JPH0432822Y2 - - Google Patents

Description

[Detailed description of the invention] [Industrial application field] This invention relates to signal input/output devices for digital equipment such as digital reverbs and audio amplifiers that have digital signal processing functions. This was achieved by increasing the number of output terminals.

[Conventional technology]

Modern digital reverberators and audio amplifiers (control amplifiers, PCM processors, etc.) have an internal A/D converter, a digital signal processing section (a circuit section that performs various signal processing such as tone control and level control using digital processing), Some are equipped with a D/A converter. These usually have digital input/output terminals in addition to analog input/output terminals, and can be used in various connection configurations.

FIG. 2 shows a schematic configuration of a conventional digital device of this type. This digital device 10 has an analog input terminal 12, an analog output terminal 14, and digital input terminals 16, 20.
and digital output terminals 18 and 22.
Further, an A/D converter 2 is installed in the digital device 10.
4, digital signal processing section 26, D/A converter 2
8 is included.

Various connection modes of the digital device 10 shown in FIG. 2 are shown in FIGS. 3 to 6. Fig. 3 shows a case where analog input is internally processed and output as an analog signal, and the A/D converter 24, digital signal processing section 26, and D/A converter 28 are directly connected to convert the analog signal into an analog signal. Input from input terminal 12, convert to analog signal after signal processing, and output to analog output terminal 14
Output from.

In FIG. 4, the signal is processed by an external digital device (for example, a digital reverberator, etc.) 30 before being passed through the digital signal processing unit 26, and the digital input terminal 3 of the external digital device 30
2. Connect digital output terminal 34 to digital device 1
0 digital output terminal 18 and digital input terminal 16, respectively. Analog input terminal 1
After A/D conversion, the signal input from 2 is processed by an external digital signal processing unit 30, further processed by an internal digital signal processing unit 26, and then D/A converted and output from an analog output terminal 14. be done.

In FIG. 5, the signal is passed through the digital signal processing unit 26 and then processed by an external digital device 36. The digital input terminal 38 and digital output terminal 40 of the external digital device 36 are connected to the digital output terminal 22 of the digital device 10. , are connected to the digital input terminal 20, respectively. After A/D conversion, the signal input from the analog input terminal 12 is processed by an internal digital signal processing section 26, further processed by a signal processing device of an external digital device 36, and then D/A converted. and is output from the analog output terminal 14.

In FIG. 6, an external digital device (such as an audio amplifier) 42 uses the digital signal processing section 26 of the digital device 10. In FIG. Digital signal processing section 44 of external digital device 42
is the digital input terminal 1 of the digital device 10
6, connected to the digital output terminal 22. The external digital device 42 converts the analog signal inputted from the analog input terminal 46 into a digital signal with the A/D converter 48, processes the signal with the digital signal processing units 44 and 26, and converts it into an analog signal with the D/A converter 50. The signal is converted into a signal and output from the analog output terminal 52.

[The problem that the idea aims to solve]

According to the configuration shown in FIG. 2, two sets of digital input/output terminals (input terminal 16 and output terminal 18 and input terminal 20 and output terminal 22) are required, and a large space is required for terminal arrangement on the rear panel, etc. There was a drawback.

This invention attempts to solve the drawbacks of the conventional technology and realize the same connection form as the conventional device with a reduced number of input/output terminals.

[Means to solve the problem]

This invention consists of an analog input terminal, an analog output terminal, a digital input terminal, a digital output terminal, an A/D converter for A/D converting the analog signal input from the analog input terminal, and an A/D converter for A/D converting the analog signal input from the analog input terminal. A digital signal processing unit that processes digital signals and a D/A
A D/A converter converts and leads to the analog output terminal, and selects one of the output digital signal of the A/D converter or the digital signal input from the digital input terminal and inputs it to the digital signal processing section. a first selector that selects either a digital signal input from the digital input terminal or a digital signal output from the digital signal processing section and inputs the selected signal to the D/A converter; a third selector that selects either the output digital signal of the /D converter or the digital signal output from the digital signal processing section and guides it to the digital output terminal, the first selector and the second selector; , and by switching the connection state of the third selector, at least the digital input terminal and the digital output terminal are connected to an external digital device inserted between the A/D converter and the digital signal processing section. a first signal path state serving as a digital input terminal and an output terminal for an external digital device in which the digital input terminal and digital output terminal are inserted between the digital signal processing section and the D/A converter; a second signal path state in which the digital input terminal and the digital output terminal serve as digital input terminals and output terminals for connecting the digital signal processing section to an external digital device; and a third signal path state serving as an output terminal.

[Effect]

According to this invention, by switching three selectors, one set of digital input/output terminals sets the connection state between an external digital device and an internal digital signal processing section to at least the above-mentioned first to third signal path states. This makes it possible to reduce the number of digital input/output terminals on the rear panel, etc. Furthermore, various connection states can be realized without replacing cables.

Note that this invention can be applied to various digital devices.

〔Example〕

An embodiment of this invention is shown in FIG. In FIG. 1, the digital device 54 has one set of analog input terminals 56 and analog output terminals 58, and one set of digital input terminals 60 and digital output terminals 62.
It is equipped with Further, the digital device 54 includes an A/D converter 64, a digital signal processing section 66,
D/A converter 68, first to third selectors 70, 7
2,74 is provided. A/D converter 64 converts the input analog signal into a digital signal.
The digital signal processing section 66 performs various signal processing such as tone control and level control by digital processing. D/A converter 6
8 converts the digital signal into an analog signal and leads it to an analog output terminal 58.

The first selector 70 selects either the output digital signal of the A/D converter 64 or the digital signal input from the digital input terminal 60 and inputs the selected signal to the digital signal processing section 66 .

The second selector 72 is connected to the digital input terminal 60
Either the digital signal input from the digital signal processor 66 or the digital signal output from the digital signal processing section 66 is selected and input to the D/A converter 68.

The third selector 74 selects either the output digital signal of the A/D converter 64 or the digital signal output from the digital processing section 66 and guides it to the digital output terminal 62 .

Various connection modes of the digital device 54 shown in FIG. 1 are shown in FIGS. 7 to 10. These correspond to the connection modes shown in FIGS. 3 to 6 in the conventional device, respectively. FIG. 7 shows a case where the analog input is internally processed and output as an analog signal. Selectors 70 and 72 are connected as shown in the figure (selector 74 is optional), and the A/D converter 64 outputs the digital signal. The processing section 66 and the D/A converter 68 are directly connected, and an analog signal is inputted from the analog input terminal 56, and after signal processing, converted into an analog signal and outputted from the analog output terminal 58.

FIG. 8 shows the first signal path state,
The signal is processed by an external digital device (such as a digital reverberator) 76 before passing through the digital signal processing section 66, and the digital output terminal 78 and digital input terminal 80 of the external digital device 76 are connected to the digital input terminal of the digital device 54. It is connected to a terminal 60 and a digital output terminal 62, respectively. In addition, selectors 70, 72, 74
Connect as shown. The analog signal input from the analog input terminal 56 is sent to the A/D converter 64.
After being converted into a digital signal by
4. The signal is processed by an external digital device 76 via the terminals 60, 80, and is further processed by the terminals 78, 60,
Digital signal processing unit 66 via selector 70
The signal is processed in the D/A via the selector 72.
The converter 68 converts the signal into an analog signal and leads it to the analog output terminal 58.

FIG. 9 shows the second signal path state,
After passing through the digital signal processing section 66, the signal is processed by an external digital device 82, and the digital output terminal 84 of the external digital device 82,
The digital input terminal 86 is connected to the digital input terminal 60 and the digital output terminal 6 of the digital device 54.
2 respectively. In addition, selectors 70, 7
Connect 2 and 74 as shown. The analog signal input from the analog input terminal 56 is converted into a digital signal by the A/D converter 64, processed by the digital signal processing section 66, and then sent to the outside via the selector 74 and the terminals 62 and 86. The signal is processed by the digital device 82, and the terminals 84, 6
0, the signal is converted into an analog signal by the D/A converter 68 via the selector 72, and then guided to the analog output terminal 58.

FIG. 10 shows a third signal path state in which an external digital device (such as an audio amplifier) 88 connects to the signal processing section 66 of the digital device 54.
It uses External digital equipment 8
A digital signal processing unit 90 of No. 8 is connected to digital input/output terminals 60 and 62 of the digital device 54 . Further, selectors 70 and 74 are connected as shown in the figure (selector 72 is optional). This results in
The digital signal processing section 66 is interconnected with an external digital device 88. That is, the external digital device 88 converts the analog signal input from the analog input terminal 92 into a digital signal by the A/D converter 94, and then converts the analog signal input from the analog input terminal 92 to the digital signal processing section 90.
The signal is processed by In addition, digital input terminal 6
0, the digital signal is processed by the digital signal processing unit 66 via the selector 70, and the digital signal is processed by the selector 70.
4. The signal is returned to the digital signal processing section 90 via the digital output terminal 62. The output of the digital signal processing section 90 is converted into an analog signal by a D/A converter 96 and then output from an analog output terminal 98.

Incidentally, the selectors 70, 72, and 74 can be implemented not only by hardware but also by software. The first example is an example realized using software.
Shown in Figure 1. This selector 100 has two inputs.
Multipliers 102 and 104 multiply x ₁ and x ₂ by coefficients a ₁ and a ₂ , and an adder 106 adds the results to output y. That is, the output y is given as y=a ₁ *x ₁ +a ₂ *x ₂ . If a ₁ = 1, a ₂ = 0, y =
x ₁ and x ₁ is selected; if a ₁ =0 and a ₂ =1, y=x ₂ and x ₂ is selected.

If noise becomes a problem when switching between the selectors 70, 72, 74, multipliers 108, 110 are installed before the selectors 70, 72, 74 as shown in _FIG . All you have to do is change b ₂ over time (usually several tens of milliseconds).
For example, when switching from y=x ₁ to y=x ₂ , the coefficient b ₁ is gradually changed from 1 toward 0 (fade out). After the coefficient b ₁ reaches 0, the selectors 70, 72,
74 from contact c to contact d, and gradually change the coefficient _b2 from 0 toward 1 (fade-in). If it is necessary to change the operating clock due to switching, the clock can be changed between the end of and before the start of. Note that when the selectors 70, 72, and 74 are realized by software as shown in FIG.
0 function, and the coefficients a ₁ and a ₂ are respectively the first
All you have to do is switch as shown in Figure 3.

