JPH0782320B2 - Music control device - Google Patents

Description

Description: TECHNICAL FIELD OF THE INVENTION The present invention relates to a musical tone control device used for an electronic musical instrument including an electronic guitar, and more particularly to a musical tone control device capable of immediately muting even when an input waveform signal is rapidly attenuated. .

BACKGROUND OF THE INVENTION Conventionally, a pitch (fundamental frequency) is extracted from a waveform signal generated by a performance operation of a natural musical instrument, and a sound source device composed of an electronic circuit is controlled to artificially obtain a sound such as a musical sound. A variety of such methods have been developed.

In this type of electronic musical instrument, the input waveform signal is attenuated, and in order to mute in accordance with this, the peak value of the maximum peak point or the minimum peak point for each cycle of the waveform level is detected, and this peak value is detected. If is less than or equal to the predetermined level value, the muffling process is performed.

8 and 9 show examples of the maximum peak detection circuit 4 and the minimum peak detection circuit 5, respectively, for detecting the maximum peak point and the minimum peak point. The input waveform signal is input to the + terminal of the operational amplifier 4-1, and the operational amplifier 4-
The output terminal of 1 is connected to the anode side of the diode D1, and the cathode side of the diode D1 is grounded via the capacitor C and the resistor R1 connected in parallel, and is also connected to the-terminal of the operational amplifier 4-1. The output of the operational amplifier 4-1 is output via the resistor R2 and the inverter 4-2.

If a waveform as shown in FIG. 10 is given to the + terminal of the operational amplifier 4-1, the capacitor C is charged when the waveform level rises and discharged when the waveform level falls, and the waveform as shown in FIG. Is input to the-terminal of the operational amplifier 4-1 and the difference value between the + terminal and the-terminal is output only when the waveform level rises, which is inverted by the inverter 4-2 and output as the signal shown in FIG.

Further, the minimum peak detection circuit 5 is obtained by adding a circuit including an operational amplifier 5-3 and resistors R3 and R4 to the maximum peak detection circuit 4, and the operational amplifier 5-3 is connected to the + terminal of the operational amplifier 5-1. Connected, input signal in is operational amplifier 5
It is given to the-terminal of -3 via resistor R4, and this-
The output is fed back to the terminal via the resistor R3. The operational amplifier 4-1 and the inverter 4-2 are the ninth
In the figure, reference numerals 5-1 and 5-2 are used.

Assuming that a waveform as shown in FIG. 10 is given to the-terminal of the operational amplifier 5-3, the capacitor C repeats the simultaneous charging and discharging with the signal of FIG. It is inverted and output as a signal as shown in FIG.

Capacitor C and resistance of such peak detection circuits 4 and 5
The time constant with R1 is very large, and the falling edge of the signal is gentle. This is to detect only the maximum or minimum peak points when there are many peak points in one cycle including many overtones as shown in FIG.

However, as shown in Fig. 11, when the input waveform is abruptly attenuated due to the mute playing method, etc., the waveform level value of the peak point is less than the predetermined level value (OFFLEV value in the figure) in the conventional one. In that case, since the muffling is performed, it is difficult to find the peak point, and there is a problem that the muffling process is extremely delayed.

[Object of the Invention] The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a mute rendition or the like that causes a sharp attenuation such that the peak point of an input waveform signal cannot be detected. It is an object of the present invention to provide an input control device for an electronic musical instrument, which can detect this attenuation quickly and surely and can immediately perform a muffling process.

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention provides a musical tone generation instruction means for instructing the generation of a musical tone when the state of an input waveform signal satisfies a predetermined condition, and a peak level of the input waveform signal. On the basis of the peak point detecting means for detecting the peak point of the input waveform signal by comparing the level of the input waveform signal with the reference level obtained corresponding to, and the peak point detected by the peak point detecting means. The tone characteristic control means for controlling the characteristic of the musical tone being generated and the level of the input waveform signal at the peak point detected by the peak point detection means are supplied to the tone characteristic control means, and then the peak point detection means A ratio for comparing a level of the input waveform signal with a predetermined value different from the reference level compared by the peak point detecting means until a new peak point is detected. Based on the comparison result of the comparison means and the comparison means, when it is determined that the state in which the predetermined value and the level of the input waveform signal have a predetermined relationship continues for a certain period of time, the sound of the musical tone being generated is muted. The main point is to have a musical tone muting instruction means for giving an instruction.

