JP2001077644A - Amplification factor controller - Google Patents

Abstract

PROBLEM TO BE SOLVED: To accurately the change characteristic of amplification factor at high flexibility, without increasing the load on a processor and memory capacity. SOLUTION: An amplification factor coefficient value 4 for multiplying an input signal 1 in a signal amplification attenuator 3 is generated in an adder- substracter 15. The amplification factor coefficient value 4, outputted from the adder-subtracter 15, is processed base on the conditions of an increase- decrease a setting value Gs, the maximum/minimum values GMAX and GMIN within a logarithmic change range, an initial value G0 of a gain and a target value GT with the loop of a selector 5, a DFF(D-type flip-flop circuit) 17, a maximum/minimum value limiter 18 and a shift arithmetic unit 19, and an increase/decreases value B is controlled for each arithmetic cycle in the adder- subtracter 15, then the amplification factor based on the logarithm change characteristic is controlled variably. The range of the logarithm change of the amplification factor coefficient value 4, based on the increase/decrease value B of the shift computing element 19, is limited between the maximum value and the minimum value with the setting/inputting of the logarithm change range.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an amplification control device for controlling an amplification factor in various kinds of signal processing equipment, signal transmission equipment, signal recording / reproduction equipment and the like.

[0002]

2. Description of the Related Art Conventionally, in the above-described various devices, an amplification factor of an input signal or the like can be set by various methods such as a volume and a rotary encoder. In this case, in order to increase or decrease the amplification factor with an acoustically preferable fade change characteristic (for example, logarithmic change), the program R is set in advance.
A desired gain value stored in an OM or the like is sequentially transmitted from a microprocessor or the like to generate a polygonal or stair-like change characteristic, so that a logarithmic change characteristic or the like is approximately realized.

[0003]

However, in order to realize the more preferable change characteristics acoustically as described above, more detailed broken line approximation or the like is necessary, and the number of amplification factor value patterns is increased accordingly. Increases the demands on the microprocessor and the like to be set,
This increases the capacity of the system and hinders other processing operations. As described above, in the case where higher-speed processing is performed, if execution is performed using conventional software, there is a problem that resources for execution increase and a controller having a larger capacity is required.

SUMMARY OF THE INVENTION An object of the present invention is to provide an amplification factor control which can set a variation characteristic of an amplification factor with a high degree of freedom and obtain a fine variation characteristic without increasing a load on a processor or an increase in memory capacity. It is to provide a device.

[0005]

According to the present invention, there is provided an amplification factor control apparatus having a signal amplification attenuator for inputting an input signal and outputting an amplified signal or an attenuated signal. Start instructing means for instructing the start of increase / decrease control of the amplification factor for the amplifier, end instructing means for instructing the end of gain / loss control of the signal amplification / attenuator, and an amplification factor of the signal amplification / attenuator in a predetermined unit Increasing / decreasing means for increasing / decreasing every time, and increasing / decreasing amount controlling means for controlling an increasing / decreasing amount per unit time by the increasing / decreasing means based on a preset increasing / decreasing rate coefficient, wherein the increasing / decreasing amount controlling means is The gain of the signal amplification / attenuator which is increased or decreased by the increasing / decreasing means is detected, and the increase / decrease amount for the increasing / decreasing means is calculated using the detection result and the increase / decrease rate coefficient. By adding or subtracting relative amplification factor of the signal amplifier attenuator decrease amount calculated by the means, characterized in that so as to increase or decrease the amplification factor of the signal amplifier attenuator.

In the gain control apparatus of the present invention, the increase / decrease control means detects the gain of the signal amplification / attenuator which is increased / decreased by the increase / decrease means, and uses this detection result and the increase / decrease rate coefficient to increase / decrease the increase / decrease means. Calculate the amount. The increase / decrease means increases or decreases the gain of the signal amplification / attenuator by adding or subtracting the increase / decrease amount calculated by the increase / decrease amount control means to / from the amplification factor of the signal amplification / attenuator. Therefore, according to the present invention, a load on a microprocessor or the like is reduced with less memory resources as compared with a method of approximately realizing a logarithmic change characteristic from a polygonal line or a stepwise change characteristic stored in a conventional ROM or the like. Without this, it is possible to perform amplification factor control having a high degree of freedom and a fine change characteristic.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of an amplification factor control device according to the present invention will be described below. FIG. 1 is a block diagram showing a first configuration example of the gain control device according to the present embodiment. FIGS. 2 and 3 are flowcharts showing an operation example of the gain control device shown in FIG. Also, FIG.
FIG. 5 is a block diagram illustrating a second configuration example of the amplification factor control device according to the present embodiment, and FIG. 5 is a flowchart illustrating an operation example of the amplification factor control device illustrated in FIG.

