JP2000298480A - Device and method for adjusting audio signal level - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a device and method for audio signal level adjustment with which evaluation for determining a level adjustment value can easily be performed and a level can be accurately and speedily adjusted. SOLUTION: An audio circuit device equipped with a MIX circuit 6 for outputting a specific digital audio signal by mixing a plurality of digital audio signals is provided with a maximum value detecting circuit 10 which detects the maximum value of the digital audio signal data outputted from the mixing circuit 6.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a mixing circuit for mixing a plurality of digital audio signals and outputting an audio signal such as an L / R signal.
The present invention relates to an audio signal level adjustment device and an adjustment method for optimally adjusting a signal level of an R output signal or the like.

[0002]

2. Description of the Related Art Conventionally, a plurality of digital audio signals such as a rhythm generating circuit are often mixed into L / R 2ch. In the case of such digital mixing, it is desirable to optimize the digital dynamic range in order to improve the S / N performance of the subsequent D / A converter (DAC). In other words, it is necessary to adjust the signal amplitude level so as to operate at a signal level that does not cause overflow and at a sufficiently large signal level, and to adjust the signal amplitude level to an optimum level.

FIG. 8 is a block diagram of a conventional rhythm generating circuit configured as a semiconductor integrated circuit (IC) having the above-described digital mixing circuit and level adjusting circuit. FIGS. 9A and 9B are examples of operation timing diagrams of the rhythm generating circuit of FIG. The rhythm generating circuit is a circuit that previously stores rhythm pattern data and sound source data in a ROM, and automatically plays a rhythm according to an operation start command from a microcomputer or the like.

The operation will be described below with reference to FIG. The rhythm ROM 3 stores the timing of sound generation, the name of the sound source, and which track (in this example, track 1,
Rhythm pattern information to be pronounced from 2, 3)
Is stored as Usually, a plurality of rhythm patterns (rhythm patterns A, B...) Can be provided, and it is possible to set which rhythm pattern is to be played by setting a microcomputer or the like.

The sound source ROM 5 stores information on digital sound source data sampled by the operation clock fs. Usually, a plurality of sound sources (sound sources 0, 1,...) Are provided, and at a timing set in the rhythm ROM 3, the sound source data of the designated sound source name is read and output.

The operation is started when the start / stop control circuit 1 outputs a rhythm start timing according to a command command of a microcomputer or the like. Rhythm ROM control circuit 2
When a rhythm start timing is received, a rhythm pattern is read out from the rhythm ROM 3 at a predetermined period (sound generation timing pulse).
Outputs 2 and 3. At the same time, the sound source name is
Output to control 4.

Upon receiving the tone generation timing tracks 1, 2, and 3, the tone generator ROM control circuit 4 starts reading data of the corresponding tone generator name from the tone generator ROM 5, and outputs the data to the tone generator output data tracks 1, 2, and 3 as the operation clock fs. Output synchronously. When the sound source output data tracks 1, 2, and 3 are monaural data, the mixing circuit (hereinafter, referred to as a MIX circuit) 6 multiplies, for example, each of the tracks 1, 2, and 3 by 0.5, and adds and multiplies the L / R. The same data is output to 2ch.

The level adjustment circuit 7 increases or decreases the gain of the signal according to the level value set by the microcomputer or the like and outputs the signal. In other words, by providing a multiplier and multiplying the data input by a coefficient that is a level value,
The gain is variable. Overflow limiter 8
Detects an overflow and outputs the maximum value that can be expressed by the specified number of bits when the maximum value of the specified number of bits determined by the hardware is exceeded. D / A converters (hereinafter referred to as DACs) 91 and 92 are Lch and Rch
Each digital input data is converted into an analog signal and output.

When the start / stop control circuit 1 outputs a rhythm stop timing according to a command command of a microcomputer or the end of the rhythm pattern,
Stop operation.

The timing chart of FIG. 9A will be described. The operation starts at the rhythm start timing. In this example, the rhythm patterns A, B, and C operate in a continuous (chain) manner.
The microcomputer operates a command to operate C and a command to operate the next C while B is operating, so that the microcomputer operates continuously. Rhythm ROM3
When the rhythm pattern is read out from the CPU and the sounding information is detected, the sounding outputs the timing tracks 1, 2, and 3. The sounding timing tracks 1, 2, 3 are timings to start reading sound source data. The reading of the sound source data is stopped when there is no more data to be output.

