JPH02179697A - Processor for electronic musical instrument - Google Patents

Abstract

PURPOSE:To generate musical sounds according with functions of an electronic musical instrument and the degree of complication of processing by generating musical sounds in response to the interrupt signal generated with the sampling period from a timer interrupt control circuit and varying the sampling period. CONSTITUTION:A microcomputer performs interrupt handling to generate musical sounds at each time of generation of the interrupt signal from an interrupt control part 40 having a timer, a thereby keeping the musical sound sampling period during the operation. The generation interval of the interrupt signal generated by the control part 40, namely, the sampling period of musical sounds is variably programmed by the microcomputer 1. Thus, musical sounds are generated with the musical sound sampling period according with functions of the electronic musical instrument, the number of polyphonics, the manner of musical sound synthesis, and the degree of complication of processing.

Description

[Detailed Description of the Invention] [Technical Field of the Invention] The present invention relates to a processing device for an electronic musical instrument, and in particular to a structural architecture for musical tone synthesis in a processing device for an electronic musical instrument.
Regarding.

[Background of the invention] In recent years, electronic musical instruments have been computerized.

However, the part involved in generating musical sounds, which requires large amounts of high-speed data calculation, is performed by specialized hardware called a sound source circuit, and a microcomputer is used to input control inputs to musical instruments (inputs from the keyboard and console panel, etc.). It merely processes MIDI and other external control inputs, inputs from internal or external performance memories, etc.) and transfers appropriate commands to the tone generator circuit.

There are several problems with the system architecture of electronic musical instruments, in which musical tone generation processing is performed by sound source circuit hardware, and musical instrument control input processing is performed by a microcomputer. First, the tone generator circuit hardware consists of storage devices that temporarily store data and arithmetic circuits that perform calculations at various stages of processing musical tone parameters, so the circuit size inevitably increases. Typically, it is about twice the size of a microcomputer. Second, there is a limit to the ability of a microcomputer to variably control the way musical tones are synthesized using sound source circuit hardware.For example, the number of simultaneous polyphonic sounds (polyphonic number) is fixed in hardware, so commands from a microcomputer Also, since the sampling frequency of musical tones is fixed by the hardware of the sound source circuit, it cannot be changed by commands from the microcomputer.
Such control limitations become a barrier when designing new sound source circuit hardware. That is, large-scale circuit changes are often necessary, which requires a great deal of development time and effort. Furthermore, the communication protocol or interface (transfer method, command set, etc.) between the microcomputer and the sound source circuit hardware must be reconsidered and redeveloped for each sound source circuit hardware.

For the above reasons, the applicant has continued to research the system architecture of a new electronic musical instrument that can generate musical tones solely through microcomputer program control without using sound source circuit hardware, and has finally achieved its realization. saw.

One of the issues that must be solved in realizing the system architecture of new electronic musical instruments is that the sampling frequency of musical tones, that is, the The problem was how to effectively maintain the interval at which a computer generates digital musical tone signals. Furthermore, there is a need for a mechanism that can easily set the optimum musical sound sampling frequency according to various uses of the electronic musical instrument, such as the method of musical sound synthesis, the degree of complexity of processing, the number of polyphonic sounds, etc.

[Object of the Invention] Therefore, the object of the present invention is to enable a microcomputer to generate musical tones by itself through program control without requiring conventional sound source circuit hardware, and to solve problems caused by program control. In particular, it solves the problem of establishing the musical sound sampling period during operation, and immediately responds to various specification changes, design changes, polyphonic number changes, changes in musical tone synthesis methods, changes in musical instrument control processing, etc. related to the mechanism of electronic musical instruments. An object of the present invention is to provide a processing device for an electronic musical instrument that realizes a function of selecting an optimum musical tone sampling period.

[Structure and operation of the invention] According to the present invention, in order to achieve the above object, there is provided a program storage means for storing a program for processing an input to control a musical instrument and a program for generating musical tones, and this program. address control circuit means for controlling the address of the storage means; data storage means for storing data necessary for generating musical tones; arithmetic circuit means; The microcomputer comprises an operating and control circuit means for controlling operations, and the microcomputer further has a timer interrupt control circuit means for generating an interrupt signal at the sampling period of musical tones. A musical tone is generated by executing a program in the microcomputer to generate the musical tone in response to an interrupt signal of the musical tone. Provided is a processing device for an electronic musical instrument characterized in that the sampling period can be variably programmed.

