JP2661481B2 - Electronic musical instrument - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a synthesizer type electronic musical instrument such as an electronic stringed musical instrument such as an electronic guitar, and more particularly to an electronic musical instrument capable of extracting pitch information from an input waveform signal and generating a musical tone at a pitch corresponding thereto. About musical instruments.

[0002]

2. Description of the Related Art A string or the like of a string is detected as an electric signal by playing a guitar or the like, and a tone generating circuit composed of a digital circuit or the like is controlled in accordance with an input waveform signal to synthesize and emit a tone. Electronic musical instruments designed to cause the electronic musical instrument have been developed.

In particular, a type in which a pitch extraction circuit extracts a pitch period from an input waveform signal and a tone generation circuit generates a tone having a pitch corresponding to the pitch period, the pitch of the tone is included in the input waveform signal. Because of direct response, it is possible to perform tone synthesis that is faithful to the performance of the player.

In such a conventional electronic musical instrument of the pitch extraction type, pitch information is generated in direct proportion to a frequency corresponding to a pitch cycle extracted from a pitch extraction circuit, and a musical tone is generated according to the pitch information. .

[0005]

However, for example, in an acoustic guitar or the like, when a string vibration waveform when a string is picked is picked up by a pickup or the like and a pitch period is extracted from the waveform signal, when the picking starts, that is, when the string vibration is picked up. At the start (when the input waveform signal rises), there is a tendency that a pitch cycle shorter than the cycle corresponding to the pitch when the fret of the actual guitar is pressed is extracted. That is, the frequency corresponding to the extracted pitch cycle becomes higher than the actual pitch.
This is due to, for example, the non-linearity of the string vibration.
Note that after the start, it matches the actual pitch.

Therefore, if pitch information directly proportional to the frequency corresponding to the extracted pitch period is generated, a pitch higher than the actual pitch is specified at the time of the rising edge of the input waveform signal. There is a problem that an electronic musical instrument whose pitch is designated by a tone starts to produce a musical tone at an incorrect pitch.

The above problem is not limited to electronic stringed musical instruments, but can generally occur in electronic musical instruments that can generate a non-linear input waveform signal when rising. An object of the present invention is to make it possible to specify a pitch that accurately corresponds to an actual pitch even when an input waveform signal rises.

[0008]

SUMMARY OF THE INVENTION The present invention relates to an electronic stringed musical instrument of the type in which, for example, a metal string vibration is detected as an input waveform signal by a pickup, pitch information is extracted therefrom, and the pitch of a musical tone is controlled based on the pitch information. An electronic musical instrument realized as an electronic guitar).

[0009] First, there is provided a pitch extracting means for extracting pitch information from the input waveform signal. The means digitizes, for example, an input waveform signal obtained in advance, sequentially detects a valid peak value and a zero-cross time immediately after the digital signal from the digital waveform, and sets a set of the valid peak value and the zero-cross time immediately after or immediately before the valid peak value. Is a means for extracting pitch information, that is, a pitch cycle, as an interval between each zero crossing time. Alternatively, it is means for extracting a pitch cycle as an interval between each peak value.

Next, the pitch information correcting means is means for correcting the pitch information at the time of rising of the input waveform extracted by the pitch extracting means. This means corrects, for example, only a pitch cycle first detected by the pitch extracting means by several percent in a state where no input waveform is detected.

The tone generator generates a tone at a pitch corresponding to the pitch information corrected by the pitch information corrector when the input waveform rises, and the pitch extractor after the rise. This is a means for generating a musical tone at a pitch corresponding to the extracted pitch information.

[0012]

The operation of the present invention is as follows. For example, in an electronic stringed musical instrument such as a guitar synthesizer, when a player picks a string, the pitch extracting means extracts a pitch period (pitch information) from a string vibration waveform (input waveform signal) detected by a pickup or the like. In this case, only at the start of picking (when the input waveform signal rises), the pitch period is extracted, for example, a few percent shorter. That is, when viewed in terms of frequency, a frequency higher than the actual pitch is extracted.

Then, the pitch period is corrected by the pitch information correcting means so as to become the original pitch period. Accordingly, the tone generating means generates a tone at a pitch corresponding to the corrected pitch cycle at the time of rising of the input waveform signal, so that even at the time of rising of the input waveform signal, the musical tone generation means accurately matches the actual pitch. A corresponding pitch designation can be made. Note that after the rise, a musical tone may be generated at a pitch corresponding to the pitch cycle extracted by the pitch extracting means.

[0014]

Embodiments of the present invention will be described below in detail. In the following description, the symbols ｛｝, (
), The items are sequentially sorted in the order of the underlined headings surrounded by <<>. << Structure of Electronic Musical Instrument According to the Present Invention >> In this embodiment, six metal strings are stretched on the body, and a desired string is pressed while pressing a fret (fingerboard) provided below the metal strings with a finger. It is realized as an electronic guitar that performs by picking. The appearance is omitted.

FIG. 1 is an overall configuration diagram of the present embodiment.
First, the pitch extraction analog circuit 1 is provided for each of the six strings (not shown) and passes each output from a hexapickup for converting the vibration of each string into an electric signal through a low-pass filter (not shown). By removing the harmonic components, each of the six types of waveform signals Wi (i = 1
To 6). Further, each time the sign of the amplitude of each waveform signal Wi changes to positive or negative, a pulse-like zero-cross signal Zi (i = 1 to 6) which becomes high level or low level is generated. Then, these six types of waveform signals Wi and zero cross signals Zi are converted into a time-division serial zero-cross signal ZCR and a digital output (time-division waveform signal) D1 by an A / D converter (not shown) and output. I do.

As shown in FIG. 2, the pitch extraction digital circuit 2 comprises a peak detection circuit 201, a time constant conversion control circuit 2
02, a peak value capturing circuit 203 and a zero cross time capturing circuit 204. These circuits shown in FIG. 2 correspond to the serial zero-cross signal ZCR and the digital output D1 from the pitch extraction analog circuit 1 (FIG. 1) obtained by time-dividing six strings.
, Time-division processing is performed on six strings. In the following description, the processing for one string will be described for ease of description, and the serial zero cross signal ZCR and the digital output D1 will be described using an image of a signal for one string. It is assumed that division processing has been performed.

In FIG. 2, first, the peak detection circuit 20
1 detects a maximum peak point and a minimum peak point of the digital output D1 based on the serial zero cross signal ZCR and the digital output D1. For this purpose, the circuit 201 includes a peak hold circuit (not shown) for holding while subtracting (attenuating) the absolute value of the past peak value, although not particularly shown. After detecting the previous peak value, the peak detection circuit 201 sets the absolute value of the digital output D1 after the next serial zero-cross signal ZCR is generated using the peak hold signal output from the peak hold circuit as a threshold. When the threshold value is exceeded, the timing of the peak value is detected. The detection of the timing of the peak value is performed for each of the case where the digital output D1 has a positive sign and the case where the digital output D1 has a negative sign. Then, at the peak value detection timing, a maximum peak value detection signal MAX is output for a positive sign, and a minimum peak value detection signal MIN is output for a negative sign. Note that these signals are also, of course, actually time-division signals for six strings.

Next, the time constant conversion control circuit 202 is a circuit for changing the attenuation rate of the peak hold circuit in the peak detection circuit 201, and the maximum / minimum peak value detection signals MAX and MIN from the peak detection circuit 201. , And a control from a central control unit (MCP, the same applies hereinafter) 3 in FIG. This will be described later.

Subsequently, the peak value capturing circuit 20 shown in FIG.
3 demultiplexes (decomposes) the digital output D1 sent from the peak extraction analog circuit 1 in a time-sharing manner into a peak value for each string, and outputs a peak value detection signal from the peak detection circuit 201. The peak value is held according to MAX and MIN. Then, the MCP 3 (FIG. 1) sequentially outputs the maximum peak value or the minimum peak value of the string accessed via the address decoder 4 (FIG. 1) to the MCP 3 via the bus BUS. The peak value capturing circuit 203 can output not only the peak value but also the instantaneous value of vibration of each string.

The zero-cross time acquisition circuit 204 outputs the output of the time base counter 2041 common to each string according to the serial zero-cross signal ZCR from the pitch extraction analog circuit 1 (FIG. 1), and more specifically, the zero-cross time of each string, strictly speaking. , Is latched at the zero crossing point immediately after the passage timing of the maximum peak point and the minimum peak point determined by the maximum / minimum peak value detection signals MAX and MIN output from the peak detection circuit 201. When this latch operation is performed, the zero-crossing time acquisition circuit 204 subsequently outputs an interrupt signal INT to the MCP 3 in FIG. Thereby, MCP3
In accordance with a control signal (described later) output from the address decoder 4 (FIG. 1), the string number at which the zero-cross has occurred, the zero-cross time corresponding to the latched string, and positive / negative information (described later) are transmitted to the bus BUS. Via MCP3
Sequentially output to

The timing generator 20 shown in FIG.
5 outputs a timing signal for the processing operation of each circuit shown in FIGS. Next, returning to FIG.
The MCP 3 has a memory such as a ROM 301 and a RAM 30
2 and a timer 303. ROM3
Reference numeral 01 denotes a non-volatile memory that stores programs for controlling various musical sounds, which will be described later. RAM 302 is a rewritable memory used as a work area for various variables and data during the control. The timer 303 is used for a note-off (silence) process described later.

The tone generator 5 includes a tone generator 501 and D
An A / A converter 502, an amplifier 503, and a speaker 504 emit a tone corresponding to tone control information from the MCP 3. Note that an interface (Musical Instrument Digital Interface) is provided on the input side of the tone generation circuit 501.
MIDI is provided, and is connected to the MCP 3 via a dedicated bus MIDI-BUS for transmitting tone control information. When the tone generator 5 is provided in the guitar body, another internal interface may be used.

The address decoder 4 outputs an interrupt signal IN from the above-mentioned zero-cross time acquisition circuit 204 (FIG. 2).
After the occurrence of T, the zero-crossing time acquisition circuit 2 according to the address read signal AR generated from the MCP 3 (FIG. 1).
04, a string number reading signal outside 1 and a time reading signal outside 2 (i = 1 to 6) are supplied. Also,

[0024]

[Outside 1]

[0025]

[Outside 2]

As described above, the waveform read signal RDj (j = 1 to 18) is output to the peak value capturing circuit 203 (FIG. 2). Details of these operations will be described later. << Schematic Operation of the Present Embodiment >> The operation of the embodiment having the above configuration will be described below.

First, the general operation of this embodiment up to generation of a musical tone will be described. D1 in FIG. 10 is an analog representation of one string of the digital output D1 output from the pitch extraction analog circuit 1 in FIG. This waveform is obtained by picking one string out of six strings of a guitar (not shown) and outputting an electric signal detected from a corresponding pickup as a digital signal. according to the position pressed on the fingerboard) waveform is generated with the pitch period, as shown in FIG. 10T ₀ through T _5, and the like.