The gain control device according to the present embodiment is used in various signal processing devices, signal transmission devices, signal recording / reproducing devices, and the like having a function of controlling the gain so that the signal level is optimized. Is a so-called fade (logarithmic change) type attenuator in which the amount of change in the amplification factor is proportional to the amplification factor at that time. The amplification factor control device according to the present embodiment operates in the “target gain coefficient value input mode” according to the basic configuration shown in FIG. 1. The numerical value increase / decrease command input mode "can be operated as an additional function.

FIG. 1 shows a first configuration example of the present invention.
The basic configuration of the amplification factor control device according to the present embodiment and the operation in the “target gain coefficient value input mode” will be described with reference to FIGS. First, the configuration shown in FIG.
Signal attenuator (AT
T) generating an amplification factor value of 4 for performing multiplication processing of the input signal 1 in the system having 3);
As control input ports for generating the amplification factor value 4, a target gain factor value input port 6, a gain factor setting command input port 7, an increase / decrease rate setting input port 8, and a logarithmic change range setting input port 9 are provided. .

[0010] target gain coefficient value target gain factor values G _T input from the input port 6 is held target gain coefficient value setting register (target value setting means) 10. And
The target gain coefficient value X set in the target gain coefficient value setting register 10 is input to one input terminal of the comparator 14 and one input terminal of the selector 5. The output value Y from the adder / subtractor 15 is input to the other input terminal of the comparator 14 and the other input terminal of the selector 5. Also,
The comparison result Z from the comparator 14 is input to the switching input terminal of the adder / subtractor 15 and the reset input terminal of the gain coefficient output setting control register 16. In the first configuration example, a signal input from the comparator 14 to the reset input terminal of the gain coefficient output setting control register 16 constitutes end instruction means for instructing the end of the gain coefficient output setting control. I have.

The gain coefficient setting command from the gain coefficient setting command input port (start instruction means) 7 is input to the set input terminal of the gain coefficient output setting control register 16. The setting control signal S / R from the gain coefficient output setting control register 16 is input to the set / reset control input terminal of the selector 5. The selector 5 selects one input X at the time of reset, selects the other input Y at the time of setting, and outputs it as an output P based on the setting control signal S / R. The output P of the selector 5 is a DFF (D
Type flip-flop circuit) 17 and this DFF
17 Output A of (ATT coefficient value 4 = G _O), the subtracter 1
5 is input to one input terminal and the maximum / minimum value limiter 18.

Further, the change from the change rate setting input port 8
Rate setting value G_SIs held in the increase / decrease rate setting register 12,
This change rate setting value G_SIs a shift operator (addition, multiplication
, Etc.) and the operation output of the shift operation unit 19
B is input to the other input terminal of the adder / subtractor 15. Ma
The logarithm input from the logarithmic change range setting input port 9
Maximum value G of change range _MAXAnd the minimum value G_MINIs the logarithmic range
The maximum value G is held in the maximum / minimum value setting register 13 and
_MAXAnd the minimum value G_MINMax and Min based on
It is input to the value limiter 18. In this example,
Rate setting value G_SAnd the maximum and minimum value G of the logarithmic change range_MAX, G_MIN
Is to control the logarithmic change of the amplification factor as described below,
For example, it is set arbitrarily by the user.

The maximum / minimum value limiter 18 outputs a logarithmic change range determination signal C to the shift calculator 19 based on the output A from the DFF 17 and the Max and Min from the register 13. The shift calculator 19 determines the calculation step amount of one calculation cycle of the adder / subtractor 15 based on the increase / decrease rate set value G _S and the logarithmic change range determination signal C. Input to the input terminal. The adder / subtractor 15 performs an operation of A + B or AB based on the comparison result Z from the comparator 14 and outputs the result as an output value Y.

