JPH0555197U - Electronic musical instrument - Google Patents

Abstract

(57) [Abstract] [Purpose] To provide an electronic musical instrument in which initial clear is always performed properly on both the control side including the CPU and the sound source side, and stable initial clear and subsequent normal operation are guaranteed. To aim. [Structure] An initial clear cancellation signal is sent to the sound source side after a lapse of a predetermined time from when the control side receives the initial clear signal.

Description

[Detailed description of the device]

[0001]

[Industrial application]

 The present invention relates to an electronic musical instrument capable of properly performing initial clear and cancellation of initial clear of a sound source.

[0002]

[Prior Art]

 In recent years, electronic musical instruments are often configured with independent integrated circuits, etc., in accordance with the higher functionality of the whole. Each independent circuit part has an independent function. For example, a circuit is roughly divided into a CPU side and a sound source side, and overall operation control (especially sound generation instruction to the sound source) is to the CPU side, and sound generation processing performed in response to an instruction from the CPU is the sound source side There are electronic musical instruments that divide the roles.

In such an electronic musical instrument, both the CPU side and the sound source side must be initially cleared when the power is turned on (or at the time of resetting after the power is turned on). Initial clear refers to the initial setting operation for setting the electronic musical instrument to a state in which it normally operates as an electronic musical instrument. Initial clear includes not only hardware reset but also operation such as setting tone to default value.

FIG. 4A shows an initial clear (IC) signal generation circuit in a conventional electronic musical instrument. FIG. 4B shows a time chart of each signal in the circuit of FIG. In this figure, when power is turned on and VCC rises, an input signal which rises with a time constant defined by the C value and R value of the CR circuit 41 is input to the inverter 42. Therefore, the inverter 42 outputs a signal which is "0" before the power is turned on, reaches a predetermined value at the rising time of VCC (power on), and gradually reaches "0". The output signal of the inverter 42 is shaped by the amplifier 43 and the pulse of the initial clear signal IC shown in FIG. 4B is output.

On the other hand, the output signal of the inverter 42 is delayed by the CR circuit 44 for a predetermined time, then shaped by the amplifier 45 and output. This becomes the initial clear cancellation signal ICK shown in FIG. 4 (b). In this way, the analog clear circuit is used to generate the initial clear signal IC and the initial clear cancellation signal ICK, the latter is delayed, and the CPU and the CPU are delayed during the delay time (section numbered 46 in FIG. 4B). I was initially clearing the sound source.

[0006]

[Problems to be solved by the device]

 In the initial clear method as described above, the initial clear time is determined by the delay time in the CR circuit 44. However, since it is realized by an analog circuit, this delay time varies. Regarding the initial clear of the CPU and the initial clear of the sound source, the initial clear of the normal sound source takes more time. Therefore, there is a problem that the initial clear cancel signal may be sent before the initial clear of the sound source is completed, and the operation may become unstable.

In view of the problems in the above-mentioned conventional example, the present invention always properly performs the initial clear on both the control side including the CPU and the sound source side, and guarantees a stable initial clear and normal operation thereafter. The purpose is to provide an electronic musical instrument.

[0008]

[Means for Solving the Problems]

 To achieve this object, the electronic musical instrument according to the present invention receives an initial clear signal to perform its own initial clear, and also receives an initial clear release signal to enable its own normal operation, and at the time of normal operation. Is provided with a tone forming means for generating a tone in response to a tone generation instruction and a control means for similarly receiving an initial clear signal to perform its own initial clear and giving a tone instruction to the tone forming means. Is characterized in that an initial clear cancellation signal is sent to the musical tone forming means after a predetermined time from the time of receiving the initial clear signal.

The initial clear signal may be directly generated from an on / off switch or a reset switch of a power source, and in particular, means for detecting on / off of these switches to generate an initial clear signal may be provided. . Further, the initial clear signal may be generated based on the signal input from the power supply means for supplying the power.

[0010]

[Action]

 The control means generates and outputs an initial clear cancellation signal to the musical tone forming means after a predetermined time from the time of receiving the initial clear signal. Since the control means can measure the time fairly accurately, the time until the initial clear release signal is generated and output can be accurately controlled. Therefore, it is possible to input the initial clear cancellation signal to the musical tone forming means after securing a time for the initial clear processing in the musical tone forming means to be properly finished.

[0011]

【Example】

 An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 shows an overall block configuration of an electronic musical instrument according to an embodiment of the present invention. This electronic musical instrument includes a control unit 1, a switch 2, a switch event detection circuit 3, a keyboard 4, a key event detection circuit 5, a program memory (ROM) 6, a port 7, a sound source 8, a sound system 9, and a bus line 17. I have it.

