JPH0336240B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a music playing device that stores music information whose bit patterns are at least scale data and note length data in a semiconductor memory or the like, and plays music according to reading of these bit patterns. This type of device generates frequency signals corresponding to each scale in response to reading scale data, and generates digital data of envelope waveforms stored in advance corresponding to each note period in response to reading note length data. An apparatus has been proposed that reads out a music scale, performs D/A conversion, applies an envelope to the frequency signal of each scale, and reproduces music. The present invention stores the bit patterns of sound strength data and tremolo effect data together as music information, and reads out these bit patterns at the same time as the scale and note length data, thereby generating envelope waveform digital data. To provide a musical piece performance device which is controlled and has increased sound attributes with a simple circuit configuration. An embodiment of the apparatus of the present invention will be described below with reference to the drawings. FIG. 1 shows an overall circuit block diagram. The device can be broadly divided into an oscillation/frequency dividing circuit 1, a tone generator section 2, an envelope generation section 3,
It is composed of an external input circuit 4, a control circuit 5, an address counter 6, a music information memory 7, an amplifier 9, and a speaker 10. The oscillation/frequency divider circuit 1 includes, for example, a crystal oscillation circuit and a frequency divider circuit, and generates a basic clock for the device. The tone generator section 2 is a section that generates a corresponding frequency signal in accordance with data output from a music information memory 7 (for example, composed of a ROM). The envelope generator 3 generates the length and envelope of the sound according to the data output from the music information memory 7. The input circuit 4 is a switch circuit that controls music selection, music start, transposition/modulation, tempo, etc. The control circuit 5 converts the switch input of the input circuit 4 into a signal and transmits it to each block. The address counter 6 specifies the address of the music information memory 7, and sequentially reads the music data stored in the music information memory 7. FIG. 2 shows the bit assignment of data stored in the music information memory 7. That is, 16 of B ₀ to B ₁₅
Bφ~ _B3 (4 bits)...Scale bits _B4 ~ _B7 (4 bits)...Note length bits _B8 , _B9 (2 bits)...Octave bits _B10 , _B11 (2 bits) )...Instrument recombination bits _B12 , _B13 (2 bits)...Sound strength bit _B14 (1 bit)...Tremolo effect bit _B15 (1 bit)...Assigned like a stop bit. <Specific configuration and operation> (1) First, a song is selected by the song designation switch of the input circuit 4. By operating this switch, the control circuit 5 decodes 3 into M ₁ to M ₃ .
Outputs a bit pattern and specifies the top address of the music information memory 7 for reading. (2) Next, when the start switch of the input circuit 4 is turned on, the music information bit pattern at the address specified above is read out. Among the read bit patterns, Bφ to B ₃ (scale bits),
The 8 bits B ₈ to _{B 11} (octave bits, instrument recombination bits) are the tone generator section 2.
Also, B ₄ ~ _{B 7} (note length bit), B ₁₀ ~ _{B 14}
Nine bits (instrument recombination bit, sound strength bit, tremolo effect bit) are transmitted to the envelope generator 3. B ₁₅ (stop bit) is transmitted to the control circuit 5. When "1" is output to the _B15 bit, the operation is stopped, but at the time of start and when playing music, it is "0" and does not affect the operation in any way. (3) Of the 8 bits transmitted to the tone generator section 2, 6 bits B ₀ to _{B 3} , B ₈ , and B ₉ are input to the adder/subtractor circuit 2-6 and stored in the scale division ratio memory 2-5. At the same time as specifying the address, the octave is selected by the octave selector 2-2. The addition/subtraction circuit 2-6 controls the data of Bφ to B ₃ , B ₈ , and B ₉ by inputting an external switch to the input circuit 4 to enable transposition and modulation. (4) One of the fundamental frequencies ₀₁ to ₀₄ corresponding to each octave is selected by the octave selector 2-2. The frequency divider circuit 2-1 is connected to the oscillation/frequency divider circuit 1, and is multiplied by (1,
2, 4, 8 times) fundamental frequencies ₀₁ to ₀₄ are prepared. The fundamental frequency _0i selected by the octave selector 2-2 is input to the frequency dividing circuit 2-3 and divided. The 9-bit binary frequency division output of the frequency dividing circuit 2-3 is compared with the same 9-bit frequency division ratio output from the frequency division ratio memory 2-5 specified by the above address in the matching circuit 2-4,
When they match, a pulse is output and the frequency divider circuit 2-3 is reset. The frequency of the pulses output at the time of this coincidence corresponds to each scale in each octave. By the way, if the frequency division ratio is 12 values between 478 and 253 (expressed by 9 bits in binary code) with respect to the reference frequency of 500 KHz, each scale frequency in the range of 1046 to 1975 Hz can be obtained. The octave can be changed by doubling the reference frequency. (5) The coincidence detection pulse is further input to the frequency dividing circuit 2-7. The frequency dividing circuit 2-7 uses its 4-bit binary frequency divided output to generate the next stage basic waveform memory 2-8.
