JP3003530B2 - Integrated circuit device for generating tone signals - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a musical sound signal generation circuit which is incorporated in various kinds of audio equipment such as electronic musical instruments, game machines, computer equipment, karaoke equipment, etc. and has a built-in music signal generation circuit for forming and outputting a music signal. Related to an integrated circuit device.

[0002]

2. Description of the Related Art Conventionally, a tone signal generating circuit for forming and outputting a tone signal by various methods such as a harmonic synthesis method, a frequency modulation method and a waveform memory method has been incorporated in an integrated circuit device. It is well known that an integrated circuit device is incorporated into various audio devices to generate musical sounds from the audio devices. In this case, there have been various demands for the tone signal formation mode when the type of acoustic device to which the integrated circuit device is applied or the same type of device is of a different model. That is, some audio equipment only needs to generate a simple tone signal, while other audio equipment can generate a complex and high-quality tone signal or have various musical effects. In some cases, additional functions, such as the ability to generate musical tone signals, are required. Therefore, conventionally, in order to meet the above-described different requirements, an integrated circuit device that only generates a simple tone signal and a circuit that realizes an additional function for modifying the tone signal are provided. In order to enable the attachment, an integrated circuit device having an input / output terminal for an external circuit has been separately manufactured.

[0003]

However, when two types of integrated circuit devices are manufactured as described above, the unit price of the integrated circuit device does not increase so much if the number of manufactures of each type is large. If the number of manufactured ICs is not large, there is a problem that the unit price of the integrated circuit device increases. SUMMARY OF THE INVENTION The present invention has been made to address the above problems, and has a purpose of generating only a simple tone signal and an external circuit for realizing an additional function for processing the tone signal. Thus, a common integrated circuit device for generating a tone signal can be used.

[0004]

In order to achieve the above-mentioned object, a structural feature of the first invention is that a tone signal path in a tone signal generating circuit incorporated in an integrated circuit device is provided .
One input / output circuit is interposed, and the first input / output circuit selectively operates according to an instruction signal from the outside of the integrated circuit device to output a tone signal supplied from the preceding stage to the outside of the integrated circuit device. A tone signal is input from the outside and supplied to the subsequent stage, or output of the tone signal to the outside and
The input of the tone signal is interrupted and the tone signal supplied from the preceding stage is directly supplied to the subsequent stage. Further, the structural feature of the second invention is the same as that of the first invention.
In addition to the key features, the key-on
A second input / output circuit is interposed in the path of the pulse train signal,
The second input / output circuit receives an instruction from outside the integrated circuit device.
Selective operation by signal and key supplied from previous stage
Outputting an on-pulse train signal to the outside of the integrated circuit device
Input a key-on pulse train signal from outside
Key-on pulse supplied to the stage or supplied from the previous stage
That is, the column signal is directly supplied to the subsequent stage. Ma
In this case, the external key-on pulse train signal is
It is preferable that the signal be synchronized with the external tone signal.

[0005]

[Action] In the first invention configured as described above, the
(1) If the input / output circuit outputs the tone signal supplied from the preceding stage to the outside of the integrated circuit device and inputs the tone signal from the outside and supplies an instruction signal from the outside to supply the tone signal to the subsequent stage, the integrated circuit The tone signal being formed by the tone signal generation circuit in the device is derived outside, and the tone signal processed by the external circuit is returned to the integrated circuit device again.
A tone signal processed by an external circuit can be generated from the integrated circuit device. Further, the first input / output circuit outputs the tone signal to the outside and the external
If an instruction signal is externally supplied so as to cut off the input of the tone signal and directly supply the tone signal supplied from the preceding stage to the subsequent stage, the internal circuit device can be used without using an external circuit as described above. The tone signal generated by the tone signal generating circuit of the above is generated from the integrated circuit device. In the second invention configured as described above,
Is the key-on pulse supplied by the second input / output circuit from the previous stage.
Output the external row signal to the outside of the integrated circuit device and
Input the key-on pulse train signal from the section and supply it to the subsequent stage
If an instruction signal is given from outside, the key
Impulse train signal derived from integrated circuit device to external circuit
And key-on pass from external circuits to the integrated circuit device.
It becomes possible to return a lus train signal. Also, the second
Key-on pulse train signal input / output circuit supplied from the previous stage
From outside to supply the signal directly to the subsequent stage
In this way, the key-on pulse train signal is derived externally.
To be supplied directly to the subsequent stage of the integrated circuit device
become. In this case, the external key-on pulse
To synchronize the row signal with the external tone signal.
In this case, the tone returned from the external circuit to the integrated circuit device
Key-on returned to integrated circuit device from signal and external circuit
The pulse train signals also match in timing.

