JPH0740191B2 - Envelope generator - Google Patents

Description

Description: TECHNICAL FIELD OF THE INVENTION The present invention relates to an envelope creating apparatus capable of keyboard follow, such as attenuating a musical sound faster and reducing harmonic components toward a high-pitched part.

[Prior art]

2. Description of the Related Art Conventionally, as an electronic musical instrument capable of such a keyboard follow, there has been realized an electronic musical instrument which is controlled by an analog method using a VCA (voltage control type amplifier), a VCF (voltage control type filter) or the like.

[Problems of conventional technology]

However, the above-mentioned analog system is easily affected by external conditions such as temperature and cannot obtain a good constant sound quality, and it is difficult to adjust the sound quality when creating a musical sound. Furthermore, in the conventional method, the characteristics of the keyboard follow are fixed and cannot be changed.

[Object of the Invention]

Therefore, the present invention makes it possible to arbitrarily create various envelope waveforms necessary for creating musical tones in an electronic musical instrument whose tone color can be arbitrarily set, and further, having a keyboard follow function and varying the keyboard follow characteristic. An object is to provide an envelope creating device.

[Main points of the invention]

In order to achieve this purpose, the level data and rate data indicating the level and the slope of each polygonal line of the envelope waveform are displaced based on the pitch information. On the other hand, the point is that the calculation is performed so as to decrease or increase based on the pitch information whose contents have been changed.

[Structure of First Embodiment] <Overall Schematic Structure> An embodiment will be described below with reference to the drawings. FIG. 1 is an overall block diagram of an electronic musical instrument. In the figure, 1 is a CPU (central processing unit), and this CPU1 is connected to the R via a bus line BUS.
An OM (read only memory) 2, a RAM (random access memory) 3, and a tone color RAM 4 are connected to each other, and a keyboard 6 is provided via an interface 5, a switch input section 8 is provided via an interface 7, and a register is provided via an interface 9. The section 10 and the tone creating section 11 are connected to the tone color register section 13 and the computing section 29 via the interface 12, respectively. The arithmetic unit 29 is connected to the tone color register unit 13 and also to the musical sound creating unit 11, and the musical sound creating unit 11 is connected to the speaker 15 via the amplifier 14.

The CPU 1 is a device that executes various operations such as arithmetic operations according to a control program stored in the ROM 2. The RAM 3 is a memory for temporarily storing the intermediate result data and the like during the processing by the CPU 1. The tone color RAM 4 is the switch input section 8
Is a memory for storing 20 kinds of tones which are arbitrarily set by various switches described later. In addition to the switch for setting the tone color, the switch input unit 8 has a switch for adding effects and rhythms.

The register unit 10 has various registers.Each time the tone color memory selection switch 27, which will be described later, is switched, these registers are used for the arithmetic processing for adding the tone color switched this time to the new ON key of this switching operation unit. This is a register used by CPU1.

On the other hand, the tone color register unit 13 has a register for storing the tone color content of the tone currently being used, and the arithmetic unit 29 creates displacement data based on the key code from the interface 12 and outputs it from the tone color register unit 13. Displace the envelope waveform of. Further, the musical tone creating section 11 assigns the operating keys of the keyboard 6 to the musical tone producing system for 8 channels formed by the arithmetic operation of the time-division processing method of the CPU 1, and produces the musical tone signals of the operating keys. Then, the synthetic musical sound is emitted through the amplifier 14 and the speaker 15. In that case, the musical tone creating section 11 receives data from the tone color register section 13 through the calculating section 29 and adds different tone colors to the musical tones of the respective operation keys.

<Structure of Switch Input Unit 8> Next, the timbre-related switches on the switch input unit 2 will be described with reference to FIG. By the way, in the case of the electronic musical instrument of this embodiment, for each tone color data pre-set in the tone color creation mode by the switch operation described in the tone color creation mode by the switch operation described below in the tone color RAM 4, To explain, as can be seen from the memory structure of the tone color RAM 4 conceptually shown in FIG.
It consists of three types of envelope data: harmonic component suppression and pitch, and waveform data indicating a basic waveform. In the memory configuration example of the tone color RAM 4 shown in FIG. 3, 10 types of volume envelope data, 10 types of waveform envelope data, 10 types of pitch envelope data, and 10 types of basic waveform are used.
There are various types of registers, and registers with the same capacity are available. There are 20 kinds of timbres, and the registers for representing each timbre have a total of 4 for each of the volume data, harmonic component suppression, pitch envelope data, and waveform data.
Each pointer is arbitrarily selected and stored by a switch operation described later.