The control unit 1 controls the entire operation of the electronic musical instrument and instructs the sound source 8 to generate musical tones. The control unit 1 includes a timer 11 for measuring time, an interrupt controller 12 that generates and outputs a timer interrupt signal based on a time measurement result signal of the timer 11, a central processing unit (CPU) 13, and various types. It has a RAM 14 used for a register or the like. The program executed by the CPU 13 is stored in the program memory 6.

The switch 2 is, for example, a power on / off switch or a switch for selecting a tone color. Events for these switches are detected by the switch event detection circuit 3. The switch event detection circuit 3 sends the event detection result of the switch 2 to the CPU 13 via the bus line 17. In response to the event of the switch 2, the CPU 13 performs, for example, a process of transmitting a predetermined tone color parameter to the tone generator 8 when selecting a tone color.

An event for each key of the keyboard 4 is detected by the key event detection circuit 5. The key event detection circuit 5 sends the key event detection result to the CPU 13 via the bus line 17. The CPU 13 performs a process of transmitting a sounding instruction to the sound source 8 according to the result of the key event detection.

The port 7 inputs the reset signal RESET and holds “0” or “1”. The port 7 can also be rewritten by the CPU 13. The value held by the port 7 is input to the sound source 8 as an initial clear signal IC. A value obtained by inverting the value held by the port 7 by the inverter 15 is input to the sound source 8 as the initial clear cancellation signal ICK. The reset signal RESET is a 1-pulse signal generated when the power is turned on. As a circuit for generating the reset signal RESET, a conventionally known circuit may be used.

The sound source 8 executes internal initial clear when the initial clear signal IC rises from “0” to “1”. This initial clear is processing such as initialization of internal registers. When the initial clear cancellation signal ICK rises from "0" to "1", the sound source 8 performs an operation as a normal sound source, for example, a musical sound generation process based on an instruction from the CPU 13. The sound system 9 actually emits a musical sound based on an instruction from the sound source 8.

FIG. 2 shows a detailed block configuration of the sound source 8 of this electronic musical instrument. The sound source 8 is, in addition to the RAM 16, a phase generation circuit (PG) 21, an address generation circuit (ADR) 22, a waveform memory (WM) 23, an envelope generator (EG) 24, a multiplier 25, an accumulator (ACC). 26, an AND circuit 27, an inverter 28, and a digital / analog converter (DAC) 29.

The RAM 16 has a plurality of areas in which the key-on pulse KONP, the key-off pulse KOFP, the key code (pitch) KC, and the velocity (volume) VEL sent from the CPU 13 can be stored, and each is stored in the RAM 16. A tone signal is generated by sequentially reading data at a predetermined timing and supplying the data to a predetermined circuit of the sound source 8. The phase generation circuit 21 forms read phase information of the waveform memory 23 according to the key-on pulse KONP and the key code KC, and outputs it to the address generation circuit 22. The address generation circuit 22 sequentially accumulates the phase information from the phase generation circuit 21 at a predetermined start address to generate a read address of the waveform memory 23. The waveform memory 23 is accessed at the read address, and waveform data having a predetermined pitch is output.

The envelope generator 24 generates and outputs a predetermined envelope waveform according to the key-on pulse KONP, the key-off pulse KOFP, the key code KC and the velocity VEL. The multiplier 25 multiplies the waveform data from the waveform memory 23 by the envelope waveform from the envelope generator 24, and outputs the waveform data to which the envelope is added. The electronic musical instrument of this embodiment has a plurality of tone generation channels, and the processing of each channel is performed in a time division manner. Waveform data of each channel output from the multiplier 25 sequentially by time division is accumulated in an accumulator 26.

The accumulated musical tone waveform data is input to the digital / analog converter 29 via the AND circuit 27, subjected to digital / analog conversion, and input to the sound system 9 in the subsequent stage. As a result, a predetermined musical sound is emitted.

The initial clear signal IC and the initial clear cancel signal I CK from the port 7 are input to the phase generation circuit 21, the address generation circuit 22, the envelope generator 24, and the accumulator 26. Each of these circuits 21, 22, 24, and 26 executes its own initial clear when the initial clear signal IC rises from "0" to "1". When the initial clear cancellation signal ICK rises from "0" to "1", normal operation is performed thereafter.

Further, the initial clear signal IC is inverted by the inverter 28 and input to the AND circuit 27. The AND circuit 27 receives the musical tone waveform data from the accumulator 26 as another input. Therefore, when the initial clear signal IC is "1", the AND circuit 27 is closed because the initial clear process is being performed, and the tone waveform data is not input to the digital / analog converter 29 in the subsequent stage. On the other hand, when the initial clear signal IC is "0", the AND circuit 27 is opened because the initial clear processing is completed, and the tone waveform data is input to the digital / analog converter 29 in the subsequent stage. This is to prevent malfunction during processing of the initial clear.

