KR0153048B1 - Sound field control device of audio system - Google Patents

Abstract

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an audio system, and more particularly, to a sound field control apparatus of an audio system that forms a sound field so that a listener can feel the presence of sound.

Conventionally, when a sound field control device is manufactured as an integrated circuit, since the DRAM delaying the digital audio signal cannot be accommodated in the integrated circuit and must be installed externally, the address bus, data bus, and read / write for the DRAM are externally performed. Since a pin for connecting a signal line for controlling a signal must be provided in an integrated circuit for a sound field control device, the chip area of the integrated circuit is increased and the package volume of the integrated circuit is increased. There is a problem that cannot be made compact.

In the present invention, since the RAM housed in the integrated circuit performs a function performed by the external DRAM of the integrated circuit, the integrated circuit does not have to include a pin for connecting an address bus, a data bus, and a signal line for write / write control to the external DRAM. Therefore, the chip area of the integrated circuit is reduced and the package volume of the integrated circuit is reduced, thereby making the audio system compact.

Description

Sound field control device of audio system

1 is a diagram for explaining sound field generation in an audio system.

2 is a configuration diagram of a sound field control device of a conventional audio system.

3 is a configuration diagram of a sound field control apparatus of an audio system according to the present invention.

* Explanation of symbols for main parts of the drawings

30: A / D conversion unit 31: multiplication unit

32, 35, 36, 40: RAM 33: Accumulation

34: D / A converter 37: RAM controller

39: audio compression unit 41: audio extension unit

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an audio system, and more particularly, to a sound field control apparatus of an audio system that forms a sound field so that a listener can feel the presence of sound in the case of reproduction of sound.

In general, in a specific place (eg, a performance hall or a hall) where sound is provided, a sound field including original sound, reflection sound, and reverberation sound is formed as shown in FIG. When the sound is reproduced by the sound field control, sound field control is performed in order to provide the listener with a sense of type.

The sound field control apparatus employed in the conventional audio system includes the A / D converter 10, the multiplier 11, the RAMs 12 and 15, the accumulator 13, and the D / A as shown in FIG. The conversion unit 14 and the DRAM 16 are provided. The A / D converter 10 converts an analog audio signal applied through an input terminal into a digital audio signal and outputs the digital audio signal to the multiplier 11 side. The RAM 12 stores reflection coefficients for reflecting sound, and applies the stored reflection coefficients to the multiplication unit 11 side. The multiplier 11 multiplies the digital audio signal applied from the A / D converter 10 by the reflection coefficient applied by the RAM 12 and outputs the result to the DRAM 16. The RAM 15 stores a delay coefficient for delaying the sound, and applies the stored delay coefficient to the DRAM 16 side.

When the digital audio signal applied from the multiplier 11 is applied, the DRAM 16 delays the digital audio signal by a delay coefficient stored in the DRAM 16 and outputs the delayed signal to the accumulator 13. The accumulator 13 accumulates digital audio signals applied from the DRAM 16 and outputs them to the D / A converter 14, and the D / A converter 14 is applied from the accumulator 13. The digital audio signal is converted into an analog audio signal and output to the speaker SP1.

That is, such a sound field control device generates a sound field by multiplying an audio signal by a reflection coefficient, delaying the audio signal multiplied by the reflection coefficient by a delay coefficient, and then accumulating and outputting the audio signal.

The conventional sound field control device described above is made of an integrated circuit, and includes an A / D converter 10, a multiplier 11, RAM 12 and 15, an accumulator 13, and a D / A converter 14. ) Is housed within a single integrated circuit, but the DRAM 16 is installed outside the integrated circuit. When generating a sound field, a delay time of about 340 msec is usually required for reflection or reverberation. If sampling at 44.1 KHz and performing 16-bit digital arithmetic processing, a DRAM (16) of about 256 Kbit is required, and thus a relatively large capacity is required. DRAM is required.