Specify the address. That is, the frequency dividing circuit 2-7 operates as a so-called address counter. Basic waveform memory 2-8 consists of 8 bits and has 16
Data is recorded so that each step creates a waveform corresponding to one cycle of the scale frequency. That is, octave selector 2-2, matching circuit 2-
The frequency output from 4 is the actual scale frequency.
This corresponds to 16 times, and one cycle of each scale frequency is divided into 16 by the frequency dividing circuit 2-7, and the addresses of 16 steps in the basic waveform memory 2-8 are sequentially designated. The waveform data read out by this addressing is input to the D/A converter 2-9, where it is D/A converted and
A basic waveform of the sound signal is formed every cycle. Further, 2 bits B ₁₀ and B ₁₁ from the music information memory 7 and the upper 2 bit binary frequency division output C of the frequency dividing circuit 3-7 of the envelope generating section 3 are inputted to the basic waveform memory 2-8. _B10 ,
_{The 11} bits in B select the waveform memory to be read out in accordance with instrument recombination control, and the 2 bits in C further divide the envelope into predetermined regions in time, and select the basic waveform to which higher-order frequencies are added as appropriate. This is to increase the naturalness and ease of listening to the sound. (6) Of the 9 bits transmitted to the envelope generator 3, 4 bits B ₄ to _{B 7} are input to the note length division ratio memory 3-6 as address designations. The two bits _B10 and _B11 are used as control bits for instrument recombination and are stored in the envelope waveform memory 3-8.
Furthermore, the three bits B ₁₂ , B ₁₃ and B ₁₄ are input to the arithmetic circuit 3-9 as bits for controlling the strength of the sound and the tremolo effect. (7) In the envelope generating section 3, when the start switch is turned on, the frequency dividing circuit 3-1 starts operating first. The 6-bit binary frequency division output of the frequency division circuit 3-1 is input to the matching circuit 3-2, and is compared with the 6-bit frequency division ratio output of the tempo frequency division ratio memory 3-3. If they match, a pulse is generated and input to the subsequent frequency divider circuit 3-4. This pulse determines the time interval of the shortest note length. If necessary, by operating the tempo control switch of the input circuit 4, the addition/subtraction circuit 3-11 adds or subtracts the frequency division ratio output of the frequency division ratio memory 3-3 to change the frequency division ratio and set the desired tempo. be able to. (8) Note length division ratio memory 3-4 is 4 from B ₄ to _{B 7} .