That is, in this invention, the work being performed by the microcomputer is interrupted by an interrupt signal from the timer interrupt control circuit means, and a program for generating musical tones is executed, so that a sample of musical tones is generated at each sampling period of musical tones. This problem can be effectively solved using a program control method. That is, the process of generating musical tones is given priority over other processes, and is executed each time an interrupt signal is generated from the timer included control circuit means. Since the timer interrupt control circuit means basically consists of a timer (counter), the interval at which the interrupt signal is generated is very stable. Furthermore, since a musical tone sample is generated each time an interrupt signal is generated, the interval at which the interrupt signal is generated is nothing but the musical tone sampling period.Furthermore, according to the present invention, the timer interrupt control circuit means is programmable. It is. Therefore, interrupt signals can be generated from the timer interrupt control circuit means at optimal intervals according to the polyphonic number, the method of musical tone synthesis, etc. For example, if the timer interrupt control circuit means is configured with a presettable down counter. shall be. The microcomputer presets data representing the sampling period in this counter upon startup (for example, during initial setting processing at power-on). The counter decrements the count value every clock (signal from a master clock source such as a crystal oscillator). When the counter value reaches zero, an interrupt signal is generated from the counter and requests an interrupt to the microcomputer. Furthermore, the preset data (held) is set in the counter again by this interrupt signal. When the value is 0 or more, an interrupt is generated from the timer interrupt control circuit means at the sampling period desired by the microcomputer, and each time the microcomputer generates a musical tone. Execute generation processing.

The musical tone generation process (interrupt process) must be completed before the next interrupt signal is output from the timer interrupt control circuit means. If this is not possible, the sampling period of musical tones cannot be maintained, which is necessary for the musical tone generation process. The time depends on the content 1, such as the polyphonic number, the method of musical tone synthesis, and the degree of complexity of the processing. In other words, the execution time of the musical tone generation processing program is 0. For example, if other conditions are kept the same and the polyphonic number is halved, the execution time of the musical tone generation processing program will be approximately halved. In this case, there is no problem with increasing the sampling rate of the musical sound; in fact, it is better to increase the sampling rate when considering the conversion of the digital-to-analog converter.On the other hand, depending on the application, it is necessary to Sometimes a rich musical tone is required. In this case, it is necessary to synthesize one sound through complex processing to provide a musical tone that meets the required conditions, although the polyphonic number is sacrificed. Even in such a case, an appropriate tone sampling period can be considered. The present invention takes into consideration the various usage conditions as described above, and makes it possible to generate musical tones at a musical tone sampling period that meets each of the conditions.

In one configuration example, the microcomputer is realized as an integrated circuit chip, and on this chip, in addition to the above means,
A digital Φ-analog (D/A) converter for converting the generated digital tone signal into an analog signal and a port for receiving input for controlling the musical instrument are also implemented. Therefore, since no sound source circuit hardware is required, the overall circuit scale can be significantly reduced. In the conventional case, the sound source circuit LSI
Since the circuit scale of the chip is large, there is a limit to the yield in chip manufacturing (yield is approximately inversely proportional to the chip area).Therefore, this invention can significantly reduce the manufacturing cost of electronic musical instruments.

[Example J Hereinafter, the present invention will be described in detail with reference to the drawings.

The overall configuration of the electronic musical instrument according to this embodiment is shown in FIG. 1, and the entire device is controlled by a microcomputer l. In particular, according to the present invention, not only the processing of control inputs for the musical instrument but also the processing of generating musical tones is executed by the microcomputer 1, and no sound source circuit hardware for musical tone generation is required. The switch section 4 is a control input source for the musical instrument, and information input from the switch section 4 is processed by the microcomputer 1. The analog-converted musical tone signal generated by the microcomputer 1 is filtered by a low-pass filter 5, amplified by an amplifier 6, and outputted through a speaker 7. Power supply circuit 8
is a microcomputer 1. Low pass filter 5. Supply the necessary power to the amplifier 6.

The internal structure of the microcomputer 1 is shown in a block diagram in FIG. 2. Each element shown in FIG. 0 is mounted on one chip. The actually manufactured chip has a chip size of 5 x 5 mm, has an eight-note polyphonic polyphony, and uses PCM (waveform readout method) as the tone synthesis method. It can also be applied to musical tone synthesis methods.

