JPH04171491A - Electronic musical instrument - Google Patents

Abstract

PURPOSE:To prevent a control program from being erroneously rewritten by providing a function controlling CPU, a flash EEPROM as semiconductor device for receiving the control program of the CPU and a means for altering the control program in the flash EEPROM. CONSTITUTION:A controller 2 is composed of a CPU 2a, a PROM 2b of PROM (flash EEPROM) receiving a control program erasable electrically in a lump and a ROM 2a as an operational area of the CPU 2a. When the content of the PROM 2b is altered, a PROM controller 5 is mounted through an outside control terminal consisting of a system bus 4 of an electronic musical instrument set, HOLD, HLDA, Vpp, WE and OE. Thus, the program in the flash EEPROM 2b can be altered without removing a semiconductor device, so that such an accident of the controller in the set as erroneously rewriting its own control program can be prevented from occurring.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to an electronic musical instrument equipped with a CPU for control.

BACKGROUND OF THE INVENTION In recent years, electronic musical instruments have been controlled in various ways by a CPU, and control programs are stored in UV-EPROMs (PROMs that can be erased all at once by ultraviolet light) or the like.

A conventional electronic musical instrument will be described below with reference to the drawings.

FIG. 7 shows the configuration of a conventional electronic musical instrument. This electronic musical instrument includes an input device 71 that specifies timbre and musical tone information, a control device 72 that performs control, an output device 73 that generates and displays musical tone information, and a system in which the control device 72 obtains information from the input device 71. An address bus used for writing information to the output device 73, etc.

System bus 7 consisting of data bus and control bus
It consists of 4. Or the control device 72 is the CPU 72a
, an EPROM 72b in which control programs are stored, and a RAM 72c as a work area.

The operation of the electronic musical instrument configured as described above will be described below.

The control device 72 receives tone information from the input device 71.

It reads pitch information, volume information, etc., processes the read information, and outputs a control signal to the output device 73. The output device 73 performs display and generates musical tone information. Inside the control device 72, the CPU 72a
Control is performed by reading a program from the ROM 72b and executing it. In addition, the RAM 72c serves as an area for temporarily storing information and as a stack area.
PU72a is used.

Problems to be Solved by the Invention However, in the conventional configuration described above, it was necessary to take several steps when changing the contents of the control program. - To change the control program stored in the UV-EPROM for boat fishing, ■Remove the UV-EPROM from the set, ■Erasing the removed UV-EPROM with an eraser, ■Use the UV-EPROM with the ROM programmer. Writing the control program into EPROM,
■Four tasks are required: attaching the UV-EPROM that has been written to the set, and it takes a lot of man-hours to maintain the set due to defects in the control program and to improve the functionality of the set using the control program. It had the following drawback.

The present invention solves the above-mentioned conventional problems, and provides means for performing this without removing the semiconductor device in which the control program is stored from the set, and solves the problem that a newly generated control program is erroneously rewritten. The purpose is to provide a means.

Means for Solving the Problems In order to solve the above conventional problems, the electronic musical instrument of the present invention has the following features:
It has a CPU for controlling functions, a flash EEPROM as a semiconductor device for storing a control program for the CPU, and means for changing the control program in the flash EEPRoM.

Furthermore, the electronic musical instrument of the present invention has means for preventing the control program in the flash EEPROM from being erroneously rewritten.

Effect: With the above configuration, the program in the flash EEPROM can be changed without removing the semiconductor device, and the program in the flash EEPROM can be prevented from being erroneously rewritten.

EXAMPLES Hereinafter, examples of the present invention will be described with reference to the drawings.

FIG. 1 shows the configuration of an electronic musical instrument according to a first embodiment of the present invention.

The electronic musical instrument shown in FIG. 1 includes an input device 1 for specifying timbre and musical tone information, a control device 2 for controlling, an output device 3 for generating and displaying musical tone information, and an input device l for the control device 2. An electronic musical instrument set is comprised of a system bus 4 consisting of an address bus, a data bus, and a control bus, which are used for obtaining information from the computer and writing information to the output device 3. The control device 2 includes a CPU 2a, a PROM 2b which is an electrically erasable PROM (flash EEPRoM) in which a control program is stored, and a CPU 2a.
It consists of a RAM 2c as a work area. Furthermore, when changing the contents of the PROM 2b, the PROM control device 5 changes the contents of the electronic musical instrument set's system bus 4. HOLD
, HLDA, Vpp.

It is attached through external control terminals consisting of WE and OE.

The operation of the electronic musical instrument configured as described above will be explained below.

In the normal state, the PROM control device 5 is in a state where the connected system bus 4 is disconnected (high impedance), and the control device 2 reads tone information, pitch information, volume information, etc. from the input device 1. It processes the information and outputs a control signal to the output device 3. Output device 3
performs display and generates musical tone information. Inside the control device 2, control is performed by the CPU 2a reading a program from the PROM 2b and executing it. Further, the RAM 2c is used by the CPU 2a as an area for temporarily storing information and as a stack area.