Using bits as addresses, 8-bit frequency division ratio data corresponding to each note length is selected and output. Correspondingly, the match circuit 3-5 compares it with the 8-bit binary frequency division output of the frequency divider circuit 3-4, and outputs a pulse when they match. The output time interval of this pulse corresponds to each note length specified by 4 bits _B4 to _B7 . However, here again, due to the following reasons, 1
It outputs 32 pulses per note length. That is, the coincidence detection circuits 3-2, 3-5
The frequency of the pulses output from etc. is usually 32 times that of the general case. This pulse is transmitted to the frequency dividing circuit 3-
7 and is frequency-divided. The envelope waveform memory 3-8 has an 8-bit configuration and stores data to form one envelope waveform in 32 steps. Like the basic waveform described above, the envelope waveform is only compressed and expanded in time for each note length, and one envelope waveform must be read out for one note length. Frequency dividing circuit 3-
Reference numeral 7 serves as a so-called address counter for the envelope waveform memory 3-8, which sequentially specifies 32 step addresses of the envelope waveform memory 3-8 for each note length by a 5-bit binary frequency divided output. The B ₁₀ and B ₁₁ bits input to the envelope waveform memory 3-8 select the waveform memory to be read out, and are combined with the basic waveform selected in the basic waveform memory 2-8 to perform musical instrument recombination control. The 2 bits of C are the high-order ones of the 5-bit binary frequency division output of the frequency divider circuit 3-7, and divide the envelope period into four equal parts. (9) The data read from the envelope waveform memory 3-8 is processed by the arithmetic circuit 3-9.
The envelope waveform data is modified by performing multiplication based on the strength bit data of B ₁₂ and B ₁₃ and addition/subtraction based on the tremolo effect bit data of B ₁₄ . The modified data is D/A converted by a D/A converter 3-10 to generate an envelope. (10) The envelope is sent as a level control signal to the D/A converter 2-9 of the tone generator section 2, and the D/A converter 2-9 multiplies the fundamental waveform and outputs an enveloped sound signal. The sound signal is emitted via an amplifier 9 and a speaker 10. (11) When the frequency dividing circuit 3-7 counts 32 steps (one envelope read), the carry pulse is input to the address counter 6 and advances the address by one. As a result, the next music information bit pattern is read out from the music information memory 7, and the operations (1) to (11) above are repeated. (12) In this way, the song information bit patterns are read out sequentially from the song information memory 7, and when "1" is output to the B ₁₅ bit, a stop signal is output from the control circuit 5, and each frequency dividing circuit 2
-1, 2-3, 2-7, 3-1, 3-4, 3-
7 and closes the internal gate circuit, completing the series of operations. <Data Capacity of Memory> Incidentally, the data capacity of each memory in the above embodiment is as follows. Scale division ratio memory 2-5...9 bits x 12 scale basic waveform memory 2-8...8 bits x 16 steps x 4 basic waveform note length division ratio memory 3-3...8 bits x 1 shortest note length note Long frequency division ratio memory 3-6...8 bits x 16 note length envelope waveform memory 3-8...8 bits x 32 steps x 4 envelope waveforms <basic waveform and envelope> As a basic waveform, for example, the time shown in Figure 3 As shown in the chart, there are a sine wave, b sawtooth wave, c rectangular wave, d triangular wave, etc. Basic waveform memory 2-
8, one cycle of these waveforms A is divided into 16 parts and stored as 8-bit, 16-step digital data. The time charts in FIGS. 1 to 4 show examples of envelope B waveforms. The envelope is divided into 32 parts and stored in envelope waveform memory 3-
8 is stored as 8-bit, 32-step digital data. The basic waveform and envelope waveform described above are just examples, and there are various other basic waveforms and envelope waveforms, and the present invention is not limited to these. If the sound of a certain instrument is as shown in Figure 5,
The basic waveform A is a in Figure 3, and the envelope B is the 4th waveform.
It consists of 2 in the figure. The frequency of the fundamental waveform corresponds to each scale, and the length of the envelope corresponds to each note length. Data specifying instrument sounds is stored in song information memory 7.