The control ROM 31 stores a program for processing various control inputs of the musical instrument and a program for generating musical tones, and a program word (instruction) at a specified address is sent from the ROM address control unit 39 via the ROM address decoder 32. Note that in the specific embodiment, the program word length is 28 bits, and a part of the program word is sent to the ROM address control unit 39 as the lower part (in-page address) of the address to be read next. Although the system uses a netast address input method, the present invention can also be applied to a program counter system. The RAM 7 address control unit 33 specifies the address of a corresponding register in the RAM 34 when an operand of an instruction from the control ROM 31 specifies a register. The RAM 34 is a group of registers, and is used for general-purpose rJi4 calculations, flag calculations, musical tone calculations, and the like. The adder/subtractor and logic operation section 35 and the multiplier 36 are used when the instruction from the control ROM 32 is an operation instruction. In particular, the multiplier 36 is used to calculate musical waveforms, and as an optimization for this purpose, it multiplies the first and second data inputs (for example, 16-bit data) to obtain data of the same length (16 bits) as the input. It is designed to be output. The RAM 34, adder/subtractor 351 and multiplier 36 constitute an arithmetic circuit (AU). The control data and waveform ROM 37 contains pitch data and envelope data (
various musical tone control parameters such as rate, level),
CM (pulse code modulation) musical waveform data is stored. Envelope data and musical waveform data are prepared for each musical tone.

Operation analysis section (operation control circuit) 3B
decodes the operation code of the instruction from the control ROM 31,
Control signals are sent to each part of the circuit to execute the instructed operation.

In order to execute the musical tone generation program in the control ROM 31 at predetermined intervals, this device employs a timer interrupt. That is, the interrupt control unit 40 having a timer sends a control signal (interrupt signal) to the ROM 7 address control unit 39 at regular intervals, and based on this signal, the ROM address control unit 39 determines the address of the next main program command. It is saved (retained) and the start address of the interrupt processing program (subroutine) in which musical tones are generated is set instead. This starts the interrupt processing program. Since there is a return instruction at the end of the interrupt processing program, when this return instruction is decoded by the operation analysis section 38, the ROM address control section 39 sets the saved address again and returns to the main program. .

The interrupt control section 40 is programmable according to the present invention. That is, the generation interval (music sampling period) of the interrupt signal of the interrupt control section 40 can be freely set by the microcomputer 1. Details will be described later.

Input port 41 and output port 42 are keyboard 2, function key 3
used for key scanning. The musical tones generated in the interrupt processing program are converted into analog signals by the digital/analog converter 43 and output to the outside.

FIG. 3(A) shows the flow of the main program of the microcomputer l of this embodiment. AI is the initial processing when the power is turned on, and the RAM of the microcomputer l
Clears (register group) 34, sets initial values such as rhythm tempo, etc.

Furthermore, in this initial processing, musical tone sampling period data is set for the interrupt control section 40. Microcomputer l in A2 is output port 4
By outputting a signal for key scanning from 2 and taking in the state of the switch section 4 from the input port 41, the state of the function key 1191 key is stored in the key buffer area of the RAM 34. In A3, from the state of function key 3 obtained in A2.

Identifies the function key whose state has changed and executes the instructed function (for example, setting musical note numbers, setting envelope numbers, mode 2 rhythm numbers, etc.).
From the state of keyboard 2 obtained in , identify the key that changed (key pressed, key released) 1 sound generation processing A from the processing result of A4 in 0th order A5
In A6, when the demo performance key is pressed with the function key 3, the demo performance data (sequencer data) is transferred from the control data/waveform ROM 37.
By sequentially reading and processing the key assignment processing for the sound production processing A9, etc.

A7 sequentially reads rhythm data from the control data/waveform ROM 37 when the rhythm start key is pressed and performs key assignment processing for the 1st sound generation processing A9.Flow-period timer processing A8 performs event necessary in the main flow. In order to know the timing of flow-same time (this can be obtained by counting the number of timer interrupts executed during one cycle of the flow. This counting process is performed in interrupt timer process B3, which will be described later). )
In the 0 sound processing A9, calculations are performed based on the data set in A5, A6, and A7 to obtain the reference value for the envelope timer (envelope calculation cycle) and rhythm.
Various calculations are performed to actually generate musical tones, and the results are set in the sound source processing register (FIG. 6) in the RAM 34. A10 is a preparation process for the next main flow pass, and NE indicating the change to the key press state obtained on this bus.
Processes such as changing the W ON state to ON or changing the NEW OFF state indicating a change to the key released state to OFF are performed.

