JPH0435760B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to an electronic musical instrument suitable for simultaneously generating a plurality of musical tones of different frequencies.

Conventionally, in the field of electronic musical instruments, there are two methods for simultaneously generating multiple musical tones of different frequencies corresponding to keyboards, etc.: A method of providing a plurality of musical tone generators each producing one sound, and a method of generating a single musical tone. There is a method of operating the instrument in a time-sharing manner to obtain multiple musical tones at the same time.

An example of the above-mentioned conventional electronic musical instrument will be described below with reference to the drawings.

FIG. 6 shows a block diagram of a conventional electronic musical instrument. In FIG. 6, 61 is a keyboard section, 62
6 is a tone selection section, 63a and 63b are musical tone generators, and 6
4a and 64b are musical waveform memories, and 65 is a musical tone reproduction section.

For electronic musical instruments, in order to obtain 16 channels that can be played simultaneously, two musical tone generators with 8 channels are installed.
Equipped with two musical waveform memories.

The musical tone generator has a configuration as shown in FIG. In FIG. 8, reference numeral 81 denotes a timing signal generating section which generates a signal for controlling the operation of the musical tone generator.
82 is a note clock generation section, 83 is an address counter, 84 is an envelope counter, 85 is a waveform calculation section, 86 is a digital-to-analog conversion circuit, 8
7a and 87b are sample and hold circuits, and 88 is a low-pass filter.

The note clock generator 82 uses a programmable counter to obtain scale information from a keyboard or the like, and generates a signal with a period proportional to the scale. When the above signal is generated, the address counter is updated in the slot corresponding to the sound channel, the musical sound waveform is read from the memory, and the next time slot performs calculations between the musical sound waveforms and between the musical sound waveform and the envelope, and the digital-to-analog conversion circuit ( DAC) 86 converts it into an analog waveform and stores it in a sample hold circuit 87a. Next, when the above signal is generated, the sample and hold circuit 87b is operated, and a musical tone having a period proportional to the note clock is obtained. FIG. 9 is a diagram showing the flow of signals corresponding to sound generation channel 1. Further, FIG. 7 shows the state of reading out the musical waveform of the musical tone generator.

In the musical tone generator described above, since the sampling frequency is proportional to the scale signal, the aliasing component matches the period of the musical tone, so it is possible to create a clear sound, but the operation of the digital-to-analog conversion circuit and sample hold circuit is When an electronic musical instrument is limited by speed and requires 16 channels that can simultaneously sound, two musical tone generators and two musical waveform memories are required.

Problems to be Solved by the Invention However, with the configuration described above, in order to obtain the number of channels that can simultaneously sound that are required for an electronic musical instrument, it is necessary to have the same number of musical tone generators and the same number of musical waveform memories. This resulted in a significant increase in costs.

In view of the above problems, the present invention takes advantage of the advantages of the above musical tone generator without significantly increasing costs.
To provide an electronic musical instrument that has the number of channels that can simultaneously produce sound, which is necessary for an electronic musical instrument.

Means for Solving the Problems In order to solve the above-mentioned problems, the electronic musical instrument of the present invention takes the period between the plurality of musical tone generators and reads musical sound waveforms from one musical sound waveform memory in a time-division manner. This is what I did.

Effects The present invention has the above-mentioned configuration, in order to obtain the number of channels that can simultaneously sound, which is necessary for an electronic musical instrument.
Even if a plurality of musical tone generators are provided, musical tones can be generated using fewer musical waveform memories than the number of musical tone generators.

Embodiment An electronic musical instrument according to an embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 shows a block diagram of an electronic musical instrument according to an embodiment of the present invention. In Figure 1,
11 is a keyboard section, 12 is a tone selection section, 13a, 13
b is a musical tone generator (TGI, TG ₂ ), which has the same basic structure. 14 is ROM (Read Only
15 is a musical tone generator.

The electronic musical instrument in this embodiment is equipped with two musical tone generators each having eight channels and one musical waveform memory in order to obtain sixteen channels that can simultaneously produce sound.

