JPS6093491A - Musical sound formation apparatus - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

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 operations such as frequency modulation operations or amplitude modulation operations. This invention relates to being able to control the ingredients.

BACKGROUND 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 in order 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. It was designed to be controlled according to the structure of the arithmetic expression. Therefore, in order to synthesize a musical tone with a satisfactory tone 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 calculating each arithmetic term in a time-sharing manner, the control clock has to be increased in speed, which tends to increase costs.

Similar problems exist not only in the FM calculation type, but also in musical tone forming apparatuses of the amplitude modulation (hereinafter abbreviated as AM) calculation type in the audible frequency range.

Purpose of the Invention The present invention has been made in view of the above points, and provides an apparatus for forming a musical waveform signal by a predetermined modulation calculation.
The purpose is to enable temporal changes in timbre and complex timbre control with a relatively simple configuration.

Summary of the Invention The present invention uses a readable and writable storage means as a waveform memory used in a musical sound waveform synthesis means that synthesizes a musical sound waveform signal by a predetermined modulation calculation, and uses a musical sound waveform newly synthesized by the musical sound waveform synthesis means The present invention is characterized in that the waveform stored in the storage means can be rewritten at any time. With this configuration, the waveform of the modulating wave or modulated wave used in the modulation calculation changes at any time and changes to the musical sound waveform that was previously synthesized by calculation), and accordingly, the overtone structure of the musical sound waveform that is newly synthesized by the calculation changes over time.

Therefore, it is possible to perform temporal changes in timbre and complex timbre control without particularly using complex arithmetic expressions such as multiple expressions or polynomials, and without particularly controlling complex arithmetic parameters.

Note that an initial waveform supplying means is provided to supply a predetermined initial waveform to the writable waveform storage means.

Embodiment FIG. 1 shows the basic configuration of an electronic musical instrument implementing a musical tone forming apparatus according to the present invention.
and the control signal generating circuit 11 correspond to the main part of the present invention. To briefly explain FIG. 1, a key press detection circuit 13 detects the press or release of each key on the keyboard 12, and based on this detection output, a 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 (signal that becomes 1" when the key is pressed and becomes θ" when the key is released) are output. The phase data generator 15 generates phase data P (instantaneous phase angle information) that changes at a rate corresponding to the pitch of the pressed key based on the key code KC.

The musical tone forming operator 1o uses the phase data P(1) as a phase parameter to calculate a predetermined modulation calculation formula (for example, FM
A musical waveform signal is formed according to the calculation formula).

The control signal generation circuit 11 supplies the operator 10 with a control signal for low calculation parameters, and the timbre selection circuit 1
The envelope generator 17 generates X from predetermined modulation index data in accordance with the timbre information TC given from 6, and also generates an initial waveform write signal -W and memory switching signals M1/M2 at a predetermined timing. Key-on signal K
The envelope waveform signal EV is generated in response to ON, and the envelope waveform to be generated is selected by the tone information TC. As will be described later, when the initial waveform write signal -INT is '0'°, the tone synthesis calculation by the operator 10 has not started, so the AND signal is used to delay the rise of the envelope waveform signal EV by that amount. circuit 18
is provided. That is, the key-on signal KON and the initial waveform write signal IN〒 are inputted to the AND circuit 18, and the key-on signal KON is prohibited from being applied to the envelope generator 17 when the ``end'' is "0". 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 is sent via a D/A converter, etc. (not shown). Finally, the sound system 20 is reached.

FIG. 2 is a diagram showing an example of the musical tone forming operator 10.
It is provided with two readable and writable waveform memos 1J21 and 22 consisting of AM (abbreviation for random access memory). Two FM operators 10A synthesize musical waveform signals by cyclic FM calculation.

10B is provided, and this corresponds to musical sound waveform synthesis means. Each waveform memo 1J21.22 is incorporated into each FM operator 10A, 10B.

Each FM operation 10A, IOB has a waveform memory 21.
22, a multiplier 23.24 which multiplies this readout output by a modulation index data ladder IDX, and an adder 2 which adds the output of the multiplier 23.24 to the phase data P(ri) to perform phase modulation.
5.26.