The flow of the interrupt processing program in which musical tones are generated is shown in Figure 3B. In B1, musical waveform data (cumulative waveform values for 8 tones) generated in B2 of the previous interrupt sound source processing is D/A converted. The signal is sent to the device 43. As a result, the musical tones of each channel are generated and accumulated in the ninth-order sound source processing B2 in which musical tone samples are provided to the D/A converter 43 at regular intervals. Conventionally, this processing was performed on the sound source circuit hardware. Details will be described later.

In the next interrupt timer 7 process B3, taking advantage of the fact that the interrupt takes a predetermined time, each time the flow-hand setting timer register (in RAM 34) is passed,
Add 1.

Note that in this embodiment, in the interrupt processing program, the registers to be written by the main program are as follows:
Since the contents are not rewritten, there is no need to save and restore registers, which is normally performed at the start and end of interrupt processing. That is, since registers in the RAM 34 related to musical tone processing and registers related to other processing are independent, the transition from the main program to interrupt processing is performed with as little delay as possible.

Details of the sound source processing B2 are shown in FIG. 3C. After the waveform addition RAM area (see FIG. 6) is cleared by the CI, processings 02 to C9 for eight channels are sequentially performed. At the end of each channel process, the tone waveform value of the channel is added to the data in the waveform addition RAM area.

FIG. 4 depicts the flow of the operation of the embodiment over one hour. A, B, C, D, E, and F are fragments of the main program (FIG. 3A), and interrupt processing (FIG. 3B) is executed at fixed time intervals (musical sound sampling times). When shown in a time chart, 0 is shown in Figure 5.
As shown in the figure, each time an interrupt occurs, a musical waveform signal is input to the D/A converter 43, and a corresponding analog signal is output to the outside.

FIG. 7 shows in detail the processing of C2 to C9 in FIG. 3C for one channel. Channel processing can be broadly divided into envelope processing (D1 to D7) and waveform processing (
08-021).

FIG. 8 shows an envelope generated by envelope processing. The envelope of one musical note consists of several steps (segments).
It is shown in segments.

MuX in the figure is the sampling period of the envelope,
Δy is the change width of the envelope value.

In the channel envelope processing (DI-D7), an envelope is calculated for each sampling time and a check is made to see if the target level of the step has been reached. When they match, the target value is set in the current envelope register (see Figure 6), so this is detected in the main program's sound generation process A9 and the data (ΔX, Δy, target value) for the next step's envelope is set. envelope value) is set in each register.

In detail, the timer register for comparing with the envelope calculation cycle ΔX is incremented for each interrupt in DI, and when it matches ΔX in D2, the addition/subtraction flag (sign bit) of the envelope displacement data Δy is tested in D3. to determine whether the envelope is rising or falling, D4 and D5 subtract or add the current envelope, respectively.D6 checks whether the current envelope has reached the target envelope value, and if it has, Set the target level to the current envelope. As a result, data for the next envelope step will be set in the sound generation process A9 of the main program. Furthermore, when the current envelope of zero is read in the sound generation process A9, it is processed as the end of sound generation.

Next, waveform processing D8-021 will be described.

In waveform processing, the integer part of the current address is used to convert the waveform RO
Read the waveform data of two adjacent addresses from M,
The expected waveform value for the current address indicated by (integer part to decimal part) is obtained by interpolation. The reason why interpolation is necessary is that the waveform sampling period due to interrupts is constant, and the added value of the address (pitch data) covers a certain range of a when applied to musical instruments. If the waveform data is prepared in
Normally, the original sound is reproduced at a faster cycle than the recording sampling cycle of 1M sound. In this embodiment, the period of reproduction of the original sound (A4) is doubled (FIG. 9). Therefore, when the address addition value is 0.5, the A4 sound can be obtained. In this case, the address addition value for A#4 is 0.5
29, and when A3, it becomes l. These address addition values are stored as pitch data in the control data dwarf waveform ROM3.
7, and when a key is pressed, in the sound generation process A9, the pitch data corresponding to the key, the waveform start address, waveform end address, and waveform loop address of the selected tone are stored in the corresponding register of the RAM 34, that is, address addition Set in the value register, start address/current address register, end address register, and loop address register.

For reference, in FIG. 6 showing interpolated waveform data with respect to time in FIG. 10, white circles indicate waveform data values at addresses in the waveform ROM, and black circles indicate interpolated values.

There are various interpolation methods, but here we use linear interpolation. To describe the waveform generation processing D8 to D021 in FIG. 7 in detail, first, an address addition value is added to the current address in the DB to obtain a new current address. D9 compares the current address with the end address, and if the current address > the end address, use 4f, Dlo, and Dll, and if the current address is the end address, use 012 to specify the next physical (address) or logical (operational) address. The waveform ROM is accessed using the integer part at 014 to obtain the next waveform data. The loop address is operationally the next address after the end address. That is, in the case of FIG. 9, the waveform shown in FIG. 1 is repeatedly read out. therefore,
When the current address = end address, read the waveform data of the loop address as the next address (D l
3).

