JPH0617194Y2 - Envelope generator - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to an envelope generator.

[Prior Art and Problems Thereof] In the conventional envelope generator, the setting of the envelope setting data requires a complicated operation, and the envelope characteristic that can be set is limited. Typically, for example, when setting the attack part of the envelope, the level at which the attack reaches and the time or the speed (rate) until reaching this level must be set separately. For example, it is necessary to set the achievement level to any of 00 to 99 and the rate to any of 00 to 99. Moreover, in this case, no matter what rate was set, the speed to reach the reached level did not change on the way, and the rate setting did not work more than simply changing one parameter of the envelope. . As described above, in the conventional envelope setting, only one envelope parameter can be selected at a time by operating a setting operator (a switch typically called a Value key).
It was difficult to determine various parameters.

[Object of the Invention] Therefore, an object of the present invention is to provide an envelope generator capable of setting an envelope that can be changed in various ways by a simple operation.

[Summary of the Invention] In order to achieve the above-mentioned object, the invention has an input means for inputting data corresponding to a time length in an envelope waveform having at least steps of a rising portion and a falling portion, and this input means. Generating means for generating an envelope waveform based on the data corresponding to the input time length, and waveform shape characteristics of each step of the envelope waveform generated by the generating means are converted into the data input by the input means. Correspondingly, it has switching means for switching to a linear or exponential characteristic.

[Embodiment] An embodiment of the present invention will be described in detail below.

The overall structure of the electronic musical instrument to which this embodiment is applied is shown in FIG. In the figure, reference numeral 1 denotes a keyboard portion, and during performance, performance operation information (key on, off, initial touch, aftertouch, etc.) input through the keyboard portion 1 is read by the CPU 2, and the CPU 2 The key generator 3 supplies control information such as a note number and an attack start signal corresponding to a key depression, and a release start signal corresponding to a key release. The tone generator circuit 3 is based on the information from the CPU 2,
The internal tone generation function is activated to generate a tone signal and output it to the sound system 4. The sound system 4 converts an analog musical tone voltage signal into an acoustic signal through a speaker or the like and outputs the acoustic signal.

The envelope operator 5 is an operator used when setting an envelope for volume, tone color, etc., and has, for example, a slide-type or volume-type switch, or a numeric keypad.

In the present embodiment, not only can the length of the envelope (for example, the length of the attack portion) be changed by the operation amount information from the envelope operator 5,
At the same time, it is possible to switch and set whether the waveform characteristic is changed linearly with time, or is changed linearly or exponentially. This setting is C
This is performed by giving envelope control information ED0-7, / D, and CU to the envelope generating circuit in the tone generator circuit 3 via PU2.

2 and 3 show examples of the configuration of the envelope generating circuit used in the tone generator circuit 3.

In FIG. 2, the data of ED0 to 7 are information for changing the length of the envelope (directly, the cycle of the clock CK0 which is the carry out of the 8-bit counter 11). In the figure, FA is a 1-bit full adder,
SR indicates an 8-bit shift register. This is 8 bits because the maximum number of envelopes for 8 channels is generated in this embodiment. The larger the value of the data ED0-7, the earlier the carry-out CK0 of the counter 11 occurs.

This carry-out CK0 is input to the lowest 1-bit half adder as a clock of the 4-bit counter 12 shown in the center. The 4-bit counter 12 outputs four count signals CK1, CK2 ', CK3', CK4 '. As shown in FIG. 4, the lowest count signal CK
The second count signal CK2 'is output for every two shots of 1, the third count signal CK3' is output for every two shots, and the highest count signal CK4 'is output for every two shots (however, the simplification of the drawing is performed. Therefore, it is shown as one channel).

In the gate circuit 13, the signals CK1 and CK2 'are ANDed to generate the clock CK2.
The clock CK3 is obtained by ANDing 2 and the signal CK3 ',
The clock CK4 is obtained by ANDing the clock CK3 and the signal CK4 '. One of these clocks CK1 to CK4 is selected by the signals E1 to E4 output from the decoder 14 in FIG. 3, and the selected signal is used as a clock for the envelope output counter 15 in FIG.
Entered in. That is, when the E1 signal is output from the decoder 14, the fastest clock CK1 is ECK.
In the case of the E2 signal, the clock CK2 of the half cycle thereof, the clock CK3 of the half cycle of the E3 signal, and the slowest clock CK3 of the half of the E4 signal are input to the envelope output counter 15 as the signal ECK. It

The envelope output counter 15 operates as an up counter when the up / down input / D is up (/ D = 0), and operates as a down counter when down (/ D = 1). Therefore, the data ED0 to
The time length of the envelope is changed according to the period of the clock ECK based on 7.