Then, returning to FIG. 2, the basic waveform memory selection switch 16
Is a switch for presetting waveform data of 10 types of basic waveforms to the corresponding register 7 of the tone color RAM 4,
The basic waveform generation unit switch 17 is a switch for designating five types of basic waveforms prepared. Switch 17A (11,
21,31,41,51) specifies one cycle in the first half, and switches 17B
(12,22,32,42,52) is a switch that specifies one cycle of the latter half. Here, among the numbers written on the switches in the switches 17A and 17B, the 10's are the waveforms shown in FIG. 4 (1), the 20's are the waveforms shown in FIG. 4 (2), 30
The number range is the waveform shown in Fig. 4 (3), and the number 40 range is
The waveform shown in FIG. 4 (4), the number 50, represents the waveform shown in FIG. 4 (5). Switch 17
Reference numeral c is an octave modulation switch for alternately designating the waveform designated in the first half and the waveform designated in the latter half for each cycle. When the switch 17c is off, only the waveform designated in the first half is designated. Switch 16A
Is a writing switch for writing the contents set by the switch 17 into the switch 16.

FIG. 4 shows the shapes and data of the five types of basic waveforms described above. FIG. 5 shows the data structure of the waveform data of the basic waveform.
The WAVE FORM is the 3 bit data set in the waveform of Fig. 4, and the next 3 bit OCT.MODULATION WAVE FORM is also the 4 bit.
The 3-bit data shown in the figure is set. The next 1-bit data is data showing the presence or absence of OCT.MODU LATION. Further L
One bit of SB is not used and is invalid.

Returning to FIG. 2, the volume envelope memory selection switch
18, harmonic component suppression envelope memory selection switch 1
9 、 Pitch envelope memory selection switch 20
This is a switch for designating a register for storing each envelope data of volume, harmonic component suppression, and pitch in the tone color RAM 4, and the actual operation is to first perform volume, harmonic component suppression, and pitch. Envelope switch 18 ~
Any one of 19 is designated, and then 8 corresponding rate value slide switches 21, 8 levels corresponding to 8 steps corresponding to 8 steps of 0 to 7, slide switch 22 for level value designation, sustain point are provided. Operate the switch of each step of the designated switch 23, then the volume currently selected,
The harmonic switch is turned on, and the write switch 24, 25, or 26 corresponding to the envelope of either pitch is turned on.

FIG. 6 shows the waveforms of the envelopes of the volume, the harmonic component suppression, and the pitch, which are arbitrarily formed by the operation of the slide switches 21 and 23 according to the above eight steps. It consists of individual fold lines. The height of the end of the polygonal line of the envelope (indicated by points A to H in the figure) is expressed as a level value, and the interval between the level values is expressed by a rate value (the inclination of the line part). .

FIG. 7 shows the data structure of the envelope data. In the figure, A to H represent the data storage sections corresponding to the points A to H at the end of the envelope waveform of FIG. 6, each having a capacity of 18 bits. Have. Then, the MSB in the upper 8 bits stores 1-bit data indicating the direction of the rate (tilt direction of the broken line portion), In each direction. The next 7 bits are rate-variable data, and the MSB in the lower 8 bits is 1-bit data representing sustain information. When the bit is "1", it indicates that the sustain point has been reached. When it is "0", it is not a sustain point. And the next 7-bit data shows the level value. Note that the direction of the rates mentioned above Is automatically determined from the change in level variation.

FIG. 8 shows an example of an actual envelope, and FIG. 9 shows an example of actual data of the envelope of FIG. In the case of this example, the point F becomes the sustain point, and the level of the envelope of this key is kept constant until the next key-off. At this time, the value of the point G becomes irrelevant.