[Embodiment] An embodiment in which the present invention is applied to an electronic guitar will be described in detail below with reference to the drawings.

In the following examples, the maximum peak detector 4, the minimum peak detection circuit 5, the zero-cross point detection circuit 6, a flip-flop 15, the counter 7 is frequency measuring means as described below, steps S ₁₇ to S _21, CPU1 to run the S ₂₅ ~S ₂₉
00 is the sound output instruction means, CPU 100 that executes steps S ₃₁ , S ₃₂ , and S ₃₄ is the level determination means, CPU 100 that executes steps S ₃₃ and S ₃₅ is the continuation determination means, and steps S ₃₆ and S ₃₇ are executed. The CPU 100 corresponds to the mute instruction means.

Overall Circuit Configuration FIG. 1 shows the overall circuit configuration of the same embodiment. The signals of the six input terminals 1 are the strings of the six strings stretched on the electronic guitar body. It is a signal from a pickup that converts vibration into an electric signal.

The tone signal from the input terminal 1 ...
P6 (In the figure, the internal structure is shown only for P1 of the first string.) It is amplified by each internal amplifier 2 ……, the high-frequency component is cut by the low pass filter (LPF) 3 ……, and the basic waveform is Maximum peak detection circuit (MAX) 4 extracted
.., to the minimum peak detection circuit (MIN) 5 ... and the zero-cross point detection circuit (Zero) 6. The maximum peak detection circuit 4 and the minimum peak detection circuit 5 have the configurations shown in FIGS. 8 and 9 described as the prior art.
In the low-pass filter 3, ..., The cutoff frequency is set to 4f, which is four times the vibration sound frequency f of the open string of each string.
This is because the frequency of the output sound of each string is within 2 octaves. Maximum peak detection circuit 4 ...
Then, the maximum peak point of the musical tone signal is detected, and the Q output of the flip-flop 14 ... Connected to the latter stage at the rising edge of the detection pulse signal becomes High level, and the output of this flip-flop 14 ... The AND output of the inverter 6 of the circuit 6 and the inverted output of the inverter 6 are given to the CPU 100 as interrupt command signals INT _{a1 to} INT _a6 via the AND gate 24, and similarly, the minimum peak detection circuit 5 ...
However, the minimum peak point of the musical tone signal is detected, and the Q output of the flip-flop 15 ... Connected to the subsequent stage becomes High level at the rise of the detection pulse signal, and the output of this flip-flop 15 ... The AND output of the circuit 6 ... Is given to the CPU 100 as the interrupt command signals INT _{b1 to} INT _b6 via the AND gate 25.

That is, the maximum peak point is detected and the flip-flop 14 is
At high level, when the waveform crosses from positive to negative, the interrupt command signals INT _{a1 to} INT _a6 are given to the CPU100, and conversely the minimum peak point is detected and flip-flop
Interrupt command signals INT _{b1 to} INT _b6 are input to the CPU 100 when the waveform changes from negative to positive while 15 is at the high level.

Immediately after receiving these interrupt command signals, the CPU 100 resets the corresponding flip-flops 14 ..., 15 ... by generating clear signals CL _{a1 to} CL _a6 and CL _{b1 to} CL _b6 . Therefore, the corresponding flip-flops 14 ..., 15 ... are in the reset state no matter how many times the zero crossing points are passed until the next maximum peak point or minimum peak point is detected, so that the CPU 100 is not interrupted. Become.