Next, the operation of the electronic musical instrument shown in FIGS. 1 and 2 after the power is turned on will be described with reference to the flowchart of FIG. When the electronic musical instrument is powered on, the reset signal RESET (FIG. 1) is generated and input to the CPU 13 and the port 7 as described above. The CPU 13 is reset (initial clear) by this. Port 7 continues to hold the input reset signal RESET. That is, port 7 keeps holding "1".

The signal “1” from the port 7 is input to the sound source 8 as an initial clear signal IC. The signal "1" from the port 7 is inverted by the inverter 15 to become "0" and is input to the sound source 8 as the initial clear cancellation signal ICK. In the sound source 8 of FIG. 2, since the initial clear signal IC is “1” and the initial clear cancellation signal I CK is “0”, execution of initial clear, that is, initialization of each circuit 21, 22, 24, 26 is started. To do.

At this time, since the initial clear signal IC is “1”, “0” which is inverted by the inverter 28 is input to the AND circuit 27, and the AND circuit 27 is closed. Therefore, the musical tone waveform data is not input to the digital / analog converter 29, and malfunction (erroneous sound) is prevented before the initial clear is properly performed.

After the initial clear, the CPU 13 advances the processing according to the flowchart of FIG. First, the RAM 16 of the sound source 8 and the registers of the RAM 14 are initialized (step S1). Next, the CPU 13 gives an instruction to initialize other circuits (step S2). Then, the timer 11 measures the time from power-on and waits until a predetermined time elapses (step S2). This predetermined time is set to such a time that the above-described initial clear of the sound source 8 and other circuits is completed. As a result, it is guaranteed that the initial clear of each unit including the sound source 8 is completed after the lapse of this predetermined time.

Next, the CPU 13 outputs “0” to the port 7. Port 7 holds "0" thereafter. As a result, "0" is output from the port 7 as the initial clear signal IC. Further, the inverted "1" is output as the initial clear cancellation signal ICK. In the sound source 8, since the initial clear signal IC is "0" and the initial clear cancellation signal ICK is "1", the normal operation as the sound source will be performed thereafter.

Since the initial clear signal IC is “0” at this time, “1” which is the inverted value of the inverter 28 is input to the AND circuit 27 and the AND circuit 27 is opened. Therefore, the musical tone waveform data is input to the digital / analog converter 29.

Next, in the key event process, a key event is detected to generate a musical tone (step S5), other processes (step S6) are performed, and the process returns to step S5. After that, steps S5 and S6 are repeated. When steps S5 and S6 are repeated, the initial clear signal IC is "0", the initial clear cancel signal ICK is "1", and the sound source 8 performs a normal operation as a sound source. It should be noted that although the above-described embodiment describes an example in which the present invention is applied to an electronic musical instrument having a sound source of a waveform memory reading system, the present invention is not limited to this. The present invention can be applied to any type of electronic musical instrument as long as it is an electronic musical instrument having a control unit including a CPU and the like and a sound source unit for forming a musical tone.

[0030]

[Effect of the device]

 As described above, according to the present invention, the initial clear cancellation signal is generated under the control of the control unit and input to the tone forming means, so that a stable initial clear operation is guaranteed. , Operation at power-on or reset and normal operation after that are stable.

[Brief description of drawings]

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

FIG. 2 is a detailed block diagram of a sound source of the electronic musical instrument according to the embodiment.

FIG. 3 is a processing flowchart of the CPU of the electronic musical instrument of the embodiment.

FIG. 4 is a conventional initial clear signal generation circuit diagram and signal diagram.

[Explanation of symbols]

1 ... Control unit, 2 ... Switch, 3 ... Switch event detection circuit, 4 ... Keyboard, 5 ... Key event detection circuit, 6 ... Program memory (ROM), 7 ... Port, 8 ... Sound source, 9
... sound system, 11 ... timer, 12 ... interrupt controller, 13 ... central processing unit (CPU), 14, 16 ...
RAM, 15 ... Inverter, 17 ... Bus line.

Claims (1)

[Scope of utility model registration request] 1. An initial clear signal is received to perform an initial clear of itself, and an initial clear release signal is received to enable a normal operation of the self. At the time of normal operation, a musical tone is generated in response to a musical tone generation instruction. And a control means for receiving the initial clear signal to perform its own initial clear, and for giving a sounding instruction to the musical sound forming means, the control means is provided with a predetermined timing from the time of receiving the initial clear signal. An electronic musical instrument characterized in that an initial clear cancellation signal is sent to the musical sound forming means after a lapse of time.