015.016, the waveform R at the integer part of the current address
Access the OM and read the current waveform data. Next, subtract the current waveform value from the next waveform value at 017, and D18
By multiplying the difference by the decimal part of the current address at 019 and adding the result to the current waveform value at 019, the linearly interpolated value of the waveform is obtained. This linearly interpolated data is multiplied by the current envelope value to obtain the musical tone data value of the channel (D
20), and adds it to the contents of the waveform addition register to accumulate musical tone data (021).

Up to this point, it is clear that the microcomputer l
The musical tone sampling period during operation is maintained by performing interrupt processing and generating musical tones each time an interrupt signal is generated from the interrupt control section 40. Further, according to the present invention, the interrupt control section 40
The interval at which interrupt signals are generated, that is, the sampling period of musical tones, can be variably programmed by the microcomputer 1. Various configurations of the programmable interrupt control section 40 are possible. Two examples will be described below.

FIG. 11 shows a first configuration example of the interrupt control section 40. This interrupt control section can generate the interrupt signal INTF at two musical tone sampling periods. To be more specific, the interrupt control section has a 13th
A lock signal φ is input as shown in the figure. This clock signal φ is the direct output of the clock oscillator or the output after passing the output through a frequency dividing circuit. -7 is input to the lowest binary counter. The outputs of all the binary counters 11-2 to 11-7 are input to the first OR gate 2-8, and the outputs of all binary counters 11-2 to 11-7 are input to the second OR gate 2-9. counter 11
-2 to 11-6 outputs are input. Therefore, the first
The output of OR gate 2-8 is 128 times basic clock φ
The output of the second OR gate 2-9 becomes "O" once for 64 basic clocks φ. 8. Which of 2-9 should be selected can be set by program control. For this purpose, the latch 11-1 is provided. In the case of the above-described embodiment, this latch 11-1 is set to "0" or "1" in the -1 to the initial setting process.

That is, 128/fφ is applied to a predetermined bit line of the data bus.
(fφ is the frequency of the basic clock φ) The control signal from the command analysis unit 38 is loaded with data “0” indicating a musical tone sampling period of half the length, or “l” indicating a musical tone sampling period of half the length. is added to the clock input of latch 11-1, and data is latched. The output of the latch 11-1 is input to an OR gate 11-10 to which the output of the first OR gate 2-8 is input.
A signal obtained by inverting the output of the second OR gate 1-1 by the inverter l1-11 is input to the OR gate 11-12 to which the output of the second OR gate 2-9 is input.

The outputs of the OR gates 11-10 and 11-12 are input to a NAND gate, and the output thereof becomes the interrupt signal INTF. Therefore, when bit "O" is set in the latch 11-1, the first OR game) 11-
When the output of 8 is selected and the interrupt signal INTF becomes "1" active once every 128 basic clocks φ and the bit "1" is set in the latch 11-1, the second OR game) The output of 11-9 is selected, and the interrupt signal INTF becomes "1'" active once every 64 basic clocks φ.

FIG. 12 shows an interrupt control section 40 of a second configuration example. This interrupt control section is more detailed than the configuration shown in FIG. 11.
The musical sound sampling period can be adjusted. Specifically, a 4-bit latch 12-1 connected to 4 bits of the data bus is used in place of the 1-bit latch 11-1. Therefore, the microcomputer 1 can set any value of o-is in this latch 12-1. The output of this 4-bit latch 12-1 is input to the B input of the comparator 12-8. Comparator 12-8
Among the outputs of 6-bit ripple counters 12-2 to 12-7 similar to the ripple counter in FIG.
The outputs of the upper 4 bits of binary counters 12-4 to 12-7 are input. The comparator 12-8 becomes "work" when the input power and the B input are equal, and the interrupt signal I
Generates NTF. This interrupt signal INTF is also input to each reset input of the ripple counters 12-2 to 12-7, and resets the ripple counters 12-2 to 12-7 to all zeros when the interrupt signal INTF is generated. Therefore, in the case of the configuration shown in FIG. 12, the generation cycle (musical tone sampling cycle) of the interrupt signal INTF can be set to any arbitrary value of 8n/fφ (n=1~).For example, the 4-bit latch 12-1 8 (B input = 1000), ripple counters 12-2 to 1
An interrupt signal INTF is generated every time the value of 2-7 becomes 1000000 (binary). That is, it is divided once every 64 basic clocks φ. If the 4-bit latch 12-1 has 9 breaths, the rate is once every 72 crossshifts φ.