In this embodiment, the pitch periods T _{0 to} T ₅
And the like in real time, the MCP in FIG.
3 generates pitch information corresponding to the pitch information and causes the tone generation circuit 501 shown in FIG. Therefore, especially when the player changes the string tension during the performance by the tremolo arm (not shown), the pitch period of the digital output D1 changes accordingly, and the pitch information also changes in real time accordingly. , Rich expressions can be added to musical sounds.

Further, in this embodiment, the peak values a _{0 to} a ₃ or b _{0 to} b ₃ of the digital output D1 shown in FIG. 10 are detected. In particular, when the MCP ₃ shown in FIG. By generating volume information based on the maximum peak value a0 of ( ₁ ) and transferring it to the tone generation circuit 501, a tone having a volume corresponding to the strength of picking a string can be generated.

Next, in this embodiment, when the pitch period T ₀ in FIG. 10 is extracted, the sound generation is not started immediately, but the first several pitch periods are logically determined.
When a stable pitch period can now extract, it begins pronunciation in FIG 10t _3, for example. This is because, when picking a string, the digital output D1 tends to be disturbed at the start of the string, and a stable pitch period cannot be extracted. If a musical tone is produced at a pitch corresponding to the pitch period as it is, a musical tone having a strange pitch is produced. This is because Therefore,
The first pitch cycle at the start of musical tone generation is, for example, as shown in FIG.
A T _1.

Here, in a general raw guitar (acoustic guitar) or the like, a string vibration waveform when a string is picked is picked up by a pickup or the like, and a pitch cycle is extracted from the waveform signal. At the start of the waveform (when the input waveform signal rises), there is a tendency that a pitch cycle shorter than the cycle corresponding to the pitch when the fret of the actual guitar is pressed is extracted. That is, the frequency corresponding to the extracted pitch cycle becomes higher than the actual pitch. FIG.
In the example of 0, the pitch cycle T _{1 and the} like are extracted longer than the actual cycle.

[0032] Therefore, in this embodiment, only for the pitch period for example T ₁ of the at the start of sounding is corrected so that its value is several percent fraction shortening, tone of Figure 1 generates the tone pitch information by the correction value Output to the generation circuit 501. Each pitch period since at the start of sounding example FIG 10T ₂ ~
The T _5, etc., correction is output to the musical tone generating circuit 501 generates tone pitch information directly corresponding not. Thus, even when the frequency corresponding to the pitch cycle is detected to be higher at the start of sound generation, the tone generation can be started at the original pitch corrected by that amount. This is a major feature of the present embodiment.

The above operation is time-division-processed for the time-division digital output D1 for the six strings of the guitar, so that the musical sound generation circuit 501 can simultaneously generate six strings of musical sounds audibly. These musical tones can be set to any volume and tone freely, and various effects can be electronically added, so that an extremely large performance effect can be obtained. << Operation of Pitch Extraction Digital Circuit >> The operation of this embodiment for realizing the above operation will be described in detail below. (Schematic Operation) First, the operation of the pitch extraction digital circuit 2 of FIG. 1 or 2 will be described. In the following description, only one string is described, and the serial zero-cross signal ZCR, the digital output D1, and the maximum / minimum peak value detection signals MAX and MIN will be described as an image of one string. Time division processing has been performed for minutes.

In the same circuit 2, the digital signal shown in FIG.
From the output D1, the peak value a₀~ A _ThreeOr b₀~ B_Threeetc
And at the same time, the zero crossing time t immediately after each peak value
₁~ T₇And the like, and further,
Extracts information indicating 1 or 0 depending on whether the peak value is positive or negative.
To the MCP 3 in FIG. Based on this, MC
P3 is the pitch of FIG. 10 from the interval of the zero crossing time.
Period T₀~ T_FiveEtc.
Generates sound information and, if necessary, as described below,
Error processing, note-off (silence) processing, relative on
・ Perform off processing.(Detailed operation) Therefore, the peak detection circuit 201 shown in FIG.
Now, the digital output D1 input as shown in FIG.
First, in the part where the value is negative, its absolute value
Timing x exceeds 0₀Then, as shown in FIG.
The small peak value detection signal MIN becomes high level.

Thus, the peak value capturing circuit 203 shown in FIG.
At the timing x ₁ immediately after the minimum peak value detection signal MIN is at high level, in particular by detecting the minimum peak value (peak value of the negative side) b ₀ (absolute value) from the digital output D1 to enter separately Is held in a latch (not shown)
At the same time, the minimum peak value detection signal MIN is returned to the low level.

On the other hand, a serial zero-cross signal ZCR as shown in FIG. 10 is input from the pitch extraction analog circuit 1 of FIG. 1 to the zero-cross time acquisition circuit 204 of FIG. This signal is a signal which is output as a high-level or low-level binary digital signal from the comparator based on a comparator (not shown) in the pitch extraction analog circuit 1 which determines whether the digital output D1 is positive or negative.

[0037] Then, the zero-crossing time receiving circuits 204, immediately after the minimum peak value detection signal MIN output from the peak detection circuit 201 becomes a high level at a timing x _0, the edge timing of the serial zero-crossing signal ZCR is changed That is, at the time of the zero crossing of the digital output D1, the time base counter 2041 of FIG.
Is latched at time t ₀ (FIG. 10). Note that a 1 or 0 positive / negative flag ( ₀ for the minimum peak value b ₀ ) indicating whether the immediately preceding peak value is positive or negative is added to the most significant bit of the latch data. .

Further, the zero-crossing time acquisition circuit 204 outputs an interrupt signal INT to the MCP 3 in FIG.
Is output. As a result, when the interrupt signal INT occurs, the peak value capturing circuit 203 of FIG. 2 holds the minimum peak value b ₀ (absolute value), and the zero-crossing time capturing circuit 204 stores the minimum peak value b ₀ . The zero crossing time including the positive / negative flag immediately after the occurrence is latched.

After the output of the interrupt signal INT,
The access (to be described later) to be performed via an address decoder 4 MCP3 of Figure 1, the zero-crossing time and the minimum peak value b ₀ containing the negative flag is transferred to MCP3 through the bus BUS. Since the above processing is time-division-processed for six strings, as described later, before the output of the above-mentioned information, information indicating which string number the interrupt has occurred is taken as a zero-crossing time. Output from the embedding circuit 204 to the MCP3.

Next, in the peak detection circuit 201 of FIG.
An internal peak hold circuit (not shown) is shown in FIG.
Is peak-held at the minimum peak value b ₀ (absolute value), and a peak-hold signal q ₀ shown in FIG. 10 is output. Thus, the peak detection circuit 201 as a threshold for the peak hold signal (absolute value), the timing x ₂ whose absolute value for the negative side exceeds the threshold value of the digital output D1, minimum peak value detected again The signal MIN is set to a high level.

As a result, in the same manner as described above, FIG.
Of the minimum peak value detection signal MI
N The following minimum peak value b ₁ (absolute value) at the timing x ₃ immediately after the high level is held at the zero-crossing time acquisition circuit 204 of FIG. 2, the positive and negative immediately after occurrence of the minimum peak value b ₁ flag zero crossing time t ₂ comprising (in this case 0 even) is latched, after delivery of the interrupt signal INT, is transferred to MCP3.

Based on the above, the digital output D of FIG.
Minimum peak values b _{0 to} b ₃ (absolute values) for the negative side of 1;
The detection of the zero-cross times t ₀ , t ₂ , t ₄ , t _6, etc., and the output operation of the peak hold signals q _{0 to} q _3, etc., are performed in exactly the same manner as the maximum peak value a ₀ for the positive side of the digital output D 1 ~ A ₃ etc., zero cross times t ₁ , t ₃ , t
_5, the detection of such t _7, and the peak hold signal p ₀ ~p ₃
Are performed in parallel. In this case,
The maximum peak value detection signal MAX from the peak detection circuit 201
Are output as shown in FIG. 10, and the peak value capturing circuit 203 and the zero cross time capturing circuit 204 in FIG.
Maximum peak value a ₀ ~a ₃ etc. Based on this signal MAX,
And zero cross times t ₁ , t ₃ , t ₅ , t _7, etc., including the positive and negative flags (in this case, 1 because of the positive peak) are latched.

[0043] By the operation shown above, the zero-crossing time receiving circuits 204 of FIG. 2, the interrupt signal INT at each time of the zero-crossing time t ₀ ~t ₇ of FIG. 10 in FIG. 1 M
Is output to CP3, each time, based on this, as a set of minimum or maximum peak value (absolute value) a zero-cross time, b ₀ and t _0, a ₀ and t _1, b ₁ and t _2, a ₁ , T ₃ ,... Are sequentially output to the MCP ₃ . Where M
In CP3, whether the peak value is the minimum peak value (negative peak value) or the maximum peak value (positive peak value) can be determined by the positive / negative flag added to the most significant bit of the zero crossing time. is there.

In addition to the above operation, the peak value capturing circuit 203 of FIG. 2 can arbitrarily output the instantaneous value of the digital output D1 by accessing from the MCP3. This will be described later.

Further, the peak hold signal p ₀ ~p _3, q ₀ ~q each attenuation factor, such as ₃ in FIG. 10 generated by the peak hold circuit of the peak detector circuit 201 of FIG. 2 (time constant)
Is controlled by the time constant conversion control circuit 20 of FIG.
2 as needed.

Basically, the time constant of the digital output D1 is changed so that the peak hold signal rapidly attenuates after, for example, one pitch cycle time has elapsed. The setting of the pitch period information at this time is performed by the MC of FIG.
P3 extracts each pitch period by an operation described later, and then, via the bus BUS, converts the time constant conversion control circuit 202
The pitch period information is set in a time constant conversion register CHTRR (described later). Thus, the time constant conversion control circuit 202 compares the pitch provided in each of the string-independent counters (not shown) provided therein with the pitch cycle information set in the time constant conversion register CHTRR from the MCP 3 for matching. When a coincidence output is generated after a lapse of time, the time constant change signal is output to the peak detection circuit 20.
Send to 1. With this operation, the peak hold signal rapidly attenuates after the elapse of one pitch period, whereby the peak of the next pitch period is appropriately detected.

If the next maximum or minimum peak value detection signal MAX or MIN is detected by the peak detection circuit 201 before one pitch period elapses, the counter is reset at the falling timing of these signals. After resetting, the next peak hold signal is generated.