Then, the CPU 100, and an interrupt command signal INT _a1 to INT _a6 or INT _b1 to INT _b6 given by the vibration output of the strings, to generate a chromatic note in accordance with at least one of the time intervals of the respective time interval. It should be noted that at the start of sounding, it is possible to start generating a scale note of the starting string and correct the frequency after pitch extraction. The operation at the start of sound generation will be described later.

Then, the above-mentioned time interval is set by the counter 7 as described later.
And the work memory 101. That is, the work memory 101 stores various data such as the count value of the counter 7 at the zero cross point immediately after the maximum peak point or the minimum peak point.

After the start of sound generation, the frequency of the musical tone being generated is variably controlled according to the time interval data that is sequentially obtained. I.e.
The CPU100 sends the data designating the scale to the frequency ROM8, and as a result, the frequency data showing the corresponding frequency is read out and sent to the tone generator circuit 9 to generate a musical tone signal, which is emitted from the sound system 10. .

The tone signal from the low pass filter 3 ...
It is given to the A / D converter 11 ... and converted into digital data according to its waveform level.

And the output of this A / D converter 11 ... is the latch 12 ...
Latched by ... The latch signal for this latch 12 ... is the signal of which the output of the flip-flop 14 ... or the output of the flip-flop 15 ... Is given through the OR gates 16 ..., 17 ..., or the AND gate 26. The clock signal CL given through the OR gate 17 ... Is used to store data indicating the maximum and minimum peak values of the waveform or the level of the input waveform signal at each time. The AND gate 26 ... Is opened by the latch instruction signals L1 to L6 from the CPU 100, and the latch instruction signal L1
~ L6 is the interrupt command signal IN when the above zero cross point is passed
T _{a1 to} INT _a6 are given, and as will be described later, after the peak value stored in the latch 12 ... Is taken in, the level becomes High, and when the maximum peak point or the minimum peak point is passed, the flip-flops 14 ..., 15 ... The signals at the peak times P _{1 to} P ₆ from the OR gate 16 are supplied to the low level. Therefore, Andgate 24 ..., Andgate 25 ...
Interrupt command signals INT _{a1 to} INT _a6 , INT _{b1 to} INT via
_{In the} period when _b6 is given, in the case of a waveform input such as a sine wave, the peak value at each time is latched from the first half of the peaks and valleys of the waveform, that is, the zero cross point to the maximum peak point or the minimum peak point, and the maximum peak value is latched. From the point or the minimum peak point to the next zero cross point, the peak value of the waveform is held.

Then, the output of the latch 12 ... Is given to the CPU 100, and sound generation start, sound generation stop, pitch extraction start, pitch extraction stop, and control of the output sound emission level (volume) are performed according to this data. The peak value, which is the peak value stored in the latch 12 ... Before the output of the latch instruction signals L1 to L6 is stopped, is sequentially written in the work memory 101.

That is, in the CPU 100, when the absolute value of the data indicating the waveform level given by the A / D converter 11 ... becomes equal to or higher than a predetermined constant value, the tone generation is started and the pitch (fundamental frequency) is extracted. When the data becomes equal to or lower than the muffling level value OFFLEV shown in FIG. 7, the volume level is rapidly attenuated and the sound emission is ended. The details of the operation are as described later.

In FIG. 1, the A / D converter 11 is independently provided in each of the pitch extraction circuits P1 to P6, but it is of course possible to use one A / D converter in a time division manner.

The frequency ROM 8 and the tone generator circuit 9 form a tone generation system of at least 6 channels by time division processing.

2 shows a time chart of the signal waveform of each part in the pitch extraction circuit P1, where the output of the low pass filter 3 is the output of the maximum peak detection circuit 4,
Is the output of the minimum peak detection circuit 5, is the output of the zero-cross point detection circuit 6, is the interrupt command signal INT _{a1 to} INT _a6 ,
Are interrupt command signals INT _{b1 to} INT _b6 , and are latch instruction signals L1 to L6.