When changing the program data in PROM2b, PR
The OM control device 5 enables the hold request manual HOLD of the CPU 2a, and monitors the hold request input signal HLDA, which is enabled after the CPU 2a disconnects the system bus. PROM control device 5 is HLDA
is enabled, after setting the program mold voltage input Vpp of PROM2b to the specified voltage, enabling the chip enable input CE and disabling the output enable manual OE, using the system bus 4 and write enable input WE, data is erased, and then new program data is written to PROM 2b. After completing the writing work to PROM 2b, the CPU 2a reads PROM 2b by physically removing the PROM control device 5 and restarting the system.
Overall control is achieved by executing a new control program within.

A second embodiment of the present invention will be described below with reference to the drawings.

The electronic musical instrument shown in FIG. 2 includes an input device 21 for specifying timbre and musical tone information, a control device 22 for controlling, an output device 23 for generating and displaying musical tone information, and a control device 2
A system bus 24 consisting of an address bus, a data bus, and a control bus used by 2 to obtain information from the input device 21 and write information to the output device 23, and CLK.
It consists of a latch 25 that latches the input data DIN at the rising edge of the input, an AND gate 26, a 5W 27 whose contacts are separated when pressed, and an auxiliary storage device 28. The control device 22 includes a CPU 22a, a PROM 22b which is an electrically erasable PROM (flash EEPRoM) in which a control program is stored, and a CPU.
It consists of a RAM 22c as a work area of 22a, and a BIO8ROM 22d in which programs for controlling reading and writing of the auxiliary storage device and controlling the PROM are stored. The auxiliary storage device 28 corresponds to a floppy disk device, a hard disk device, or the like.

Further, the waveform of the SNS signal is shown in FIG. In the waveform, the horizontal axis represents time T, and the vertical axis represents SNS signal V. The state in which the power of the set is turned on is T=A.

The set power supply Vcc becomes sufficiently stable at T=B. The SNS signal is a signal that shows the passage of time, going from LOW level to Hl level at T=B, and then immediately going back to LOW level at T=C.

Next, the operation of the electronic musical instrument shown in FIG. 2 will be explained using the flowchart shown in FIG.

When the set is powered on while holding down 5W27, the latch 25 latches the H1 level data at the rise of the SNS signal. After that, the input device 21 inputs the PROM2
2b, the control program comes to the start position of the flowchart shown in FIG. 4. In this process, it is determined in step 41 whether the user really desires to rewrite the program data by reading the latch contents. That is, 5W
This judgment is made based on whether or not the set is turned on while pressing 27. In this case, since the data read from the latch is HI, it is determined that the user really wants to change the program data, and the process proceeds to step 42. Here, a check is made to see if a medium with program data properly stored in the auxiliary storage device is set. If the check is NG, a display is made in step 44 to prompt the user to set the medium. In the case of READY, the process advances to step 43, PROM rewriting processing.

In step 43a, the contents of the PROM 22b are erased. In step 43b, new program data is read from the auxiliary storage device 28 and the program data is written to the PROM 22b. After writing all the data, in step 43c, the CPU 22a
resets itself. The set will then restart and
The CPU 22a performs overall control by executing a new control program in the PROM 22b. In this case, the PROM rewriting process 43 is performed entirely on the BIO3ROM22.
It is executed within the dIO3ROM 52d. On the other hand, if the set is turned on without pressing 5W27, latch 25 is L.
Since the OW level is latched, the process proceeds to step 45 after checking the latch contents in step 41. Here, the danger of accidentally rewriting the data in the PROM 22b can be prevented by displaying to the user that the power must be turned on while pressing 5W27 in order to rewrite the program data. In addition, even if the CPU goes out of control due to a malfunction in the control program, AND
Due to the action of the gate 26, the content of the latch 25 is not transmitted to the WE of the CPU's WE ratio output PROM 22b unless it is at Hl level, so if the set is powered on without pressing 5W27, the content of the PROM 22b will be rewritten. No danger arises. Further, since the SNS signal changes only around the time when the power is turned on, and then stabilizes at a LOW level, the contents of the latch 25 will not change even if the switch 5W27 is pressed while the power of the set is turned on.

A third embodiment of the present invention will be described below with reference to the drawings.

The electronic musical instrument shown in FIG. 5 includes an input device 51 for specifying timbre and musical tone information, a control device 52 for controlling, an output device 53 for generating and displaying musical tone information, and a control device 5.
2, a system bus 54 consisting of an address bus, a data bus, and a control bus used for obtaining information from the input device 51 and writing information to the output device 53;
It consists of a latch 55 that latches input data DIN at the rising edge of the input, an AND gate 56, a 5W 57 whose contacts are separated when pressed, and a serial interface device 58. The control device 52 is a CPU 52a
, PROM5, which is an electrically erasable PROM (flash EEPROM) in which a control program is stored.
2b, RAM 52c as a work area for the CPU 52a
, a BIO3ROM 52d storing programs for data transmission/reception processing from the serial interface device and PROM control. PROM5
When changing the stored contents of 2b, the data supply device 59 is connected to the outside of the electronic musical instrument set through an external control terminal consisting of SIN and 5OUT. Further, the SNS signal is the same as the SNS signal in FIG.