As described above, when a sound field control device is manufactured as an integrated circuit, an address bus, a data bus, and a read / write to an external DRAM 16 are required because the DRAM 16 cannot be accommodated in the integrated circuit and installed outside. Since the pins for connecting the read / write control signal lines must be provided in the integrated circuit for the sound field control device, the chip area of the integrated circuit is increased and the package volume of the integrated circuit is increased. There is a problem that the audio system cannot be made compact.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems. The present invention provides an audio system by reducing the chip area of an integrated circuit and reducing the package volume of the integrated circuit by accommodating DRAM functions used for sound field control in an integrated circuit for sound field control. It is an object of the present invention to provide a sound field control device for an audio system that is compactly manufactured.

The sound field control apparatus of the audio system according to the present invention for achieving the above object, A / D conversion means for converting the input analog audio signal into a digital audio signal and outputs; First storage means for receiving and storing a reflection coefficient for reflecting sound and outputting the reflection coefficient; Multiplication means for multiplying and outputting a digital audio signal applied from said A / D conversion means by a reflection coefficient applied by said first storage means; Accumulating means for accumulating and outputting a digital audio signal applied from said multiplication means; A sound field control apparatus for an audio system having a second storage means for receiving and storing a delay coefficient for delaying sound and outputting the same, according to a delay coefficient applied from the second storage means. RAM control means for generating and outputting an address and a read / write control signal; Compress the digital audio signal applied from the accumulating means by a predetermined multiple, delay the compressed digital audio signal according to the address and read / write control signal applied from the RAM control means, and extend the delayed digital audio signal by a predetermined multiple to output it. Compression delay stretching means; And third storage means for storing the digital audio signal applied from the compression delay decompression means and outputting the digital audio signal to the multiplication means side.

According to a preferred embodiment of the present invention, the compression delay expanding means comprises: audio compression means for compressing and outputting the digital audio signal applied from the accumulation means by a predetermined multiple; Fourth storage means for delaying and outputting the digital audio signal applied from said audio compression means in accordance with an address applied from said RAM control means and a read / write control signal; And an audio extension unit for extending the digital audio signal applied from the fourth storage means by a predetermined multiple and outputting the digital audio signal to the third storage means.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

As shown in FIG. 3, the sound field control apparatus according to the present invention includes an A / D converter 30, a multiplier 31, a RAM 32, 35, 36, 40, an accumulator 33, and a D / D. A conversion section 34, RAM control section 37, audio compressor 39, and audio expansion section 41 are provided, and all circuit sections are provided in a single integrated circuit.

In the same figure, the A / D converter 30 converts an analog audio signal applied through an input terminal into a digital audio signal and outputs it to the multiplier 31, and the RAM 32 reflects a reflection coefficient for reflecting sound. Is received from the microcomputer and stored, and the stored reflection coefficient is applied to the multiplier 31 side.

The multiplier 31 multiplies the digital audio signal applied from the A / D converter 30 and the RAM 35 by the reflection coefficient applied by the RAM 32 and outputs the result to the accumulator 33.

The accumulator 33 accumulates the digital audio signal applied from the multiplier 31 and outputs the digital audio signal to the audio compressor 39 and the D / A converter 34.

The audio compressor 39 compresses the digital audio signal applied from the accumulator 33 to 8: 1 and outputs it to the RAM 40 side. The RAM 36 receives and stores a delay coefficient for delaying the sound from the microcomputer, and applies the stored delay coefficient to the RAM controller 37 side. The RAM controller 37 generates corresponding addresses and read / write control signals according to the delay coefficients applied from the RAM 36 and outputs them to the RAM 40 side. When the compressed digital audio signal is applied from the audio compression unit 39, the RAM 40 delays the digital audio signal in accordance with an address applied from the RAM control unit 37 and a read / write control signal. To the side. The audio extension unit 41 extends the digital audio signal applied from the RAM 40 to 1: 8 and outputs it to the RAM 35 side, and the RAM 35 is a digital audio signal applied from the audio extension unit 41. Is stored and output to the multiplication unit 31 side. In addition, the D / A converter 34 converts the digital voice signal applied from the accumulator 33 into an analog voice signal and outputs the analog voice signal to the speaker SP2.

Referring to the overall operation of the sound field control device of the present invention configured as described above is as follows.

