JPS6238714B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an electronic musical instrument in which the conversion of a musical sound waveform controlled by a timbre control device does not affect the generation of the musical sound waveform and has a fast response to the conversion of the musical sound waveform. .

Conventionally, in a device that has a large number of key switches, such as the keyboard of an electronic musical instrument, in order to transfer the information associated with the opening and closing of the switches to the required circuits, the amount of wiring would be enormous if you tried to connect each switch directly to the circuit. It is uneconomical. Furthermore, if a semiconductor integrated circuit or the like is to be used, the number of pins will be too large, making it difficult to use as is.

Currently, in view of these points, all switches are scanned for a predetermined period of time, and a pulse is generated at the time corresponding to the key switch turned on in the time sequence according to the scan, and a pulse is generated between many switches and the required circuit. A method to save wiring is being considered.
For example, by scanning each key switch in a time-division manner, the information of the turned-on switches can be transmitted using TDM (time division modulation) signals or PCM (pulse code modulation).
A key code multiplexing method in which signals are sent as signals is generally used. However, since the time required to scan all the key switches is fixed, a fixed scanning time is required even when only a few key switches are turned on, resulting in waste.

When playing a normal keyboard instrument, the number of keys that are turned on at the same time is 11, considering both hands and feet. If we consider one block to be one octave unit, it is impossible to press keys for more than two octaves with one hand, so five blocks is the maximum number of blocks that can be occupied at the same time. Therefore, the keyboard switches are divided into a plurality of blocks and scanned, and if even one switch is turned on, scanning is stopped at that block to detect an on switch. Since a block without an on switch is passed through, it is possible to shorten the time required for one scan to obtain information about an on switch.

Recently, the applicant of the present invention has proposed a key code generation circuit and a key code detection circuit with reduced scanning time, or a digitally processed electronic musical instrument using these circuits, in accordance with the above-mentioned idea.

In such electronic musical instruments, there is a method in which the main oscillator generates the required frequency via a variable frequency divider circuit in response to the key closing signal captured by the channel determined by the maximum number of sounds of the key code detection circuit. used. On the other hand, a tone waveform is generated by calculating the tone waveform data required by the timbre control device with a waveform calculator to obtain a synthesized tone waveform, and reading this out at the readout frequency associated with the above-mentioned key closing. . Conventionally, the method for generating this musical tone signal is to write a synthesized sound waveform calculated by a waveform calculator based on the above-mentioned musical sound waveform data into a buffer register, and from this, notes corresponding to each channel CH ₁ to _{CH o} are generated. They are written to the register simultaneously and within a short period of time, regardless of the tone period. Therefore, when waveform calculation is performed when a key is pressed, noise is generated, which adversely affects the generation of musical sound waveforms controlled by the timbre control device.

SUMMARY OF THE INVENTION An object of the present invention is to provide an electronic musical instrument in which the conversion of musical sound waveforms controlled by a timbre control device does not affect the generation of musical sound waveforms and has a fast response to the conversion of musical sound waveforms.

In order to achieve the above object, the electronic musical instrument of the present invention calculates the musical waveform data required by the timbre control device, obtains a synthesized waveform, and reads it out at the readout frequency associated with key closing. A digitally processed electronic musical instrument that generates a musical sound waveform includes a calculation circuit that calculates musical sound waveform data in connection with the operation of the tone control device and generates a plurality of write signals, and a scale frequency corresponding to a closed key. a readout signal generation circuit that generates a plurality of readout signals related to the counting circuit; and first and second storage circuits that store musical waveform data from the counting circuit using the plurality of write signals and read out using the plurality of readout signals. and a transmission cycle end signal TES indicating the end of the plurality of write signals from the calculation circuit,
a synchronization detection end signal that detects the cycles of each of the plurality of read signals and indicates the end of detection of the cycles of all the signals;
two sets of synchronization detection circuits 12 that generate CES and output it alternately to the first and second storage circuits, respectively;
A, 12B; first, the synchronization detection circuit 12B detects the period of each of the plurality of read signals when the musical waveform data of the first storage circuit is being read;
Period detection end signal when detection of the period of all the signals is completed
The calculation circuit outputs CES and receives the period detection end signal CES, and calculates new musical tone waveform data, and also applies the new musical tone waveform data to the second musical tone waveform data.
Write data to the memory circuit using the plurality of write signals, and when the write signals end, a transmission cycle end signal is generated.
The synchronization detection circuit 12A outputs TES and receives the transmission cycle end signal TES, and sequentially transfers the plurality of read signals to the second storage circuit, and transfers the tone waveform data from the second storage circuit to the plurality of read signals. The first step is to start reading by a read signal, and then, when the musical waveform data in the second storage circuit is being read, the synchronization detection circuit 12A reads the next new data by the same operation as above. is calculated by the calculation circuit and then written to the first storage circuit, and upon completion of the writing, the synchronization detection circuit 12A receives the output of the transmission cycle end signal TES and sequentially sends the plurality of read signals to the first storage circuit. a second memory circuit that transfers the musical waveform data and starts reading out the musical waveform data from the first memory circuit;
This method is characterized in that the steps of (1) and (2) are repeated alternately.