FIG. 9A shows an example in which the operation is immediately stopped by the rhythm stop timing.
In the example of (b), there is no rhythm pattern setting after the rhythm pattern B, and the rhythm pattern B naturally stops after the end.

Here, the necessity of the level adjusting circuit 7 will be described in more detail. The performance such as S / N and distortion of the analog audio signal converted by the DAC largely depends on the level of the digital signal after MIX6. That is, if the level of the digital audio signal is too low overall, D
The dynamic range of AC output is not sufficient, and performance is not obtained. On the other hand, if the level is too large as a whole, the overflow limit is frequently applied, and the performance is deteriorated. Therefore, it is necessary to adjust the signal level to an optimum level so as to operate at a signal level which does not overflow and at a sufficiently large signal level. As described above, the level adjustment circuit 7
Has a multiplier, and multiplies a data input by a coefficient which is a level value to make the gain variable (both gain up and gain down) and adjust the amplitude level of the signal.

Although the method of setting the optimum level value using the level adjustment circuit 7 is very effective, the evaluation for determining the set value takes time and is difficult to obtain quantitatively. is there. The method that is determined in advance by functional simulation is very time-consuming because it has to be verified with all combinations of all rhythm patterns for all sound sources. Furthermore, if a combination of the time periods of the sounding timing pulses is added, it takes too much time and the verification may be omitted, which is not realistic.

On the other hand, even in the case where the actual circuit evaluation of an IC circuit is performed, it is necessary to evaluate the analog signal after DAC with all combinations of waveforms and trial listening. Takes a considerable amount of time. Further, in this case, the listening process is largely discontinued, and the optimum value cannot be quantitatively determined. Therefore, it is effective to provide a method (circuit) that facilitates the evaluation for determining the level adjustment value.

[0015]

SUMMARY OF THE INVENTION It is an object of the present invention to provide an audio signal level adjusting apparatus and an adjusting method capable of easily performing an evaluation for determining a level adjusting value and performing an accurate and quick level adjustment. Is what you do.

[0016]

An audio signal level adjusting device according to a first aspect of the present invention includes an audio circuit device having a mixing circuit for performing a mixing process on a plurality of digital audio signals and outputting a predetermined digital audio signal. And a maximum value detection circuit for detecting a maximum value of the digital audio signal data output from the mixing circuit.

In the audio signal level adjusting device according to the second invention, an audio circuit device including a mixing circuit for performing a mixing process on a plurality of digital audio signals and outputting a predetermined digital audio signal is configured as a semiconductor integrated circuit. Wherein a maximum value detection circuit for detecting a maximum value of digital audio signal data output from the mixing circuit is provided inside the semiconductor integrated circuit, and an output thereof is led out of the semiconductor integrated circuit. It is.

In the audio signal level adjusting device according to the third invention, a maximum value detecting circuit for detecting a maximum value for each of the input patterns corresponding to the plurality of rhythm patterns is provided.

In the audio signal level adjusting device according to a fourth aspect of the present invention, an audio circuit device including a mixing circuit for performing a mixing process on a plurality of digital audio signals and outputting a predetermined digital audio signal is configured as a semiconductor integrated circuit. A maximum value detection circuit for detecting a maximum value of digital audio signal data output from the mixing circuit is provided inside the semiconductor integrated circuit, and an output of the maximum value detection circuit is output from the mixing circuit. A level calculation circuit for setting a level for adjusting the level of the digital audio signal is provided inside the semiconductor integrated circuit.

In the audio signal level adjusting apparatus according to the fifth aspect of the present invention, a clock generating circuit capable of generating a clock operating at a higher speed than in the normal operation when the maximum value is detected by the maximum value detecting circuit is provided.

In the adjusting method of the audio signal level adjusting device according to the sixth invention, the audio signal of the audio circuit device provided with the mixing circuit for performing the mixing process on the plurality of digital audio signals and outputting the predetermined digital audio signal. In adjusting the level, the maximum value of the digital audio signal data output from the mixing circuit is detected, and the level is adjusted based on the maximum value.

