JP2001215970A - Extended waveform storage medium and electronic musical instrument - Google Patents

Abstract

PROBLEM TO BE SOLVED: To configure a system capable of optimizing operation according to future improvement in performance avoiding occurrence of a large increase in costs and a problem of parts management, concerning an electronic musical instrument which reads sampled values from an extended waveform board with mounted waveform memory storing the values sampled by sampling a musical sound waveform in order of storing addresses with a prescribed sampling frequency, and reproduces the musical sound waveform. SOLUTION: An extended wave board 20 in which waveform memory 21 with a stored musical sound waveform, and characteristic memory 22 storing a characteristic (especially, an access time) of the waveform memory or the extended waveform board 20 are mounted is prepared.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an extended waveform storage medium storing sample values obtained by sampling musical tone waveforms at a predetermined sampling frequency in the order of storage addresses, and an extended waveform storage medium having the extended waveform storage medium mounted thereon. The present invention relates to an electronic musical instrument for reading out the above-mentioned sample values and reproducing a musical tone waveform.

[0002]

2. Description of the Related Art Conventionally, electronic musical instruments which incorporate a waveform memory for storing musical tone waveforms and read musical tone waveforms from the waveform memory to reproduce musical tones have been widely put into practical use. For this purpose, a system has been put into practical use in which an extended waveform storage medium such as an extended waveform card storing a musical tone waveform is prepared and an electronic musical instrument can be mounted in advance with the extended waveform storage medium.

Here, a user who purchases an electronic musical instrument uses the electronic musical instrument for a certain period of time once purchasing the electronic musical instrument, but an extended waveform board that can be mounted on the electronic musical instrument sells the electronic musical instrument. In recent years, new ones have been developed, and with the rapid development of LSI technology in recent years, an extended waveform storage medium with a shorter access time than the extended waveform board considered at the time of electronic musical instrument development has been developed. May be developed.

When the access time for reading a waveform from an extended waveform storage medium is shortened, the waveform can be read at a high speed, and the number of tones (voices) that can be generated simultaneously can be increased or generated. It is possible to generate a higher-pitched tone by raising the highest pitch of the tone that can be performed.

[0005]

However, when developing a new type of electronic musical instrument, it is already commercially available.
In order to use an extended waveform storage medium having a slow read speed, it is necessary to adjust the waveform read speed to the access time of the extended waveform board, and to match the access time of the latest and faster extended waveform board. There is a problem that can not go. Alternatively, the specifications are divisible, and only the latest high-speed extended waveform storage media can be used.
It is conceivable to match the waveform reading speed to the high-speed extended waveform storage medium, but in this case, there is a possibility that an extra burden is imposed on the user. Even if the specifications are divided in this way, if a higher-speed extended waveform storage medium is developed in the future, the high-speed performance of the extended waveform storage medium cannot be utilized.

In view of the above circumstances, an object of the present invention is to provide an extended waveform storage medium and an electronic musical instrument that can be employed in a system that makes the most of the performance of an extended waveform storage medium.

[0007]

According to the present invention, there is provided an extended waveform storage medium for storing a sample value obtained by sampling a musical tone waveform at a predetermined sampling frequency in the order of storage addresses. An access time value for reading a sample value is stored in a readable manner.

The electronic musical instrument of the present invention that achieves the above object is provided with an extended waveform storage medium storing sample values obtained by sampling musical tone waveforms at a predetermined sampling frequency in the order of storage addresses. An electronic musical instrument for reading and reproducing a musical tone waveform is provided with an extended waveform storage medium in which an access time value for reading the sample value in addition to the sample value is readablely stored, and an access time stored in the extended waveform storage medium is stored. A reading means for reading the sample value from the extended waveform storage medium at an access time according to the time value is provided.

According to the present invention, since the access time value for reading the sample value from the extended waveform storage medium is stored in the extended waveform storage medium, the electronic musical instrument side uses the extended access time value based on the access time value. A sample value can be read at an access time that makes the best use of the performance of the waveform storage medium.

[0010]

Embodiments of the present invention will be described below.

FIG. 1 shows a first example of an extended waveform storage medium according to the present invention.
1 is a block diagram showing a configuration of a first embodiment of an electronic musical instrument of the present invention in a state where an extended waveform board according to the first embodiment is mounted.

The electronic musical instrument 10 shown here has a program ROM 11 in which a program is stored, and a program R
CP for reading and executing programs stored in OM
U12, a RAM used as a work area when the CPU 12 executes a program, and a sound source 14 for generating a musical tone waveform in response to an instruction from the CPU 12 are provided, and are connected to each other via a bus 15. .

The electronic musical instrument 10 shown in FIG.
Further, a waveform ROM 16 storing sample values obtained by sampling the musical tone waveform at a predetermined sampling frequency in the order of storage addresses is built in. The sound source 14 sequentially reads each sample value from the waveform ROM 16 in accordance with an instruction from the CPU 12. A tone waveform (digital tone waveform signal) is generated through a read interpolation operation and the like. The tone waveform generated by the sound source 14 is D /
The signal is converted into an analog musical sound waveform signal by the A-converter 17 and is emitted as acoustic musical sound into space by a sound system 18 including an amplifier 18a and a speaker 18b.