The present invention will be described in detail below with reference to examples.

First, an outline of an example of an electronic musical instrument with a novel configuration to which the present invention is applied will be explained, and then a detailed embodiment of the musical sound waveform generating section of the present invention will be explained as a part of the configuration.

An electronic musical instrument to which the present invention is applied is a digital musical instrument that calculates musical waveform data required by a tone control device, obtains a synthesized waveform, and generates a musical tone by reading this at a readout frequency associated with key switch closure. It is an electronic musical instrument.

FIG. 1 is a basic block diagram showing the overall configuration of an electronic musical instrument to which the present invention is applied. In the figure, key information associated with the closing of a key switch from a keyboard 4 is generated by a key code generation circuit 5. In the key code generation circuit 5, the keyboard switches are divided into a plurality of blocks, and when one or more key switches in a block are closed, the ON state of the key switches in that block is detected, and one frame is composed of the detection blocks. Scanning is performed using a variable frame method, and a key code signal KCD and frame synchronization signal FP are generated. The key code detection circuit 6 has a number of channel circuits 6 (CH ₁ ), 6 corresponding to the maximum number of simultaneous sounds.
(CH ₂ ), ...6 (CH _o ), and whether it is the key code signal KCD that was previously captured by the key code detection circuit 6 using the key code signal KCD and frame synchronization signal FP mentioned above. , it also detects whether the key switch is opened or not, and the common logic circuit 7
give to The common logic circuit 7 determines whether or not to capture the key code signal KCD, and if captured, supplies the key code detection circuit 6 with a signal specifying the channel. Key code detection circuit 6 for channels designated for capture
Then, the key code signal KCD is captured, the envelope counter circuit 8 starts counting, and the corresponding channel pulse generated by the sequential pulse generation circuit 2 operated by the master clock MC from the master clock generation circuit 1 is generated.
The signal is time-divided by CH _po and supplied to the envelope generation circuit 8 via the bus line. The envelope generation circuit 8 uses an envelope master clock.
The envelope data that corresponds to the envelope data constantly read by MC' is calculated based on the count value to obtain an envelope waveform. The state transitions of the musical sound waveform in the attack, decay, and sustain states are controlled by set values given to the envelope generating circuit 8.

Furthermore, the release associated with the key switch closing, that is, the transition to the open state, is performed in the key code detection circuit 6 using the frame synchronization signal FP and the key code signal KCD, which are supplied to the envelope generation circuit 8, and are also transmitted in response to the release state. This is done by calculating the current data. The note signal NC in the key code signal KCD captured by the key code detection circuit 6 is time-divided by its corresponding channel pulse, and the note clock generating circuit 3
given to. Note clock generating circuit 3 includes note clock generators corresponding to 12 notes, and generates signals B ₀ to B ₁₀ corresponding to each note by master clock MC. The given note signal NC is decoded and distributed to the note generator corresponding to the note signal NC,
The octave frequency selection circuit 9 outputs the octave signal via the bus line by turning on the gate circuit.
Signal B ₀ from note signal generation circuit 3 by OC
~B Select ₁₀ and main memory circuit ()10, ()11
The address read signal (ADD ₀ to _{ADD 4} ) R is input to the waveform correction circuit 14, and the correction control signal (ADD′ ₀
~ADD′ ₅ ).