In the adjusting method of the audio signal level adjusting device according to the seventh invention, the audio integrated circuit is provided as a semiconductor integrated circuit including a mixing circuit for performing a mixing process on a plurality of digital audio signals and outputting a predetermined digital audio signal. In adjusting the audio signal level of the circuit device, the output of the maximum value detection circuit for detecting the maximum value of the digital audio signal data output from the mixing circuit provided inside the semiconductor integrated circuit is led out of the semiconductor integrated circuit. The level is adjusted based on the output.

In the adjusting method of the audio signal level adjusting device according to the eighth invention, the audio signal of the audio circuit device provided with the mixing circuit for performing the mixing process on the plurality of digital audio signals and outputting the predetermined digital audio signal. In adjusting the level, the maximum value of the digital audio signal data output from the mixing circuit is detected in accordance with an input pattern corresponding to a plurality of rhythm patterns, and the level is adjusted based on the maximum value. .

[0024] In the adjusting method of the audio signal level adjusting device according to the ninth aspect, the audio signal of the audio circuit device having the mixing circuit for performing the mixing process on the plurality of digital audio signals and outputting the predetermined digital audio signal. In adjusting the level, the maximum value of the digital audio signal data output from the mixing circuit is detected and the level is adjusted based on the maximum value. The maximum value is detected using a clock that operates at high speed.

[0025]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiment 1 FIG. 1 is a block diagram showing a first embodiment according to the present invention. In the drawings, the same reference numerals indicate the same or corresponding parts. In the figure, 1 is a start / stop control circuit, 2 is a rhythm RO
M control circuit, 3 is a rhythm ROM, 4 is a sound source ROM control circuit, 5 is a sound source ROM, 6 is a MIX circuit, 7 is a level adjustment circuit, 8 is an overflow limiter, and 91 and 92 are DAs.
C. These have the same configuration as the conventional device shown in FIG. 8 and perform the same operation. 10 is a maximum value detection circuit, and 50 is a clock generation circuit. These components are integrally formed as a rhythm generating circuit IC, and are configured as an internal circuit of the IC. Reference numeral 20 denotes a microcomputer outside the IC.

In the figure, the maximum value detection circuit 10
This circuit receives L / R digital data output from the X circuit and detects the maximum value. The MIX output L / R digital data is monitored and started at the rhythm start timing, and the operation of detecting the maximum value is performed. At the rhythm end timing, the microcomputer notifies the end of the microcomputer and outputs the detection result of the maximum value so that the microcomputer can read the result.

FIG. 2 is a specific circuit configuration example of the maximum value detection circuit 10 in FIG. 1 showing the first embodiment according to the present invention, and FIG. 3 is a timing chart thereof. In the figure,
When the rhythm start timing is input, the internal registers FF1: 102 are reset in synchronization with the operation clock fs to prepare for the start of the maximum value detection operation.

M inputted in synchronization with the operation clock fs
The L / R digital data output from the IX circuit is first converted into an absolute value by the absolute value conversion circuit 100. The data is stored in the internal register FF that stores the maximum value so far.
The data value of 1: 102 is compared with the data value of the comparator 101, and when it is determined that the data value is larger than the data thus far, the AND gate 103 is enabled and newly stored in the internal register FF1: 102. By continuing this operation, the maximum value data is always stored in the internal register FF1: 1.
02 will be stored.

When the rhythm end timing is input, the data of the maximum value is transferred to the internal register FF2: 106 and output. At the same time, the internal registers FF1: 102 are reset to prepare for the next maximum value detection operation.

FIG. 4 is an overall timing diagram in FIG. 1 showing the first embodiment according to the present invention. When the rhythm start timing is input, the maximum value detection operation starts. The rhythm pattern continuously plays A, B, and C. When all the rhythm patterns have been played, the rhythm ROM control circuit 2 outputs a rhythm end timing. At the rhythm output timing, the maximum value in the L / R digital data of the MIX output up to that time is output from the maximum value detection circuit 10.

In this manner, all rhythm patterns are played, and the maximum value of the L / R digital data output from the MIX circuit can be detected by the microcomputer 20 or the like outside the IC. By determining the level adjustment value based on this maximum value, the evaluation for determining the level adjustment value becomes very easy. For example, it may be set to a value as long as the maximum value does not overflow.