FIG. 2 shows the main part of the timing signal generating section of the musical tone generator used in the electronic musical instrument of the present invention. Second
In the figure, reference numeral 21 denotes a timing signal generating section of the musical tone generator 13a of FIG. 22 is a timing signal generating section of the musical tone signal generator 13b shown in FIG. To explain this figure, 23a and 23b are quinary counters, which output sequence numbers 0 to 4 by frequency-dividing the master clock MCK. Numerals 25a and 25b are octal counters, which change from 1 to 8 in synchronization with the fall of the master clock MCK at the timing when the output values of the quinary counters 23a and 23b change from 4 to 0. 26a is a synchronization circuit, and as shown in FIG.
Output SYN.

Now, if the SYN signal is sent from the synchronization circuit 26a to the timing signal generator 22 at the timing shown in FIG.
The quinary counter 23b is reset, and the sequence of the timing signal generator 22 is generated with a delay of one sequence. In this way, the operation timing in the musical tone generator 13a and the musical tone generator 13
The operation timing in b is shifted by one sequence. If the timing of reading out the musical sound waveform of the musical tone generator is set to the sequence numbers 1 and 3 as shown in FIG. The musical sound waveform can be read out by dividing.

In this embodiment, the waveform is read twice from the tone waveform memory, but the waveform and/or the envelope may be read out.

Further, in this embodiment, the musical tone generator has two channels (8) that can simultaneously produce sound, but as in the second embodiment shown in FIG.
It is also possible to have as many 3Ps as there are channels that can simultaneously produce sounds that require an electronic musical instrument. Furthermore, the keyboard section 5
1. Tone selection section 52, each tone generator 53a to 53
The p-waveform memory 54 inputs and outputs data signals and the like via a data bus (DB). 55 is a musical tone reproduction section.

As described above, according to this embodiment, even if a plurality of musical tone generators having the same configuration are used, by synchronizing the musical tone generators, it is possible to read out musical sound waveforms in a time-sharing manner without having to have multiple musical waveform memories. can.

Effects of the Invention As described above, in the electronic musical instrument according to the present invention, the musical tone generator outputs a synchronization signal indicating at which timing it is currently operating, and other musical tone generators are operated based on this synchronization signal. Since the timing of its own operation is shifted from the timing of the musical tone generator that is generating the synchronization signal, even when trying to obtain more musical tone generation channels by using multiple musical tone generators, One tone waveform memory can be accessed when neither one is accessing it, and there is no need to add tone waveform memories even when the number of tone generators is increased. Therefore, it is possible to increase the number of channels that can simultaneously produce sounds on an electronic musical instrument without significantly increasing costs.

[Brief explanation of drawings]

FIG. 1 is a block diagram of an electronic musical instrument according to a first embodiment of the present invention, FIG. 2 is a block diagram of a timing signal generation section in a musical tone generator, FIG. 3 is a timing chart thereof, and FIG. 4 is a musical tone generator. 5 is a block diagram of the second embodiment of the present invention. FIG. 6 is a block diagram of a conventional electronic musical instrument. FIG. 7 is a timing chart of memory read. The block diagram of the musical tone generator, FIG. 9, is a timing chart of its waveform generation. 11...Keyboard section, 12...Tone selection section, 13
a, 13b... musical tone generator, 14... musical waveform memory, 15... musical tone reproduction section.

Claims (1)

[Scope of Claims] 1. A memory for storing a plurality of sets of sample values of musical sound waveforms, means for generating a timing signal, and selecting sample values of musical sound waveforms from the memory according to a calculation sequence based on the timing signal. an electronic musical instrument comprising: a plurality of musical tone generators each having arithmetic means for generating musical tones by reading the sample values and performing predetermined arithmetic processing on the sample values; The first musical tone generator includes means for generating a synchronization signal indicative of the operational timing status of the musical tone generator, and at least one of the other musical tone generators is configured to generate a synchronizing signal indicative of the operating timing status of the musical tone generator. at least two of the plurality of musical tone generators; An electronic musical instrument characterized in that a musical tone generator reads sample values from the same memory.