Further, since the vibration period of each string varies widely depending on the position where the player presses the string on the fret, when the waveform corresponding to each string of the digital output D1 rises, the vibration of the waveform is immediately increased. For detection, the peak hold signal rapidly attenuates at the passage of the highest sound period of each string, and immediately after that, the open string period (lowest sound period) of each string elapses so as not to pick up harmonics of each pitch period. Is set so as to rapidly decay. Then, after the pitch period is effectively extracted, a setting is made so as to rapidly attenuate as the pitch period elapses, and follows a change in the pitch period of each string of the digital output D1 due to the performance operation.

Further, in the pitch detection circuit 201, which of the positive and negative peak values is to be subjected to the peak hold control is determined by whether the serial zero cross signal ZCR is at a high level or a low level. (See FIG. 10). << Operation of Central Control Unit (MCP) >>
Based on the maximum or minimum peak value, the zero-crossing time, and the positive / negative flag indicating the positive / negative of the peak value supplied from the pitch extracting circuit 2 of FIG. 1, the MCP 3 of FIG. As a result, tone control information for controlling the tone generator 501 is generated. Note that the MCP 3 executes the operation flowcharts shown in FIGS. 3 to 9 according to the program stored in the ROM 301 as described in detail below. (Explanation of Variables) First, each variable used in the control program shown in the operation flowcharts of FIGS. 3 to 9 described below will be listed below.

AD: input peak value (instantaneous value) directly reading the input waveform D1 to the pitch extraction digital circuit 2 of FIG. 1 AMP (0, 1): positive or negative previous (old) wave High value (peak value) AMRL1... This is the previous amplitude value (peak value) for checking relative off (off) stored in the amplitude register. Here, the relative off is equivalent to a silencing process when the fret operation is stopped and the sound is shifted to an open string by canceling the sound based on a sudden decrease in the peak value.

AMRL2... The amplitude value (peak value) of the last two times for the relative off stored in the amplitude register, to which the value of AMRL1 is input.

CHTIM: a cycle corresponding to the highest tone fret (22nd fret) CHTIO: a cycle corresponding to the open string fret CHTRR: a time constant conversion register, which is a time constant conversion control circuit 202 (FIG. It is provided inside 2).

DUB: a flag indicating that the waveforms have successively come in the same direction; FOFR: a relative off counter; HNC: a waveform number counter MT: a flag from which the pitch is to be extracted (positive =
1, negative = 0) NCHLV: No change level (constant) OFTIM: OFF time (e.g., corresponding to the open string cycle of the string) OFPT: Normal off check start flag ONF: Note-on flag RIV ... Flag for switching processing routes in step (STEP 4) described later ROFCT ... Constant that determines the number of relative off checks STEP: Registers that specify the flow operation of MCP3 TF: previous zero-crossing time data that became valid TFN (0, 1) ... previous zero-crossing time data immediately after a positive or negative peak value TFR: time storage register THLIM ... Frequency upper limit (constant) TLLIM ... Frequency lower limit (constant) TP (0, 1) ... positive or negative previous cycle data T LAB (0, 1) ... positive or negative absolute trigger level (note-on threshold) TRLRL ... relative-on (start of re-generation) threshold TRLRS ... resonance removal threshold TTLIM ...・ Lower frequency limit at trigger TTP ・ ・ ・ Period data extracted last time TTR ・ ・ ・ Period register, TTU ・ ・ ・ Constant (product of 17/32 and current period information tt) TTW ・ ・ ・ Constant (31/16) VEL: Information that determines the velocity (velocity) and is determined by the maximum peak value of the waveform at the start of sound generation.

X: Flag indicating abnormal or normal state b: Current positive / negative flag stored in working register B (1 at zero point next to positive peak, at zero point next to negative peak) 0) c: current crest value (peak value) stored in the working register C e: crest value (peak value) before last stored in the working register E h: stored in the working register H The cycle data extracted two times before the current time t... The current zero-crossing time stored in the working register T0 tt... The current cycle information stored in the working register TOTO (operation of the interrupt processing routine) FIG.
3 is a diagram showing an operation flowchart of an interrupt processing routine showing a process when an interrupt is applied from a zero-cross time acquisition circuit 204 (FIG. 2) in the pitch extraction digital circuit 2 to the circuit 3 by an interrupt signal INT.

As described above, when the interrupt signal INT is output from the zero-cross time acquisition circuit 204, the peak value acquisition circuit 203 of FIG. 2 holds the maximum or minimum peak value (absolute value). The zero-crossing time capturing circuit 204 has a zero-crossing time immediately after the occurrence of the peak value, and a positive / negative flag indicating 1 when the immediately preceding peak value is the maximum (positive) peak value and 0 when the previous peak value is the minimum (negative) peak value. Is latched.

Therefore, the MCP 3 first sets a predetermined address read signal AR to the address decoder 4 at I1 in FIG.
Output a string number reading signal out3.
This allows the circuit 204

[0057]

[Outside 3]

First, the string number indicating which string number the interrupt has occurred is stored in the M via the bus BUS.
Output to CP3. Subsequently, the MCP 3 sets another address read signal AR to the address decoder 4 and sends a signal corresponding to the string number among the time read signals 4 to 5 to the zero-cross time capturing circuit 204.

[0059]

[Outside 4]

[0060]

[Outside 5]

Is output. As a result, from the same circuit 204, the time reading signal

[0062]

[Outside 6]

The zero-crossing time information set in the latch corresponding to the string number specified by (i = 1 to 6) is output to the MCP 3 via the bus BUS.
This is defined as the current zero cross time t as shown in FIG. 3I1.

Subsequently, as described in the section "Operation of the pitch extraction digital circuit" in I2 of FIG.
The plus / minus flag added to the most significant bit of the zero-crossing time information is extracted and set as the plus / minus flag b this time.

Thereafter, at I3 in FIG. 3, the MCP 3 sends the peak value reading signal 203 to the peak value capturing circuit 203 in FIG.

[0066]

[Outside 7]

(J = 1 to 12) is output. Here, although not particularly shown, the circuit 203 has 12 latches for holding the maximum peak value and the minimum peak value for six strings, so that the MCP 3 determines based on the string number and the positive / negative flag b. , And selects and outputs the above peak value read signal 8. Thereby, the circuit 20

[0068]

[Outside 8]

From 3 on, the peak value read signal is set in the latch specified by

[0070]

[Outside 9]

The maximum peak value or the minimum peak value (absolute value) is output to the MCP 3 via the bus BUS. This is set as the current peak value c as shown by I3 in FIG. After the above operation, the values of t, c, and b obtained as described above are set in registers T0, C, and B (not shown) in the MCP 3 at I4 in FIG. Each time the interrupt processing is performed, such zero-crossing time information, peak value information (absolute value), and positive / negative flag information indicating the type of peak are written into this register as one set. In a routine, processing is performed on such information for each string.

There are six registers T0, C, and B corresponding to six strings, and the tone control processing described below with reference to FIGS. 4 to 9 is performed in a time-division manner for all six strings. However, the processing for one string will be described hereinafter for simplicity. (Operation of Main Routine) FIG. 4 is an operation flowchart showing the processing of the main routine. Here, initialization (initialization) after power-on, note-off (silence) processing of a musical tone, and STEP0 to STEP4 (or 5)
Of each of the above processes is performed. In the present embodiment, the tone control process is performed based on the concept of steps as described later, and as described later, STEP0 → STEP1 → S
STEP2 → STEP3 → STEP4 (→ STEP5) →
The tone control is performed in the order of STEP0. << Basic Operation >> In FIG. 4, first, when power is turned on (power is turned on), various registers and flags are initialized in M1, and the register STEP is set to 0. In this case, as described in the description of the time constant conversion control circuit 202 (FIG. 2) in the section "Operation of the pitch extraction digital circuit", in the initial state, the peak detection circuit 201 (FIG. 2) outputs the digital output D1. MCP3 so that the vibration at the rise of the waveform can be detected quickly.
Is stored in the time constant conversion register CHTRR in the time constant conversion control circuit 202 via the bus BUS.
TIM is set, and a peak hold signal output from the peak hold circuit in the peak detection circuit 201 (FIG. 10)
p ₀ or q ₀ ) is controlled so as to rapidly attenuate when the maximum sound period elapses.

Subsequently, at M2 in FIG. 4, it is determined whether or not the register described in the section "Operation of the interrupt processing routine" is empty, and if NO (hereinafter referred to as NO), M
Proceeding to 3, the contents of the registers B, C and T0 are read.
Subsequently, in M4, some values of the register STEP are determined. In M5, STEP0 is determined, and in M6, STEP0 is determined.
In steps M1, M7, the processing in STEP2, M8 in STEP3, and M9 in STEP4 are sequentially executed. The update to the next step is performed in STEP0 to STE as described later.
This is performed in the process of P4. << Note-off operation >> When the buffer is empty in M2, that is, when the buffer is empty (hereinafter, referred to as YES), M10
To M19, where the normal note-off algorithm processing is performed. The note-off algorithm is an algorithm for turning off the note when the peak value of the digital output D1 (FIG. 1) is equal to or less than the off (OFF) level for a predetermined off-time period.

First, it is determined at M10 whether STEP = 0 or not. If YES, the note-off does not need to be performed because the musical tone is not generated, and the process returns to M2. On the other hand, in the case of NO, the process proceeds to M11.

At M11, the digital output D at that time is output.
The input peak value (instantaneous value) AD of 1 is directly read. This is because the MCP 3 sends the peak value read signal to the peak value capture circuit 203 (FIG. 2) via the address decoder 4.
Any of 0 to 11

[0076]

[Outside 10]

[0077]

[Outside 11]

The circuit 203 outputs the current instantaneous value of the digital output D1 to the M via the bus BUS.
This can be achieved by outputting to CP3. And this value A
It is determined whether or not D is equal to or lower than a preset off level. If NO, the process returns to M2 because there is no need to perform note-off, and if YES, the process proceeds to M12.

At M12, it is determined whether or not the previous input peak value AD is equal to or less than the off level.
7, the timer 303 in the MCP 3 is started, and
Return to Then, the next time this processing is performed, M1
2 is YES, the process advances to M13, where the timer 3
It is determined whether the value of 03 is the off-time OFTIM. As the off-time OFTIM, for example, the open string fret cycle CHTIO of the string being processed is set. If NO in M13, the process returns to M2, and the process is repeated. If YES, the process proceeds to M14 and the register STEP
After writing the highest tone fret period CHTIM in the time constant conversion register CHTRR, the process proceeds to M16 via M15 (described later). That is, when the level of the digital output D1 is attenuated, if the input peak value AD equal to or less than the off level continues for a time corresponding to the off time OFTIM, it can be determined that the digital output D1 is not input and the string is no longer played. And the note-off process is performed.

In M16, the MCP 3 is used by the tone generation circuit 50.
1 (FIG. 1), a note-off instruction is sent out, thereby stopping the tone generation. When the note-off is performed in this manner, the process always returns to STEP0.