In another example, for example, 95% of the maximum value
Until, the value is set to a value that does not overflow, and the sound quality is determined by trial listening. In this case, it is necessary to audition, but since the overflow is known in advance, it is possible to find the optimum value of the level adjustment value earlier than the evaluation of only the audition, and to judge the validity of the value. It is easy to stick.

According to the first embodiment of the present invention, an audio circuit device having a mixing circuit 6 for performing a mixing process on a plurality of digital audio signals and outputting a predetermined digital audio signal is configured as an IC. Since the maximum value detection circuit 10 for detecting the maximum value of the digital audio signal data output from the mixing circuit 6 is provided inside the IC, the output is led out of the IC and detected by the microcomputer 20 or the like. Thus, there is an effect that an audio signal level adjusting device capable of performing the level adjustment more accurately and quickly can be obtained.

According to the first embodiment of the present invention, the audio signal of the audio circuit device configured as an IC including a mixing circuit for performing a mixing process on a plurality of digital audio signals and outputting a predetermined digital audio signal is provided. In adjusting the level, the output of the maximum value detection circuit for detecting the maximum value of the digital audio signal data output from the mixing circuit provided inside the IC is derived outside the IC, and the level is adjusted based on this output. Therefore, there is an effect that it is possible to provide a method of adjusting the audio signal level adjusting device, which can perform the level adjustment more accurately and quickly.

Embodiment 2 FIG. 5 is a timing chart showing the second embodiment according to the present invention. The basic block configuration is the same as FIG. 1 showing the first embodiment according to the present invention. In FIG. 5, the difference from the timing chart 4 of the first embodiment is the rhythm end timing. In the second embodiment, at the end of each rhythm pattern (A, B, C...), A rhythm end timing is output.

In the actual circuit, the circuit for generating the rhythm end timing of the rhythm ROM control circuit 2 in FIG. 3 is configured to generate the rhythm end timing at the timing shown in FIG. 4 in the first embodiment. On the other hand, in the second embodiment, the rhythm end timing is generated at the timing shown in FIG.

That is, in the case of Embodiment 1, the final rhythm pattern is determined in advance, and the rhythm end timing is output when the pattern ends or when the rhythm stops. On the other hand, in the second embodiment, a rhythm end pattern is output for each rhythm pattern.

According to the second embodiment, the maximum value of the L / R digital data of each MIX output can be detected in each rhythm pattern. Thus, in addition to the effect of the first embodiment, level adjustment considering the whole becomes possible. For example, when the level of only one pattern among a plurality of rhythm patterns is extremely large, a level value that allows overflow (deterioration of sound quality) of the one pattern and does not overflow the other patterns is selected.
It is effective for the judgment of etc. In addition, since a pattern that easily overflows (has a high level) can be known in advance, a trial listening (sound quality) can be intensively evaluated for the specific pattern.

According to the second embodiment of the present invention, an audio circuit device including a mixing circuit 6 for performing a mixing process on a plurality of digital audio signals and outputting a predetermined digital audio signal is configured as an IC. A maximum value detection circuit 10 for detecting a maximum value for each of input patterns corresponding to a plurality of rhythm patterns with respect to the digital audio signal data output from the mixing circuit 6, provided inside the IC;
Since the output is led out of the IC and detected by the microcomputer 20 or the like, in addition to the effect of the first embodiment, the maximum value of each digital audio signal can be grasped for a plurality of rhythm patterns. This makes it possible to obtain an audio signal level adjusting device capable of performing a level adjustment more accurately and quickly.

According to the second embodiment of the present invention, the audio signal level of an audio circuit device having a mixing circuit for performing a mixing process on a plurality of digital audio signals and outputting a predetermined digital audio signal is adjusted. In doing so, the maximum value of the digital audio signal data output from the mixing circuit is detected corresponding to an input pattern corresponding to a plurality of rhythm patterns, and the level is adjusted based on those maximum values. In addition to the effect of the first embodiment, since the maximum value of each digital audio signal can be grasped for a plurality of rhythm patterns, evaluation suitable for each rhythm pattern can be performed in detail, and level adjustment can be performed more accurately and promptly. Adjustable audio signal level adjustment device Way there is an effect that can provide.

Embodiment 3 FIG. 6A is a block diagram showing a third embodiment according to the present invention. In the figure, reference numeral 50 denotes a clock generation circuit that generates an operation clock fs having a variable operation frequency.