FIG. 6 is an explanatory diagram showing a change characteristic of a gain in the logarithmic change attenuator according to the present embodiment, in which the vertical axis indicates gain (ATT coefficient value) and the horizontal axis indicates time.
As shown, in this logarithmic change attenuator, the maximum and minimum values G _MAX , G _MIN (M on the vertical axis)
ax, Min), the gain is changed logarithmically with respect to time. That is,
In this logarithmic change region, the value B per unit time added / subtracted by the adder / subtractor 15 depends on the ATT coefficient value A,
It is a fluctuation value controlled by the operation of the shift operation unit 19. Also, outside of the log change range, a predetermined maximum gain from the maximum value G _MAX of the logarithmic change range (in this example +
Up to 12 dB) and the minimum value G _{MIN of the} logarithmic change range
To a predetermined minimum gain (0 dB in this example). That is, in this linear change region, the value B per unit time added or subtracted by the adder / subtractor 15 is a fixed value controlled by the operation of the shift calculator 19 based on the values of the maximum and minimum G _MAX and G _MIN . As the fixed value in this case, the rate of change in the maximum and minimum values G _MAX and G _MIN of the logarithmic change range is fixedly used. The above-described change rate setting value G _S is an input for setting the overall slope in such a change characteristic of gain versus time, that is, an overall gain, and a change characteristic line in a logarithmic change range according to this value. Changes.

In the logarithmic change attenuator of this embodiment, the adder / subtracter 15, the selector 5, the DFF 17,
By the loop of the maximum / minimum value limiter 18 and the shift operation unit 19, each condition such as the increase / decrease rate setting value G _S , the maximum / minimum value G _MAX , G _{MIN of} the logarithmic change range, the initial value G _{O of the} gain, and the target value G _T. , The adder / subtracter B for each operation cycle in the adder / subtractor 15 is controlled by the shift calculator 19, thereby realizing variable control of the amplification factor based on the change characteristic as shown in FIG. In the present embodiment, the adder / subtractor 15 constitutes an increasing / decreasing means, and the shift calculator 19 constitutes an increasing / decreasing amount controlling means. And the shift calculator 19
Outputs the final addition / subtraction value B to the addition / subtraction unit 15 and obtains the change characteristic shown in FIG. 6, but the operation of the combination of the shift operation unit 19 and the maximum / minimum limiter 18 is based on the initial gain. in which the value G _O and the target value G _T is calculated by dividing the case whether present in any position resulting in the characteristic change described above.

[0016] Figures 7-10 are explanatory views showing the positional relationship between the gain versus time relationship of the initial value G _O and the target value G _T with respect to the change characteristic of the gain in the log change attenuator to the present embodiment . In these figures, G _O is an initial gain value, and G _S is an increase / decrease rate set value. G _TU is the upper target value, and G _LU is the maximum value of the logarithmic change range. G _LL
Is the minimum value of the logarithmic change range, and _GTL is the lower target value. Further, as a time element, T _SUU is a gain rise time in a linear change region from G _LU to G _TU , and T _SU is a gain rise time from G _O to G T
_This is the gain rise time of the logarithmic change region up to the _LU . Also,
T _SL is the gain fall time in the logarithmic change region from G _O to G _LL , and T _SLL is the gain fall time in the linear change region from G _LL to G _TL .

FIG. 7 shows that G _TU > G _LU > G _O > G _LL
> G _TL , and FIG. 8 shows G _TU > G _O > G
_{The case of LU} > G _LL > G _TL is shown. Also, FIG.
It shows the case of G _TU > G _LU > G _LL > G _O > G _TL ,
FIG. 10 shows the case of G _LU > G _TU > G _O > G _TL > G _LL . Then, in these cases, the gain and the time are represented by a relational expression as shown. Shift calculator 1
In step 9, the set gain target value G _T , gain initial value G _O , maximum / minimum value G _MAX , G _{MIN of} the logarithmic change region, and the like are determined. The output value B is calculated over time so that the output value B changes along the way, and is output to the adder / subtractor 15.