Returning to FIG. 2 again, the tone color memory selection switch 27 is a switch for designating the registers (registers 1 to 20 in FIG. 3) in the tone color RAM 4 for storing the data of the above 20 types of tone colors. In the timbre creation mode, for the timbre data (fundamental waveform waveform data, volume, harmonic component suppression, pitch envelope data) currently selected by any combination operation of the switches 16 to 20. Four numbers are written in the registers 1-20 when the write switch 28 is turned on. Further, in the normal performance mode, by turning on any one of the tone color memory selection switches 27, four pointers of the corresponding tone color data are read from the registers 1 to 20, and the third pointer is read based on these pointers. The data is read from the registers of the volume envelopes 1 to 10, the harmonic component suppression envelopes 1 to 10, the pitch envelopes 1 to 10 and the basic waveforms 1 to 10 and processed.

<Structure of Calculation Unit 29> Next, the structure of the calculation unit 29 will be specifically described with reference to FIGS. In the figure, reference numeral 60 denotes a conversion unit, which generates displacement data based on a key code indicating pitch information from the keyboard 6 given through the interface 12 and produces a subtractor 6
1, give to the adder 62. The relation between this displacement data and the key code is given by the relation of exponential function as shown in FIG. 13, and the displacement data increases rapidly toward the high range (C ₂ → C ₇ ).

The subtractor 61 is provided with a level variable indicating the height of each point of the harmonic component suppression envelope data from the tone color register unit 13 to subtract the value of the displacement data,
It is output to the musical sound creating section 11. As the level value becomes smaller after subtraction, the amplitude becomes smaller and the modulation degree becomes smaller, and the harmonic component decreases accordingly. Further, the adder 62 is given a rate value indicating the inclination of each polygonal line portion of the volume envelope data from the tone color register section 13, the values of the displacement data are added, and the result is output to the musical tone creating section 11. It As the rate variation is added and becomes larger, the rising and decay of the musical sound becomes steeper, and the decay rate becomes faster. In this way, the harmonic component suppression and volume envelope data are displaced by addition and subtraction, but the pitch envelope data is not displaced and is sent to the musical sound creating unit 11 as it is.

<Structure of Musical Sound Creating Unit 11> Next, a specific structure of the musical sound creating unit 11 will be described with reference to FIG. Reference numeral 30 in the figure is an interface through which displacement processing by addition / subtraction shown in FIG. Envelope data composed of the rate-value, level-value, etc. that were made (as shown in FIG. 10,
Each data is also called AMP Ramp, WAVE Ramp, Freq.Ramp)
Is supplied. And each envelope circuit 31, 32, 33,
The current current value is calculated from the rate variable and the level variable, and the current current value is calculated and the corresponding EXP. (Exponential) ROM 34, band limit circuit 35,
Give to frequency ROM36. When the current value reaches the rate value at that time, each envelope circuit 31, 32, 33 generates an interrupt signal INT and sends it to the CPU 1 through the interface 9 to send the next step 0-7.
Data for (Points A to H) AMP Ramp, WAVE Ramp, Fre
q.Ramp output is requested (however, in the case of the sustain point described above, the interrupt signal INT is not output).

The Freq.ROM 36 generates frequency information (phase angle information) FI according to the output from the pitch envelope circuit 33, and supplies it to the band limit circuit 35 and phase generator 37. The phase generator 37 accumulates the phase angle information FI and supplies the resultant data to the division circuit 38. The band limit circuit 35 prevents the occurrence of aliasing distortion based on the sampling theorem based on the output from the waveform envelope circuit 32 and the phase angle information, and supplies the output to the division circuit 38. Further, the division circuit 38 includes an interface 30 and a waveform generation circuit.
Predetermined waveform type selection data sent from CPU 1 via 39 is also given. And the division circuit 38 performs division processing on each output from the phase generator 37, the band limit circuit 35, and the waveform generation circuit 39, and accesses the wave generator 40 according to the result data to obtain the waveform data. Is generated and sent to the multiplication circuit 41. For the specific configuration of the division circuit 38, the implementation circuit described in the patent application specification of Japanese Patent Application No. 57-221266 already proposed by the present applicant can be used.