The operation clock fs in the normal operation operates at the sampling frequency. When the maximum value is detected, the operation is performed by increasing the operation frequency of the operation clock fs. The signal during the detection of the maximum value is controlled by an external test pin or a test register that can be set from a microcomputer. Thereby, there is an advantage that the detection time of the maximum value detection is shortened.

FIGS. 6B and 6C are specific block diagrams of the clock generation circuit 50 shown in FIG. 6A. FIG. 6B shows the operation clock f when the maximum value is detected.
In this example, the operation is performed with a multiplied clock of the master clock input as s.

FIG. 6C shows an example in which when the maximum value is detected, the operation is performed with the operation clock fs having the same frequency as the master clock input, and in the normal operation, the operation is performed with the clock whose frequency of the master clock input is reduced by the frequency divider. . Normally, the master clock input often uses a frequency such as fs × 256−fs × 128 for the operation of other blocks, and the example of FIG. 6C is more realistic.

The third embodiment is used in combination with the first or second embodiment. In the third embodiment, when the maximum value is detected, the operation frequency of the operation clock fs is increased so that the operation is performed. Therefore, there is an advantage that the detection time of the maximum value detection is shortened. Actually, it may take several minutes at a normal speed to operate all the test patterns, so that time reduction is effective.

According to the third embodiment of the present invention, when the maximum value is detected by the maximum value detection circuit, the clock generation circuit that can generate a clock that operates faster than during normal operation is provided. This makes it possible to obtain an audio signal level adjusting device capable of shortening the audio signal level and dramatically speeding up the level adjustment.

Further, according to the third embodiment of the present invention, the audio signal level of the audio circuit device having the mixing circuit 6 for performing the mixing process on a plurality of digital audio signals and outputting a predetermined digital audio signal is determined. In making the adjustment, the maximum value of the digital audio signal data output from the mixing circuit 6 is detected, and the level is adjusted based on the maximum value. Since the maximum value is detected by using the operating clock, there is an effect that an adjustment method of the audio signal level adjustment device which can shorten the detection time of the maximum value detection and dramatically speed up the level adjustment can be provided.

Embodiment 4 FIG. 7 is a block diagram showing a fourth embodiment according to the present invention. In the figure, 6
Is a MIX circuit, 7 is a level adjustment circuit, 10 is a maximum value detection circuit, and 11 is a level value calculation circuit. Each element including the level value calculation circuit 11 forms a rhythm generation circuit IC, and is configured as an element inside the IC.

In the fourth embodiment, the maximum value of the MIX output L / R digital data is detected by the maximum value detection circuit 10 for all rhythm patterns. Then, at the rhythm end timing, the level value calculation circuit 11 automatically calculates and sets a level adjustment value as long as the detected maximum value does not overflow.

As a result, since the level adjustment value is automatically set, there is an advantage that it is not necessary to set the level adjustment value externally using a microcomputer or the like. In particular, the rhythm pattern length is short,
This is effective when the level adjustment value can be detected in a short time during setup after reset.

According to the fourth embodiment of the present invention, an audio circuit device having a mixing circuit 6 for performing a mixing process on a plurality of digital audio signals and outputting a predetermined digital audio signal as an IC. A maximum value detection circuit 10 for detecting the maximum value of the digital audio signal data output from the mixing circuit 6 is provided inside the IC, and the output of the maximum value detection circuit 10 is output from the mixing circuit 6. Since the level calculation circuit 11 for setting the level for adjusting the level of the digital audio signal is provided inside the IC, it is possible to obtain an audio signal level adjustment device capable of performing the level adjustment accurately and quickly without trouble. it can.

As described above, according to the first to fourth embodiments of the present invention, there is an effect that the evaluation for determining the level adjustment value is facilitated. In the case of a system in which the rhythm pattern and the sound source are fixed and the combination of the input data can be FIXed when the design is completed as described above, it is very effective to provide the level adjustment circuit. It is effective to facilitate the method of determining the level adjustment value as in the present invention even in the case of responding to serialization.

[0053]

According to the first aspect of the present invention, in an audio circuit device having a mixing circuit for performing a mixing process on a plurality of digital audio signals and outputting a predetermined digital audio signal, the audio signal output from the mixing circuit is provided. Since the maximum value detection circuit for detecting the maximum value of the digital audio signal data is provided, it is possible to obtain an audio signal level adjustment device capable of performing the level adjustment accurately and quickly.

