the initial waveform write signal and the memory switching signal M1/2, and the waveform read from the waveform change data memory 27 changes accordingly. The waveform function f _n (θ) used in the FM calculation changes, and as a result, the timbre of the musical waveform signal obtained by the FM calculation changes over time.
This pattern of temporal change in timbre is determined according to the waveform change sequence (waveform combination) in the waveform change data memory 27 and the temporal generation sequence of the memory switching signal M1/2, both of which depend on the timbre information TC. controllable. Incidentally, the change in the count value of the counter 28 is "0" →
An example of a change in the read waveform of the waveform change data memory 27 in response to "1" → "2" → "3", etc. is shown in FIG. 4.

The method for reading out the waveform modification data memory 27 is not limited to the above-mentioned method, and any method can be used. For example, by providing an appropriate sequence memory,
A waveform address signal having an arbitrary value may be generated from the memory at an arbitrary timing, thereby specifying the waveform to be read in the memory 27.

In the above embodiment, two waveform memories 21 and 2 are used.
2 is alternately rewritten, however, the waveform memory may be configured using only one RAM that can be read and written at the same time. In addition, although a cyclic FM operator is used in the above embodiment, a regular FM operator (one in which a waveform memory for modulating waves and a waveform memory for carrier waves are prepared separately; however, one waveform memory is used in a time-division manner) Of course, the present invention can also be implemented in Also,
The present invention can be applied not only to mononomial but also to multiple or polynomial FM calculation type musical tone forming devices. In that case, one or more of the plurality of waveform memories prepared for the modulated wave or the carrier wave may be used as a readable/writable memory, and the present invention may be applied to that part.

Further, although the above embodiment has been described as a monophonic musical instrument, it can be made into a multi-tone type by replacing the single-note priority circuit 14 of FIG. 1 with a key assigner. In that case, by providing as many readable and writable waveform memories as the number of sound generation channels, it is possible to realize temporal changes in timbre independently for each sound.

The present invention is not limited to the above-mentioned FM calculation type musical tone forming apparatus, but can also be applied to AM calculation type musical tone forming apparatuses such as those disclosed in Japanese Patent Laid-Open No. 56-62297 and others. In that case, only the calculation configuration of the operator is changed, and the read/write control of the read/write waveform memory can be performed in the same manner as in the above embodiment.

Effects of the Invention As described above, according to the present invention, the read address signal of the waveform storage means is modulated in accordance with the waveform data read out from the waveform storage means.
Frequency modulation calculation is performed with a simple configuration, and the waveform stored in the waveform storage means is sequentially rewritten into different waveforms according to the selection contents of the timbre selection means and a predetermined time sequence.
The waveforms of the modulated wave and carrier wave used in frequency modulation calculations change from time to time. As a result, it is possible to easily perform timbre change over time and complex timbre control without particularly performing complicated modulation calculations or complicated calculation parameter control, and the configuration is simple.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing an example of the basic configuration of an electronic musical instrument implementing a musical tone forming device according to the present invention, and FIG. 2 shows an example of the present invention. A block diagram showing the configuration, FIG. 3 is a timing chart showing an example of the operation in FIG. 2, and FIG. 4 is an example of a change in the waveform read from the waveform change data memory in response to a change in the count value of the counter in FIG. FIG. 10...Musical sound formation operator, 10A, 10B
...FM operator, 11 ... control signal generation circuit, 15 ... phase data generator, 21, 22 ...
Readable/writable waveform memory, 27...waveform change data memory, 28...counter, 36...selector.

Claims (1)

[Scope of Claims] 1. A readable and writable waveform storage means; a timbre selection means for selecting a desired timbre from a plurality of timbres; For each of the plurality of tones, data of different waveforms is sequentially read out from a waveform change data memory in which waveform data is stored in advance, and according to the selection contents of the tone color selection means and a predetermined time sequence. stored waveform rewriting means for rewriting the stored waveform in the waveform storage means according to the output waveform data; and an address signal for supplying an address signal for reading out the stored data in the waveform storage means according to a desired pitch. A musical tone forming device comprising: supply means; and address signal modulation means for modulating the address signal supplied from the address signal supply means to the waveform storage means in accordance with the waveform data read from the waveform storage means. .