JPH0210399B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an integrated circuit for generating a melody having an envelope waveform.

Most of the sound generating devices used in conventional watches and the like produce only a monotonous buzzer sound, and of course cannot expect to produce multiple types of sounds or songs. On the other hand, it is possible to equip a clock with a conventional mechanical music box and make small sounds as an alarm, but the mechanism is complicated and expensive when equipped with a conventional mechanical music box. Also, if you try to generate a melody electronically, the circuit becomes complicated and the result is a simple sound with no lingering resonance.

An object of the present invention is to eliminate such conventional drawbacks and to realize an integrated circuit for generating a melody which can generate an electronic melody sound to which an envelope is added.

An example in which the melody generation integrated circuit according to the present invention is used in an electronic timepiece will be explained below. 1st
The figure shows an application example of the integrated circuit for a watch with a melody generation function according to the present invention. 101 is an integrated circuit for a watch with a melody generation function; 102 is a time;
Time display body for minutes, seconds, etc., 103 is an amplifier, 104
105 is a speaker, 105 is a power supply unit, 106 is a time adjustment unit, and a selection unit for selecting a song or tone as an alarm. As shown in FIG. can be configured.

FIG. 2 shows the structure of the melody generating integrated circuit shown in FIG. 1. Oscillation circuit 201, frequency dividing circuit 202, presettable time counting circuit 20
3. Each circuit of the decoder and the drive circuit 204 constitutes a clock section, and the decoder and the drive circuit have an output terminal to the time display body and a time counting circuit 2.
03 has an input terminal for time correction and alarm time setting. The oscillation circuit 201 is preferably a crystal oscillation circuit in terms of accuracy, and therefore it is necessary to provide a terminal for connecting the crystal resonator.

Next, the configuration of the melody generation circuit, which is a feature of the present invention, will be explained. When a preset time is reached, a reset cancellation signal is sent from the presettable time counting circuit 203 to the melody generation function section, and at the same time as this reset cancellation, the memory circuit 21
Reading of information in which 3,215 is stored starts. The tone length information stored in the memory circuit 215 is
The frequency division ratio in the programmable divider 211 that divides the signals from the beat oscillation circuit 209 and the frequency division circuit 210 is determined. The signal divided to a predetermined frequency is supplied to an address designation circuit 212, and the address signal from the address designation circuit 212 sequentially scans addresses in a storage circuit 213 that stores envelope information. The envelope information from the storage circuit 213 is given to an envelope generation circuit 214 consisting of a DA conversion circuit, where an envelope waveform is created. 301 in FIG. 3 is an example of an envelope waveform, and the length of the waveform changes depending on the output of the programmable divider. On the other hand, the address designation circuit 212 also outputs a signal to an address designation circuit 216 for determining the address of the storage circuit 215 that has note length information and scale information. are sequentially scanned, and the read tone length information is given to the programmable divider 211 as described above, and the scale information is given to the programmable divider 206. The programmable divider 206 divides the output of the scale oscillation circuit 205 based on the scale information, and divides the output of the scale oscillation circuit 205 into the waveform shaping circuit 20.
Supply to 7. A plurality of melodies are stored in the memory circuit 215, and the address designation circuit 216 is provided with a terminal for setting a readout start address of the memory circuit 215, thereby making it possible to select the number of melodies. The waveform shaping circuit 207 shapes a rectangular wave into a waveform such as a sine wave or a sawtooth wave.If an input terminal for waveform selection is provided to select the type of waveform, the desired tone can be selected from the outside. It is convenient to carry out. An example of the output waveform of the waveform shaping circuit 207 is shown at 302 in FIG. Waveform shaping circuit 207
The output from the above envelope signal from the envelope generation circuit 214 is multiplied by the multiplication circuit 208 and outputted. 303 in FIG. 3 is a waveform 302
The result of multiplying the envelope waveform 301 by the envelope waveform 301 is shown.

FIG. 4 shows another example of the structure of the integrated circuit for a watch with a melody generation function according to the present invention.
Scale oscillation circuit 20 of the melody generation function part shown in the figure
5 and the beat oscillation circuit 209 as the oscillation circuit 2 of the clock section.
01 and a part of the circuit 202 are shared for rationalization. In FIG. 4, parts having the same functions as those in FIG. 2 are given the same numbers.

As another embodiment of the timepiece with melody generating function according to the present invention, the following configuration can be easily adopted. That is, the waveform shaping circuit 207 in FIG. 2 is removed, and a plurality of programmable dividers are provided to form an integrated circuit for generating a melody for chord generation.

As described above, the melody generation integrated circuit according to the present invention includes a storage means that stores scale information and tone length information of a plurality of electronic tones, and a first circuit that divides a reference signal at a division ratio according to the scale information. a programmable divider, a second programmable divider that divides the reference signal with a frequency division ratio according to tone length information, and an addressing circuit that sequentially advances addresses by signals from the second programmable divider, and an addressing circuit. By providing a terminal for setting the readout start address for selecting the electronic sound, it is possible to generate the electronic sound with a simple circuit configuration without the need for multiple frequency dividers corresponding to the musical scale. , a plurality of melodies can be arbitrarily selected and switched. Further, a second storage means for storing an envelope waveform, a second addressing circuit, and an addressing circuit including a multiplication circuit are provided.
Since the output of the programmable divider is inputted and an envelope is generated at a speed corresponding to the note length, an extremely effective envelope can be added with a simple configuration.

[Brief explanation of drawings]

FIG. 1 is an application example of the integrated circuit for melody generation according to the present invention. FIG. 2 shows a configuration example of an integrated circuit for melody generation according to the present invention. Figure 3, waveform example. Fourth
Fig. 3 shows another example of the configuration of the melody generation integrated circuit used in the present invention. 101...Melody generation integrated circuit, 102...
Time display body, 103... Amplifier, 104... Speaker, 105... Power supply section, 106... Time adjustment section, 20
DESCRIPTION OF SYMBOLS 1... Oscillation circuit, 202... Frequency dividing circuit, 203... Presettable time counting circuit, 204... Decoder circuit and drive circuit, 205... Scale oscillation circuit, 2
06... Programmable divider, 207... Waveform shaping circuit, 208... Multiplication circuit, 209... Beat oscillation circuit, 210... Frequency division circuit, 211... Programmable divider, 212... Address designation circuit, 213
...Memory circuit, 214...Envelope generation circuit, 2
15...Storage circuit, 216...Address designation circuit, 3
01...Example of envelope waveform, 302...Example of output waveform from the waveform shaping circuit, 303...Example of output waveform from the multiplication circuit.

Claims (1)

[Claims] 1. A first storage means that stores scale information and tone length information of a plurality of electronic sounds, a first programmable divider that divides the first reference signal at a division ratio according to the scale information, and a second standard. a second programmable divider that divides the signal at a frequency division ratio according to the tone length information; a first addressing circuit that sequentially advances the address of the first storage means; and a second storage means that stores an envelope waveform. , a second addressing circuit that sequentially reads envelope waveform information from the second storage means, and a multiplication circuit that adds the envelope waveform to the signal from the first programmable divider, A signal from the second programmable divider is input to the addressing circuit, and the first addressing circuit is further provided with a terminal for setting a readout start address for selecting an electronic sound. An integrated circuit for generating melody.