According to a second aspect of the present invention, there is provided an audio circuit device having a mixing circuit for performing a mixing process on a plurality of digital audio signals and outputting a predetermined digital audio signal as a semiconductor integrated circuit. A maximum value detection circuit for detecting the maximum value of the digital audio signal data output from the mixing circuit is provided inside the semiconductor integrated circuit, and the output is led out of the semiconductor integrated circuit. There is an effect that an audio signal level adjusting device that can be executed accurately and quickly can be obtained.

According to the third aspect of the present invention, since the maximum value detection circuit for detecting the maximum value for each of the input patterns corresponding to the plurality of rhythm patterns is provided, the audio signal level can be adjusted more accurately and quickly. There is an effect that an adjusting device can be obtained.

According to a fourth aspect of the present invention, an audio circuit device having a mixing circuit for performing a mixing process on a plurality of digital audio signals and outputting a predetermined digital audio signal as a semiconductor integrated circuit is provided. A maximum value detection circuit for detecting the maximum value of the digital audio signal data output from the mixing circuit is provided inside the semiconductor integrated circuit, and the digital audio signal output from the mixing circuit is output from the maximum value detection circuit. Since the level calculation circuit for performing the level setting for the level adjustment is provided inside the semiconductor integrated circuit, it is possible to obtain an audio signal level adjusting apparatus capable of executing the level adjustment accurately and quickly without troublesome level adjustment.

According to the fifth aspect, when the maximum value is detected by the maximum value detection circuit, the clock generation circuit that can generate a clock that operates faster than in the normal operation is provided, so that the detection time of the maximum value detection can be shortened. There is an effect that an audio signal level adjusting device that can dramatically speed up the level adjustment can be obtained.

According to the sixth aspect of the invention, when adjusting the audio signal level of an audio circuit device having a mixing circuit for performing a mixing process on a plurality of digital audio signals and outputting a predetermined digital audio signal, the mixing is performed. Since the maximum value of the digital audio signal data output from the circuit is detected and the level is adjusted based on the maximum value, an adjustment method of an audio signal level adjustment device capable of executing the level adjustment accurately and quickly is provided. There is an effect that can be.

According to the seventh aspect, the audio signal level of an audio circuit device configured as a semiconductor integrated circuit including a mixing circuit for performing a mixing process on a plurality of digital audio signals and outputting a predetermined digital audio signal is adjusted. In doing so, the output of the maximum value detection circuit for detecting the maximum value of the digital audio signal data output from the mixing circuit provided inside the semiconductor integrated circuit is led out of the semiconductor integrated circuit and the level is adjusted based on this output. As a result, there is an effect that it is possible to provide a method of adjusting the audio signal level adjusting device, which can perform the level adjustment more accurately and quickly.

According to the eighth aspect, when adjusting the audio signal level of an audio circuit device having a mixing circuit for performing a mixing process on a plurality of digital audio signals and outputting a predetermined digital audio signal, the mixing is performed. The maximum value of the digital audio signal data output from the circuit is detected in accordance with the input pattern corresponding to a plurality of rhythm patterns, and the level is adjusted based on the maximum values. The digital audio signal maximum value can be grasped, so that the evaluation suitable for each rhythm pattern can be performed in detail, and a method for adjusting the audio signal level adjusting device capable of performing the level adjustment more accurately and quickly can be provided. effective.

According to the ninth aspect, in adjusting the audio signal level of an audio circuit device having a mixing circuit for performing a mixing process on a plurality of digital audio signals and outputting a predetermined digital audio signal, the mixing is performed. The maximum value of the digital audio signal data output from the circuit is detected and the level is adjusted based on the maximum value.At the time of detecting the maximum value of the digital audio signal data, a clock that operates faster than in the normal operation is used. Since the maximum value detection is performed, there is an effect that an adjustment method of the audio signal level adjustment device which can shorten the detection time of the maximum value detection and dramatically speed up the level adjustment can be provided.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a first embodiment according to the present invention.

FIG. 2 is a configuration diagram showing a specific circuit of a maximum value detection circuit according to the first embodiment of the present invention.