The musical waveform calculation circuit 13 receives the signal from the synchronization detection circuit 12, detects which key switches of each drawbar switch and tablet switch are turned on, and stores the corresponding waveform data in the main memory circuit ().
10, detect and read from ()11,
A new musical tone synthesis waveform is calculated one after another, and the sign bit D3, which indicates the sign bit _D3 indicating the sign bit of the difference value between the amplitude value _D1 and the difference value _D2 of the musical sound waveform at the sampling point, is synchronized by the address write signal ( _ADD0 to _ADD4 ) W. Main memory circuit specified by detection circuit 12 ()
10, ()11.
Upon completion of writing, the synchronization detection circuits 12A, 12
A main memory circuit () 10, () in which one cycle of musical tone due to key switch closing is detected from the address read signal (ADD ₀ to ADD ₄ ) R in the circuit specified by B, and new musical waveforms are sequentially written. 1
Start reading to 1. When the reading of the new musical sound waveform to the main memory circuits ( ) 10 and () 11 in which it has been written is completed, a new musical sound synthesized waveform is calculated by the musical sound waveform calculation circuit 13, and circuit ()10, ()
11.

The musical sound waveform read out by the address readout signal (ADD ₀ to ADD ₄ ) R is corrected by the correction control signal (ADD' ₀ to ADD' ₄ ) given to the waveform correction circuit 14, and the step noise frequency is is always constant regardless of the readout frequency, and the multiplier circuit 1
given to 5. In the multiplication circuit 15 , the signal is multiplied by the envelope waveform from the envelope generation circuit 8 and inputted to the cumulative adder 16 . An envelope is added to the closed musical sound waveform of the key switch of all channels, and a digital analog (D-
A) It is converted into analog by the converter 17 and the sound is emitted via the sound system 18.

FIG. 2 is a detailed explanation of an embodiment of the main memory circuits () 10, () 11 and the synchronization detection circuit 12, which are the main parts of the present invention in FIG.

To summarize the diagram, the synchronization detection circuit 12 has two
Consisting of two synchronization detection devices 12A and 12B,
The following procedures are cyclically repeated in association with the main memory circuits ( ) 10 and ( ) 11.

First, when the musical tone cycles of all channels are detected by the synchronization detection device 12B, a synchronization detection end signal CES is generated, and the musical sound waveform calculation circuit 13
sent to.

On the other hand, all address read signals (ADD ₀
~ _ADD4 ) _R is given to the main memory circuit 10.

A new tone waveform is calculated by the tone waveform calculation circuit 13 and written into the main memory circuit 11 using address write signals ( _ADD0 to _ADD4 ) _W . At this end, the transmission cycle end signal TES is sent to the synchronization detection device 12.
Sent to B.

As a result, the address read signal (ADD ₀ ~
ADD ₄ ) The transfer of _R is sequentially transferred from the main memory circuit 10 to the main memory circuit 11 in each channel period.

In this case, when the synchronization detection device 12A detects the musical tone cycles of all channels, a synchronization detection end signal CES is generated and sent to the musical waveform calculation circuit 13.

On the other hand, all address read signals (ADD ₀
~ _ADD4 ) _R is given to the main memory circuit 11.

A new tone waveform is calculated by the tone waveform calculation circuit 13, and an address write signal ( _ADD0 to _ADD4 ) _W is written into the main memory circuit 10. At this end, the transmission cycle end signal TES is sent to the synchronization detection device 12.
Sent to A.

As a result, the address read signal (ADD ₀ ~
ADD ₄ ) The transfer of _R is sequentially transferred from the main memory circuit 11 to the main memory circuit 10 every channel period, and then returns to .

Following the above procedure, the detailed configuration and operation will be explained. Figure 4 ~ is the main memory circuit ()
10, () 11 and a waveform diagram showing the operation of the synchronization detection circuit 12, and according to the explanation of FIG. 2, FIGS.
will be explained with reference to it in parentheses.

In FIG. 2, when "1" is output from the AND circuit 12-5 due to the output of 12B of the synchronization detection devices 12A and 12B constituting the synchronization detection circuit 12 [FIG. 4], the flip-flop 12-8 is set. At the same time [Figure 4], OR circuit 12-
A synchronization detection end signal CES is output from 10 [FIG. 4]. The musical waveform calculation circuit 13 receives this signal and detects which key switches of each drawbar switch and tablet switch of the tone control device are turned on, and performs a drawbar detection cycle TDR.
During the tablet detection cycle TTA, each musical tone waveform is calculated and synthesized [Figure 4], and the transmission cycle
At TTR, musical waveform data D ₁ , D ₂ , D ₃ and address write signals (ADD ₀ to ADD ₄ ) W are sent to main memory circuits ( ) 10 and ( ) 11 [fourth
figure〕. Since the flip-flop 12-8 is in the set state, the write signal W is applied to the main memory circuit 11-1 and the gate circuit 11-3 is turned on. That is, the address write signal (ADD ₀
~ADD ₄ ) W is gate circuit 11-3 and OR circuit 1
1-4 to the main memory circuit 11-1,
Write the musical sound waveform data D ₁ , D ₂ , D ₃ .
After this writing is completed, the flip-flop 12-8 is reset by the transmission cycle end signal TES from the tone waveform calculation circuit 13 (FIG. 4).
As a result, the reset state of the synchronization detecting device 12A in the set state of the flip-flop 12-8 is released and becomes the set state, and the address read signal (ADD ₀ to _{ADD 4} ) is transferred from the octave frequency selection circuit 9 via the bus line. Detection of R is started.

Time-division address read signals (ADD ₀ to ADD ₄ ) R are generated by channel pulses CH _p1 to _{CH po} to all “0” detection circuits (12A-1) ₀ to (12A-1) _o provided for each channel. Address "0" is detected for each channel and given to period detection circuits (12A-2) ₁ to (12A-2) _o . This period detection circuit (12A-2) ₁ ~
(12A-2) At _o , one cycle of each channel is detected by detecting an address "0" signal that arrives after a predetermined time from the first detected address "0" signal.

Figure 3 shows the all “0” detection circuit (12-1) _1~
A detailed circuit example of _o and period detection circuit (12-2) _{1 to o} is representatively shown. FIGS. 5A and 5B are waveform diagrams for explaining these operations. FIGS. 6 to 6 show readout musical sound waveforms in multi-channels related to FIGS. 2 and 3, and show the relationship between musical sound waveforms and address "0". The following will be explained in accordance with FIG. 3 with reference to FIGS. 5 to 6 in parentheses.

In Figure 3, the address read signal (ADD ₀
~ADD ₄ ) Address "0" in R [Figure 5] is detected by the NOR circuit 12-1-1, and the channel pulse corresponding to that channel is detected.
It is selected by CH _po through AND circuit 12-1-2 (FIG. 5), and sets flip-flop 12-2-1 in period detection circuit 12-2. This causes flip-flop 12-2-1 to transition to the set state, thereby operating monostable multivibrator (MS) 12-2-4 (FIG. 5).
From this, in order to turn off the AND circuit 12-2-2, the monostable multivibrator (MS) 12-2
-4 is operating, all “0” detection circuit (12-
1) The address “0” detected by ₁ to o is
It continues to be turned off by the AND circuit 12-2-2. This monostable multivibrator (MS) 12
-2-4, the address "0" detected after the completion of the operation is [Fig. 5] flip-flop 12-2.
-3 (Figure 5). The output signal Q of this flip-flop 12-2-3 is applied to the AND circuit 1.
2A-5 and AND circuit 12
The output signal from -2-2 is applied to OR circuit 12A-4. Monostable multivibrator (MS)
The operation time of 12-2-4 may be set to be longer than the address read signal (ADD ₀ ) R time in the lowest tone cycle. This state is maintained while the flip-flop 12-8 is set, and the flip-flop 12-8 is reset, and each flip-flop 12-2-1, 12-2
-3 is reset.

