JP3295996B2 - Digital effector - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a digital effector for adding an effect to an input waveform.

[0002]

2. Description of the Related Art Conventionally, there has been known a digital effector that adds various effects to an input waveform by using a digital signal processing technique. This digital effector
The DSP is configured to perform various arithmetic processing on an input waveform by using a DSP and add an effect to the input waveform. Therefore, the waveform output from the digital effector is D / A converted and sounded to generate a musical tone to which an effect according to the content of the arithmetic processing is added.

[0003]

However, in the conventional digital effector, since the input waveform is subjected to the arithmetic processing as described above and the effect is added, a multiplier and an adder for executing the arithmetic processing are used. It is necessary to prepare hardware, programs for effect processing, and various parameters such as operation coefficients. For this reason, there is a disadvantage that not only the circuit size is inevitably increased, but also the control becomes complicated.

An object of the present invention is to provide a digital effector having a small circuit configuration and capable of adding an effect to an input waveform without requiring complicated control.

[0005]

In order to solve the above-mentioned problems, according to the present invention, a first latch means for latching an input waveform signal, and a bit having an output from the first latch means are provided. It has output means for replacing the other bits and outputting, and second latch means for latching the output of the output means.

[0006]

In the above arrangement, after the input waveform is latched by the first latch means, a certain bit is replaced by another bit and output by the output means. Therefore, when the output from the output means is latched and output by the second latch means, the output waveform from the second latch means is distorted with respect to the input waveform in accordance with the replaced bits.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 shows an overall configuration of an electronic musical instrument to which a digital effector according to an embodiment of the present invention is connected. A CPU 1 has a switch unit 2, a program ROM 3, and a work RAM 4 via bus lines. And the sound source unit 5 are connected. The switch unit 2 includes a keyboard switch provided for each key of the keyboard and various switches required for the electronic musical instrument. The CPU 1 controls the electronic musical instrument as a whole and also controls the sound source unit 5 based on operation information of these switches, programs stored in the ROM 3 and the like. The sound source unit 5 generates a musical tone waveform based on an instruction necessary for sound generation or the like performed by the CPU 1 and outputs the tone waveform to the D / A converter 6 at a predetermined output rate. D /
The analog-converted waveform of the A-converter 6 is converted to an LPF 7
After the harmonic components are removed, the signal is supplied to the amplifier 8 and emitted from the speaker 12 to the outside.

An output terminal 10 is connected between the tone generator 5 and the D / A converter 6.
Is connected to the input terminal 12 of the digital effector 11 according to the present embodiment shown in FIG. Inside the digital effector 11, there are provided a first latch 13 to which a waveform signal is input from the input terminal 12, and a clock generating unit 14 to which a sampling clock φfs having a constant frequency is input. Further, the first latch 1
The output stage 3 is provided with a second latch 15 connected to an output terminal 16 and the clock generation unit 1.
There is provided a delay 17 for delaying the phase of the sampling clock φfs output from 4 by １ ／ cycle and inputting it to the second latch 15.

The first latch 13 and the second latch 15 are both composed of 8 bits. Then, each sample data of the MSB to bit 4 of the first latch 13 is
The data is output to the MSB to bit 4 of the latch 15, respectively. However, the sample data of bit 3 of the first latch 13 is
In the bit 14 of the latch 14, the sample data of the bit 2 is output to the LSB, and the LSB of the first latch is output.
Is output to bit 3 of the second latch.

A panel 18 is mounted on the outside of the digital effector 11. The panel 18 has a numeric keypad operated when setting the frequency of the sampling clock φfs generated by the clock generator 14. 19, a display section 20 for displaying a frequency set by operating the numeric keypad 19, and an enter key 21 operated when operating the digital effector 11 are provided.

In the embodiment having the above configuration, when the digital effector 11 is used, the display unit 2
By operating the numeric keypad 19 while visually checking the numerical value displayed as 0, the frequency of the sampling clock φfs generated from the clock generator 14 is adjusted to the output rate of the tone generator 5. When the enter key 21 is operated after that, the clock generator 14 is activated to generate the sampling clock φfs having a constant frequency. This clock generator 14
Is input to the first latch 13, and the first latch 13 latches the input waveform at the timing of the input sampling clock φfs. At this time, since the frequency of the sampling clock φfs is previously adjusted to the output rate of the sound source unit 5 as described above, the waveform input from the sound source unit 5 is latched in the first latch 13 as it is and output. Is done.

On the other hand, the second latch 15 delays the sampling clock φfs generated from the clock generator 14 by 周期 cycle by the delay 17 and
Therefore, the second latch 15 is connected to the first latch 13
The output from the first latch 13 is latched at a timing delayed by １ ／ cycle. At this time, the MSB of the first latch 13
~ Bit4 sample data is the MSB of the second latch 15.
To bit4, but b of the first latch 13
The sample data of it3, 2 and LSB are latched by the LSB, bit2, and bit3 of the second latch 15, respectively, whereby the order of the sample data of the lower 3 bits is changed.
Therefore, the output waveform from the second latch 15 is distorted with respect to the input waveform from the sound source unit 5 according to the replaced bits. Therefore, by applying D / A conversion and amplification to the waveform output from the second latch 15 for sound generation, it is possible to add an effect by a noisy sound.

In the description of the embodiment, the frequency of the sampling clock φfs generated from the clock generator 14 is set to match the output rate of the tone generator 5. However, if a different frequency is set by operating the numeric keypad 19, The waveform latched by the first latch 13 and the input waveform from the sound source section 5 are different, and the waveform from the sound source section 5 is changed in a more complicated manner, so that various effects can be added.

[0014]

As described above, according to the present invention, a certain bit of a digital waveform signal is replaced with another bit between two-phase latches, thereby distorting the input waveform signal. Therefore, an effect can be added to an input waveform with a small-scale circuit configuration without requiring hardware such as a multiplier and an adder for performing arithmetic processing on the input waveform and complicated program control as in the related art.

[Brief description of the drawings]

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

FIG. 2 is a block diagram showing one embodiment of the present invention.

[Explanation of symbols]

 11 Digital Effector 13 First Latch 14 Clock Generator 15 Second Latch 17 Delay

Claims (1)

(57) [Claims] A first latch unit for latching an input waveform signal; an output unit for replacing a certain bit of an output of the first latch unit with another bit; and outputting the output of the output unit. 2. A digital effector comprising: second latch means for latching.