[0006]

As can be understood from the above description of the operation,
According to the first and second aspects of the present invention, the presence or absence of an additional circuit for the same integrated circuit device can be switched by a simple method of externally supplying an instruction signal to the integrated circuit device. In addition, the same type of integrated circuit device can be commonly used, and the unit price of the integrated circuit device can be reduced. In the case where no circuit is externally attached to the integrated circuit device, an output terminal (output pad) for outputting a tone signal to the outside and an input terminal (input pad) for inputting a tone signal from the outside are not used. Therefore, connection pins for connecting both terminals to an external circuit are unnecessary,
The size of the package for covering the chip constituting the integrated circuit device can be reduced, and in this case, the space for mounting the integrated circuit device on the audio equipment can be reduced. In particular, according to the second aspect, the external circuit
Signal processing using key-on pulse train signal
Can be applied.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a schematic block diagram showing an entire electronic musical instrument to which an integrated circuit device 100 for generating a tone signal according to the present invention is applied. I have. The integrated circuit device 100 is formed of a semiconductor chip, and has a microcomputer bus 1 via address lines and control lines 101 and data lines 102.
Connected to 0.

The bus 10 is used for setting a keyboard device 20 for instructing a tone pitch of a generated musical tone, an operation switch device 30 for instructing a tone color and a volume of the musical tone, and setting a tone color and a volume of the musical tone. A display device 40 and a microcomputer 50 are connected. Microcomputer 5
Numeral 0 comprises a CPU 50a, a ROM 50b, and a RAM 50c, and controls display on the display device 40 in response to operations of the keyboard device 20 and the operation switch device 30,
The generation of a tone signal in the integrated circuit device 100 is controlled.

The integrated circuit device 100 is always supplied with a system clock signal φ, a first reference voltage VDD (positive or negative voltage), and a second reference voltage VSS (ground voltage).
The waveform memory 60 and the D / A converter 70 are always connected. The waveform memory 60 stores sampling data representing a tone waveform signal from the start of sound generation to the end of sound generation for each timbre. The D / A converter 70 is an integrated circuit device 10
The digital tone signal output from 0 is converted into an analog tone signal, and the analog tone signal is output as an acoustic signal from a sound system 80 including an amplifier, a speaker, and the like.

Further, the integrated circuit device 100 has an input / output terminal (input / output pad) and an optional circuit for enabling connection of an optional circuit 200 as an external circuit which performs an additional function of forming a tone signal. An input terminal (input pad) for connecting an instruction signal LF for externally instructing whether or not to use 200 is provided. In this embodiment, first, the optional circuit 2 is added to the integrated circuit device 100.
00 will be described. In this case, FIG.
As shown in FIG. 3, the first reference voltage VDD is
0 so as to be supplied as an instruction signal LF, and the option circuit 200 is connected to the integrated circuit device 1.
Connect to 00. Note that a control signal is also supplied to the option circuit 200 via the bus 10.

Next, the details of the integrated circuit device 100 will be described with reference to FIG. 2. The integrated circuit device 100 includes a control register circuit 110, an address generator 120, an interpolator 130,
Input / output circuit 140, digital filter 150, volume control circuit 160, channel accumulator 170, and effect circuit 1
80. In this case, the address generator 1
20, the interpolator 130, the digital filter 150, the volume control circuit 160, the channel accumulator 170, and the effect circuit 180 constitute a tone signal generation circuit in the present invention.