[0018] What Specifically, previous gain value A obtained by calculation cycle (G _O), if included in the log change region, multiplied by the change rate set value G _S to the gain value A As an output value B to the adder / subtractor 15. Also,
When the gain value A (G _O ) is larger than the maximum value G _MAX of the logarithmic change region, the output value B is obtained by multiplying the change rate L at the maximum value G _MAX by the increase / decrease rate set value G _S as the output value B. Output to Further, when the gain value A (G _O) is the minimum value G _MIN is smaller than the log change area, this minimum value G
And outputs to subtracter 15 are multiplied by change rate set value G _S on the change rate M at _MIN as an output value B.

In the logarithmic change attenuator according to this embodiment,
As described above, the logarithmic change range can be freely set, and the other range can be set as the change rate of the contact point with the logarithmic change range. Therefore, the change rate increases in the range of the small gain value. It is possible to realize the A-curve approximation characteristic like an analog fader by preventing the inconvenience that the convergence time increases and the change rate becomes too coarse in the range of the value where the gain is large. Becomes

With the above control processing, the adder / subtractor 1
The output of No. 5 asymptotically approaches and passes the target gain coefficient value in each operation cycle. Then, by this passage, the polarity of the output from the comparator 14 is inverted from that before.
Then, when the gain coefficient output setting control register 16 is reset due to the polarity inversion by the comparator 14, the selector 5 outputs the target gain coefficient value X set in the target gain coefficient value setting register 10 and reflects it on the DFF 17. Thus, a series of fade-type operations are completed.

Next, a specific control operation of the logarithmic change attenuator according to the present embodiment having the above configuration will be described with reference to FIGS.
This will be described with reference to the flowchart of FIG. First, in FIG. 2, in the initial stable state of the system, the output S / R of the gain coefficient output setting control register 16 is in the reset mode, and the value of the target gain coefficient value setting register 10 Used as numerical value 4. Here, the gain coefficient value (target gain coefficient value G _T ) to be finally given to the signal amplification / attenuator 3 is input from the target gain coefficient value input port 6 and set in the target gain coefficient value setting register 10 (S1). . Next, the comparator 14 determines the output Y of the adder / subtractor 15 and the value X of the target gain coefficient value setting register 10 which are the latest amplification factor coefficient values (S
2), if X ≦ Y (Y−X = Z <0) (S3),
Subtraction is set in the adder / subtractor 15 (S4), and if not, addition is set in the adder / subtractor 15 (S5).

As described above, one input terminal (A) of the adder / subtractor 15 is provided with the current amplification factor value 4 and the other input terminal (B) is provided with an amplification factor value 4 described later. The processed value is given. Therefore, the two input values are subtracted or added to obtain Y as the operation result (S6).
In this system, some auxiliary processing is provided in order to allow the signal processing according to the present invention to function stably without a malfunction loop, but the processing in S7 to S12 is one of them. That is, if an overflow or an underflow occurs in the operation of the adder / subtracter 15, the polarity of the gain coefficient value is inverted and a malfunction occurs, so that the operation output Y of the adder / subtracter 15 is such that the maximum value = FFFF and the minimum value = 0000. The limiter is set so as not to exceed (when the flow is performed, the maximum value = FFFF or the minimum value = 0000 is substituted). In this way, the value of the operation output Y of the adder / subtracter 15 is determined and supplied to the selector 5.

The gain coefficient output setting control register 16 inverts the polarity of the output Z from the comparator 14 (S13 to S1).
5) and the input (S16) of the gain coefficient setting instruction 11 for starting the operation of the present system is monitored. If there is no input of the polarity inversion of the output Z and the input of the gain coefficient setting instruction 11, the selection signal of the selector 5 is received. Is set to S / R = 1, the selection of the selector 5 is set to the output X (= G _T ) of the setting register 10, and this is set as an amplification factor coefficient value 4 through the DFF 17.
(S17 to S22).

When the gain coefficient setting command 11 for starting the operation of the present system is input from the port 7, the selection signal S / R of the gain coefficient output setting control register 16 becomes the set mode (S / R = 1) (S16). ), The selection of the selector 5 is set as the operation output Y of the adder / subtractor 15, and this is supplied to the amplification attenuator 3 through the DFF 17 as the amplification factor value 4 (S17 to S22). In the logarithmic change attenuator of the present example, in the operation of the above-described “target gain coefficient value input mode”, the target gain coefficient value is normally input by a continuous operation and a setting command is input. The operation of S12 and the operations of S13 to S22 are executed as a concurrent operation.