Operation Next, the operation of this embodiment will be described. Figure 3 shows CPU 100
FIG. 4 is a main flow of the interrupt routine of FIG. Although FIG. 3 and FIG. 4 only show the processing for one string, the processing for all strings is exactly the same, so if the CPU 100 executes the processing for each string in a time-division manner. good.

Registers in Work Memory 101 Now, before describing specific operations of the CPU 100, main registers in the work memory 101 will be described.

The STEP register takes four stages of 0, 1, 2, and 3, and as string vibration is made (see FIG. 5 (a) or FIG. 6 (a)), FIG. 5 (b) or FIG. The contents change as shown in (b). When this STEP register is 0, it indicates a note-off (silence) state.

The SIGN register indicates whether the zero-cross point for period measurement is the next zero-cross point after the maximum peak (MAX) point or the minimum peak (MIN) point.
When it is 1, it is the former, and when it is 2, it is the latter.

The REVERSE register is a register that stores data that checks whether or not interrupt processing has been performed due to the arrival of the zero-cross point after the peak point on the side opposite to the zero-cross point represented by the SIGN register has elapsed. Used to check pitch (fundamental frequency) extraction control.

The T register stores the value of the counter 7 at a specific point for measuring the cycle of the input waveform. The counter 7 is performing a free running operation of counting with a predetermined clock.

The AMP (i) register stores the maximum or minimum peak value (actually an absolute value) latched in the latch 12 from the A / D converter 11, and AMP (1) is for the maximum peak.
MP (2) is the minimum peak register.

Data representing the measured period is input to the PERIOD register, and the CPU100 determines the frequency based on the contents of this register.
Frequency control is performed on the ROM 8 and the tone generator circuit 9.

The OF register is a register that becomes "1" when the level data of the input waveform latched by the latch 12 becomes equal to or lower than the mute level value OFFLEV shown in FIG. 7, and becomes "0" when it is equal to or higher than the OFFLEV being sounded. is there.

The OFT register is a register in which the count value of the counter 7 is set when "1" is set in the OF register. Based on this count value, the time when the value of the OF register is "1" is set. When the required time, for example, the time of the open string cycle of the string, specifically, the sixth string, for 12 milliseconds or more, the mute (note-off) process is executed.

Furthermore, as will be described later, the present embodiment is not limited to 3 for various judgments.
Two constants (threshold levels) are set in CPU100.

The first one is ONLEV I, which is shown in FIG.
As shown in Figure (a), note-off is now in progress,
When a peak value larger than the value of ONLEV I is detected, the string is picked and the CPU 100 starts the operation for period measurement.

ONLEV II is in the note-on state (while sounding), and if the difference between the previous detection level and the current detection level is more than this value, it is determined that there is an operation by the tremolo playing method, etc. , Relative on) processing.

As shown in FIG. 7 (a), OFFLEV is in a note-on state (while sounding), and a waveform level value below this value is detected for a predetermined time (for example, one cycle time of open string pitch). And note-off (silence) processing.

From the above description, it will be easy to understand the operation of the interrupt routine and the main routine described below.

Interrupt processing Well at the zero-crossing point, the interrupt command signal INT _a, which is the output of the AND gate 24 or AND gate 25, the advent of the CPU100 of INT _b, performs interrupt processing of FIG. 3.

That is, the interrupt command signal to the INT _a at the input, first the process in step P _1, the a register in the CPU100 to 1, an interrupt command signal INT _b On input, first the process in step P ₂ in the a register 2 Set.

And then at step P _3, the t registers in CPU 100, presets the value of the counter 7. Then read the level data in step P ₄ in the input waveform to run from the latch 12 is set to b register in the CPU 100.

In this case, the interrupt command signals INT _{a1 to} INT _a6 , INT _{b1 to} INT
_b6 is given when the zero-cross point arrives immediately after passing through the maximum peak point and the minimum peak point, and until this zero-cross point is passed, the latch 12 has the peak of the immediately preceding maximum peak point or the minimum peak point. Since the level data is held, the peak level data of the input waveform is set in the b register.