The control data read from the EXP.ROM 34 is also input to the multiplication circuit 41, and accordingly, the waveform data and the control data are multiplied and the resultant data is given to the accumulation circuit 42. The accumulating circuit 42 gives the accumulated data to the DA converter via the DAC I / F (DA converter interface) 43 every time the result data for 8 channels is accumulated, and as a result, Musical sounds are emitted from the speaker 15.

<Structures of Envelope Circuits 31, 32, 33> Next, the structures of the envelope circuits 31, 32, 33 for volume, harmonic component suppression, and pitch will be specifically described with reference to FIG. Since the circuits 31 to 33 have the same configuration, the circuit shown in FIG. 11 is, for example, the volume envelope circuit 31.

In the figure, reference numeral 45 is a shift register group in which 8 stages of shift registers each having a capacity of 8 bits are connected in parallel, and a level variable sent from the CPU 1 through the transfer gate 46 is input in parallel to the first stage. . The shift register group 45 is formed by connecting the shift registers in parallel in eight stages in order to correspond to the existence of a musical sound producing system for eight channels. And another shift register group described later
The same applies to 50 and 55.

The level variable input to the first stage of the shift register group 45 is sequentially shifted to the rear stage side, output from the eighth stage, returned to the first stage via the transfer gate 47, and given to the B input terminal of the comparator 48. To be Further, the transfer gate 46 is applied with a preset signal sent from the CPU 1 via an inverter 49 to be opened / closed, and the transfer gate 47 is directly applied with the preset signal to be opened / closed. The preset signal is at "0" level only when the level value is sent.

On the other hand, the rate value is input to the shift register group 50 through the transfer gate 51, and when the rate value is output from the shift register group 50, the rate value is returned to the shift register group 50 through the transfer gate 52, It is also applied to the B input terminal of the adder / subtractor 53. Then, the transfer gates 51 and 52 are controlled to be opened / closed by applying the preset signal via the inverter 54 or directly.

Further, output data (current value) from itself is input to the shift register group 55 after being returned via the transfer gate 56 and is also given to the A input terminal of the adder / subtractor 53. Then, the result data ANS1 of the adder / subtractor 53 is given to the shift register group 55 via the transfer gate 57 and also to the A input terminal 48 of the comparator 48. Then, to the control terminal SUB of the adder / subtractor 53, the MSB data of the rate value output from the shift register group 50 (data indicating the direction of the rate) is input as a subtraction command, and this subtraction command is " When "1", subtraction is performed, and when "0", addition is performed. Further, the MSB data of the rate variation is input to the control terminal ≧ of the comparator 48 as a comparison method selection command. Therefore, when this comparison method selection command is “1”, if A ≦ B, the comparison result of the comparator 48. The signal ANS2 is "1", and if A> B is "0". On the other hand, when the comparison method selection command is "0", if A≥B, the comparison result signal ANS2 is "1", A <B.
Then, it becomes "0". The comparison result signal ANS2 is applied to the transfer gates 56 and 57 directly or via the inverter 58 to control the opening and closing, and the NAND gate 59 is provided.
Is also given at one end of. On the other hand, the other end of the NAND gate 59 is provided with a level variable output from the shift register group 45.
The MSB data (sustain information) is inverted and input, and the output of the NAND gate 59 is sent to the CPU 1 as the interrupt signal INT.

[Operation of First Embodiment] Next, the operation of the present embodiment will be described.

<Tone Color Setting Operation> First, after turning on the power switch of the electronic musical instrument, the tone color creation mode is set by a predetermined switch operation. Then, first, arbitrary basic waveforms are set in the basic waveform registers 1 to 10 (FIG. 3), respectively. First, the switch number 1 of the basic waveform memory selection switch 16 is turned on, and then the switch 17A of the selected waveform (see FIG. 4) of the numbers 11 to 51 in the first half of the basic waveform generator switch 17 is set to 1. Turn on each. Next, if you want to make the first half and the second half of the basic waveform for two cycles different, turn on the octave switch 17c, and then select the number 12 to 52 that is different from the first half (switch 17
B) is turned on, and finally write switch 16A is turned on. On the other hand, if only the first half of the waveform is designated, the octave switch 17c is not operated.