The electronic musical instrument 10 has an extended waveform board 2
0 is attached. The extended waveform board 20 is developed for a user who thinks that the built-in waveform ROM 16 does not have enough tone color.
A waveform ROM 21 storing sample values obtained by sampling a new tone waveform not stored in the memory at a predetermined sampling frequency in the order of storage addresses, and an EPROM 22 storing characteristics of the waveform ROM 21 or the extended waveform board 20 itself are mounted. Have been.

The EPROM 22 stores the following access time (1). Also, this EPROM
22 may further store (2) the following characteristic information in addition to the (1) access time. (1) Access time of the waveform memory 21. Based on the access time information, the waiting time when the tone generator 14 reads out the tone waveform from the waveform ROM 21 is adjusted. When the access time is shortened, the waiting time for the access is shortened, and high-speed access is enabled. As described above, the number of tones (voices) that can be generated simultaneously can be increased or generated. It is possible to generate a higher-pitched tone by increasing the highest pitch of the tone that can be played. (2) Information on the memory space used by one extended waveform board. FIG. 1 shows only one extended waveform board 20, but depending on the electronic musical instrument, the extended waveform board 2 may be used.
For example, in such an electronic musical instrument, a plurality of extended waveform boards having different memory capacities may be mixed by knowing information on a memory space used by each extended waveform board. This makes it easy to adjust the allocation of memory addresses when the memory is used. (3) Signal delay time of the extended waveform board. This signal delay time may affect the access time. (4) Types of waveform memory mounted on the extended waveform board (mask ROM, flash ROM, DRAM, SDR
AM, SRAM, etc.). Access according to the type of the waveform memory can be performed. (5) Extension waveform board version and type. Or the type of electronic instrument that fits. When the extended waveform board is attached to an electronic musical instrument, it is determined whether the extended waveform board is compatible with the electronic musical instrument, even if the extension waveform board can be attached on the type of the connector,
The user can be notified. (6) Other. For example, information other than the characteristic information, such as a CRCC error code, may be stored together.

Returning to FIG. 1, the description will be continued.

When power is supplied to the electronic musical instrument 10 shown in FIG. 1, the above contents (characteristic information including access time) of the EPROM 22 are transferred to the sound source 14 and the characteristic information set for the sound source 14 is transmitted. The waveform is read out by the CPU 12 and the speed of reading out the waveform from the extended waveform board 20 of the electronic musical instrument 10 is determined.

FIG. 2 is a timing chart for accessing the waveform memory when the access time is long.

After the address (wave address: WA) on the waveform memory is determined and the chip select CS is asserted, the output enable OE is asserted. At the rising edge of the output enable OE, the data of the address WA on the waveform memory is changed. Is read.

FIG. 3 is a timing chart of access to the waveform memory when the access time is shortened.

Access is completed in a shorter time as compared with the case shown in FIG. 2, so that more data can be read in a unit time, and as described above, the number of voices increases and the maximum pitch is raised. Etc. can be performed.

FIG. 4 shows a second example of the extended waveform storage medium of the present invention.
It is a block diagram which shows 2nd Embodiment of the electronic musical instrument of this invention in the state with which the extended waveform board which is embodiment of 1 is mounted. The differences from the first embodiment shown in FIG. 1 will be described.

In the second embodiment shown here, the EPROM 22 mounted on the extended waveform board 20
When it is mounted on the bus 15, it is configured to be directly connected to the bus 15.

In this case, in the initialization program that operates when the power of the electronic musical instrument 10 is turned on, the CPU 1
2 can read the contents of the EPROM 22 directly.

The contents of the waveform ROM 21 on the extended waveform board 20 are read out by the sound source 14, similarly to the contents of the waveform ROM 16 built in the electronic musical instrument 10.

Although an extended waveform board has been described above as an example, the extended waveform storage medium of the present invention does not need to have the shape of a board, but has the shape of a memory card. Or in the form of a floppy disk, CD-ROM, or the like.

[0027]

As described above, according to the present invention,
The performance of the extended waveform storage medium can be maximized.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a configuration of a first embodiment of an electronic musical instrument of the present invention in a state where an extended waveform board, which is a first embodiment of an extended waveform storage medium of the present invention, is mounted.

FIG. 2 is a timing chart of access to a waveform memory when an access time is long.

FIG. 3 is a timing chart of access to a waveform memory when an access time is shortened.

FIG. 4 is a block diagram showing a second embodiment of the electronic musical instrument of the present invention in a state where an extended waveform board which is a second embodiment of the extended waveform storage medium of the present invention is mounted.

[Explanation of symbols]

 Reference Signs List 10 electronic musical instrument 11 program ROM 12 CPU 14 sound source 15 bus 16 waveform ROM 17 D / A converter 18 sound system 20 extended waveform board 21 waveform ROM 22 EPROM

Claims (2)

[Claims] 1. An extended waveform storage medium storing sample values obtained by sampling musical tone waveforms at a predetermined sampling frequency in the order of storage addresses, wherein said access time value for reading said sample values is readably stored. . 2. An electronic musical instrument for reading and reproducing said sample values from an extended waveform storage medium storing sample values obtained by sampling musical tone waveforms at predetermined sampling frequencies in the order of storage addresses, wherein said sample values are added to said sample values. Reading means for reading the sample value from the extended waveform storage medium with an access time according to the access time stored in the extended waveform storage medium, wherein the extended waveform storage medium storing the value of the access time to be read is readable. Electronic musical instrument with.