Then, in step P ₅ , the flip-flop 14 or the flip-flop 15 is cleared.

In the following step P ₆ , the contents of the a, b, and t registers are transferred and stored in the work memory 101, and the interrupt processing is ended.

Thus, every time the zero cross point is passed, data (a register) indicating whether the zero cross point is after the maximum peak point has passed or after the minimum peak point has passed, the maximum peak point or the minimum peak point, Peak level data (b register), count data (t) of the counter 7 at this zero-cross point for measuring the period (pitch) of the input waveform.
Register) is set.

Main Processing In the main routine (FIG. 4), in step S ₁ , the contents of a ′, b ′, t ′ (same as a, b, t above) are recorded in the work memory 101 by the interrupt processing as described above. by a in that a ', b', denoted t '.) is judge whether or not written, when not been made any interrupt processing by the determination of nO, a step S ₃₀ to be described later - This step S ₁ is performed via the silencing processing flow of S _38.
Is repeatedly executed.

Then, if YES is determined in the above step S ₁ , the process proceeds to the next step S ₂ to read the contents a ′, b ′, t ′.
In step S _3, the AMP (a ') register are stored in, that the same type (maximum / minimum) reading the peak value of the peak point to the c register in CPU100 of this extracted peak value b' Is set in the AMP (a ') register.

Now, next step S ₄ to S _6, the contents of the STEP register is judge whether each 3,2,1. Now
If it is the first state, the STEP register is 0, so
NO is determined in steps S ₄ , S ₅ , and S ₆ . Then, in step S ₇ , the peak value b ′ detected this time is ONLEV I
Judge whether it is greater or not.

If the peak value b'is smaller than ONLEV I, the tone generation start process is not yet performed, and the process returns to step S ₁ . If an input larger than ONLEV I is obtained as shown in FIGS. 5 (a) and 6 (a), the determination in step S ₇ is YE.
S, and the process proceeds to step S _8.

Then, in step S ₈ , 1 is set in the STEP register, then 0 is set in the REVERSE register in step S ₉ , and then in step S ₁₀ , a ′ (that is, 1 at the zero cross point immediately after the maximum peak point, the minimum At the zero-cross point immediately after the peak point, enter the value in 2) into the SIGN register.

Then, in step S _11, it sets the value of t 'to the T register. As a result, the contents of a'are stored in the SIGN register (SIGN is now 1 (FIGS. 5 (a) and 6 (a))), the contents of b'are stored in the AMP register, and the contents of t '. Is T
It has been set in the register. Then return to step S ₁ again.

Now, with the above description, the processing of the main routine immediately after the zero-cross point Zero1 in FIGS. 5 (a) and 6 (a) is completed.

Now, the process in the main routine immediately after the zero-cross point Zero2 will be described. In that case, the above steps S ₁ → S ₂
→ S ₃ → S ₄ → S ₅ → S ₆ Data set processing and pronunciation step discrimination processing is executed, and YES is determined in this step S ₆ ,
Then go to step S ₁₂ .

When the waveform changes in the positive direction at the time of input as shown in FIGS. 5 (a) and 6 (a), the SIGN register is 1, and since the peak in the negative direction has passed this time, a ' Since the register is 2, judge NO. Incidentally, if the time arrives zero-cross point immediately after the peak value of the same polarity, step without operation continues any by the determination of YES in step S ₁₂
Return to S ₁ .

Well, now snow to step S ₁₃ is the judge of step S ₁₂ in NO, the STEP register and 2. (Fifth
See FIG. 6B and FIG. 6B.

And performs step S ₁₄ following the step S _13, the previous peak value (AMP (SIGN)) between the current peak value (b ')
To compare. Now, as shown in FIG. 5A, if the previous value x ₀ is smaller than the current value (x ₁ > x ₀ ), the determination result is YES, and the current time t ′ should be set as the measurement start point of the cycle ( executing step S _10, S ₁₁ from FIG. 5 (c) refer) step S _14, SIGN
The register is set to 2, and the contents of the t'register are transferred to the T register.