Waveform memory 21゜2 corresponding to the output of adders 25 and 26
2 phase address input AD.

The waveform function stored in the waveform memory 21 is fm (Table 4
If the instantaneous value of the phase address input signal is θ, and the output of the multiplier 23 is IDX-fn, (θ1) (where θ1 is the phase address value one sample point before the current θ, the adder 25, a delay of one sample time is set in the loop of the waveform memory 21 and the multiplier 23), the output of the waveform memory 21 is fIll (-4, , (P(L) + IDX) -f,
,,(1/,)l-,,(1), which is the modulation calculation formula for musical tone synthesis in the FM operator IOA.

The same applies to the other FM operator 10B.

The initial waveform memory 27 is composed of a ROM (abbreviation of read-only memory) in which one period (or a plurality of periods may be synchronized) of a predetermined initial waveform is stored in advance, and this initial waveform is read out one piece according to the phase data P.

The read output of this memory 27 is given to the B input of the selector 28. Waveform memory 2 is connected to the A input of selector 28.
2 readout outputs are provided. The selection control input A/100 of this selector 28 is given the initial waveform write signal y〒, and when the signal IN is "0", the B input (initial waveform data) is selected, and when it is 1", the A Select the input.The output of the selector 28 is the data input DIN of one waveform memory 21.
given to. Data manual DI of the other waveform memory 22
The readout output of the waveform memory 21 is given to N.

The AND circuit 29 is supplied with the initial waveform write signal IN〒 and the memory switching signal M1/M2, and its output is supplied to the read/write control manual R/W of one of the waveform memories 21. A signal obtained by inverting the memory switching signal M1/M2 by an inverter 30 is given to the read/write control manual R/W of the other waveform memory 22.

The read outputs of the waveform memories 21 and 22 are separately given to the A and B inputs of the selector 61. The selector 61 selects the output of the waveform memory 21 (that is, the output of the FM operator 10A) that is added to the A input when the memory switching signal M1/M2 is ``1'', and selects the output that is added to the B input when the memory switching signal M1/M2 is ``o''. The output of the waveform memo 1 22 (that is, the output of the FM operator 1013) is selected.

The third example of generation of each control signal -INT, M1/M2 is as follows.
As shown in the figure. That is, the control signal generation circuit 11 (FIG. 1) inputs the key-on signal KON and the phase data P(ri), and when the key-on signal KON rises to 1", it generates a waveform based on the phase data P(ri). The time for one cycle is detected, and the initial waveform write signal INT is set to "0" during this period.

Also, at first, the memory switching signal Ml/M2 is set to "1",
The waveform memory 21 of the operator 10A is selected. Signal I
When N〒 is open to O''', the selector 28 selects B manual power, and during this period, one period's worth of initial waveform data read from the memory 27 is input to the waveform memory 21.

Furthermore, while the signal INT is "QI+", the output of the AND circuit 29 is "0", and the waveform memory 21 is "0" of the R/W input.
The write mode ('W) is set by OI+ (see the column of mode of memory 21 in FIG. 3).

Therefore, initial waveform data is written into the waveform memory 21.

Incidentally, at this time, the output of the multiplier 26 is 11011, and the write address is specified by the phase data P(ri).

When the initial waveform write signal LOW rises to "1", the antenna circuit 29 is enabled and the waveform memory 21 is set to read mode (R). Therefore, the waveform data stored in the waveform memory 21 is read out in accordance with the phase address signal θ applied to the address input AD, and the tone synthesis calculation according to the above-mentioned equation (1) is performed in the operator 10A. Initially, the function fm (corresponds to the initial waveform. Also, during this time, the memory switching signal M1/M2+7)
1 ' From the MC, selector 31 selects the output of waveform memory 21 (output of operator 10A), and outputs it as a musical sound waveform signal formed by this musical tone forming operator 10. Meanwhile, during this period, "l" of signals M1/M2 '' (output ``0'' of the inverter 60) causes the other waveform memory 22 to enter the write mode (W), and the musical waveform signal (output of the full waveform memory 21) synthesized by the FM operator 10A is sequentially written to the waveform memory 22. At this time, the multiplier 24
The output of is O'' (because the memory 22 has not been read), and the write address of the waveform memory 22 is specified by the phase data P(ri).

Eventually, when the memory switching signal M1/M2 falls to 0'',
The read/write mode (R, W) of the waveform memos 1J21, 22 is reversed, and the selector 61 selects the readout output of the waveform memory 22 (that is, the musical waveform signal synthesized by the operator 10B) via the B input. The waveform stored in the waveform memory 22 at this time is different from the initial waveform, and is one cycle of the musical sound waveform synthesized by the previous calculation by the FM operator 10A. Therefore, the calculation formula of the FM operator 10B is basically the same as the above formula (1), but the function fm (is different from the previous one, and as a result,
The overtone composition of the musical waveform signal to be synthesized will also be different from the previous one. Note that the initial waveform write signal INT has already reached °°l'.
' has risen, so the selector 28 selects the readout output of the waveform memory 22 via the A input, and the readout output of the waveform memory 22 (that is, the readout output of the waveform memory 22 (that is, synthesized by the operator 10B) is input to the waveform memory 21 in the write mode. the musical sound waveform signal) is written.

Eventually, when the memory switching signal M1/M2 rises again to °'1'', the read/write mode of the waveform memo 1J21, 22 is reversed again, and the selector 31 selects the output of the waveform memory 21 through the eight-way power. At this time, the waveform stored in the waveform memory 21 is the same as that of the previous operator 10.
It is one cycle of the musical sound waveform synthesized by the calculation of B,
Therefore, the function fm (of 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 waveform function f111 used in FM calculation gradually changes, and the timbre of the resulting musical waveform signal changes over time, and its overtone structure can also be made complex.The pattern of this change is Memory switching signal M1/M
2. Therefore, it is preferable to control the generation sequence of the memory switching signals M1/M2 in accordance with the tone color information TC.

Incidentally, the change in the resulting musical sound waveform is schematically shown in FIG. 4. FIG. 4(a) is a diagram showing changes in the phase address signal, and (1) is a diagram showing changes in the waveforms stored in the waveform memo 1J21, 22 and the obtained tone waveform.

A solid line AI indicates the initial waveform stored in the waveform memory 21,
al indicates the regular phase address signal P (
Since the signal is modulated according to l, the signal applied to the address input of the waveform memory 21 becomes, for example, a2, and the waveform read out from the waveform memory 21 becomes A2.

Before the memory read/write mode is switched, waveform A2
is stored in the waveform memory 22, then al is A
2, the address input to the waveform memory 22 becomes a3, and the waveform read out from the waveform memory 22 becomes A3. In this way, the output musical sound waveform can be changed at any time.

In the above embodiment, the two waveform memos 1, 121, and 22 are alternately rewritten, but the waveform memory may be constructed using only one RAM that can be read and written at the same time. In that case, one of the operators 10B is unnecessary, and the readout output of the waveform memory 21 may be appropriately delayed by the delay circuit 32 and input to the memory 21 via the selector 28, as shown in FIG. . Further, the output of the selector 31 shown in FIG. 2 may be applied to the data input DIN of the waveform memo IJ 21 and 22.

Furthermore, although a traveling FM operator is used in the above embodiment, it is of course possible to implement the present invention using a regular FM operator as shown in FIG. Modulated wave phase data ω11. The waveform memory 66 is read out according to t,
The multiplier 34 multiplies the modulation index data IDX, and the adder 35 outputs the carrier wave phase data ω. t is modulated by a modulated wave signal, and the output of the adder 35 is used to store the waveform in the waveform memory 36.
is read out, and a musical waveform signal obtained by FM calculation is obtained as the output of the waveform memory 66. Here, both or one of the waveform memos IJ 33 and 36 is constructed of RAM, and the output of the waveform memory 36 is inputted to the data input of the RAM as shown by the broken line to rewrite the stored waveform. This waveform rewriting method may be either a method using two RAMs as shown in FIG. 2 or a method using one RAM and a delay circuit as shown in FIG. 5, and detailed illustration thereof will be omitted. Further, in FIG. 6, the initial waveform memory, the circuit for rewriting control, etc. are not shown, but they can be easily understood from FIG. 2.

Of course, the present invention can be implemented not only in a mononomial FM calculation circuit but also in a multiplex or polynomial FM calculation circuit. In that case, one or more of the plurality of waveform memories is configured with RAM, and the musical waveform signal (not necessarily the final musical waveform signal) extracted from an arbitrary location is input to the data input of this RAM. All you have to do is enter it. An example of this is shown in FIG. 7, where operator op1 is the same as that in FIG. 6, and operator op2, which inputs the output of operator OP1 as a modulation signal, receives carrier wave phase data ω. It includes an adder 37, a waveform memory 38, and a multiplier 39 for phase modulating 2t.

IDX, , IDX2 added to each multiplier 34.40.39
゜IDX3 is a modulation index or amplitude coefficient. Configure any of the waveform memories 33, 36, or 38 with RAM, and use this RAM.
A musical waveform signal is supplied to the data input of M through the route shown by the broken line, and the stored waveform is rewritten. The rewriting method may be either two RAMs or one RAM and a delay circuit as described above, and this point is omitted from illustration. Also, the initial waveform memory and circuits for rewriting control are not shown.

Omitted.

Of course, each operator in a multiplex or polynomial FM operation
1, op2, . . . do not need to be separate pieces of hardware, and may be one in which one FM operator/)-doware is shared in a time-division manner.

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 Application 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 carried out in the same manner as in the above embodiment #2.

Effects of the Invention As described above, according to the present invention, since the waveform stored in the waveform memory used for modulation calculation is rewritten at any time with the musical sound waveform obtained by modulation calculation, it is possible to easily realize temporal changes in timbre. Moreover, it is possible to obtain a musical sound waveform containing many overtone components with a ratio+Iff-like simple arithmetic circuit configuration, and it is possible to expand the possibilities of timbre control.

[Brief explanation of the drawing]

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. FIG. 3 is a timing chart showing an example of the operation of FIG. 2, FIG. 4 is a waveform diagram showing an example of a change in waveform obtained by the circuit shown in FIG. 2, and FIG. A block diagram showing an embodiment of the FM
FIG. 6 is a block diagram schematically illustrating application examples of the present invention according to changes in the calculation format. 10...Musical tone formation operator, IOA, IOB. OPI, OF2 FM operator, 11 Control signal generation circuit, 15... Phase data generator, 21.22 Readable and writable waveform memory, 27 Initial waveform memory, 28.
51 ・Selector, 62 ・Delay circuit. Patent applicant Yoshihito Iizuka, agent of Nippon Musical Instruments Manufacturing Co., Ltd.

Claims (1)

[Claims] 1. A readable/writable waveform storage means, an initial waveform supply means for supplying initial waveform data to the waveform storage means, and a predetermined waveform stored in the waveform storage means. a musical waveform synthesizing means for synthesizing a new musical waveform signal in accordance with a modulation calculation of the musical waveform synthesizing means, and a memory waveform rewriting means for rewriting the stored waveform in the waveform storage means in accordance with the musical waveform signal synthesized by the musical waveform synthesizing means. Musical tone forming device. 2. The waveform storage means is composed of two storage means, and when one storage means is being rewritten by the stored waveform rewriting means, the other storage means is used by the musical sound waveform synthesis means. The musical tone forming device according to claim 1, wherein the reading and writing modes are alternately switched. 3. The stored waveform rewriting means includes means for delaying the musical waveform signal synthesized by the musical waveform synthesizing means, and □ the waveform storage means is rewritten by the delayed musical waveform signal. The musical tone forming device according to scope 1. 4. The predetermined modulation calculation in the musical sound waveform synthesis means is as follows:
The musical tone forming device according to claim 1, which complies with a predetermined single wave number modulation calculation formula in the audible frequency region. 5. The predetermined modulation calculation in the musical sound waveform synthesis means is as follows:
The musical tone forming device according to claim 1, which follows a predetermined amplitude modulation calculation formula in the audible frequency range.