One cycle of detected channel pulses CH _p1 to _{CH po} generated by the OR circuit 12A-4 is applied to the gate circuit 12A-6 from the AND circuit 12A-7, and further to the gate circuit 1 of the main memory circuit () 11.
1-2 is given. As a result, one cycle of the detected address read signal (ADD ₀ to ADD ₄ ) R is
It is applied to the main memory device 11-1 via the OR circuit 11-4 to start reading. In this way, cycle detection circuits (12A-2) ₁ to (12A-
2) One cycle of each channel is detected by _o , and the reading of newer tone waveforms from the detected ones is sequentially started from the main storage device 11-1 (FIGS. 6-).

For channels whose keys are closed, the address “0” is set for each channel pulse CH _p1 to CH _po .
Since signals are transferred, one cycle detection is performed at high speed. Furthermore, the AND circuit 12B-7 prohibits the main memory device 10-1 from reading out the main memory device 11-1 first.
AND circuit 12B-7 has OR circuit 12A-4, 1
Each output signal of 2B-4 and AND circuit 12B-
Since the output signal of 5 is input, OR circuit 12
When channel pulses of the same channel are generated from A-4 and 12B-4, the AND circuit 12B- of the synchronization detection device 12B that was performing the readout first
Since the output of 5 is "1", the AND circuit 12B-7 outputs an inhibit signal to the gate circuit 12B-6, turning off the gate circuit 12B-6. In this way, reading from the two main memory circuits ( ) 10 and ( ) 11 is prohibited in one channel at the same time. Read signals (ADD ₀ to ADD ₄ ) from all main memory circuits () 10 R
is transferred to the main memory circuit ( ) 11, and after the reading and transfer of the musical tone signal is completed, "1" is output to the AND circuit 12A-5, setting the flip-flop 12-9, and transmitting the write signal W to the main memory circuit () 10. At the same time, the synchronization detection end signal CES is sent to OR circuit 1.
2-10 to the musical tone waveform calculation circuit 13 to instruct calculation of a new musical tone waveform. Drawbar detection cycle in musical sound waveform calculation circuit 13
TDR, the musical sound waveform calculated by the tablet detection cycle TTA is written to the main memory 10-1 via the gate circuit 10-3 and the OR circuit 10-4 by the transmission cycle TTR, and the flip-flop 12-9 is At the same time, the synchronization detection device 12B performs the same detection as described above, and the main memory circuit () 11 is read out from the main memory circuit () 11 in which new tone waveforms are stored sequentially from the detected channel. Let's move to 10.

The musical sound waveform is generated from the "main memory circuit (2011)" when reading or writing from the "main memory circuit (2010)",
It continues to be generated from the "main memory circuit () 10" when writing to the "main memory circuit () 11", and therefore, changes in the musical sound waveform due to the operation of the timbre control device have no effect on the generation of the musical sound waveform. . Furthermore, since the period detection of different musical sound waveforms is detected by the period detection circuits (12-2) ₁ to (12-2) _o connected in parallel, it is done quickly, and even when the musical sound waveform is changed, it is done instantaneously. .

In the embodiment, synchronization detection was explained in units of one cycle, but this is determined by the tablet detection cycle, drawbar detection cycle, transmission cycle, and the highest frequency of the musical waveform to be obtained.
It goes without saying that detection may be performed in units of multiple cycles.

As explained above, according to the present invention, when the first memory circuit is being read by locking,
A new musical sound waveform accompanying the operation of the timbre control device is stored in the second storage circuit, and the readout is transferred to the second storage circuit in synchronization with the readout cycle by the first storage circuit. After the read transfer from the memory circuit to the second memory circuit is completed, a new music waveform accompanied by the operation of the timbre control device is written in the first memory circuit. In this way, the conversion of the musical sound waveform controlled by the timbre control device, that is, the writing from the musical sound waveform calculation circuit to the memory circuit, and the generation of the musical sound waveform, that is, the reading of the musical sound waveform from the memory circuit, are separated in terms of time and circuit. Therefore, the conversion of the tone waveform does not affect the generation of the tone waveform. Furthermore, by detecting musical tone cycles in parallel as described above, it is possible to realize an electronic musical instrument with excellent responsiveness to musical sound waveform conversion.