Next, in FIG. 3, the maximum / minimum value G of the logarithmic change range input from the logarithmic change range setting input port 9 is shown.
_MAX (= M) and G _MIN (= L) are set in the logarithmic change range maximum / minimum value setting register 13 (S31). Then, these values are converted by the maximum / minimum limiter 18 into DF
It is compared with the gain coefficient value A (G _O ) set in F17 (S32, S33), and a determination signal C corresponding to the result is obtained (S34 to S37). In other words, the decision signal C, and according to one cycle before the gain factor value A (G _O),
This gain coefficient value A or the maximum value G of the logarithmic change area
Change rate L at _MAX or minimum value G of logarithmic change area
The change rate M in _MIN is substituted. On the other hand, the change rate setting value G _S input from the change rate setting input port 8 is
It is set in the change rate setting constant register 12 (S38).
Therefore, in the shift computing unit 19 performs multiplication of the decision signal C and change rate set value G _S, and outputs the operation result B (S
39).

In this system, some auxiliary processing is provided in order to make the signal processing according to the present invention function stably without a malfunction loop, but the processing in S40 to S43 is one of them. That is, in the operation of the adder / subtractor 15, an input smaller than the minimum operation unit (LSB) is not operated, so that the output B of the shift operation unit 19 is set to
B) If it is less than the above, the fade operation will stagnate. Therefore, the output B of the shift operation unit 19 is the minimum operation unit (LS
B) If it becomes less than or equal to (S40), the minimum operation unit (LSB) is substituted for the output B (S41), otherwise, the output B is selected as it is (S42), and this is added to the adder / subtracter 15 (S43).

Next, as a second configuration example of the present invention, an additional configuration of the amplification factor control device according to the present embodiment and the operation of the “gain coefficient value increase / decrease command input mode” will be described with reference to FIGS. explain. In the "gain coefficient value increase / decrease command input mode", the target gain coefficient value is not determined as described above, and the gain coefficient value increase / decrease command is directly input, and the user does not need to increase / decrease the gain coefficient value while monitoring the actual operation. This is a function for releasing a command at the point in time to obtain a desired gain. The additional configuration shown in FIG. 4 adds a configuration for selectively executing the “gain coefficient value increase / decrease command input mode” and the “target gain coefficient value input mode” described above. In addition to the configuration shown in FIG. 7, a setting mode switching input port 20, an increase / decrease instruction input port 21, and selectors 23, 24, and 25 are provided.

The setting mode switching input port 20 selects the above-mentioned “target gain coefficient value input mode” or
A selection signal T / S indicating whether to select the “gain coefficient value increase / decrease command input mode” is input. In each of the selectors 23, 24, and 25, the input T is the selection signal T.
/ S is an input path selected when “target gain coefficient value input mode” is instructed by / S, and input S is selected when “gain coefficient value increase / decrease command input mode” is instructed by selection signal T / S. Is the input path to be performed.

When the "target gain coefficient value input mode" is instructed by the selection signal T / S, the operation is the same as that of the first configuration example, but the "gain" is selected by the selection signal T / S. When the "coefficient value increase / decrease command input mode" is instructed, the gain coefficient value increase / decrease instruction 22 input from the increase / decrease instruction input port 21 executes the gain coefficient value increase / decrease operation. That is, in this example, the gain coefficient value increase / decrease instruction 22
Constitute the start instruction means and the end instruction means of the increase / decrease control.

When this “gain coefficient value increase / decrease command input mode” is instructed, the target gain coefficient value setting register 10 has a DFF through the S input path of the selector 23.
The value A set to 17 is input. Selector 2
4, the increase / decrease setting by the gain coefficient increase / decrease command 22 is input to the switching input terminal of the adder / subtractor 15,
Similarly, an increase / decrease command by the gain coefficient value increase / decrease command 22 is input to the set / reset control input terminal of the selector 5 through the S input path of the selector 25. Therefore, the addition / subtraction unit 15 switches between addition and subtraction according to the increase / decrease setting by the gain coefficient value increase / decrease instruction 22. In addition, selector 5
In, the set / reset is switched according to the increase / decrease command by the gain coefficient value increase / decrease command 22.