These are the instrument recombination bits B ₁₀ and B ₁₁ outputted from the instrument, and here the instrument sound can be switched for each note at most. Instrument recombination bits
The data of B ₁₀ and B ₁₁ are stored in the basic waveform memory 2-8,
The signals are input to the envelope waveform memory 3-8, and the corresponding fundamental waveform and envelope waveform are selected. In this way, in this embodiment, it is possible to reproduce a song with a desired musical instrument sound by combining the envelope waveform and the basic waveform. <Transposition/modulation, tempo adjustment> The chord diagram of the scale data (Bφ to B ₃ bits) is shown in FIG. 6, and the chord diagram of the note length data (B ₄ to _{B 7} bits) is shown in FIG. Here, as shown in the figure, scale data and note length data are encoded in sequential correspondence with 4-bit binary codes.
Note that when the scale data is "0000" (code 0H), it represents a rest, and the rest length is set using the note length data. If we consider the transposition and transposition of a scale using the above code, it becomes addition and subtraction of a certain number of binary codes.
For example, moving up a semitone from C major changes it to D flat major. The first octave of C major is “0100” (code
4H) to “1111” (code FH), and one octave of D flat major is expressed as “0101” (code 5H) to 1
It becomes “0100” (code 4H) an octave higher, which is the C major chord plus “0001”. Also, if you move down a semitone from C major, you get B major. The first octave of B major at this time is "1111" (code FH) one octave below, "0101" (code 4H) to "1110" (code EH) in the same octave, and you can feel "0001" from C major. It becomes something.
The upper and lower octaves are “0100” by the above addition and subtraction.
It is represented by carries and borrows from (code 4H) to “1111” (code FH). The addition/subtraction circuit 2-6 of the tone generator section 2 executes this, and in this example, the scale from do to shi, including the semitone part, is
Since "0100" (code 4H) to "1111" (code FH) are made to correspond sequentially according to the binary code, transposition and transposition can be performed using a simple addition/subtraction circuit. The tempo is also changed to 6 by a similar addition/subtraction circuit 3-11.
This can be achieved by adding or subtracting an arbitrary number (binary code) to the output of the bit frequency division ratio memory 3-3 to change the shortest note length. <Naturalness and audibility of the sound> The 2-bit C signal input to the basic waveform memory 2-8 increases the naturalness and audibility of the sound. Generally, as shown in the typical envelope waveform in Figure 4, the time from the rise of the sound to the peak is called the attack time A, the time from the peak to the hold level is called the decay time D, and the hold level. The time is called the sustain time S, and the falling time is called the release time R.
The basic waveform may also change during these periods. In this embodiment, the envelope period is equally divided into four by a 2-bit C signal and approximated to this. The basic waveform can be changed in various ways, such as slight changes by adding higher-order frequencies, or a certain period of a certain musical instrument sound having a completely different basic waveform. In this case, since it is specified by the instrument recombination bits B ₁₀ and B ₁₁ , and it is necessary to select the basic waveform in each of the four periods of the envelope, 4 x 4 basic waveforms are stored in memory, and the data in basic waveform memory 2-8 is The capacity is 8 bits x 16 steps x (4 x 4) basic waveform. <Sound strength and tremolo control> The strength of the sound is determined by the magnitude of the amplitude, so by adjusting the level of the entire envelope, and since the tremolo effect is so-called low frequency amplitude modulation, the envelope waveform can be adjusted to a low frequency. This can be achieved by amplitude modulation at . FIG. 8 shows the arithmetic circuit 3- of the envelope generator 3.
9 and its peripheral circuits are shown. Arithmetic circuit 3-
9 is an addition/subtraction circuit 3-9-1 and a shift circuit 3-9
-2. The data of the tremolo bit _B14 is sent to the adder/subtractor circuit 3-9-1, and the data of the sound strength bits _B12 and _B13 is sent to the shift circuit 3-9-2.
is input. If the data of bit B ₁₄ is "1" when reading the song information memory 7, tremolo is applied.
Tremolo is often applied to the latter half of the envelope waveform, and in this example as well, the timing of tremolo is controlled by adding the most significant bit output ₀₅ of frequency divider circuit 3-7 to AND gate A. The frequency divider circuit 3-7 sequentially specifies the addresses of 32 steps in the envelope waveform memory 3-8 by outputting a 5-bit binary frequency division, and outputs the most significant bit.