First, when an analog audio signal is applied to the A / D converter 30, the A / D converter 30 converts the corresponding analog audio signal into a digital audio signal and outputs the digital audio signal to the multiplier 31. . At this time, the RAM 32 receives and stores reflection coefficients for reflecting sound from the microcomputer, and applies the reflection coefficients to the multiplier 31 side, and the multiplier 31 is the A / D converter 30. ) Is multiplied by the reflection coefficient applied by the RAM 32 and output to the accumulator 33. The accumulator 33 accumulates the digital audio signal applied from the multiplier 31. Is outputted to the audio compression section 39 and the D / A conversion section 34 side. In addition, when the digital audio signal is applied from the accumulator 33, the audio compressor 39 compresses the digital audio signal to 8: 1 and outputs the digital audio signal to the RAM 40 side. At this time, the RAM 36 receives and stores a delay coefficient for delaying the sound from the microcomputer and applies the delay coefficient to the RAM controller 37, and the RAM controller 37 is applied from the RAM 36. The address and the read / write control signal corresponding to the delay coefficient are generated and output to the RAM 40 side. Accordingly, the RAM 40 delays the compressed digital audio signal applied from the audio compression unit 39 to the audio extension unit 41 by delaying the compressed digital audio signal in accordance with the address and the read / write control signal, and outputs the audio extension unit 41. Expands the digital audio signal applied from the RAM 40 to 1: 8 and outputs it to the RAM 35 side, and the RAM 35 stores the digital audio signal applied from the audio extension unit 41 and then multiplies the multiplier. Output to the accumulator 33 side via the 31, and the D / A converter 34 converts the digital voice signal applied from the accumulator 33 into an analog voice signal and outputs it to the speaker SP2 side. do. By continuously performing such processing, the original sound, the reflected sound, and the reverberation sound are output to the speaker SP2 in the form as shown in FIG. 1 to form a sound field, thereby providing the listener with a realistic sound.

As described above, the sound field control device of the present invention is installed in a single integrated circuit and the RAM 40 performs a conventional external DRAM function. After the digital audio signal is compressed to 8: 1 using the audio compressor 39, By delaying the corresponding digital audio signal using the RAM 40, the capacity of the RAM 40 can be reduced to 32 Kbit compared to an external DRAM having a conventional 256 Kbit capacity, which is accommodated in an integrated circuit without significantly increasing the chip area. You can do it. In addition, according to the present invention, since the RAM 40 contained in the integrated circuit performs a function performed by the external DRAM of the integrated circuit, a pin for connecting an address bus, a data bus, and a read / write control signal line to the external DRAM is integrated. Since it is not necessary to provide the circuit, the chip area of the integrated circuit is reduced and the package volume of the integrated circuit is reduced, thereby making it possible to manufacture the audio system compactly.

Claims (2)

A / D conversion means for converting the input analog audio signal into a digital audio signal and outputting it; First storage means for receiving and storing a reflection coefficient for reflecting sound and outputting the reflection coefficient; Multiplication means for multiplying and outputting a digital audio signal applied from said A / D conversion means by a reflection coefficient applied by said first storage means; Accumulating means for accumulating and outputting a digital audio signal applied from said multiplication means; A sound field control apparatus for an audio system having a second storage means for receiving and storing a delay coefficient for delaying sound and outputting the same, according to a delay coefficient applied from the second storage means. RAM control means for generating and outputting address and read / write control signals; Compress the digital audio signal applied from the accumulating means by a predetermined multiple, delay the compressed digital audio signal according to the address and read / write control signal applied from the RAM control means, and extend the delayed digital audio signal by a predetermined multiple to output it. Compression delay extending means; And a third storage means for storing the digital audio signal applied from the compression delay decompression means and outputting the digital audio signal to the multiplication means side. 2. The apparatus of claim 1, wherein the compression delay decompression means comprises: audio compression means for compressing and outputting a digital audio signal applied from the accumulation means by a predetermined multiple; Fourth storage means for delaying and outputting the digital audio signal applied from said audio compression means in accordance with an address applied from said RAM control means and a read / write control signal; And an audio extension unit which extends the digital audio signal applied from the fourth storage unit by a predetermined multiple and outputs the digital audio signal to the third storage unit.