The control register circuit 110 includes a write control unit 111 as shown in FIG. 3, and the control unit 111 controls the data line 102 in accordance with an address signal and a control signal supplied through an address line and a control line 101. In addition to controlling the storage of the data supplied through the various registers, the transfer of the stored data to various circuits is controlled. As an example of the storage and transfer of various data, the storage and transfer of key-on data indicating the pressed state of each key of the keyboard device 20 will be described. At the same time as being supplied via data line 102,
A control signal indicating the supply of the key-on data is supplied via the address line and the control line 101. The write control unit 111 decodes the control signal supplied via the control line 101, instructs the key-on registers 112a to 112d to take in the key-on data supplied via the data line 102, and thereafter, Key-on register 1 for serial converter 113
It instructs to take in 8-bit parallel data output from 12a to 112d, convert the data into serial data, and output. Therefore, the key-on register circuit 1
Reference numerals 12a to 112d fetch key-on data for 32 channels supplied via the microcomputer 50 and output the key-on data to the parallel-to-serial converter 113. The parallel-to-serial converter 113 has one bit having a time-division time slot for the same 32 channels. Output a key-on pulse train signal.

The 1-bit key-on pulse train signal is output to the gate circuit 114 and the selector circuit 115.
Gate circuit 114 has an instruction signal LF at its control input terminal.
When the signal LF is at the first reference voltage VDD, the signal path is made conductive and the signal LF
When the voltage is at the reference voltage VSS, the signal path is cut off. The selector circuit 115 also has an instruction signal LF at its selection control input terminal.
When the signal LF is at the first reference voltage VDD, the key-on pulse train signal KONP ₂ from the option circuit 200 is selectively output, and when the signal LF is at the second reference voltage VSS, the parallel-serial converter 1
13 to selectively output the key-on pulse train signal. In this case, since the instruction signal LF is set to the first reference voltage VDD, the key-on pulse train signal from the parallel-serial converter 113 is supplied to the option circuit 200 via the gate circuit 114 as the key-on pulse train signal KONP _{1 and} The key-on pulse train signal KONP ₂ from the option circuit 200 is supplied to various necessary circuits via the selector circuit 115.

The address generator 120 is for sequentially specifying the address of the sampling data stored in the waveform memory 60 for each channel based on the data representing the tone color, pitch, etc., supplied from the control register circuit 110. Is supplied to the waveform memory 60. The interpolator 130 performs an interpolation operation on the sampling data read by the waveform memory 60 based on the signal from the address generator 120, and inputs sampling data representing the tone signal waveforms of 32 channels for each channel. The output is time-divisionally output to the output circuit 140 (see the interpolator output data in FIG. 5). The sampling data is 16 bits.

The input / output circuit 140, as shown in FIG.
It has parallel-serial converters 141a to 141d that input 16-bit sampling data for each time-division channel from the interpolator 130. The parallel-serial converters 141a to 141d input 16-bit sampling data from the interpolator 130 based on timing signals φ0 to φ3 supplied from a timing signal generation circuit (not shown), and convert the input 16-bit sampling data. Each of them is converted into parallel-serial data and output (see data lines 0 to 3 in FIG. 5).

The output 4-bit sampling data is output to the gate circuit 142 and the selector circuit 143. The gate circuit 142 receives an instruction signal LF at its control input terminal. When the signal LF is at the first reference voltage VDD, the gate circuit 142 conducts the signal path, and when the signal LF is at the second reference voltage VSS. Cut off the signal path. The selector circuit 143 also receives an instruction signal LF at its selection control input terminal, and when the signal LF is at the first reference voltage VDD, selects and outputs the sampling data SDAT ₂ from the option circuit 200 and outputs the same signal LF. Is at the second reference voltage VSS, the sampling data from the parallel-serial converter 113 is selectively output. In this case, since the instruction signal LF is set to the first reference voltage VDD, the parallel-serial converters 141a to 141a
The sampling data from 141d is supplied to the gate circuit 142.
The sampling data S to the option circuit 200 via
Is supplied as a DAT _1, the sampling data SDAT ₂ from the optional circuit 200 (see data lines 0-3 of FIG. 5) will be supplied to the serial-parallel converter 144a~144d via selector 143 .

The serial / parallel converters 144a to 144
d is sampling data SDAT _{2 of} 1 bit each.
Is converted into 16-bit sampling data by serial-parallel conversion, and the converted sampling data is output to the selector circuit 145.
The selector circuit 145 is also controlled by the timing signals .phi.0 to .phi.3 so that the serial / parallel converters 144a to 144a are controlled.
At 4d, the sampling data sequentially converted into 16 bits is selectively output to the latch circuit 146. Therefore, the latch circuit 146 outputs sampling data of the same format as the 16-bit sampling data for each time-division channel from the interpolator 130, although the timing is different.

The digital filter 150 applies a predetermined frequency characteristic to the sampling data supplied from the input / output circuit 140 in accordance with the tone color control parameter supplied from the control register circuit 110 to provide a volume control circuit 160
Output to The volume control circuit 160 controls the amplitude value of the sampling data supplied from the digital filter 150 according to the volume control parameter supplied from the control register circuit 110, and outputs it to the channel accumulator 170. The channel accumulator 170 accumulates and outputs the sampling data of each channel supplied from the volume control circuit 160. The effect circuit 180 includes the control register circuit 1
In accordance with the effect control parameters supplied from 10, a music effect is added to the accumulated sampling data and output.

On the other hand, the option circuit 200 connected to the control register circuit 110 and the input / output circuit 140
As shown in (1), an arithmetic circuit 210, a control circuit 220, and a memory circuit 230 are provided. The arithmetic circuit is an input / output circuit 1.
Input the sampling data SDAT ₁ from 40,
The sampled data SDAT ₁ is subjected to various signal processing in order to perform additional modification on the tone signal waveform represented by the input sampled data SDAT ₁ , and the sampled data SDAT ₂ subjected to the signal processing is input / output circuit. Output to 140. The signal processing includes, for example, changing the frequency characteristics of the tone signal waveform by a complicated filter process, and adding a special reverberation effect, modulation effect, or the like to the tone signal waveform.

The control circuit 220 controls the mode of signal processing in the arithmetic circuit 210, utilizing a key-on pulse train signal KONP ₁ from the control register circuit 110 for the timing specification of the signal processing. Note that the key-on pulse train signal KONP ₂ is the key-on pulse train signal K
The ONP ₁ is delayed by a predetermined time in accordance with the signal processing performed on the sampling data SDAT ₁ , and the delay is caused by the sampling data SDAT ₂ supplied to the digital filter 150 after being subjected to the signal processing by the option circuit 200. It is performed to synchronize the key-on pulse train signal KONP ₂ and. The memory circuit 230 includes a ROM and an R
The RAM is used for temporarily storing sampling data necessary for the signal processing, and the ROM stores control parameters required for the signal processing in advance.

In the electronic musical instrument having the structure shown in FIG. 1, the keyboard device 2 is operated after the operation switch device 30 is operated.
When the performance starts at 0, the microcomputer 50
Under the control of the address generator 120 and the interpolator 130 in the integrated circuit device 100 and the waveform memory 60 connected to the integrated circuit device 100, the tone waveform having the tone specified by the operation switch device 30 is generated. Sampling data representing a signal is read out at the keyboard device 20 at a rate corresponding to the designated pitch. The sampling data is converted into serial data by the parallel-serial converters 141 a to 141 d of the input / output circuit 140, output to the outside of the integrated circuit device 100, and supplied to the option circuit 200. The option circuit 200 modifies the supplied sampling data such as a change in frequency characteristics and effects, and returns the modified sampling data to the input / output circuit 140 in the integrated circuit device 100 in a serial format. The serial / parallel converters 144a to 144d in the input / output circuit 140 return the serial sampled data to the parallel form and supply the data to the digital filter 150 and the volume control circuit 160.