In step M15, a determination of YES is made in a normal state. However, the register STEP takes a value other than 0 even when the tone generation is not instructed by the processing described later. (For example, due to noise input), and in such a case, M1
By returning to M2 after the processing of 4, M15, it is initialized to STEP0. (Processing Operation of STEP 0) Next, details of each routine for branching and performing corresponding processing in the main routine of FIG. 4 will be described.

First, FIG. 5 shows M in the main routine of FIG.
The operation flow of the processing of Step 0 (STEP 0) shown as 5
It is a low chart. In this process, pitch extraction
Initial setting for processing, etc., and shift to next STEP 1
Perform processing. Hereinafter, description will be given using the basic operation explanatory diagram of FIG.
I do. FIG. 11 shows the same waveform as FIG. "basic action" Now, the main routine of FIG.
By repeating the “0” loop, the “interrupt processing
Pitch extraction as described in section
When an interrupt is issued from digital circuit 2 (FIG. 1),
Waiting for data to be input to registers T0, C and B
You.

Then, when data is input and the contents of the registers are read through M2 to M3 in FIG.
Then, the process proceeds to M5, that is, STEP0 in FIG. In this state, for example, as shown in FIG. 11, the current zero-crossing time t = t ₀ , the current positive / negative flag b = 0, and the current peak value c is the minimum peak value b = b ₀ (absolute value).
It is. In FIG. 11, b and b _{0 to} b ₃ are different symbols.

First, in S01 of FIG. 5, it is determined whether or not the value of the current peak value c is greater than an absolute trigger level (a positive threshold value for note-on) TRLAB (b). This determination is made for each of the positive and negative polarities (maximum peak value or minimum peak value) based on the value of the current positive / negative flag b, and the positive absolute trigger level TRL
AB (1) and negative side absolute trigger level TRLAB (0)
Can be empirically set to different values in consideration of the case where an offset is superimposed on the digital output D1 (FIG. 1). The same value may be used in an ideal system. FIG.
In the example of FIG. 1, the current minimum peak value c = b ₀ (absolute value) and T
RLAB (b) = TRLAB (0) is compared and c =
b ₀ > TRLAB (0), that is, the determination is YES.

Next, after passing through S02 (described later), S0
Step 3 is executed. Here, first, the current positive / negative flag b is written into the flag MT, and 1 is set in the register STEP.
Is written to prepare for transition to the next step, and the current zero-cross time t is set as the previous zero-cross time data TFN (b) for the subsequent processing. In the example of FIG. 11, MT = b = 0, as shown in FIG.
TFN (b) = TFN (0) = t = t ₀ .

Subsequently, in S04, "description of variable"
Other flags (except for the constant value) other than the above-mentioned flags described in the above item are initialized. Further, in S05, the current peak value c is changed to the previous peak value AM for the subsequent processing.
It is set as P (b) (absolute value), and returns to the processing of M2 in the main routine of FIG. In the example of FIG. 11, the AMP (b) = AMP (0 ) = c = b 0 as shown in FIG.

With the above processing, in the example of FIG. 11, the current positive / negative flag b = 0 of the register B is written in the flag MT as shown in FIG. Register TFN in the data TFN (0)
The current zero-crossing time data t = t _{0 of 0} is written, and the current minimum peak value c = b ₀ of the register C is written in the previous negative peak value AMP (0). << Resonance Elimination Operation >> If the value of the current peak value c is equal to or less than the absolute trigger level TRLAB (b) in S01 of FIG.
At 05, the current peak value c is simply set to the previous peak value AMP (b), and the process returns to the main routine of FIG. However, when picking one string causes another string to resonate, the vibration level of the other string gradually increases, and the determination result of S01 in FIG. 5 eventually becomes YES, Move on to the processing of S02. However, in such a case, since normal picking is not performed, it is not appropriate to shift to a sounding (note-on) operation. Thus, the resonance is removed in the process of S02. That is, in the above case, since the current peak value c is hardly larger than the previous peak value AMP (b), the difference c-AMP (b) is not larger than the resonance removal threshold value TRLRS. In
It is determined that the above-described resonance state has occurred, and the process does not shift to the tone generation process. Only the value of the current peak value c is set to the previous peak value AMP (b) in S05, and the process returns to the main routine of FIG. On the other hand, when normal picking as shown in FIG. 11 is performed, the waveform suddenly rises, and the difference c-AMP (b) between the peak values is equal to the resonance removal threshold TR.
After exceeding the LRS, the process proceeds from S02 to S03 as described above. << Entry Operation of Relative ON >> In FIG. 5, A is an entry of relative ON (reproduction start) described later, and jumps to S06 from the flow of STEP 4 described later. Then, in S06, the musical tone output so far is once erased (note off), and the process proceeds to S03 to start re-sounding. The process for starting re-sound generation is the same as that for starting normal sound generation, and is as described above. Here, the note-off process in S06 is performed in the M
This is the same as the processing of step 16. (STEP1 processing operation) Next, FIG. 6 is an operation flow chart of the processing of Step 1 (STEP1), shown as M6 in the main routine in FIG. In this processing, initialization such as pitch extraction processing subsequent to STEP 0 described above and subsequent processing to STEP 2 or double processing (error processing) when a strange waveform is input is performed. << Basic Operation >> First, after the initial setting for the first data is performed in STEP0, in the main routine of FIG. 4, the loop of M2 → M10 → M11 → M2 is repeated to repeat the pitch extraction digital circuit 2 (FIG. An interrupt is applied again from 1), and it is waiting for the next data to be input to the registers T0, C, and B.

Then, when data is input and the contents of the registers are read through M2 to M3 in FIG.
The process proceeds to M6 via STEP4, that is, STEP1 in FIG. In this state, for example, as shown in FIG. 11, the current zero crossing time t = t ₁ , the current positive / negative flag b = 1, and the current peak value is c = a ₀ at b = 1, which is the maximum peak value.

First, through S11 in FIG. 6 (described later), the value of the current peak value c is determined in S12 in exactly the same manner as described in the description of S01 in FIG. Is the absolute trigger level TRLA
It is determined whether it is larger than B (b). In the example of FIG. 11, the current maximum peak value c = a ₀ and TRLAB (b) = T
RLAB (1) and c = a ₀ > TRLAB
(1), that is, the determination is YES.

Next, in step S13, 2 is written into the register STEP, and preparations are made for shifting to the next step. Subsequently, in S14, the current zero-cross time t in the register T0 is set as the previous zero-cross time data TFN (b) for the subsequent processing. Further, in S15, the current peak value c of the register c is set as the previous peak value AMP (b) for the subsequent processing, and the process returns to the main routine M2 in FIG. In the example of FIG.
As shown in the figure, TFN (1) = t = t ₁ , AMP
(1) = c = a ₀ Note that the contents of the MT are not rewritten and remain at 0. If the normal digital output D1 as shown in FIG. 11 "operation of doubling processing" is entered, after the negative (positive) side of the minimum (large) peak value (absolute value) is extracted in the STEP0 the , STEP1, on the contrary, the maximum (small) peak value on the positive (negative) side is extracted. Therefore, S11 of FIG.
In this case, the positive / negative flag b = 1 (0) is set in STEP 0
Since the flag MT is different from the flag MT = 0 (1), the process proceeds to S12 as described above.

In some cases, however, a waveform as shown in FIG. 12A or 12B may be input in STEP 1 after STEP 0. In this case, after the minimum peak value b ₀ of the negative side it is extracted with STEP0, the minimum peak value b ₁ again negative in STEP1 is extracted I dub. Therefore, FIG.
In S11, the positive / negative flag this time becomes b = 0,
It matches the flag MT = 0 set in STEP0.
In this case, the process proceeds to S16 in FIG. 6, and the double processing (error processing) is performed.

In S16, it is determined whether or not the value of the peak value c is larger than the previous peak value AMP (b) of the same sign. Now, in the case of FIG. 12A, c = b ₁ > AMP
(B) = AMP (0) = b ₀ does not hold. In such a case, the minimum peak value b ₁ of this ignores a funny waveform (hatched portion), without STEP update, returns to the M2 of the main routine of FIG. 4, the input is the next normal peak Wait for it to be done.

On the other hand, in the case as shown in FIG.₁
> APM (b) = AMP (0) = b ₀Holds. this
In such a case, the minimum peak extracted in the previous STEP0
Value b ₀Is ignored as a strange waveform (shaded area) and S
Previous zero cross on negative side set in TEP0
Time data TFN (0) and previous negative peak value A
The contents of MP (0) are updated this time by S14 and S15 in FIG.
At the zero-crossing time t and the current peak value c.
Change. That is, in the example of FIG. 12B, TFN (0) = t
= T₁, AMP (0) = c = b₁Becomes This double
After the processing, the STEP is not updated (see S13 in FIG. 6).
4), returning to the process of M2 in the main routine of FIG.
Wait for the normal peak to be entered.

[0094] After the above operation, when the normal peak value is input, processing the by S11 → S12 → S13 → S14 → S15 in FIG. 6 is performed, for example, t = t ₁ as shown in FIG. 11, the following Is transferred to the processing of STEP2. (Processing Operation of STEP2) Next, FIG. 7 is an operation flowchart of the processing of step 2 (STEP2) shown as M7 in the main routine of FIG. In this processing, detection of the first pitch cycle for pitch extraction,
Velocity setting, transition processing to STEP3, error processing when a strange waveform is input (double processing), and the like are performed. << Basic Operation >> First, after the processing in STEP 1 is performed, in the main routine of FIG. 4, M2 → M10 → M1
Due to the repetition of the loop from 1 to M2, the pitch extraction digital circuit 2 (FIG. 1) interrupts again and waits for the next data to be input to the registers T0, C and B.

Then, when data is input and the contents of the registers are read through M2 to M3 in FIG.
Then, the process proceeds to M7, that is, STEP2 in FIG. In this state, for example, as shown in FIG. 11, the current zero-cross time t = t ₂ , the current positive / negative flag b = 0, and the current peak value is c = b _1, which is the minimum peak value from b = 0.

First, after going through S20 of FIG. 7 (described later)
In S21, the MCP 3 sets the open string fret cycle CHTIO of the string currently being processed in the time constant conversion register CHTRR in the time constant conversion control circuit 202 in FIG. 2 via the bus BUS. This is equivalent to the time constant conversion control circuit 20 described in the section "Operation of the pitch extraction digital circuit".
2, the peak detection circuit 201
After FIG. 2 detects the oscillation at the rising edge of the waveform of the digital output D1, the peak hold signal (FIG. 2) output from the peak hold circuit in the peak detection circuit 201 so as not to pick up the overtone of each pitch cycle. 10p ₁ , q ₂ etc.)
Are rapidly attenuated with the passage of the open string period of each string, that is, the minimum sound period CHTIO.