In such a configuration, when the gain coefficient value increase / decrease instruction input mode is selected, the addition / subtraction mode of the adder / subtractor 15 is controlled directly by the increase / decrease setting / increase / decrease instruction by the gain coefficient value increase / decrease instruction 22, and at the same time, The selector 5 is set to the set mode, and the operation of the fade type attenuator is started and executed. At this time, the current amplification coefficient value 4 (D
The setting value A) of the FF 17 is always input and reflected. Next, when the increase / decrease instruction is released, the selector 5 is set to the reset mode, and the value of the target gain coefficient value setting register 10 is input to the DFF 17. The current amplification factor value 4 is fixed by the above data path loop. The operation when the target gain coefficient value input mode is selected is the same as that in the above-described first example, and thus the description is omitted.

Next, a description will be given with reference to the flowchart of FIG. 5. First, the current amplification coefficient value 4 is input to the target gain coefficient value setting register 10 and is reflected on the output X (S51). The increase / decrease setting by the gain coefficient value increase / decrease command 22 is based on the comparison result Z by the comparator 14 described above.
Is input to the adder / subtracter 15 (S52), and the addition / subtraction mode is determined based on the determination in S3 described above. Thereafter, the process proceeds to the same processing as in S4 to S12 described above. Further, the increase / decrease command by the gain coefficient value increase / decrease command 22 is input to the selector 5 instead of the selection signal S / R by the gain coefficient output setting control register 16 (S53),
The set / reset mode is determined by the above-described determination in S18, and thereafter, the process proceeds to the same processing as in S19 to S22 described above. Also, S31 to S43 shown in FIG.
Is the same in the present example, and a description thereof will be omitted.

[0033] In the log change attenuator according to the embodiment as described above, and having a change rate setting input ports 8 and change rate setting register 12 for inputting setting the change rate setting value G _S, log change range Has a logarithmic change range setting input port 9 for input setting and a logarithmic change range maximum / minimum value setting register 13,
By fixing these values in advance and setting them in a memory or the like, a configuration in which the ports 8 and 9 and the registers 12 and 13 are omitted can be adopted. Further, in the logarithmic change attenuator of the present embodiment, when it is desired to immediately set a gain coefficient value without performing a fade operation, the setting instruction 11
Is stopped, or the gain coefficient value output setting register 16 is set to a reset state.

In the above-described configuration of the logarithmic change attenuator, the signal processing cycle clock used in the DFF 17 and the like is a word clock of a normal signal. Change. However, other clocks can be used. The arithmetic unit and the like used in the present embodiment may be of a parallel operation type or a serial operation type. Particularly, by using a serial operation type signal processing circuit, the circuit scale can be significantly reduced. There is an effect that can be realized by the hardware described above. Further, in the above-described example, a configuration example using hardware has been described. However, the algorithm of the present invention can be implemented by software using a high-speed microprocessor or the like. In this case, as compared with the above-described conventional method using ROM data reference, memory resources can be significantly reduced, and an attenuator with fine change characteristics can be realized.

The function similar to the "gain coefficient value increasing / decreasing command input mode" according to the second configuration example is the same as that of the first basic configuration example shown in FIG. Can be realized by substituting the values to obtain an increase (increase) operation or a decrease (decrease) operation of the gain coefficient value. For example, as a specific example, in the gain coefficient value increase command, the maximum gain coefficient value (12 dB in the above example) is input as the target gain coefficient value, and conversely, in the gain coefficient value decrease command, the minimum gain coefficient value (in the above example, By inputting 0 dB) as the target gain coefficient value, it is possible to execute the increase / decrease command for all the gains.
In this case, a desired amplification factor can be obtained by the monitor by providing an end instruction means for forcibly stopping the operation by a switch operation or the like during the increase / decrease control.