On the contrary, if the previous peak value is larger than the current peak value, that is, if x ₁ <x ₀ as shown in FIG. 6A, NO judgment is made in step S ₁₄ and REVERSE is executed in step S ₁₅ . Set the register to 1. The SIGN register will retain the previous value of 1. Therefore, in this case, the previous zero-cross point (Zero1) is the start point of the period measurement (see FIG. 6 (c)).

Then, after passing through the next zero cross point (Zero3), the first time to perform a main flow proceeds is the YES judge at step S ₅ to step S _16. This time, a'is 1, and SIGN is 2 in the case of FIG. 5 and SIGN in the case of FIG.
Since 1 is 1, in the case of FIG. 5, N in step S ₁₆
After being judged by O, he goes to step S ₁₅ and returns to step S ₁ . That is, the CPU 100 recognizes that the first peak (amplitude x ₂ ) has passed since the start of period measurement.

Further In the case of FIG. 6 is a determination of YES in step S _16, snow REVERSE register is judge whether 1 to step S _17. If it is not 1, NO is determined and the process returns to step S ₁ , but as described above, this register is set to 1 by executing step S ₁₅ , and step S ₁₇
And 3 snow STEP register to step S ₁₈ from (FIG. 6 (b) refer), followed by step S _19, the value from the value of the counter 7 which is accepted by the current interrupt in the t 'register to the T register That is, the time at the zero-cross point Zero1 is subtracted and stored in the PERIOD register.

That becomes a length of one cycle size shown in FIG. 6 (c), to transfer the contents of t 'in the T register at the next step S ₂₀ to the beginning of a new period measurement.

In step S _21, with the contents of the above PERIOD register CPU100 frequency ROM 8, issues a sound command to the tone generator 9. Therefore, a musical sound is generated from this point.

Now, in the case of FIG. 5 described above, again in the processing of the main flow after the next zero cross point (ZERO4), it jumps from step S ₅ to step S _16. Now, SIGN register is 2, a determination of YES in step S _16, continues in the same manner as described above executes the sounding start processing in step _{S 17 → S 18 → S 19} → S 20 → S 21 and, this time the fifth The CPU 100 recognizes the zero-cross points Zero2 to Zero4 shown in FIG. 7C as one cycle, and starts to produce a musical sound of a frequency based on this length (see FIG. 5D).

In this way, the process of periodic measurement is started from the zero cross point next to the peak point with a large value, and the measurement is finished at the zero cross point next to the peak point on the same side as that peak point. One cycle of a 3-output waveform is extracted.

After the start of sounding process, the main routine proceeds from step S ₄ to step S _23, so as to whether judges whether the processing of the relative-on (relative on). That is, specifically, this peak value (b ')
Is judged to be ONLEV II larger than the previous peak value (c), that is, whether or not the extracted peak value suddenly increased during sound generation.

If vibration normal strings, since the natural attenuation, this step S ₂₃ is the determination NO, the the like if tremolo, while the previous string vibrations Finished attenuated, are operated string again, determination of step S ₂₃ is sometimes is YES.

In that case, step S ₂₃ is the step to a judge's YES
Jump to S _8, to perform the preparation process of the sound the start of the step S ₉ ~ step S _11. As a result, the STEP register becomes 1, and the operation exactly the same as the operation at the start of sounding is executed thereafter. That is, to the process of re-start of sounding and thereafter executes the sounding start processing in step S ₁₆ to S ₂₁ again.

Now, in the normal state by performing the steps S ₂₄ following the step S ₂₃ as described above, the coincidence comparison of the contents of content and SIGN register a ', the matched unless the process proceeds to S ₁₅ following the zero-crossing point interrupt provided to the process, if they match, so has the peak already have opposite characteristics (positive / negative peaks) in each pass, the process proceeds to step S _25, the rEVERSE register 1
Whether to judge, if it returns to step S ₁ without the NO if any processing, if the is a determination of YES in step S ₂₅ is made, a new cycle proceeds from step S ₂₅ to step S ₂₆ In order to obtain (pitch), the contents of the T register are subtracted from the contents of the t'register and set in the PERIOD register.