The sampling data returned to the parallel format is supplied to the digital filter 150 and the volume control circuit 1.
At 60, the timbre and volume are controlled according to the operation of the operation switch device 30, and the sampling data of all the channels are accumulated at the channel accumulator 170 and supplied to the effect circuit 180. In the effect circuit, an acoustic effect is applied to the accumulated sampling data in accordance with the operation of the operation switch device 30, and the sampling data with the effect is output from the integrated circuit device 100. The sampling data output from the integrated circuit device 100 is converted into an analog signal by the D / A converter 70, and a tone corresponding to the analog signal is generated from the sound system 80.

In the electronic musical instrument that operates as described above,
Basically, the characteristics of the tone signal such as tone, volume, and effect are determined by an address generator, an interpolator 130, a digital filter 150, and a volume control circuit 60 provided in the integrated circuit device 100.
And a tone signal generating circuit composed of an effect circuit 180. Since the optional circuit 200 performs additional modification such as more complicated frequency characteristics and sound effects on the tone signal having the basic characteristics, the tone signal can be made complicated and high quality. . When the sampling data is supplied to the option circuit 200, the parallel-format sampling data is converted into the serial-format sampling data by the parallel-serial converters 141a to 141d in the integrated circuit device 100. The sampling data in the serial format supplied from the circuit 100 to the integrated circuit device 100 is transmitted to the serial / parallel converter 1 in the circuit device 100.
Since it is converted to a parallel format at 44a to 144d,
The number of pins provided in the integrated circuit device 100 for outputting sampling data to the outside can be reduced. Further, when outputting the key-on data to an optional circuit 100 from the control register circuit 110 also, since the outputs by converting the key-on data in the parallel-serial converter 113 into a time division key-on pulse train signal KONP _1, integrated The number of pins for outputting key-on data in the circuit device 100 can be reduced.

Next, an optional circuit 2 as an external circuit in the integrated circuit device 100 for generating a tone signal according to the present invention.
A case where a tone is generated without connecting 00 is described. The configuration of the electronic musical instrument in this case is as shown in FIG. In this case, the option circuit 200 is the integrated circuit device 1
In addition, wiring is performed such that the second reference voltage VSS is supplied to the integrated circuit device 100 as the instruction signal LF while not being connected to the first reference voltage VSS.

With this connection, as shown in FIG. 3, the gate circuit 114 is cut off in the control register circuit 110, and the selector circuit 115 outputs a key-on pulse train signal from the parallel-serial converter 113. On the other hand, as shown in FIG. 4, in the input / output circuit 140, the gate circuit 142 is cut off and the selector circuit 14 is turned off.
Reference numeral 3 selectively outputs sampling data from the parallel-serial converters 141a to 141d. As a result, the tone signal is not modified in the option circuit 200, and the characteristics of the tone signal, such as tone, volume, and effect, are changed by the address generator 120 and the interpolator 1 provided in the integrated circuit device 100.
The tone signal is basically determined by a tone signal generation circuit including the digital filter 30, the digital filter 150, the volume control circuit 60, and the effect circuit 180.

As can be understood from the above description, if the external instruction signal LF for the integrated circuit device 100 for generating a tone signal is set to the second reference voltage VSS, the integrated circuit device 100 is not connected to the option circuit 200. Available at Further, if the instruction signal LF from the outside is set to the first reference voltage VDD, the option circuit 200 external to the integrated circuit device 100 can be used. Thus, according to the integrated circuit device 100 of the above embodiment,
With a simple method of externally setting the instruction signal LF,
Since the presence or absence of the option circuit 200 external to the integrated circuit device 100 can be switched, the integrated circuit device 100
Can be used in common, and the unit price of the integrated circuit device 100 can be reduced.

When the optional circuit 200 is not connected to the integrated circuit device 100, an output pad for outputting a tone signal to the outside and an input pad for inputting a tone signal from the outside are not used. In addition, connection pins for connecting both pads to an external circuit are not required. Therefore, the size of the package for covering the chip constituting the integrated circuit device 100 can be reduced, and in this case, the integrated circuit device 100 for audio equipment can be provided.
Mounting space can be reduced. At this time, the gate circuit 114 in the control register circuit 110 is shut off so that the key-on pulse train signal from the parallel-serial converter 113 is not transmitted to the output pad for connecting the option circuit 200, and the input / output circuit Since the gate circuit 142 in the block 140 is also shut off so that the sampling data from the parallel-serial converters 141a to 141d is not transmitted to the output pad for connecting the option circuit 200, the potential of these output pads is fixed. As a result, it is possible to suppress the generation of noise due to the potential fluctuation of the pad.