Next, in S22, it is determined whether or not the value of the current peak value c is greater than 7/8 times the previous peak value AMP (b) of the same sign. Although this processing will be described in detail later, usually, the waveform obtained by picking the strings smoothly attenuates smoothly, so that this determination is YES, and the next S
Then, the processing proceeds to S24 (described later) via S23.

In S24, ｛(current zero cross time t)-(previous zero cross time data TFN of the same sign
(B)) The first pitch period is detected by calculating｝. Then, this result is described in STEP 3 described later.
Is set as the previous cycle data TP (b) in order to use it as a condition for note-on (start of sound generation) in the above. FIG.
In the example of TP (0) = t-TFN as shown in FIG.
(0) = t ₂ −t ₀

In S24, the current zero-cross time t is set to the previous zero-cross time data T for subsequent processing.
Set as FN (b). In the example of FIG. 11, TFN (0) = t = t ₂ as shown in FIG. Note that ST
TFN (0) = t ₀ set in EP0 becomes unnecessary and is deleted because the previous cycle data TP (b) = TP (0) can be calculated.

Similarly, in S24, 3 is written in the register STEP, and preparations for shifting to the next step are made. Further, in S24, the current peak value c and the previous peak values AMP (0), AMP (1)
Is set as the velocity VEL. Note that the velocity VEL is used as a value for determining the volume of a musical tone as described later in STEP3. Similarly, the current peak value c is changed to the previous peak value AMP.
(B), and returns to the process of M2 in the main routine of FIG. In the example of FIG. 11, VEL = max ｛c, AM
P (0), AMP (1)｝ = max ｛b ₁ , b ₀ ,
a ₀ }, and AMP (0) = c = b ₁ . In addition,
AMP (0) = b ₀ set in STEP ₀ becomes unnecessary and is deleted because the velocity VEL can be calculated. << Operation of Dubble Processing >> When the normal digital output D1 as shown in FIG. 11 is input, after the maximum (small) peak value on the positive (negative) side is extracted in STEP1,
On the contrary, the minimum (large) peak value on the negative (positive) side is extracted in STEP2. Accordingly, the sign of the peak value in STEP 2 in this case is opposite to that in STEP 1 and is the same as in STEP 0. In S20 in FIG. 7, the positive / negative flag b = 0 (1) is set in STEP 0 this time. The flag MT is equal to 0 (1), and the process proceeds to S21 as described above.

However, the "processing operation of STEP 1"
In the same manner as described in the description of the "operation of dubble processing", the waveform may be dubbed in some cases, and a waveform as shown in FIG. In this case, after the maximum peak value a ₀ on the positive side is extracted in STEP 1, the maximum peak value a ₀ on the positive side is extracted again in STEP 2.
₁ is dubbed and extracted. Accordingly, in S20 of FIG. 7, the current positive / negative flag becomes b = 1, which coincides with the flag MT = 0 set in STEP0. In this case, the process proceeds to S25 in FIG. 7, and the double processing (error processing) is performed.
13 and 14, the hatched peaks indicated by simple hatching are the peak hold signals p ₀ , p ₁ , and q in FIG. 13 or FIG. 14 generated from the peak hold circuit in the peak detection circuit 201 in FIG. _This is a portion that was not detected as a peak because it did not catch ₀ or the like.

In S25, first, the doubling flag DUB is set to 1 (described later), and the flow advances to S26 to determine whether or not the value of the current peak value c is larger than the previous peak value AMP (b) of the same sign. Is done.

Now, in FIG. 13, STEP 0 (t = t
₀ ), after the processing of STEP 1 (t = t ₁ ), if STEP 2 is executed at t = t ₂ , c = a ₁ > AMP
(B) = AMP (1) = a ₀ does not hold. That is, FIG.
Is NO in S26. In such a case,
The maximum peak value a ₁ this time is ignored as a strange waveform (the cross-hatched portion in the figure) and
Without updating, returns to the process of M2 in the main routine of FIG. 4 and waits for the next normal peak to be input. And
At t = t ₃ , the minimum peak value c = b ₁ is input, so that S20 in FIG. 7 becomes YES, and the processing of S21 → S22 → S23 → S24 is performed as in the case of FIG. in t = t ₃ in FIG. 16 proceeds to the process in next STEP3. Incidentally, the previous period data TP (0) is set in S24 in FIG. 7, as shown in FIG. 13, the current zero-crossing time t _3, it becomes difference between the previous zero-crossing time point t ₀ set in STEP0. In addition, S
The starting point of the next periodic data Tx calculated in STEP 3 is the previous zero-crossing time set in STEP 1 because the hatched peak (c = a ₁ ) is ignored as shown in FIG. TFN (1) = t
_Is one.

On the other hand, in the case of FIG. 14, c = a
₁ > AMP (b) = AMP (1) = a ₀ holds. That is, the determination result in S26 of FIG. 7 is YES. In such a case, the maximum peak value a extracted in the previous STEP 1
_{The zero} is ignored as a strange waveform (the cross-hatched portion in the figure), and the previous zero-cross time data TFN (1) set in STEP 1 and the previous peak value AMP (1) on the positive side are set. The contents of S2 in FIG.
9, the current zero crossing time t and the current peak value c
Replace with That is, in the example of FIG. 14, TFN (1) = t = t ₂ , AMP (1) = c as shown in FIG.
= A ₀ . After the dubbing process, the process returns to M2 of the main routine in FIG. 4 without updating, and waits for the next normal peak value to be input. Hereinafter, the processing after the minimum peak value c = b ₁ is input at t = t ₃ is the same as that in FIG. However, since the peak extracted in STEP 1 (the peak c = a ₀ hatched by the cross hatching in FIG. 14) is ignored and the peak is changed to c = a ₁ , the TP calculated in STEP 3 described later is used. the next starting point of the period data T _y of (0), ST
The previous zero-crossing time TFN (1) = t ₂ set in the dubbing process of EP2 is different from the case of FIG.

As described above, when the waveform is doubled as shown in FIG. 13 or FIG. 14, the smaller peak value is ignored as a strange waveform, and error processing is performed. Next, a description will be given of the branch of S22 in FIG. 7 for processing in another case of the doubling processing.

Now, when the processing in STEP 2 of FIG. 7 is executed, the normal waveform obtained by picking the strings smoothly attenuates smoothly, so that the value of the current peak value is changed to the previous peak value AMP (b) of the same sign in S22. ) Is larger than ／ times the value in S), the determination in S22 is YES, and the next S23
Proceed to.

However, in some cases, c> (7/8) × A
MP (b) may not be established. In the first case, for example, by picking a string near the bridge, the waveform may not be a normal but smooth attenuation waveform, and the determination result in S22 may be NO.
However, even in such a case, S24 in FIG.
Must be performed normally. In this case, since the waveform is normal, the above-described double does not occur, and since the branch from S20 to S25 in FIG. 7 has not been made before that, the value of the double flag DUB remains 0. . Therefore, if DUB = 1 does not hold in S27 of FIG. 7, S again regardless of the determination result of S22.
Returning to the processing of 24, the processing described in the above-mentioned "Basic operation" is performed. It should be noted that the double flag DUB is the same as the one shown in FIG.
In the process of S04 of EP0, the value is initialized to 0.

On the other hand, as a second case where S22 in FIG. 7 is not satisfied, there is a case where the above-described double occurs in the waveform. This case will be described below with reference to FIG.

Now, as described with reference to FIG.
As shown in STEP 0 (t = t ₀), STEP1
(T = t₁), T = t_TwoAt the dub
Reprocessing is performed, c = a₀Peak (cross-hatched in the figure)
Hatched peak) is removed, and c = a₁The pea
(The hatched peak in the figure)
I do. It should be noted that a simple hatched peak (c =
a₁) Is not originally detected as in FIG. 13 or FIG.
It is a peak.

When the double occurs as described above, the next t
= T ₃ , the positive / negative flag is b =
0, the flag MT set in STEP0 =
Matches 0. Therefore, the process proceeds from S20 to S22 through S21 in FIG. However, the current minimum peak value c = b ₁ detected at t = t ₃ is the previous minimum peak value AMP (0) =
It is far from b ₀ and has a large attenuation. Therefore, as shown in FIG. 15, the determination result in S22 of FIG. 7 may be NO.

In the above case, t = t ₂ before t = t ₂
Since the doubling process is performed in
The value of UB is 1. Accordingly, the determination result in S27 of FIG. 7 is NO, and the process proceeds to S29 (described later) via S28.

In S29, in order to obtain a normal waveform after t = t ₃ in FIG.
The previous zero-crossing time data TFN (0) set in STEP 0 and the previous negative peak value AMP
The content of (0) is changed by replacing the current zero-cross time t and the current peak value c in S29 of FIG. That is, in the example of FIG. 15, TFN (0) =
At t = t ₃ , AMP (0) = c = b ₁ , and the hatched peak (c = b ₀ ) in the horizontal line in FIG. Note that the double flag DUB is reset to 0 in S28 of FIG. 7 for the subsequent processing. After these operations, the process returns to M2 of the main routine in FIG. 4 without updating the value of STEP, and waits for the input of the next peak.

Then, in the above case, as shown in FIG. 15, at step t = t ₄ and t = t ₅ , after step 2 of FIG. 7 is repeated, the process proceeds to step 3. Such an STE
Since there are various patterns for the repetition operation of P2, a detailed description thereof will be omitted, but a normal waveform can be obtained as a whole flow, and the next STEP3
TFN (0), AMP for use in
After operating such that (0), TFN (1), and AMP (1) are effectively determined, the process proceeds to STEP3. In the case of FIG. 15, TP (0) = t ₅ −t ₃ , and the starting point of the next periodic data Ti calculated in STEP 3 described later is TFN (1) = t ₄ . (Processing Operation of STEP 3) Next, FIG. 8 is an operation flowchart of the processing of step 3 (STEP 3) shown as M8 in the main routine of FIG. In this processing, note-on (sound generation) processing, extraction of a pitch cycle for setting a pitch at the time of note-on, particularly correction of the extracted pitch cycle, calculation of velocity, ST
Processing for shifting to EP4, error processing when a strange waveform is input, and the like are performed. << Basic Operation >> First, after the processing in STEP 3 is performed, in the main routine of FIG. 4, M2 → M10 → M1
Due to the repetition of the loop from 1 to M2, the pitch extraction digital circuit 2 (FIG. 1) interrupts again and waits for the next data to be input to the registers T0, C and B.

Then, when data is input and the contents of the above registers are read through M2 to M3 in FIG.
The process moves to M8 via STEP4, that is, STEP3 in FIG. In this state, for example, as shown in FIG. 11, the current zero crossing time t = t ₃ , the current positive / negative flag b = 1, and the current peak value is c = a ₁ which is the maximum peak value from b = 1.