The upper 3 bits of the count output of the envelope output counter 15 are input to the decoder 14. Further, the envelope switching signal CU for switching the envelope waveform linearly or exponentially and the above-mentioned up / down signal / D are input to the decoder 14. Decoder 14
Always outputs the E1 signal regardless of the value of the upper 3 bits of the envelope output when the envelope switching signal CU is CU = 0, and selects the clock CK1 having the fastest signal E1 as the clock ECK of the counter 15. Therefore, the envelope output changes linearly. On the other hand, when CU = 1, the decoder 14 outputs the signals E1 to E according to the value of the upper 3 bits of the envelope output.
4 is output, and this switches the cycle of the clock ECK of the envelope output counter 15, so that the output waveform of the counter 15 changes in a polygonal line shape (see FIG. 5).

Specifically, in the polygonal line mode (CU = 0) and the rising mode (/ D = 0), the most significant bit MSB of the envelope output is 0, that is, the upper 3 bits are 000, 00.
During the period of 1, 010, 011 the signal E1, and therefore the envelope clock ECK becomes the fastest clock CK1, and the upper 3 bits of the envelope output are 100, 101.
Signal E2 during and therefore the second fastest clock CK
2 becomes ECK, the envelope output rises at a rate of 1/2, the signal E3 while the upper 3 bits are 110, and thus ECK = CK3, and the envelope output rises at a further 1/2 slope, and the upper 3 E while bit is 111
CK = CK4, and the envelope output further increases with a gradient of ½.

Similarly, in the polygonal line mode (CU = 0), in the case of the falling mode (/ D = 1), the steepest slope is obtained when the upper 3 bits of the envelope output are 111, 110, 101 and 100. The envelope decreases with 011, 01
The envelope decreases at a slowest rate at a gradient of 1/2 during 0, a gradient of 1/2 during 001, and a gradient of 1/2 during 000.

As described above, the signal CK1 is generated by the data ED0-7.
˜CK4, and hence the speed of the clock ECK of the envelope output counter 15, the data ED0 to ED7 are parameters of the envelope time length. on the other hand,
The switching signal CU serves to switch the envelope shape according to its value. Therefore, by combining the two, as shown in FIG. 6, the rise of the envelope,
The characteristics of the trailing edge can be variously changed with two parameters.

According to the present embodiment, these two parameters (ED0-7
And CU) can be simultaneously changed and set based on the operation amount from the envelope operator 5.

That is, as shown in FIG. 7, when an attack is selected and an operation amount (attack time data) is input from the envelope operator 5 for attack setting (step S1), the CPU 2 sets the input data to ID0 to ID0. It is read as 7 (step S2). And the internal table T
To obtain the values of the corresponding envelope length data ED0 to ED7 and the linear / exponential switching data CU, and send them to the tone generator circuit 3 to set the attack envelope (steps S2 and S4). Further, when setting the falling part of the waveform such as decay or release, the table of the falling part is activated according to the input operation amount by the same flow as in FIG. Obtained and set in the tone generator circuit 3.

[Effect of Device] As is apparent from the above description, according to this device, the envelope waveform is generated based on the data corresponding to the time length of the envelope waveform, and the shape characteristic of the waveform at each step of this envelope waveform is determined. By switching linearly or exponentially in accordance with the input time length data, it becomes possible to generate an envelope waveform that varies in various ways.

[Brief description of drawings]

FIG. 1 is an overall configuration diagram of an embodiment of the present invention, FIG. 2 and FIG.
FIG. 4 is a diagram showing a configuration example of an envelope generating circuit, FIG.
FIG. 5 is a diagram used for explaining the operation of the envelope generating circuit, and FIG. 6 is a diagram showing changes in characteristics of the rising and falling of the envelope due to combinations of various envelope time data and straight line / exponential switching data. The figure is a flow chart of the operation of the embodiment. 2 ... CPU, 3 ... tone generator circuit, 5 ... envelope operator, ED0-7 ... envelope time data, CU ...
... Line / index switching data, T ... Manipulation amount / envelope attack data conversion table.

Claims (1)

[Scope of utility model registration request] 1. An input means for inputting data corresponding to a time length of an envelope waveform having at least respective steps of a rising portion and a falling portion, and based on the data corresponding to the time length input by the input means. Generating means for generating an envelope waveform, and the waveform shape characteristic of each step of the envelope waveform generated by this generating means is switched to a linear or exponential characteristic in accordance with the data input by the input means. An envelope generator comprising: switching means.