This concludes the description of the embodiments, but various modifications and changes can be made without departing from the scope of the invention. For example,
In some applications, electronic musical instruments may be capable of synthesizing multiple different tones. In this case, programs for each tone synthesis are stored in the program memory (control R
OM31). Assume that there is an optimal sampling frequency for each musical tone synthesis method. It is also assumed that the user can select which tone synthesis method to use using a mode selector switch. For that purpose, we inspected the mode selector switch on the main flow, and! 2! The selected tone synthesis number is set in the memory (RAM 34). Furthermore, a table of sampling frequency data for each musical tone generation process (for example, stored in the control ROM 41) is accessed, data corresponding to the selected musical tone synthesis number is found, and the data is set in the interrupt control section 40. When an interrupt signal is generated from the interrupt control unit 40, the entry point table (
For example, access (located in the control ROM 41)
The entry point corresponding to the selected musical tone synthesis number is found, and the musical tone generation program is executed starting from that position.

In addition, various changes are possible.

[Effect of generation 1jl] As described above, in this invention, when the microcomputer itself generates musical tones under program control,
The musical tone synthesis process is started in response to an interrupt signal signal from the timer interrupt control circuit means, and the generation cycle of the interrupt signal of the interrupt control means can be programmed from the microcomputer, so that the sampling cycle of musical tones can be maintained during operation. On the other hand, electronic musical instruments feature polyphonic numbers,
It is possible to generate musical tones at a sampling period suitable for the method of musical tone synthesis and the degree of complexity of processing, and further,
In order to realize this, there is no need to make any special changes to the circuit, and there is an advantage that electronic musical instruments can be designed and developed with a high degree of freedom.

[Brief explanation of the drawing]

FIG. 1 is an overall configuration diagram of an electronic musical instrument according to an embodiment of the present invention, FIG. 2 is a block diagram showing the configuration of a microcomputer according to the embodiment, FIG. 3A is a diagram showing the flow of the main program of the microcomputer, and FIG. Figure 3B is a flowchart of the interrupt processing in which musical tones are generated, Figure 3C is a detailed flowchart of the sound source processing in Figure 3B, Figure 4 is a diagram showing the flow of the program over time, and Figure 5 is a diagram showing the flow of the program over time. 6 is a diagram showing a table of the musical tone generation RAM placed in the RAM 34 of FIG. 2, FIG. 7 is a detailed flowchart of one channel processing of FIG. 3C, FIG. 8 is a diagram showing an envelope, FIG. 9 is a diagram showing waveform data of the waveform ROM, FIG. 10 is a diagram showing interpolation calculation waveforms along time, and FIG. 11 is a diagram showing the first configuration example of the included control section. FIG. 12 is a diagram showing a second configuration example of the interrupt control section. FIG. 13 is a time chart of the clock of the interrupt control section. l...Microcomputer, 31.Old control ROM, 34...RAM, 35...
・Adder/subtractor and logical operation unit, 36...multiplier,
37... Control data/waveform ROM, 38...
...Operation analysis section, 40... Interrupt control section.

Claims (2)

[Claims] (1) Program storage means for storing a program for processing input to control a musical instrument and a program for generating musical tones, and address control circuit means for controlling the address of the program storage means, necessary for generating musical tones. a microcomputer comprising: a data storage means for storing data; an arithmetic circuit means; and an operation control circuit means for decoding each instruction of the program in the program storage means and controlling the operation of each of the means; , the microcomputer has timer interrupt control circuit means for generating an interrupt signal at a sampling period of musical tones, and a program for generating the musical tones in response to the interrupt signal from the timer interrupt control circuit means is executed by the microcomputer. A processing device for an electronic musical instrument, characterized in that a musical tone is generated by executing the processing in the timer interrupt control circuit means, and a sampling period of the musical tone, which is an interval at which the interrupt signal is generated in the timer interrupt control circuit means, can be variably programmed. . (2) The processing device for an electronic musical instrument according to claim 1, wherein the microcomputer is composed of an integrated circuit chip;
A processing device for an electronic musical instrument, characterized in that the chip is further provided with a digital-to-analog converter for converting a digital tone signal into an analog signal, and a port for receiving input for controlling the musical instrument.