First, steps S30, S31 and S32 in FIG.
(Described later), the velocity VEL is set in S33.
Calculate. Now, the "basic operation" of the "STEP 2 processing operation"
As described in the section “Operation”, in S24 of FIG.
The peak values of the last three times, b in the example of FIG.₀, A₀, B₁
Of the values (absolute values) is the velocity VEL
Is stored in Therefore, in S33 of FIG.
Judge the larger of the loss VEL and the current peak value c
Then, a tone is generated by the tone generator 501 (FIG. 1).
New velocity VEL at the time of In the example of FIG.
Is VEL = a ₀, C = a₁Thus, VEL = max [a
₀, A₁] = A₀Becomes

After the above operation, MT is set to b in S33 in FIG. 8 (described later), and in S34,
By calculating {(current zero-crossing time t)-(previous zero-crossing time data TFN (b) of the same sign)}, the pitch cycle is detected and the previous cycle data TP (b) is calculated.
Set as In the example of FIG. 11, as shown in FIG.
P (1) = t ₃ becomes the -t _1.

Subsequently, after going through S35 to S38 in FIG. 8 (described later), in S39, the previous cycle data TP (b) obtained in S34 and the TP (b) set in S24 in FIG. b) is almost the same as the previous cycle data of opposite polarity

[0118]

[Outside 12]

It is determined whether or not this is the case. If the result of the determination is YES, it is determined that the pitch period has begun to be stably extracted, and after S301 (described later),
In S302, note-on (start of sound generation) processing is performed. In the example of FIG. 11, the previous cycle data TP (1) on the negative side
= T ₃ −t ₁ and the previous cycle data TP (0) on the positive side = t ₂
It is determined that −t ₀ is substantially the same, and the processing shifts to note-on processing. The case where the determination result is NO will be described later.

Next, in S302, S33 in FIG.
The volume information is generated on the basis of the velocity VEL calculated in the above, and the previous pitch period TP (b) is set to 1.02
The corresponding pitch information is generated based on the multiplied correction value. That is, the pitch period is corrected to be longer by 2%. As described above, a significant feature of the present embodiment is that the pitch information is generated after the pitch period is corrected at the start of sound generation, and thus, as described in the section “Schematic operation of the present embodiment”. In addition, it is possible to prevent the pitch period from being extracted at the start of sound generation, thereby preventing higher pitch information from being designated. The volume information and the pitch information generated by the above processing are output to the tone generation circuit 501 via the MIDI-BUS and the interface MIDI in FIG. In the same circuit 501, a musical tone having a volume and a pitch corresponding to each of the information is generated in real time.

Since the processing in FIG. 8 is performed for each of the six strings of the guitar, the above processing is also performed independently for each of the six strings. Along with the above note-on processing,
In S38 and S301 of FIG. 8, after setting the parameters used in the next STEP4, S3
02, the process returns to the process of M2 in the main routine of FIG.
It moves to the next STEP4. That is, in S38, S3
4 is set as the previously extracted cycle data TTP, and the previous zero-crossing time data out 13 set in S24 of STEP2 in FIG. 7 is stored in the time storage register in S301.

[0122]

[Outside 13]

This is set in TFR, the current zero-cross time data t is set as the previous zero-cross time data TF which became valid, the waveform number counter HNC is cleared to 0, the value of the register STEP is updated to 4, and The ON flag ONF is set to 2 (sound generation state), the constant TTU is set to 0 (minimum MIN), the constant TTW is set to the maximum MAX, and the previous amplitude value AMRL1 for the relative off check is cleared to 0. You. Each of these parameters will be described later in STEP4. << Operation in Case of Inappropriate Cycle >> When the previous cycle data TP (b) is detected in S34 of FIG. 8, this pitch cycle is set to a value larger than the cycle when the corresponding string is played at the highest fret. And have a value less than the open string period of the string.

Therefore, a pitch period two to three semitones higher than the pitch determined by the highest pitch fret of the string currently being processed is set as the constant of the upper limit frequency THLIM, and the same string as the constant of the lower frequency limit TTLIM is set. 8 is set to a pitch period about 5 semitones lower than the pitch determined by the open string state of S.
36, in S37, the previous cycle data TP (b) obtained in S34 is larger than THLIM and TTLI
It is determined whether it is smaller than M. If both the determination results are YES, the process proceeds to S39 and performs the above-described cycle determination process.

Here, if the determination results in S36 and S37 are NO, the previous cycle data TP (b) extracted in S34 is not an appropriate value. Therefore, in such a case, the M2 of the main routine of FIG.
Then, the process returns to step 3 and STEP3 is repeated.

Next, in S39 of FIG. 8, if the previous cycle data TP (b) obtained in S34 is different from the previous cycle data TP (b) having a different polarity from the previous cycle data TP (b),
Overtone

[0127]

[Outside 14]

It is highly probable that the correct pitch period was erroneously extracted due to the extraction of the pitch period, and the pitch period was not stably extracted. Therefore, in such a case, S
The determination result at 39 is NO, returning to the process of M2 in the main routine of FIG. 4 and repeating STEP3.

Here, when STEP 3 is repeated by the above operation, in a normal waveform, the peak newly detected via M2 and M3 in FIG. 4 has its polarity switched alternately and the value of b becomes 0. 1 is alternately inverted, and FIG.
In S33, the value of the flag MT is changed alternately. Similarly, in S34, TP (b) is newly calculated and TF (b) is calculated.
The contents of N (b) are also rewritten. Therefore, S36, S
The determination at 37 is made for the most recently obtained pitch cycle. Further, the determination at S39 is made of the most recently obtained pitch cycle and the immediately preceding (about half cycle before) pitch cycle on the opposite polarity side. And the process shifts to the note-on process when the pitch period can be stably extracted.

Each time, at S33 in FIG.
The velocity VEL is updated to correspond to the newly detected peak. << Operation of Noise Removal Process >> The process of S31 in FIG. 8 is a process for coping with a case where noise occurs at the rising portion of the waveform. Now, for example, as shown in FIG.
Peaks a ₀ due to noise in EPs ₀ , ₁ , and ₂ ,
If b ₀ , a _1, etc. are detected, if the start of sound generation is instructed by detecting the cycle of these noises, a completely strange musical sound will be generated.

Therefore, in S31 of FIG. 8, when the continuous peak value changes greatly, it is determined that noise has occurred, and the abnormality detection flag X is set to 1, and S31 is set.
By making a NO determination at 35, note-on is prevented from occurring based on the noise portion.

Specifically, if the value obtained by subtracting １ ／ from the current peak value c is smaller than the previous peak value AMP (b) having the same sign, it is determined that the value is normal and X = 0. Let X = 1. If it is determined in step S35 that X is not equal to 0, the process proceeds to M2 of the main routine in FIG.
Then, the process returns to step 3 and STEP3 is repeated. In this case, since the previous peak value AMP (b) is sequentially updated in S32 of FIG. 8, the process in S31 is performed on the most recently detected peak value and the immediately preceding peak value of the same sign, When the continuous peak value does not change significantly, the process shifts to the note-on process. FIG.
In the example of (2), note-on is not performed because X = 1 at S31 for both t = t ₃ and t = t _4, and it is determined that a normal peak is input for the first time at t = t ₅ , so that X = 0. , T = t ₅ , the note-on is performed. And in this case,
The continuous pitch period TP (b) and 外 15 are normal values.

[0133]

[Outside 15]

[0134] << Operation of Double Duty Processing >> The determination processing in S30 of FIG. 8 is a determination for double doubling processing. Now, when a normal waveform D1 as shown in FIG. 11 is entered, the positive and negative flag b = 1 this at t = t ₃ does not match the flag MT = 0, the process proceeds to S31 as described above.

However, the above-mentioned "STEP 1 processing operation"
Or, “operation of double doubling processing” in “processing operation of STEP 2”
In the same manner as described in the above section, when the waveform is doubled, the determination result in S30 of FIG. 8 is NO.

When the peak value c of the doubled peak is smaller than the peak value AMP (b) immediately before the same sign, the determination result of S303 in FIG. Is ignored, and after returning to the process of M2 in FIG. 4, STEP3 is repeated. This is based on the same concept as in FIG.

On the other hand, if the peak value c of the doubled peak is larger, the determination result of S303 is YE
The result is S, and the process proceeds to S304. Then, in S304, ignoring the immediately preceding peak, the content of AMP (b) is reset to the current peak value c, the velocity VEL is recalculated using the value, and the value is then changed to M2 in FIG. Go back and STE
Repeat P3. This is based on the same concept as in FIG.

After the above processing, when a normal peak is input, the determination result in S30 becomes YES, and furthermore,
Each of the determination results in S35, S36, S37 and S39 is Y
By the ES, the note-on process is performed, and the tone generation starts. (Operations of STEP4) Next, FIG. 9 is an operation flow chart of the processing of Step 4 (STEP4), shown as M9 of the main routine of FIG. In this processing, pitch extraction / change processing, relative-on / relative-off processing, processing when the pitch period is inappropriate, and double processing are performed. Although this process is not directly related to the present invention, it is important for controlling the pitch of musical tones.
The description will be made sequentially. First, in the pitch extraction / change processing, there is a route for performing only the pitch extraction and a route for actually changing the pitch, and is usually repeated alternately each time a new peak is input. << Route Operation >> First, S40, S41, S42, S
The routes from 63 to S67 will be described. S40
In the above, the waveform number counter HNC> 3 is determined, and in the case of YES, the process proceeds to S41. In S41, it is determined whether or not the relative-on threshold value TRLRL <(current peak value c−previous peak value AMP (b) of the same sign), and if NO, the process proceeds to S42 (if YES, a description will be given later). Do). In S42, the current positive / negative flag b = flag M
It is determined whether T is the pitch change side, and if YES, the process proceeds to S43.

By the way, in the initial state, the waveform number counter HNC is 0 (see S301 in FIG. 8), so that a negative determination is made in S40 and the process proceeds to S42. Then, if the waveform input as shown in FIG. 11, for example, t = t ₄
At b = 0 and MT = 1 (S33 of STEP3 in FIG. 8)
From S42 to S63.
Proceed to.

In S63, it is determined whether or not the register RIV = 1 to check whether or not a peak having the same polarity is continuously input (whether the peak is a double). S6)
8 to perform the dub processing (described later).
In the case of (i.e., not double), the process proceeds to S64, where the following processing is performed.

That is, in step S64, the current peak value c is input to the previous peak value AMP (b), and the previous amplitude value AMRL1 is input to the immediately preceding amplitude value AMRL2 for the relative-off process (described later). In the beginning, AMR
The content of L1 is 0. (S301 in STEP3 of FIG. 8)
reference).