Then, the contents of t 'register in step S ₂₇ T
PERIO obtained in step S ₂₈ after being transferred to the register
The CPU 100 controls the frequency (pitch) for the frequency ROM 8 and the tone generator circuit 9 based on the value of the D register.

That is, in the present embodiment, the change in the vibration frequency of the string is grasped momentarily, and the frequency control corresponding to it is performed in real time.

Then, proceed from step S ₂₈ to step S ₂₉ to REVERSE
The next cycle is measured with the contents of the register set to 0.

Then, as shown in FIG. 7 (a), the string vibration is rapidly attenuated by the mute playing method, and the peak value becomes OFFL.
When it becomes to fall below the EV, in step S ₃₀ After determining that the value of the current STEP register is "3",
As shown in FIG. 7C, the waveform level value latched by the latch 12 from the A / D converter 11 is the silence level value OFFL.
When it becomes equal to or less than EV (step S ₃₁ ), “1” is set to the OF register which was “0” until then, the count value of the counter 7 is set to the OFT register, and the process proceeds to step S ₁ . Back (step S ₃₂ ~S _34).

Since the peak value also falls below OFFLEV, the waveform level value latched by the latch 12 from the A / D converter 11 does not exceed OFFLEV even when the input waveform reaches a peak, so steps S ₃₀ , S ₃₁ From step S38 to step _S38 , the state where the OF register becomes "1" is maintained.
If the OFF string does not exceed OFFLEV, the length of one wavelength of the open string pitch of the relevant string, for example, in the case of the sixth string as described above, if it continues for 12 milliseconds or longer, the CPU 100 will display as shown in FIG. 7 (d). in step S _35, to determine this from the difference between the current count value of the count value and the counter 7 which has been set in the OFT register, clears the sTEP register and oF register in step S _36, in step S ₃₇ The CPU 100 instructs the tone generator circuit 9 to perform the note-off process (silence process) and to mute the musical sound that has been generated so far.

In this way, by detecting that the waveform level becomes CFFLEV or less for, for example, 12 milliseconds, it is possible to perform the muffling process quickly and reliably even if there is a rapid attenuation of the waveform level.

If the attenuation is temporary and the peak value exceeds OFFLEV again, the CPU 100 determines this in step S ₃₁ , clears the OF register in step S ₃₈ , and does not perform the muffling process. Accordingly, if rapid peak value is attenuated interrupt signal INT _a like Fig. 11, even INT _b is not generated, the latch 12 is given a clock signal CL at all times, that is the second
Since the latch instruction signal L shown in the figure maintains the high level, the output of the A / D converter 11 is given through to the CPU 100 through the latch 12 and processed according to the given peak value, so that the mute response is generated. Sexuality improves.

In the above embodiment, the waveform level is 12 for the sixth string.
Although the sound is muted if it is OFFLEV or less for a millisecond, it may be muted for a time other than 12 milliseconds, that is, a pitch period generated by the electronic guitar or a time longer than that. , The CPU100 interrupts at the zero-cross point immediately after each peak point to start sound generation, cycle calculation, relative on, mute start, etc., but these processes are performed directly when each peak point is detected. May be. In that case, the exact same result can be obtained. In addition, the same processing as above may be performed, for example, by detecting the zero-cross point immediately before the peak point. In addition, the way of taking the reference points can be variously changed.

Further, in the above embodiment, each process is executed in the main flow, but the same process may be executed in the interrupt process.

Furthermore, in the above embodiment, the present invention was applied to an electronic guitar, but the present invention is not necessarily limited thereto, and pitch extraction is performed from a voice signal or an electric vibration signal input from a microphone or the like, Any form may be used as long as it is a system that generates an acoustic signal different from the original voice signal at a corresponding pitch or scale frequency. Specifically, it can be similarly applied to those having a keyboard, such as an electronic piano, an electronic wind instrument, and an electronic string instrument such as a violin or a koto.