Similarly, for switch numbers 2-10, an arbitrary basic waveform is set and set in the corresponding register.

The volume envelope is then preset in registers 1-10 of FIG. In this case, first, the switch 1 number 1 is turned on, and the rate-variable designated slide switch 21, level-variable designated slide switch 22, and sustain point designated switch 23 are set to desired states, and then the write switch 24 is turned on. Then, the data of the volume envelope is set in the register 1.

The same applies to the registers 2 to 10 of the volume envelope. Regarding the harmonic component suppression envelope and pitch envelope, write switch 25 or
Each envelope data is set by the same operation except that 26 is operated.

As described above, the basic waveform, volume, harmonic component suppression,
When each envelope of the pitch is preset in the corresponding register (Fig. 3) in the tone color RAM4, the basic waveform and volume are next set for each tone color register (registers 1 to 20 in Fig. 3) of the tone color RAM4. , Harmonic component suppression, pointers for each envelope of pitch are set. In this case, first, the number 1 of the tone color memory selection switch 27 is turned on, for example, the number 5 of the switch 16, the number 1 of the switch 18, the number 3 of the switch 19 and the number 7 of the switch 20 are turned on, respectively, and then the write switch.
Turn on 28. Therefore, the pointers 5, 1, 3, 7 are preset to the tone color register 1 in the tone color RAM 4.

The desired pointers are preset in the same manner for the tone color registers 2 to 20.

<Tone Color Reading Operation> When the preset operation is completed in the tone color registers 1 to 20 as described above, the normal performance operation can be performed thereafter. That is, one of the switches 27 to 20 having a desired tone color is turned on in advance before the performance is started. When the performance is started, the key code of the keyboard 6 is supplied to the CPU 1 through the interface 5 and the bus line BUS, the operation keys are assigned a predetermined channel, and the musical tone generation command is supplied to the musical tone generating unit 11. Further, the tone color register section 13 is set with the tone color data currently being set, and the level variation of the harmonic component suppression envelope data of this tone color data and the rate variation of the volume envelope data are added to the subtracter 61 in the arithmetic unit 29. vessel
Entered in 62. Further, the CPU 1 gives the above-mentioned key code to the conversion unit 60 in the calculation unit 29 via the interface 12, and thereby the displacement data having a larger value as the pitch becomes higher is given to the subtractor 61 and the adder 62. Then, the level variation is subtracted and displaced by the displacement data, while the rate variation is additionally displaced by the displacement data and is given to the musical sound creating unit 11.

Considering the addition / subtraction displacement in this case individually for rate-variable and level-variable respectively, if only the rate-variable is subjected to additive displacement, the slope of the broken line part of the envelope becomes large as shown by the broken line in Fig. 14 (1). The rise and decay are steep and the sound emission time is short. Further, if only the level variation is subtracted and displaced, as shown by the broken line in Fig. 14 (2), the height of each point of the envelope becomes lower, the modulation degree becomes smaller, and the harmonic component becomes smaller. This displacement data increases as the key code value increases and the pitch increases.
Such a displacement becomes more significant as the pitch becomes higher.

In this way, the keyboard follow is performed such that the higher the pitch, the faster the attenuation and the less harmonic components. In addition, if both the level and rate variants are subtracted and displaced, the 14th
As shown in FIG. 3C, it is possible to make an envelope waveform in which only the sound emission time does not change. This is the same even if the quantity variation is added and displaced.

[Second Embodiment] A second embodiment will be described with reference to FIGS. In this embodiment, as shown in FIG. 15, the decoders 63, 6 are provided in the arithmetic unit 29.
The decoders 63 and 64 are provided with data of any of 0 to 9 levels from a sensitivity switch (not shown) of the switch input unit 8 and are decoded and multiplied by multipliers 65 and 6, respectively.
It is given to 6 and outputs sensitivity data. The displacement data from the conversion unit 60 is given to the multipliers 65 and 66, which are doubled to values according to the sensitivity data and given to the subtractor 61 and the adder 62, respectively.