Further, in S64, the previous peak value out of the opposite sign 16 and the current peak value c

[0143]

[Outside 16]

The larger value of the previous amplitude value AM
Input to RL1. In other words, two positives in the cycle,
For the negative peak value, the larger peak value is the amplitude value AM.
Set to RL1.

Then, in S65, the waveform number counter H
It is determined whether or not NC> 8. Here, the waveform number counter (zero-cross counter not on the pitch changing side) HNC
Is incremented by 1 and counted up. Therefore, the upper limit of the waveform number counter HNC is 9. And S6
After 5 or S66, the process proceeds to S67.

In S67, the register RIV is set to 1, the content of the time storage register TFR is subtracted from the current zero crossing time t, and the result is input to the period register TTR. In the example of FIG. 11, the cycle register TTR has the cycle information TTR =
It shows t-TFR = t ₄ -t ₂ . Then, the current zero cross time t is saved in the time storage register TFR,
Thereafter, the process returns to the process of M2 in the main routine of FIG.

As described above, the route is subjected to the following processing according to the example of FIG. That is, MT = 1
≠ b, RIV = 0, AMP (0) ← c = b ₂ , AMRL
2 ← AMRL1 = 0, AMRL1 ← max ｛AMP
(1) = a ₁ , c = b ₂ (whichever is greater)｝, H
NC ← {HNC + 1} = 1, RIV ← 1, TTR ← ｛t
−TFR｝ = {t ₄ −t ₂ }, and TFR ← t = t ₄ . Therefore, the difference between the time information from the previous zero-cross point t = t ₂ (the time point of the change from STEP 2 to 3) of the same polarity to the current zero-cross point t = t _4, that is,
This means that the cycle information has been obtained. Then, the process returns to the process of M2 in the main routine of FIG. 4, and waits for the input of the next peak. << Route Operation >> Next, a description will be given of a case where the vehicle has proceeded to the route shown in S40 to S62. Now, since the waveform number counter HNC = 1 (see S66), S40 to S
The process proceeds to S42 (S40 will be described later).

In S42, for example, in the case of FIG.
Since MT = 1 and b = 1, YES is determined, and the process proceeds to S43.
In S43, it is determined whether or not the register RIV = 1. Since the register RIV is already set to 1 in the route (see S67), the determination in S43 is YES, and the process proceeds to S44. The dubbing process performed when the determination result of S43 is NO will be described later.

In S44, it is determined whether or not the register STEP = 4. If YES, the process proceeds to S45 (the case of NO will be described later). In S45, it is determined whether or not the current peak value c <60H (H indicates hexadecimal notation). If a large peak value is input, the determination result is NO, and the process proceeds to S47. On the other hand, if the value is smaller than 60H, the determination becomes YES and the process proceeds to S46.

In S46, the amplitude value (peak value) two times before
AMRL2-previous amplitude value (peak value) AMRL1 ≦
(1/32) × the amplitude value (peak value) AMRL2 two times before
It is determined whether the answer is YES, and if YES, the process proceeds to S47,
Relative off counter FOFR is set to 0.
In the case of NO, the process proceeds to S74 and the relative off process is performed. The relative off processing will be described later.

In S48, a cycle calculation is performed. Specifically, (the current zero-cross time t-the previous zero-cross time data TF) is stored in the register T as the current cycle information tt.
Set to OTO. Then, the process proceeds to S49.

In S49, it is determined whether or not this cycle information tt> frequency upper limit THLIM (upper limit after the start of sound generation). If YES, the process proceeds to S50 (if NO, it will be described later). The frequency upper limit THLIM of S49 is the same as the STLI in FIG.
It is the same as the upper limit of the allowable range of the frequency at the time of triggering (at the start of sound generation) used in S36 of EP3 (therefore, the period is the minimum and corresponds to the pitch period two to three semitones above the highest note fret). .

Next, the following processing is performed in S50.
That is, the register RIV is set to 0, the current zero-cross time t is input as the previous zero-cross time data TF,
In addition, the previous peak value AMP (b) is input as the peak value e two times before, and the current peak value c is changed to the previous peak value AM.
It is input to P (b).

Then, after the processing of S50, the process proceeds to S51,
In S51, the frequency lower limit TLLIM> the current cycle information t
If it is YES, that is, if the current cycle is less than or equal to the lower limit of the pitch extraction range during note-on, the process proceeds to S52. In this case, the lower frequency limit TLLIM is
For example, it is set one octave below the open string scale.
That is, the lower frequency limit TTLIM (S
37, the allowable range is widened. By doing so, it becomes possible to cope with a frequency change due to operation of the tremolo arm or the like.

By the above operation, the process proceeds to S52 only when the upper and lower limits of the frequency fall within the allowable range.
If not, the flow returns to the processing of M2 in the main routine of FIG. 4 from S49 and S51, and waits for the input of the next peak.

Next, in S52, the cycle data TTP is input to the cycle data h extracted two times before, and the current cycle information tt is input to the cycle data TTP extracted last time.

Then, in S53, the current peak value c is written in the velocity VEL, and the flow advances to S54. In S54, it is determined whether or not the no-change level NCHLV> (the peak value e before the previous time-the current peak value c). If YES, the process proceeds to S55. That is, the previous peak value of the same polarity (e
= AMP (b) and the current peak value c greatly change, the difference exceeds NCHLV,
In such a case, if the pitch is changed based on the extracted period information, an unnatural pitch change is likely to occur. Therefore, if the determination of NO is made in S54, the process returns to the process of M2 in the main routine of FIG. 4 without performing the processes after S55, and waits for the input of the next peak.

Next, in the case of YES in S54, it is determined whether or not the relative off counter FOFR = 0. When the relative off processing described later is being performed, the relative off counter FOFR is not 0, and in such a case, the determination of NO is made in S55 without performing the pitch change processing (see S61). It returns to the process of M2 of the main routine of FIG. Then, when a determination of YES is made in S55, the process sequentially proceeds to S56 and S57.

In S56 and S57, a two-wave ternary coincidence condition is determined. In S56, current cycle information tt × 2 ⁻⁷ > | current cycle information tt−pre-last cycle data h | is determined,
In the case of YES, the process proceeds to S57. In S57, the current cycle information tt × 2 ⁻⁷ > | current cycle information tt−contents of cycle register TTR | is determined, and in the case of YES, S58.
Proceed to. That is, in S56, in the example of FIG. 11, the current cycle information tt = t ₅ -t ₃ (see S48) is approximately the value of the previous period data _{h = TTP = t 3 -t 1} ( see S52) it is determined whether match, the S57, the current cycle information tt = t ₅ -t _3, the period TTR = t overlapping therewith
_It is determined whether or not _4- t ₂ (see S67) substantially coincides. The limit range is set to 2 ⁻⁷ · tt, and the value changes depending on the period information. Of course,
This may be a fixed value, but better results can be obtained with the technique employed in this embodiment.

In the next S58, it is determined whether or not the current cycle information tt> constant TTU. If YES, the process proceeds to S59, where it is determined whether or not the current cycle information tt <constant TTW, and if YES, the process proceeds to S60. move on. Note that S58,
The case where the determination is NO in S59 will be described later.

At S60, it is determined whether or not the register STEP = 4. If YES, the process proceeds to S61. In S61, the tone generation circuit 5 from the MCP 3 in FIG.
The pitch is changed to 01 (based on the current cycle information tt), and the process proceeds to S62. In the pitch changing process in S61, it is not necessary to correct the pitch cycle (see S302 in FIG. 8) as at the start of sound generation.

At S62, the time constant is changed according to the current cycle information tt, and the constant TTU is changed to (17/3).
2) × Rewritten to the current cycle information tt, and furthermore a constant T
TW is rewritten as (31/16) × current cycle information tt.

As will be described later, only when the relative off process is performed, STEP = 5. In this case, the process directly proceeds from S60 to S62, and the pitch is not changed in S61. Perform a constant change.

The time constant change processing is performed by the time constant conversion register CH in the time constant conversion control circuit 202 shown in FIG.
This means that the MCP 3 in FIG. 1 sets the cycle data based on the value of the current cycle information tt in TRR. This is as already described in the section "Detailed operation" of the "Operation of the pitch extraction digital circuit".

Then, upon completion of the process of S62, the process returns to the process of M2 in the main routine of FIG. As described above, in the route, the following processing is performed in the example of FIG. That is, it is determined that HNC = 1, MT = 1 = b, RIV = 1, FOFR ← 0, tt ← t-TF = t ₅ −t ₃ , RI
V ← 0, TF ← t = t ₅ , e ← AMP (1) = a ₁ , A
MP (1) ← c = a ₂ , h ← TTP = TP (1) = t ₃
−t ₁ , TTP ← tt = t ₅ −t ₃ , VEL ← c = a ₂
Further, the pitch is changed in accordance with tt when the three conditions of TTP ≒ TTR ≒ tt, TTU <tt <TTW, and AMP (0) −c <NCHLV are satisfied.
Then, TTU ← (17/32) × tt, TTW ← (3
1/16) × tt is set.

By the above operation, the pitch of the actual tone generation circuit 501 (FIG. 1) is changed in the route, and the route is processed in the subsequent zero-cross interrupt (detection of the next peak). Route processing is performed. Thus, in the route, the cycle is simply extracted (see S67).
On the route, actual pitch change (see S61) and time constant change processing (see S62) are performed. << Relative On Processing Operation >> After the waveform number counter HNC is counted up so as to exceed 3 in S66 of the route in STEP 4 of FIG. 9, a YES determination is made in S40, and then the process goes to S41, where the relative on is performed. Condition is detected.

This is because c-AMP (b)> TRLRL, and when the current peak value c exceeds the threshold value TRLRL as compared with the previous peak value AMP (b), that is, when the string is Such a situation occurs when the same string is picked again after the operation (for example, by tremolo playing technique). In this case, the determination result in S41 is YES, and the process proceeds from S41 to S78 in order to perform the relative on process.

In S78, the time constant conversion control circuit 202
The cycle CHTIM of the highest tone fret (for example, 22th fret) is set in the time constant conversion register CHTRR of FIG. After the above-described processing, the process proceeds to S06 in STEP0 in FIG. 5, and after note-off of the musical tone being sounded, re-sounding is started. According to the normal performance operation, the STE in FIG.
In S41 of P4, a determination of NO is made, and the process proceeds to S42.
Proceed to the route or route described above. << Relative Off Processing Operation >> Next, the relative off processing will be described with reference to FIG. Relative off means that a silencing operation is performed in accordance with an operation of shifting from a state in which the fret operation is being performed to an open string state without picking.

In this case, the amplitude level of the waveform drops sharply, and the difference between the previous peak value (peak value) AMRL2 and the previous peak value (peak value) AMRL1 is (1/32).
• It exceeds AMRL2, and the process proceeds from S46 to S74 in STEP4 of FIG.