Next, the operation of the electronic musical instrument shown in FIG. 5 will be explained using the flowchart shown in FIG.

When the set is powered on while pressing 5W57, the latch 55 latches the H1 level data at the rising edge of the SNS signal. After that, the input device 51 inputs the PROM5.
2b, the control program comes to the start position of the flowchart shown in FIG. 6. In this process, it is determined in step 61 whether the user really desires to rewrite the program data by reading out the contents of the latch. That is, 5W
This judgment is made based on whether or not the set is turned on while pressing 57. In this case, since the data read from the latch is H1, it is determined that the user really wants to change the program data, and the process proceeds to step 62. Here, it is checked whether the program data is prepared in the data supply device 59. If the check is NG, in step 64 the data supply device [59 is
A message is displayed to the user to connect to the external control terminal consisting of and 5OUT. In the case of READY, the process advances to step 63, PROM rewriting processing. Step 6
In step 3a, the contents of the PROM 52b are erased. In step 63b, new program data is read from the data supply device 59 through the serial interface device 58, and the program data is written into the PROM 52b. After writing all data, the CPU 52a resets itself in step 63c. The set will then restart and the CPU 52a will be set to F.
Overall control is achieved by executing a new control program in ROM 52b. In this case, the PROM rewriting process 63 is executed only by the program inside the BIO8ROM 52d. On the other hand, if the set is powered on without pressing 5W57, the latch 55 latches the LOW level, so after checking the latch contents in step 61, the process advances to step 65. Here, the danger of accidentally rewriting the data in the PROM 52b can be prevented by displaying to the user that the power must be turned on while pressing 5W57 in order to rewrite the program data.

In addition, even if the CPU goes out of control due to a malfunction in the control program, the latch 55
The WE output of the CPU is PR except when the content is at HI level.
There is no information transmitted to WE of OM52b, so if you turn on the power of the set without pressing 5W57, PROM52b
There is no risk of the contents being rewritten. Also, S.N.
The S signal changes only around the time the power is turned on, and then remains stable at LOW level.
Even if the switch is pressed, the contents of the latch 55 do not change.

Effects of the Invention As is clear from the above embodiments, flash EEPROM is used as a semiconductor device for storing control programs.
When changing the control program in the flash EEPROM by adding an external PROM control circuit to the electronic musical instrument set using a It is only necessary to provide an external control terminal for adding an external PROM control circuit without providing any additional circuit. Also, in this case, flash EEP
Since the write enable terminal of the ROM is connected only to the external PROM control circuit, in principle, it is impossible for the set's internal control device to rewrite its own control program.

When the set includes a means for rewriting program data, an auxiliary storage device, and its control program,
The control program can be changed without removing the flash EEPROM from the set. Also, Flash E
By providing hardware between the write enable input of the EPROM and the write enable output of the control device to determine whether the user consciously desires to change the control program, the control device inside the set can be prevented from making mistakes. It is possible to prevent the accident of rewriting the own control program.

When a means for rewriting program data, a serial interface device, and its control program are built into the set, and a data supply device is connected to the outside of the electronic musical instrument set through an external control terminal, a flash EEPR is used.
The control program can be changed externally without removing the OM from the set, and even if the electronic musical instrument set does not have an auxiliary storage device built-in.

[BRIEF DESCRIPTION OF THE DRAWINGS] FIG. 1 is a block diagram showing the configuration of an electronic musical instrument according to the first embodiment of the present invention, and FIG. 2 is a block diagram showing the configuration of the electronic musical instrument according to the second embodiment of the present invention. , FIG. 3 is a waveform diagram showing changes over time of the SNS signals in FIGS. 2 and 5,
FIG. 4 is a flowchart of the second embodiment, FIG. 5 is a block diagram showing the configuration of an electronic musical instrument in a third embodiment of the present invention, FIG. 6 is a flowchart of the third embodiment, and FIG. FIG. 1 is a block diagram showing the configuration of a conventional electronic musical instrument. 1...Input device, 2...Control device, 2
a...CPU, 2b...PROM, 2
c --RAM, 3... Output device, 5...
...PROM control device. Name of agent: Patent attorney Haruaki Koebi and two others Figure 3 Time 9) O C1 Figure 6

Claims (4)

[Claims] (1) A CPU for controlling the functions of the musical instrument, and a flash EEPROM (electrically erasable programmable memory) for storing control programs and control data for the CPU.
ROM); and means for changing the memory contents of the flash EEPROM. (2) The electronic musical instrument according to claim 1, further comprising means for preventing the control program in the flash EEPROM from being erroneously rewritten. (3) The electronic musical instrument according to claim 1, further comprising an external control terminal as means for changing the contents stored in the flash EEPROM. (4) The electronic musical instrument according to claim 1, further comprising a function of automatically changing the stored contents of the flash EEPROM by performing a specific operation or setting when the electronic musical instrument set is powered on.