0 ₅ Becomes “1” from the moment an address after the intermediate step is specified. B If _{the 14-} bit data is “1” and the output ₀₅ becomes “1” from the midpoint of the envelope, it is a low frequency signal.
_T passes through AND gate A to addition/subtraction circuit 3-9-
1 is input. “1” of this low frequency signal _T ,
Based on the "0" signal, a predetermined number is added to or subtracted from the 8-bit binary code representing the envelope waveform. That is, this causes the digital quantity of the envelope waveform to change at low frequency _T. Assuming that it is not affected by the shift circuit 3-9-2, it is input to the D/A converter 3-10 after the shift circuit 3-9-2, and an analog signal whose amplitude is modulated in the latter half of the envelope with a low frequency _{T is} input. Output. The strength of the sound is determined by the shift circuit 3-9-2.
This is done by appropriately shifting the output of the addition/subtraction circuit 3-9-1 by the bit specified by the strength control bits _B11 and _B12 . for example,

In [Table], each of the 32-step binary codes supplied according to the B ₁₂ and B ₁₃ bit data is sequentially shifted by a specified number of bits, and the digital amount of the entire envelope is changed by a predetermined amount. The shifted binary output is changed into an analog signal by the D/A converter 3-10, and the signal is doubled for a 1-bit shift, quadrupled for a 2-bit shift, and
With a 3-bit shift, an analog signal with eight times the amplitude is output. That is, the intensity of the sound is controlled by changing the amplitude by a factor of 1, 2, 4, or 8 using B ₁₂ and B ₁₃ bit data. As described above, according to the present invention, it is possible to perform playback by applying an envelope to the frequency signal indicating each scale, and it is possible to perform with rich tones including musical instrument sounds. This can be achieved with simple arithmetic circuits such as addition/subtraction circuits and shift circuits.
It is possible to provide a useful music playing device with increased sound attributes with a simple circuit configuration.

[Brief explanation of the drawing]

FIG. 1 is an overall circuit block diagram showing one embodiment of the present invention, FIG. 2 is a diagram showing the allocation of song information bits, FIGS. 3 a to d are time charts showing examples of basic waveforms, and FIG. 4 ~4 is a time chart showing an example of an envelope waveform, Figure 5 is a time chart showing an example of mixing the basic waveform and envelope waveform, Figure 6 is a diagram showing an example of chords corresponding to each scale, and Figure 7 is a time chart showing an example of mixing the basic waveform and envelope waveform.
The figure shows chord examples corresponding to each note length.
This figure is a circuit block diagram showing the main part of FIG. 1 in more detail. 1... Oscillation/frequency dividing circuit, 2... Tone/generator section, 3... Envelope generation section, 6... Address counter, 7... Song information memory, 3-7
...Frequency divider circuit, 3-8...Envelope waveform memory, 3-9...Arithmetic circuit, 3-10...D/A
Converter, 3-9-1... Addition/subtraction circuit, 3-9
-2...Shift circuit, Bφ~ _B3 ...Scale bit,
_B4 to _B7 ...Note length bits, _B12 / _B13 ...Sound strength bits, B...Tremolo effect bits.

Claims (1)

[Scope of Claims] 1. Stores music information having at least scale data and note length data as bit patterns, generates a frequency signal corresponding to each scale in response to reading of the scale data, and reads out the note length data. In a device that reads a pre-stored envelope waveform corresponding to a long period of each note and applies an envelope to the frequency signal to reproduce a song, the song information includes sound strength data and tremolo effect data. It has a bit pattern of data, performs a shift operation of the digital data of the read envelope waveform according to the data for the sound strength, and shifts the digital data of the read envelope waveform according to the data for the tremolo effect. A music performance device characterized by being provided with an arithmetic circuit that performs addition and subtraction.