FIG. 3 is an operation timing chart in FIG. 2;

FIG. 4 is an operation timing chart in FIG. 1;

FIG. 5 is an operation timing chart showing a second embodiment according to the present invention;

FIG. 6 is a block diagram showing a third embodiment according to the present invention.

FIG. 7 is a block diagram showing a fourth embodiment according to the present invention.

FIG. 8 is a block diagram showing a conventional technique.

FIG. 9 is an operation timing chart showing a conventional technique.

[Explanation of symbols]

1 Start / stop control circuit, 2 rhythm ROM control circuit, 3 rhythm ROM, 4 sound source ROM control circuit, 5
Sound source ROM, 6 MIX circuit, 7 level adjustment circuit,
8 overflow limiter, 91, 92 DAC, 1
0 Maximum value detection circuit, 20 microcomputers, 50 clock generation circuit.

Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat II (Reference) H03G 3/30 H03G 3/30 C H04R 3/00 310 H04R 3/00 310 // H04S 7/00 H04S 7/00 E

Claims (9)

[Claims] 1. An audio circuit device comprising a mixing circuit for performing a mixing process on a plurality of digital audio signals and outputting a predetermined digital audio signal, wherein the maximum value of the digital audio signal data output from the mixing circuit is determined. An audio signal level adjusting device comprising a maximum value detecting circuit for detecting. 2. An audio circuit device comprising a mixing circuit for performing a mixing process on a plurality of digital audio signals and outputting a predetermined digital audio signal as a semiconductor integrated circuit, wherein the audio signal is output from the mixing circuit. An audio signal level adjusting device, wherein a maximum value detection circuit for detecting a maximum value of digital audio signal data is provided inside the semiconductor integrated circuit, and an output thereof is led out of the semiconductor integrated circuit. 3. The audio signal level adjusting device according to claim 1, further comprising a maximum value detecting circuit for detecting a maximum value for each of the input patterns corresponding to the plurality of rhythm patterns. . 4. An audio circuit device provided with a mixing circuit for performing a mixing process on a plurality of digital audio signals and outputting a predetermined digital audio signal as a semiconductor integrated circuit, wherein the output from the mixing circuit is provided. A maximum value detection circuit for detecting the maximum value of the digital audio signal data is provided inside the semiconductor integrated circuit, and receives the output of the maximum value detection circuit to adjust the level of the digital audio signal output from the mixing circuit. An audio signal level adjusting device, wherein a level calculation circuit for setting a level is provided inside the semiconductor integrated circuit. 5. When a maximum value is detected by a maximum value detection circuit,
5. The audio signal level adjusting device according to claim 1, further comprising a clock generation circuit capable of generating a clock that operates faster than during a normal operation. 6. A digital signal output from the mixing circuit when adjusting an audio signal level of an audio circuit device having a mixing circuit for performing a mixing process on a plurality of digital audio signals and outputting a predetermined digital audio signal. A method for adjusting an audio signal level adjusting device, comprising detecting a maximum value of audio signal data and adjusting a level based on the maximum value. 7. A method for adjusting the audio signal level of an audio circuit device configured as a semiconductor integrated circuit including a mixing circuit for performing a mixing process on a plurality of digital audio signals and outputting a predetermined digital audio signal. An audio device wherein an output of a maximum value detection circuit for detecting a maximum value of digital audio signal data output from a mixing circuit provided inside a circuit is derived outside a semiconductor integrated circuit and a level is adjusted based on the output. An adjustment method for the signal level adjustment device. 8. A digital signal output from the mixing circuit when adjusting an audio signal level of an audio circuit device having a mixing circuit for performing a mixing process on a plurality of digital audio signals and outputting a predetermined digital audio signal. 8. The audio signal according to claim 6, wherein a maximum value of the audio signal data is detected in correspondence with an input pattern corresponding to a plurality of rhythm patterns, and a level is adjusted based on the maximum value. Adjustment method of the level adjustment device. 9. A digital signal output from the mixing circuit when adjusting an audio signal level of an audio circuit device having a mixing circuit for performing a mixing process on a plurality of digital audio signals and outputting a predetermined digital audio signal. Detecting the maximum value of the audio signal data and performing level adjustment based on the maximum value, and detecting the maximum value of the digital audio signal data using a clock that operates faster than during normal operation when detecting the maximum value of the digital audio signal data. 9. The adjusting method of the audio signal level adjusting device according to claim 6, wherein: