JPH0239796B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an electronic musical instrument whose operation is controlled by a microcomputer, microprocessor, etc., so that appropriate measures can be taken when the control goes out of control.

In electronic musical instruments whose operations are controlled according to a predetermined program using a microcomputer or microprocessor, external pulses (particularly those transmitted via the power line)
Alternatively, control may go out of control due to pulses caused by static electricity that is charged on the player's body. This is caused, for example, by the program counter going out of control due to these noise pulses. Conventionally, when such an out-of-control situation occurred, the player had to operate the power switch each time to restore the normal state. However, until the return operation is performed, various uncontrolled sounds are emitted from the speaker, which is not desirable.

This invention was made in view of the above points,
To provide an electronic musical instrument that automatically detects runaway control, prohibits the generation of uncontrolled musical tones (or noise) based on this, and automatically returns control to its initial state. That is.

In the electronic musical instrument according to the present invention, control of the electronic musical instrument becomes out of control by detecting that a predetermined signal that is repeatedly output when the electronic musical instrument is operating normally according to a program is not output for a predetermined period of time. a runaway detection means for detecting that the runaway has occurred; and a runaway detection means for generating a first detection signal when the runaway detection means detects the runaway, and a second detection signal when the runaway detection state by the runaway detection means continues for a predetermined period or more.
A control means for generating a detection signal, prohibiting the production of musical tones based on the first detection signal, and returning the electronic musical instrument to an initial state based on the second detection signal. It is.

According to this invention, when a program runaway is detected, the first detection signal is first generated, and then the second detection signal is generated on the condition that the runaway detection state continues for a predetermined period or longer. . Based on this first detection signal, the production of musical tones is prohibited,
Control of the electronic musical instrument is returned to the initial state based on the second detection signal. As described above, a feature of the present invention is that a time delay is provided between prohibition of sound generation upon detection of runaway and reset processing to the initial state. As a result, when a runaway is detected, the sound is immediately disabled to prevent the production of undesirable sounds, while at the same time it is possible to delay returning the control of the electronic musical instrument to its initial state for a while, allowing the runaway to be resolved. If the runaway is resolved, the second detection signal is not generated, thereby making it possible to avoid returning the control to the initial state.

In this way, even if a runaway is detected, it is important to avoid returning the control to its initial state as much as possible. This is extremely advantageous in order to prevent information from being lost.

Hereinafter, an embodiment of the present invention will be described in detail with reference to the accompanying drawings.

In FIG. 1, the conventional parts of a microcomputer-controlled electronic musical instrument include a key switch section 10, a tone switch section 11, a tone generator section 12, and a central processing section (hereinafter referred to as a CPU).
) 13 , a read-only memory section (hereinafter abbreviated as ROM section) 14 , a random access memory section (hereinafter abbreviated as RAM section) 15 , and a sound system 16 . The key switch section 10 includes key switches corresponding to each key on the keyboard, and the tone switch section 11 includes switches corresponding to various tone color and effect selection operators on the console panel. The ROM unit 14 includes a program ROM in which a control program is pre-stored and a data ROM in which other necessary data is pre-stored.
Based on the control by the CPU 13, the common bus 17
Data and commands are sent and received through each section 10, 11, 12, 14, and 15, and predetermined processing is performed at each section, and finally musical tone signals corresponding to the selections at the key switch section 10 and tone switch section 11 are generated. It is generated from the tone generator section 12.

A gate 18 is provided between the tone generator section 12 and the sound system 16, and a timer 19 is newly provided. Timer 19 is
It is reset by a timer reset pulse RST generated in the process of executing a program under the control of the CPU 13, and based on this, a predetermined timer operation is started. The gate 18 is always on, and the tone generator section 12
The output musical tone signal of the tone generator section 12 is allowed to be given to the sound system 16, but it is turned off by the output signal OFF of the timer 19 issued under predetermined conditions, and the output musical tone signal of the tone generator section 12 is allowed to be given to the sound system 16. prohibited from being given to

FIG. 2 shows an example of a control program executed by the CPU 13, and since the main routine 21 of this program itself is not the gist of the present invention, only an outline thereof is shown. The program starts when the power is turned on, and in block 20 labeled "Initialize", processing is performed to set the RAM section 15 and various other circuits to the initial state. The main routine 21 broadly includes steps for performing processing of "key event detection,""tone event detection," and "automatic rhythm event detection."
"Key event detection" is to detect an on/off change of a key switch in the key switch section 10, and when an on or off change is detected, a "key assignment routine" is executed. The "key assignment routine" is a process that assigns a musical tone generation corresponding to a key switch turned on to one of multiple musical tone generation channels and performs a key-off process, and through this process, the keys assigned to each channel are A key code indicating the key and a key-on signal indicating whether the key is on or off are stored in the RAM section 15. "Tone event detection" is to detect an on/off change of a switch in the tone switch section 11, and when a change is detected, a "tone data writing routine" is executed. "Tone data write routine" writes tone data related to the turned-on tone switch to ROM.
The tone data related to the turned-off tone switch is written from the RAM section 14 to the RAM section 15.
Delete with 5. The "automatic rhythm event detection" detects changes in the automatic rhythm pattern, and based on this detection, the "automatic rhythm routine" performs processing for assigning and deleting automatic rhythm tones. If no event detection (change detection) is performed in each event detection process, the process immediately moves to the next step. Immediately after completing the predetermined processing in the "key assignment routine", "tone data writing routine", and "automatic rhythm routine", the routine returns to the predetermined step of the main routine 21.

At the end of the main routine 21, a step 22 is provided for generating a timer reset pulse RST. This step 22 is not limited to the last step,
It may be provided at any stage of the main routine 21.
When the program progress reaches this step 22, a timer reset pulse RST is generated and supplied to the timer 19 (FIG. 1). Step 22
When the pulse RST is generated at , the program immediately moves to the next step, the first step of the main routine 21 . Thus, the timer reset pulse RST is generated one pulse each time the main routine 21 is executed one cycle.

The timer 19 is reset to the start state by the reset pulse RST and starts a predetermined timer operation. This operating time is set to be sufficiently longer than the execution time of one cycle of the main routine 21. As an example, main routine 2
The time required to execute one cycle of 1 is 3 to
The operating time of timer 19 is approximately 4ms.
Set to 10ms to several seconds.

When the program control is normally executed, the main routine 21 is cycled at an appropriate time (3 to 4 ms) depending on the number of program steps, and the reset pulse RST is generated frequently accordingly. Therefore, timer 19 is repeatedly reset to the start condition before its operating time expires and no output signal is produced. An example of this state is A in Figure 3.
shown in the interval.

If a runaway occurs in the program control, the program progress will be disturbed and the processing of the main routine 21 will not be performed normally. As a result, the timer reset pulse RST is not generated, or even if it is generated, the interval between occurrences becomes abnormally long. Therefore, the timer 19 performs the timer operation until its operating time expires, and an output signal is generated. An example of this state is shown in section B in FIG.

In this embodiment, timer 19 generates two types of output signals: OFF and CPURST. One output signal OFF is for turning off the gate 18 as described above, and the other output signal OFF is for turning off the gate 18.
CPURST is used to reset the CPU 13 (to a state equivalent to turning off the power and then turning it on again) and return the program to its initial state. As an example, the timer 19 has three operating times T ₁ , T ₂ , T ₃ as shown in section B in FIG.
The output signal OFF and CPURST are output at predetermined timings according to these operating times T ₁ to _{T 3} .

The first operating time _T1 in the timer 19 is set to detect runaway program control, and the timer 19 is started by the reset pulse RST until the next reset pulse RST is not generated. When this time T ₁ expires, it is considered that a runaway has occurred. At the same time as this first operation time _T1 expires, one output signal is turned off.
is generated (becomes “1”). First operating time
When the second operating time _T2 expires without the reset pulse RST being generated after the expiration of _T1 , the other output signal CPURST is generated. Second
Reset pulse still after expiration of operating time T ₂
When the third operating time _T3 expires without RST being generated, the output signal OFF disappears (becomes "0"). That is, the timer output signal OFF continues to be generated during the second and third operating times T ₂ and T ₃ to turn off the gate 18 . As a result, the output musical tone signal of the tone generator unit 12 is prohibited for a certain period of time (T ₂ +T ₃ ), and the generation of random (uncontrolled) musical tones or noises caused by runaway is prohibited. Other timer output signal
CPURST is a pulse that occurs instantaneously when the second operating time _T2 expires, which causes CPU1
3 is reset. This resetting of the CPU 13 is equivalent to turning off the power. That is, the timer output signal CPURST automatically performs the same operation as turning off the power switch for a moment, thereby automatically returning the runaway program to its initial state and returning it to its normal state.