In the above-described example, when the amplification factor reaches the target value, the setting command is reset, and the value of the target gain coefficient value setting register 10 is sent from the DFF 17 to the signal amplification / attenuator 3. However, as a method for keeping the gain of the signal amplification / attenuator 3 constant after the end of the gain coefficient value increase / decrease control, the increase / decrease operation in the adder / subtractor 15 is stopped to fix the output Y, or the shift calculator 19 It is also possible to employ a method of fixing the output B of the adder to zero and eliminating the fluctuation of the output Y due to the increase / decrease operation of the adder / subtractor 15. Further, in the above example, by the shift calculator 19 performs calculation of C × G _S, was to obtain a decrease amount B of the adder-subtracter 15, as such a calculation method may employ other methods It can be appropriately modified according to the required logarithmic change.

[0037] As a further application of the present invention, in the case of using a log change attenuator described above in two-channel stereo system, set the same target gain value G _T in each channel of the left and right by default, set by subsequent optional in only one of the channels of the left or right by setting a new target gain value G _TL or G _TR, it is also possible to adopt a configuration such as to achieve more efficient settings. However, since most of the settings are expected to be used for the left and right sides, this function is effective for use in special cases. The maximum minimum value G _MAX defining a log change the above-mentioned range, G _MIN and the coefficient G _S defining the amplification characteristic of the amplification factor value G _T, by configuring the exponential term and a temporary number term, setting a wide range of An efficient data representation of the value becomes possible.

[0038]

As described above, in the gain control apparatus of the present invention, the gain of the signal amplification / attenuator which is increased or decreased by the increasing / decreasing means is detected, and the detection result and the increasing / decreasing rate coefficient are used for the increasing / decreasing means. An increase / decrease amount control means for calculating an increase / decrease amount, and an increase / decrease amount calculated by the increase / decrease amount control means is added to or subtracted from the amplification rate of the signal amplification / attenuator, thereby increasing / decreasing the amplification rate of the signal amplification / attenuator. With the increasing / decreasing means, the amplification factor in the signal amplification / attenuator can be controlled by a desired change characteristic. Therefore, according to the present invention, an amplification factor control device capable of setting a variation characteristic of an amplification factor with a high degree of freedom and obtaining a fine variation characteristic without increasing a load on a processor or increasing a memory capacity. There is an effect that can be provided.

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating a first configuration example of an amplification factor control device according to an embodiment of the present invention.

FIG. 2 is a flowchart showing an operation example of the amplification factor control device shown in FIG.

FIG. 3 is a flowchart illustrating an operation example of the amplification factor control device illustrated in FIG. 1;

FIG. 4 is a block diagram illustrating a second configuration example of the amplification factor control device according to the embodiment of the present invention;

FIG. 5 is a flowchart showing an operation example of the amplification factor control device shown in FIG. 4;

FIG. 6 is an explanatory diagram showing a change characteristic of a gain of the amplification factor control device shown in FIG. 1;

7 is an explanatory diagram showing a specific example of a gain change characteristic of the gain control device shown in FIG. 1 and a relational expression of gain versus time.

8 is an explanatory diagram showing a specific example of a gain change characteristic of the gain control device shown in FIG. 1 and a relational expression of gain versus time.

9 is an explanatory diagram showing a specific example of a gain change characteristic of the gain control device shown in FIG. 1 and a relational expression of gain versus time.

10 is an explanatory diagram showing a specific example of a gain change characteristic of the gain control device shown in FIG. 1 and a relational expression of gain versus time.

[Explanation of symbols]

3 ... Signal attenuator, 5 ... Selector, 6 ... Target gain coefficient value input port, 7 ... Gain coefficient setting command input port, 8 ... Change rate setting input port, 9 ... Logarithmic change range setting input Port 10, target gain coefficient value setting register 12, 12 increase / decrease rate setting register 13, 13 logarithmic change range maximum / minimum value setting register 14, comparator 15
...... Addition / subtraction unit, 16 ... Gain coefficient output setting control register, 17 ... DFF, 18 ... Maximum / minimum limiter, 19 ...
... Shift computing unit.