Further, instead of the configuration shown in FIG. 12, a configuration as shown in FIG. 14 may be used. This is the multiplier 111
is arranged after the selectors 70, 72, and 74, and the coefficient c of the multiplier 111 is changed over time. For example, when switching from y=x ₁ to y=x ₂ , the coefficient c is gradually changed from 1 toward 0 (fade out). After the coefficient c reaches 0, the selectors 70, 72,
74 from contact e to contact f, and gradually change coefficient c from 0 toward 1 (fade-in).

[Other Examples]

Another embodiment of this invention is shown in FIG. This receives word clocks from connected devices and generates an operating clock using a PLL circuit.
The operating clock generated by this PLL circuit is selected as necessary to operate each part of the circuit. In addition to the first to third selectors 70, 72, and 74, the digital device 102 includes a fourth selector 104 for switching the operating clock.
It is equipped with An operating clock normally used by the device 102 is generated from the oscillator 106 and inputted to one input of the selector 104. Further, the word clock output from the word clock output terminal 110 of the digital device 103 is inputted from the word clock input terminal 112, and is input to the PLL circuit 108.
An operating clock is generated and input to the other input of the selector 104. The selector 104 is the first to third
When the selectors 70, 72, and 74 are switched to change the connection mode, the operation clock is switched at the same time if it is necessary to change the operation clock. A/D converter 6
4, digital signal processing section 66, D/A converter 6
8 is operated by the operating clock selected by the selector 104. Note that the operating clock output from the selector 104 is output from the word clock output terminal 1.
14 and word clock input terminal 11
6 to the digital device 103. Thereby, the digital device 103 can be similarly operated by the operation clock of the digital device 102.

[Effect of idea]

As explained above, according to this invention, by switching the three selectors, one set of digital input/output terminals can control the connection state between an external digital device and an internal digital signal processing section at least as described above.
Since the third signal path state can be established, the number of digital input/output terminals on the rear panel etc. can be reduced. Further, various connection modes can be realized without replacing cables.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing one embodiment of this invention. FIG. 2 is a block diagram showing a conventional device. 3 to 6 are block diagrams showing various connection modes in the conventional device shown in FIG. 2. 7 to 10 are block diagrams showing various connection modes in the device of FIG. 1, in which FIG. 8 shows the first signal path state, FIG. 9 shows the second signal path state, and FIG. is the third signal path state. FIG. 11 is a block diagram showing an example of implementing the selectors 70, 72, and 74 of FIG. 1 by software.
FIG. 12 is a block diagram showing an example of a configuration for preventing noise caused by switching. FIG. 13 is a diagram showing how the coefficients a ₁ and a ₂ change when the multipliers 102 and 104 of FIG. 11 are provided with a noise prevention mechanism. FIG. 14 is a block diagram showing another embodiment in which the same output as that in FIG. 12 can be obtained. 1st
FIG. 5 is a block diagram showing another embodiment of this invention. 56...Analog input terminal, 58...Analog output terminal, 60...Digital input terminal, 62...
...Digital output terminal, 64...A/D converter,
66...Digital signal processing unit, 68...D/A
Converter, 70...first selector, 72...second selector, 74...third selector.

Claims (1)

[Claims for Utility Model Registration] An analog input terminal, an analog output terminal, a digital input terminal, a digital output terminal, an A/D converter that A/D converts an analog signal input from the analog input terminal, and a digital signal. a digital signal processing section that inputs and processes a digital signal; a D/A converter that converts the digital signal into an analog signal and leads it to the analog output terminal; and an output digital signal of the A/D converter or the digital signal a first selector that selects one of the digital signals input from the input terminal and inputs it to the digital signal processing section; and a first selector that selects one of the digital signals input from the digital input terminal or the digital signal output from the digital signal processing section. a second selector that selects one of the output digital signals of the A/D converter and inputs the digital signal to the D/A converter; and a second selector that selects one of the output digital signal of the A/D converter or the digital signal output from the digital signal processing section and outputs the digital signal. a third selector leading to the terminal, the first selector, the second selector, and the third selector.
By switching the connection state of the selector, at least the digital input terminal and the digital output terminal are connected to a digital input terminal for connecting to an external digital device inserted between the A/D converter and the digital signal processing section. a first signal path state serving as a terminal and an output terminal; and a first signal path state in which the digital input terminal and the digital output terminal are connected to the digital signal processing section and the D/A.
a second signal path state serving as a digital input terminal and an output terminal for connecting to an external digital device inserted between the converter; and a second signal path state in which the digital input terminal and the digital output terminal connect the digital signal processing unit to an external A signal input/output device characterized in that it is capable of forming a digital input terminal for mutual connection with a digital device and a third signal path state serving as an output terminal.