The reason for providing the time delay _T2 between the gate-off signal OFF and the CPU reset signal CPURST is to avoid as much as possible the situation in which the memory contents of the RAM section 15 must be cleared. In other words, when the CPU 13 is reset (the power is turned off), the RAM section 15 is cleared, and all the tone information and other performance information written to the RAM section 15 up to that point are erased, and the player can then read them again. The trouble of having to set the information again occurs. Therefore, when a runaway is detected, the sound is immediately disabled to prevent inconvenient sounds from being produced. However, the CPU 13 is not reset immediately, but the next timer reset pulse RST is delayed a little longer ( _T2 only). ), and when the reset pulse RST still does not occur, the signal CPURST is generated.
Therefore, if the reset pulse RST is applied to the timer 19 during the second operating time _T2 , the timer 19 is returned to the start state and the signal CPURST is not generated. This is a case where the control temporarily goes out of control, but returns to normal by chance. In this case, only the random sounds that occur during the runaway are prohibited, and the program is not reset. As an example,
Set T ₁ to 50 ms, T ₂ to 1 sec, and T ₃ to about 1 sec.

As explained above, according to the present invention, when the program control goes out of control, uncontrolled and random sounds are not produced, and the program progress is automatically returned to the initial state. It has the excellent effect of automatically resolving the situation. Moreover, according to the present invention, a time delay is provided between prohibition of sound generation when runaway is detected and reset processing to the initial state, so that when runaway is detected, sound generation is immediately inhibited to immediately prevent the production of inconvenient sounds. On the other hand, it is possible to delay returning the control of the electronic musical instrument to the initial state for a while, wait for the runaway to be resolved, and avoid returning the control to the initial state if the runaway is resolved. RAM
This has the excellent effect of preventing the timbre information and other performance information that have been previously written into volatile storage devices, such as the following, from being lost as much as possible.

In other words, if the control of the electronic musical instrument is returned to its initial state, the tone information and other performance information previously written to volatile storage devices such as RAM will be erased, and the player will then have to read them again. However, with this invention, it is possible to immediately prevent inconvenient sounds from being produced, and to avoid returning the control to its initial state as much as possible, thereby eliminating inconveniences. This has the excellent effect of preventing the above-mentioned troubles as much as possible while fully enjoying the advantage of preventing noise from being produced.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing an embodiment of an electronic musical instrument according to the present invention, FIG. 2 is a flowchart showing an example of a control program executed by the CPU shown in FIG. 1, and FIG. 2 is a timing chart for explaining an example of the operation of a timer in FIG. 12...Tone generator section, 13...
CPU (central processing unit), 14...ROM section, 15...
RAM section, 16... Sound system, 18...
Gate, 19...Timer, 21...Main routine of control program, 22...Program step for generating timer reset pulse.

Claims (1)

[Claims] 1. In an electronic musical instrument whose operation is controlled based on a program stored in a storage device, a predetermined signal that is repeatedly output when the electronic musical instrument is operating normally according to the program. a runaway detection means for detecting that the control of the electronic musical instrument has gone out of control by detecting that the electronic musical instrument is not output for a predetermined period of time; When the state of runaway detection by the runaway detection means continues for a predetermined period or longer, a second detection signal is generated, the generation of musical tones is prohibited based on the first detection signal, and the generation of the musical tone is prohibited based on the second detection signal. An electronic musical instrument characterized by comprising a control means for returning the musical instrument to its initial state. 2. The electronic musical instrument according to claim 1, wherein the first detection signal continues to inhibit the production of musical tones at least while the runaway detection state by the runaway detection means continues.