Claims (14)

[Claims] An amplification control device having a signal amplification attenuator for inputting an input signal and outputting an amplification signal or an attenuation signal thereof, wherein a start instruction for instructing a start of an increase / decrease control of an amplification factor for the signal amplification attenuator. Means, end instruction means for instructing the end of increase / decrease control of the amplification factor for the signal amplification / attenuator, increase / decrease means for increasing / decreasing the amplification factor of the signal amplification / attenuator every predetermined unit time, and a unit by the increase / decrease means An increasing / decreasing amount control means for controlling an increasing / decreasing amount for each time based on a preset increasing / decreasing rate coefficient, wherein the increasing / decreasing amount control means adjusts an amplification factor of a signal amplification / attenuator which is increased / decreased by the increasing / decreasing means. Detecting and calculating an increase / decrease amount for the increase / decrease means using the detection result and the increase / decrease rate coefficient, wherein the increase / decrease means calculates the increase / decrease amount calculated by the increase / decrease amount control means as a signal amplification attenuation. An amplification factor of the signal amplification attenuator is increased or decreased by adding or subtracting to or from the amplification factor of the amplifier. 2. The method according to claim 1, wherein the start instruction unit includes a target value setting unit that sets a target value of an amplification factor for the signal amplification attenuator, and the end instruction unit includes a target value set by the target value setting unit. And comparing the gain of the signal amplification attenuator with the value of the amplification factor, and when the values match, instructing to end the increase / decrease control of the amplification factor for the signal amplification attenuator. Item 2. An amplification factor control device according to Item 1. 3. The signal amplification / attenuator according to claim 1, wherein the increase / decrease means compares a target value set by the target value setting means with a value of an amplification factor of the signal amplification / attenuator. 3. The gain control device according to claim 2, wherein the gain of the signal amplification attenuator is increased when the target value is large. 4. A target value set by said target value setting means as an amplification factor of said signal amplification attenuator when said end instruction means instructs the end of increase / decrease control of an amplification factor for a signal amplification / attenuator. 3. The amplification factor control device according to claim 2, further comprising input switching means for inputting. 5. The end instructing means includes means for instructing a forced stop of an increase or a decrease in an amplification factor of the signal amplification attenuator, and wherein the increase / decrease means includes a target value set by the target value setting means. When a forced stop is instructed by the end instruction means during the execution of the increase / decrease control of the gain by comparing the gain with the value of the gain of the signal attenuator, the gain at that time is increased by the signal amplification. 4. The gain control device according to claim 3, wherein the gain of the attenuator is fixed. 6. The start instructing means is means for instructing an increase or decrease in the amplification factor of the signal amplification / attenuator, and the end instruction means is an instruction for increasing or decreasing the amplification factor in the signal amplification / attenuator. 2. The amplification factor control device according to claim 1, wherein the amplification factor control device is means for canceling. 7. When the end instructing means instructs the end of the increase / decrease control of the amplification factor for the signal amplification / attenuator, the increase / decrease operation in the increase / decrease means is stopped, so that the amplification factor at that time is increased by the signal amplification. 2. The gain control device according to claim 1, wherein the gain of the attenuator is fixed. 8. When the end instructing means instructs the end of the gain increase / decrease control for the signal amplification / attenuator, the increase / decrease amount sent from the increase / decrease amount control means to the increase / decrease means is set to zero value. 2. The gain control device according to claim 1, wherein the gain at the time is fixed as the gain of the signal attenuator. 9. An amplification rate control device according to claim 1, further comprising an increase / decrease rate coefficient setting means for arbitrarily setting an increase / decrease rate coefficient for controlling an increase / decrease amount of said increase / decrease means by said increase / decrease amount control means. . 10. The amplification factor control device according to claim 1, further comprising a logarithmic change range setting unit that sets an area in which the amount of increase / decrease per unit time by the increase / decrease unit is controlled by a variation value. 11. The area other than the area set by the logarithmic change range setting means is a linear change area in which the amount of increase / decrease per unit time by the increase / decrease means is controlled by a fixed value. An amplification factor control device as described in the above. 12. The logarithmic change range setting means sets a range of the logarithmic change region by inputting a maximum value and a minimum value of the logarithmic change region, and sets a fixed amount of increase / decrease used in the linear change region. 12. The method according to claim 11, wherein a change in the maximum value or the minimum value of the logarithmic change area set by the logarithmic change range setting means is fixedly used.
An amplification factor control device as described in the above. 13. The amplification rate control device according to claim 1, wherein said increase / decrease rate coefficient is composed of an exponent term and a mantissa term. 14. The amplification factor control device according to claim 12, wherein a maximum value or a minimum value of the logarithmic change area set by said logarithmic change range setting means is constituted by an exponent term and a mantissa term.