The decoder 63 in this case has the characteristics shown in FIG.
Also, the decoder 64 has the characteristics shown in FIG. on the other hand,
Level subtraction data for the harmonic component suppression envelope is input to one end of the subtractor 61, and rate variation data for the volume envelope is input to one end of the adder 62.

Here, the sensitivity data is multiplied by the displacement data as shown in FIG. 18, and the upper 8 bits of the multiplication result data are processed as new displacement data.

According to the present embodiment, the characteristic of the keyboard follow can be changed by changing the displacement data by the sensitivity data which can be set arbitrarily, and the characteristic of the keyboard follow can be set programmable rather than being fixed.

Further, in the above-described embodiment, the harmonic component suppression envelope and the volume envelope are displaced, but the pitch envelope may be displaced.

Further, since the displacement data corresponding to the keyboard follow can be easily changed by a switch operation or the like, the characteristic of the keyboard follow can be set programmable.

〔The invention's effect〕

As described above, the present invention changes the inputted pitch information into two types of pitch information having different contents, and based on the changed pitch information, the level data and the rate data showing the envelope waveform are selected. , Level data is decreasing,
Since the rate data is configured to be displaced in the increasing direction, it is possible to displace the level data and the rate data of the envelope in which the pitch information is reflected in different modes, and to add keyboard follow of various different characteristics. This makes it possible to obtain good sound quality without being influenced by external conditions and to simplify the circuit configuration because the control processing is performed with digital data.

[Brief description of drawings]

FIGS. 1 to 14 show a first embodiment of the present invention, and FIGS. 15 to 18 show a second embodiment. FIG. 1 is an overall circuit diagram of an electronic musical instrument, and FIG. 2 is a key. Switch configuration diagram of the input unit 8,
FIG. 3 is a memory block diagram of the tone color RAM 4, FIG. 4 is a waveform diagram of a basic waveform, FIG. 5 is a data configuration diagram of waveform data of the basic waveform, FIG. 6 is an envelope waveform diagram, and FIG. 7 is its data configuration. FIG. 8 is a diagram showing a specific example of the envelope waveform,
FIG. 9 is a data content diagram thereof, FIG. 10 is a concrete circuit diagram of the musical tone creating section 11, FIG. 11 is a circuit diagram of an envelope circuit, and FIG.
FIG. 13 is a specific circuit diagram of the arithmetic unit 29. FIG. 13 is a diagram showing a relationship between key codes and displacement data. FIG. 14 is a diagram showing a state in which each envelope waveform is displaced. FIG. 15 is a second embodiment. FIG. 16 is a diagram showing the relationship between the sensitivity switch for the harmonic component suppression envelope and the sensitivity data, and FIG. 17 is the sensitivity switch for the volume envelope and the sensitivity data. 18 is another diagram showing the relationship of FIG. 18 and FIG. 18 is a diagram showing a process for multiplying displacement data based on sensitivity data. 1 ... CPU, 2 ... ROM, 3 ... RAM, 4 ... tone RAM, 6
...... Keyboard, 8 ... Switch input section, 10 ... Register section,
11 …… Music tone creating section, 13 …… Sound color register section, 14 …… Amplifier, 15 …… Speaker, 29 …… Computing section, 60 …… Conversion section, 61
…… Subtractor, 62 …… Adder.

Claims (1)

[Claims] Claims: 1. Envelope storage means for storing level data indicating a level at each polygonal line of a polygonal envelope waveform and rate data indicating an inclination of each polygonal line, and reading for reading the level data and the rate data from the envelope storage means. Means, a pitch information receiving means for receiving pitch information, a first changing means for changing the value of the pitch information received by the pitch information receiving means, and a pitch information receiving means for receiving the pitch information. Second changing means for changing the value of the pitch information, and reducing the level data read by the reading means based on the content of the pitch information from the first changing means and the second changing Calculating means for increasing the rate data read by the reading means based on the content of the pitch information from the means; Envelope drawing apparatus characterized by having, envelope waveform generating means for generating an envelope waveform by reading the computed level data and rate data by computing means.