[Effects of the Invention] As described in detail above, according to the present invention, the peak point detecting means compares the reference level obtained corresponding to the peak level of the input waveform signal with the level of the input waveform signal. The peak point of the input waveform signal is detected and the comparison means
The level of the input waveform signal at the peak point detected by the peak point detecting means is supplied to the musical tone characteristic control means for controlling the characteristic of the musical tone being generated based on the peak point, and then a new peak is detected by the peak point detecting means. Until a point is detected, a predetermined value different from the reference level compared by the peak point detection means is compared with the level of the input waveform signal, and the tone muting instruction means determines the predetermined value based on the comparison result. When it is determined that the state in which the input waveform signal and the level of the input waveform signal have a predetermined relationship continues for a certain period of time, it is instructed to mute the sound that is being generated, so that the level value of the conventional peak point falls below the predetermined value. Unlike the one that detects that the sound has turned off and silences, even if there is a sudden attenuation that cannot detect the peak point of the input waveform signal due to the mute playing method, etc., this attenuation is detected quickly and reliably. Te, immediately mute processing can be performed, in addition to it is possible to perform the musically excellent performance, able to enter faster pronunciation processing of the next new musical tone,
An effect such as smoother playing can be achieved.

[Brief description of drawings]

FIG. 1 is a diagram showing an overall circuit configuration of an input control device for an electronic musical instrument showing an embodiment of the present invention, FIG. 2 is a time chart diagram showing waveforms appearing in respective parts in FIG. 1, and FIG. The figure shows CP
The figure which shows the flowchart of the interruption routine of U, the 4th
The figure shows the flowchart of the main routine of the CPU.
5 and 6 are time charts showing the operation of each part at the start of sounding, FIG. 7 is a time chart showing the operation at the start of muffling, and FIGS. 8 to 11 are conventional arts. FIG. 8 and FIG. 9 are circuit diagrams of the maximum peak detection circuit 4 and the minimum peak detection circuit 5, and FIGS. 10 and 11 are views of respective parts in FIG. 8 and FIG. It is a figure which shows an operating waveform. 1 ... Input terminal, 4 ... Maximum peak detection circuit, 5 ... Minimum peak detection circuit, 6 ... Zero-cross point detection circuit, 7 ...
… Counter, 9 …… Sound source circuit, 12 …… Latch, 14,15…
… Flip-flops, 100 ……… CPU, 101… Work memory, P1 to P6… Pitch extraction circuit.

Claims (2)

[Claims] 1. A tone generation instruction means for instructing the tone generation when a state of an input waveform signal satisfies a predetermined condition, a reference level obtained corresponding to a peak level of the input waveform signal, and the input waveform. Peak point detecting means for detecting a peak point of the input waveform signal by comparing with a signal level, and tone characteristic control for controlling the characteristic of a musical tone being generated based on the peak point detected by the peak point detecting means Means and the level of the input waveform signal at the peak point detected by the peak point detecting means is supplied to the tone characteristic control means until the new peak point is detected by the peak point detecting means. A comparison means for comparing a level of the input waveform signal with a predetermined value different from the reference level compared by the peak point detection means, and based on a comparison result of the comparison means. When the predetermined value and the level of the input waveform signal are in a predetermined relationship for a certain period of time and it is determined that the state of the input waveform signal has continued for a certain period of time, the tone canceling means for instructing the mute of the tone being generated is provided. Tone control device. 2. The tone characteristic control means detects a fundamental cycle of the input waveform signal based on a time interval at which the peak point detection means detects at least one of the maximum peak point and the minimum peak point. The musical tone control apparatus according to claim 1, wherein the musical tone control device controls the pitch of the musical tone based on the fundamental period of the input waveform signal detected by the period detecting means.