In the above embodiment, the instruction signal L
The first or second reference voltage VDD, VSS from outside as F
The option circuit 200 as an external circuit is connected to the integrated circuit device 100 to be used or not connected to the integrated circuit device 100 by using the external circuit. An instruction signal LF is supplied into the integrated circuit device 100 via the line and control line 101 or the data line 102, and the gate circuits 114 and 142 and the selector circuits 115 and 1 are supplied based on the signal LF.
43 may be controlled.

In the above embodiment, the waveform memory 6
The present invention is applied to a tone signal generating circuit for forming a tone signal by reading out sampling data representing a tone signal waveform stored in a zero, but the present invention has an input / output circuit 140 interposed in a tone signal path. The present invention can be applied to a tone signal generating circuit that forms a tone signal by another method such as a harmonic synthesis method or a frequency modulation method. Further, the integrated circuit device 100 for generating a tone signal according to the present invention.
The electronic musical instrument is incorporated in various audio equipment such as game equipment, computer equipment, and karaoke equipment other than electronic musical instruments, and can be used for generating musical tones in the various audio equipment.

[Brief description of the drawings]

FIG. 1 is a schematic block diagram showing an entire electronic musical instrument to which an integrated circuit device for generating a tone signal according to the present invention is applied in a state where an optional circuit is used.

FIG. 2 is a block diagram showing details of the integrated circuit device of FIG. 1;

FIG. 3 is a block diagram showing details of a control register circuit of FIG. 2;

FIG. 4 is a block diagram showing details of an input / output circuit of FIG. 2;

FIG. 5 is a time chart for explaining the operation of the input / output circuit.

FIG. 6 is a block diagram showing details of an option circuit shown in FIGS. 1 and 2;

FIG. 7 is a schematic block diagram showing an entire electronic musical instrument to which the integrated circuit device for generating a musical tone signal according to the present invention is applied without using an optional circuit.

[Explanation of symbols]

10 bus, 20 keyboard device, 30 operation switch device, 50 microcomputer, 60 waveform memory,
80: sound system, 100: integrated circuit device for generating tone signals, 110: control register circuit, 120: address generator, 130: interpolation circuit, 140: input / output circuit,
150: Digital filter, 160: Volume control circuit,
170: channel accumulator, 180: effect circuit, 200
... optional circuits.

Claims (3)

(57) [Claims] An integrated circuit device for generating a tone signal having a tone signal generating circuit for forming and outputting a tone signal, wherein a first input / output circuit is interposed in a tone signal path in the tone signal generating circuit. The first input / output circuit selectively operates according to an instruction signal from the outside of the integrated circuit device to output a tone signal supplied from a preceding stage to the outside of the integrated circuit device. A tone signal is input and supplied to the subsequent stage, or output of the tone signal to the outside and
An integrated circuit device for generating a tone signal, wherein the input of the tone signal from the outside is cut off and the tone signal supplied from the preceding stage is directly supplied to the subsequent stage. 2. A tone signal generating apparatus according to claim 1,
Key on the integrated circuit device of
A second input / output circuit is interposed in the path of the pulse train signal, and the second input / output circuit is external to the integrated circuit device.
Selective operation according to these instruction signals, supplied from the previous stage
To the outside of the integrated circuit device
And a key-on pulse train signal from the outside.
Key to supply to the subsequent stage or
That the impulse train signal is supplied directly to the subsequent stage.
An integrated circuit device for generating a tone signal. 3. A tone signal generating apparatus according to claim 2,
In the integrated circuit device of the above, the external key-on pulse train signal is
An integrated circuit for generating a tone signal synchronized with the tone signal
Road equipment.