Then, the relative off counter FOFR
From S74 to S75 so as to count up until the value exceeds the constant ROFCT. Continue from S75 to S48
To perform the processing of S49 to S55, but FOFR = 0
Therefore, the determination result in S55 is NO, and the process returns to the process of M2 in the main routine of FIG. 4 without changing the pitch immediately before entering the relative off process.

Then, peaks at the time of relative off are successively input, and if NO is determined in S74, that is, in the example of FIG. 17, when the value of FOFR becomes 3 (ROFCT is 2), S74 to S76 are performed. Move to.

However, if the determination in S46 is YES at least once, the process proceeds from S46 to S47, and the FOFR is reset. Therefore, if the condition of S46 is not satisfied continuously for the number of times specified by ROFCT,
No relative off processing is performed. In addition, ROFCT
If the value of is set to a large value for a string with a high pitch,
After a lapse of a substantially constant time, the relative off processing can be performed for any of the strings.

Next, when going from S74 to S76, the relative off counter FOFR is reset and the register ST is reset.
The EP is set to 5, and the flow advances to S77 to instruct the tone generation circuit 501 (FIG. 1) to perform note-off.

In the state in which STEP is 5, the pitch extraction processing is executed in the same manner as in STEP 4, but the process proceeds from S60 to S62 without going through S61, so that the tone change circuit 501 is instructed to change the pitch. Not done. However, the time constant changing process is performed according to the cycle extracted in S62.

Then, in the state of STEP 5, the relative-on process is accepted (S41, S78), but otherwise, it is detected that the vibration level has decreased in the main routine of FIG. M14
, STEP becomes 0 and returns to the initial state.

The AMRL1 and AM used in S46
RL2 is made in S64, and the peak having the higher level (one of the maximum peak and the minimum peak) in one cycle is set to this value, and the maximum peak a in FIG.
where k is always greater than the maximum peak bk -1, where an + 1 and an + 2, an + 2 and an + 3, an +
Both the difference between 3 and an + 4 exceeds a predetermined value.

At this time, in the route processing, since the minimum peaks bn + 1, bn + 2, bn + 3 have been extremely reduced, the determination of NO is made in S54, and the process returns to the processing of M2 in the main routine of FIG. No pitch change processing is performed. << Processing operation when pitch cycle is inappropriate >> Next, when the pitch cycle is inappropriate, that is, when the pitch is
Alternatively, a description will be given of the processing when the harmonics having an octave relationship, that is, the octave higher period and the octave lower period are continuously detected in S59.

Now, the constant TT of S58 in STEP 4 of FIG.
U is set to the minimum value 0 in S301 of STEP 3 in FIG. 8, and the constant TTW is set to the maximum value MAX similarly.
When this flow is passed for the first time, the determination of YES is always made in S58 and S59, but thereafter, in S62,
The constant TTU is set to (17/32) · tt (almost one octave high pitch period information), and the constant TTW is similarly set at S62 to (31/16) · tt (almost one octave low pitch period information). Is set.

Therefore, when the octave is suddenly raised (this occurs when the vibrating string is muted with a finger to stop the vibration), or when the octave is lowered (this occurs when the peak of the waveform is missed). Happens)
When the pitch change occurs, it becomes unnatural if the pitch is changed. Therefore, branching is performed so as not to change the pitch.

That is, in S58, when tt does not exceed TTU, that is, when it becomes smaller than the value TTU which is 17/32 times the cycle extracted last time, the flow proceeds to S76. In other words, when an octave higher sound is extracted, it is considered that a mute operation has been performed, and the process goes from S58 to S76 without outputting an octave higher sound. To stop.

In S59, when tt does not exceed TTW, that is, when TTW is larger than the value TTW which is 31/16 times the previously extracted cycle, the process does not proceed to S60, and M2 of the main routine of FIG. Return to the processing of.

This state is shown in FIG. Usually, when the waveform is very small near the note-off, the waveform picks up due to crosstalk of the hexa pickup and resonance of the body due to other picking. Then, for example,
An input waveform as shown in FIG. 18 may be obtained, and an input waveform one octave lower may be continuously detected.

In such a case, if no processing is performed,
It suddenly outputs a sound one octave lower, which is extremely unnatural. Therefore, Tan + 2 ＋ T in S56 and S57
Even if an + 3 ≒ Tbn + 2 is detected, Tan + 3> T
Since an + 1 × (31/16), the process returns from S59 to the processing of M2 in the main routine of FIG. 4 without changing the pitch. << Operation of Dubbing Process >> Next, a process in a case where a waveform is dubbed and extracted, that is, a case where peaks having the same polarity are continuously detected will be described.

First, in the route in which the determination result in S42 in STEP4 of FIG. 9 is NO, in the case of YES in S63, the flow proceeds to S68 to perform the dubbing process. That is, S6
In the case of YES in 3, the process proceeds to S 68, and it is determined whether or not the current peak value c> the previous peak value AMP (b) of the same sign. In the case of YES, the process proceeds to S 69.

In S69, the previous peak value AMP (b) is rewritten to the current peak value c, and the flow advances to S70. S7
At 0, the current peak value c> the previous amplitude value (peak value) AM
It is determined whether it is RL1, and if YES, the process proceeds to S71, where the current peak value c is set to the previous amplitude value (peak value) AMRL1.

As soon as NO is determined in S68, the process returns to the process of M2 in the main routine of FIG. Therefore, only when the peak of the new input waveform is large, it is considered that the harmonic peak is not spread,
A new waveform peak value is registered.

When the result in S70 is NO and the process in S71 ends, the process returns to the main routine. FIG. 19 shows an example of the above-described dubbing processing. In this case, the state of MT = 0 is shown. In general, since the fundamental wave period and the period of the harmonic component are non-integer multiples, the phases of the harmonics are shifted, and a zero-cross of the same polarity is detected. I have to do it. In the case of the example shown in this figure, a state of double occurs where “double” is indicated.

At this time, the process goes from S42 to S63, and Y
After the determination of ES, go to S68. In S68, in this case, (an + 2) and (an + 3) are compared to obtain (a
Only when (n + 3) is larger than (an + 2), go to S69 and rewrite AMP (1). Then, the previous amplitude value (peak value) AMRL1 is compared with the current amplitude information (peak value c) in S70, and if YES, S71 is performed.
To the current peak value c and the previous amplitude value (peak value)
AMRL1.

Next, in the route in which the determination result in S42 of STEP 4 in FIG. 9 is YES, the next S43 is NO.
If so, the process proceeds to S72, and the dubbing process is performed in the same manner as described above.

That is, if NO in S43, the process proceeds to S72, where the current peak value c> the previous peak value AMP having the same sign.
(B) is determined, and in the case of YES, the process proceeds to S73. After the current peak value c is replaced with the previous peak value AMP (b), the process returns to the process of M2 in the main routine of FIG.

As soon as NO is determined in S72, the process returns to the process of M2 in the main routine of FIG. Therefore, also in this case, the peak value of the new waveform is registered only when the peak of the new input waveform is large.

FIG. 20 shows an example. In this example, MT
= 1. In this case, in the process of STEP 4 at the time of the zero cross which is written as “double” in the figure, the process goes from S42 to S43, and YES is determined in S43 and S72 is performed.
Proceed to. Here, the magnitudes of (an + 3) and (an + 2) are compared. If (an + 3) is greater than (an + 2), a determination of YES is made in S72, and AMP (1)
The value of (an + 3) is set, and if not, no change processing is performed.

By the way, in the case of the above-described double processing, since the extracted time data is not used at all, the period information T
an + 3 does not change at all. Also, the pitch is not changed based on the cycle data. << Other Embodiments of the Present Invention >> In the above embodiments, the present invention is applied to an electronic guitar (guitar synthesizer), but is not limited thereto. A tone generator that detects a performance operation as an input waveform signal and generates an acoustic signal different from the original signal based on the input signal.When the input waveform signal rises, the pitch period deviates from the true pitch from that waveform. Various ones can be applied as long as they have a tendency to be extracted.

[0194]

According to the present invention, when the pitch information is extracted from the input waveform signal by the pitch extraction means, only when the input waveform signal rises, the pitch information correction means corrects the original pitch cycle. Therefore, even if the frequency corresponding to the pitch information is extracted from the true value at the time of the rise of the input waveform signal, the pitch corresponding to the actual pitch can be specified accurately, and the accurate sound It becomes possible to start producing a musical tone at a high altitude.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of an electronic musical instrument according to the present invention.

FIG. 2 is a configuration diagram of a pitch extraction digital circuit.

FIG. 3 is a diagram illustrating an operation flowchart of an interrupt processing routine.

FIG. 4 is a diagram showing an operation flowchart of a main routine.

FIG. 5 is a diagram showing an operation flowchart of STEP0.

FIG. 6 is a diagram showing an operation flowchart of STEP1.

FIG. 7 is a diagram showing an operation flowchart of STEP2.

FIG. 8 is a diagram showing an operation flowchart of STEP3.

FIG. 9 is a diagram showing an operation flowchart of STEP4 (5).

FIG. 10 is a schematic operation explanatory diagram of the present embodiment.

FIG. 11 is an explanatory diagram of a basic operation of the present embodiment.

FIGS. 12A and 12B are diagrams illustrating the operation of the dubble process in STEP1.

FIG. 13 is a diagram illustrating the operation of the dubbing process in STEP2.

FIG. 14 is an explanatory diagram of the operation of the dubbing process in STEP2.

FIG. 15 is a diagram illustrating the operation of the dubbing process in STEP2.

FIG. 16 is an explanatory diagram of the operation of the noise removal processing in STEP3.

FIG. 17 is an explanatory diagram of the operation of the relative off process in STEP4.

FIG. 18 is an explanatory diagram of a processing operation when a pitch cycle is inappropriate in STEP4.

FIG. 19 is an explanatory diagram of the operation of the doubling process in the route.

FIG. 20 is an explanatory diagram of the operation of the doubling process on the route.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Pitch extraction analog circuit 2 Pitch extraction digital circuit 3 Central control unit (MCP) 4 Address decoder 5 Tone generator 201 Peak detection circuit 202 Time constant conversion control circuit 203 Peak value capture circuit 204 Zero cross time capture circuit 501 Musical tone generation circuit D1 Digital output

Claims (1)

(57) [Claims] 1. A pitch extracting means for extracting pitch information from an input waveform signal, a pitch information correcting means for correcting pitch information at the time of rising of the input waveform extracted by the pitch extracting means, and a rising of the input waveform At the time, a tone is generated at a pitch corresponding to the pitch information corrected by the pitch information correction means, and after the start, a tone is generated at a pitch corresponding to the pitch information extracted by the pitch extraction means. An electronic musical instrument comprising: a musical sound generating means.