[Brief explanation of the drawing]

FIG. 1 is a schematic explanatory diagram of an electronic musical instrument to which the present invention is applied, FIG. 2 is an explanatory diagram showing the configuration of an embodiment of the present invention, and FIG. 3 is a detailed explanatory diagram of the main part of the embodiment of FIG. Fig. 4 is an operating waveform diagram of the main part of Fig. 2, Fig. 5 is an operating waveform diagram of the main part of Fig. 3, Fig. 6 is the operating waveform diagram of the main part of Fig. 2,
This is an example of a readout musical sound waveform related to FIG. 3, in which 1 is a master clock generation circuit, 2 is a sequential pulse generation circuit, 3 is a note clock generation circuit, 4 is a keyboard, 5 is a key code generation circuit, and 6 is a key code. Detection circuit, 7 common logic circuit, 8 envelope generation circuit, 9 octave frequency selection circuit, 10
is the main memory circuit (), 11 is the main memory circuit (), 1
2 is a synchronization detection circuit, 13 is a musical sound waveform calculation circuit, 1
4 is a waveform correction circuit, 15 is a multiplication circuit, 16 is an accumulation adder, 17 is a D-A converter, 18 is a sound system, 10-1, 11-1 are main storage devices, 10
-2, 10-3, 11-2, 11-3 are gate circuits, 10-4, 11-4 are OR circuits, 12A, 1
2B is a synchronization detection device, (12A-1) ₁ to (12
A-1) _o is an all “0” detection circuit, (12A-
2) ₁ to (12A-2) _o is a period detection circuit, 12-
8, 12-9 indicate flip-flops.

Claims (1)

[Claims] 1. Digital processing that generates a musical sound waveform by calculating musical sound waveform data required by a timbre control device, obtaining a composite waveform, and reading this at a readout frequency associated with key closing. An electronic musical instrument comprising: a calculation circuit 13 that calculates musical waveform data in connection with the operation of the timbre control device and generates a plurality of write signals; and a plurality of read signals related to scale frequencies corresponding to closed keys. read signal generation circuits 1 to 7, 9 that generate signals, and first and second storage circuits that store musical waveform data from the calculation circuit 13 using the plurality of write signals and read out using the plurality of read signals. 10, 11, and synchronization detection which inputs the transmission cycle end signal TES indicating the end of the plurality of write signals from the calculation circuit 13, detects the period of each of the plurality of read signals, and shows the end of detection of the period of all the signals. end signal
two sets of synchronization detection circuits 12 that generate CES and output it alternately to the first and second storage circuits, respectively;
First, when the musical waveform data of the first storage circuit 10 is being read out, the synchronization detection circuit 12B detects the period of each of the plurality of readout signals, and detects the period of each of the plurality of readout signals. When the period detection ends, the period detection end signal CES is output, and the period detection end signal CES is output.
The calculation circuit 13 that has received the calculation circuit 13 calculates new musical tone waveform data, writes the new musical tone waveform data into the second storage circuit 11 using the plurality of write signals, and outputs a transmission cycle end signal TES when the writing is completed. and the transmission cycle end signal
Upon receiving the TES, the synchronization detection circuit 12A sequentially transfers the plurality of read signals to the second memory circuit 11, and starts reading musical waveform data from the second memory circuit 11 using the plurality of read signals. In the first step, when the synchronization detection circuit 12A is reading out the musical waveform data from the second storage circuit 11,
By the same operation as above, the next new data is calculated by the calculation circuit 13, and this time, the first storage circuit 1
0, and upon completion of the writing, the synchronization detection circuit 12A, which receives the output of the transmission cycle end signal TES, sequentially transfers the plurality of read signals to the first storage circuit 10 and retrieves the musical waveform data from the first storage circuit 10. 1. An electronic musical instrument characterized in that the second procedure of starting reading of the data is repeated alternately.