JP2601338Y2 - Check device - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a check device for a digital signal processor, and more particularly to a digital audio processor.
The present invention relates to a check device suitable for use in checking digital audio equipment such as a tape recorder (hereinafter, referred to as DAT).

[0002]

2. Description of the Related Art Conventionally, various digital audio devices for handling digital audio signals have been developed. For example, as a device for recording and reproducing digital audio signals, DA
There is a CD player as a device for reproducing a digital audio signal recorded on a compact disc (CD), and a broadcast satellite tuner (B) for receiving a digital audio signal as a broadcast wave transmitted from a broadcast satellite.
S tuner). There is also a digital amplifier device that performs processing for reproducing digital audio signals transmitted from these digital audio devices.

In order to directly transmit digital audio signals between these digital audio devices, it is necessary to transmit digital audio signals in a format called a digital audio interface.
By transmitting a digital audio signal conforming to a format called a digital audio interface, any digital audio device can be freely connected. That is, in the case of a digital audio signal, there are various sampling frequencies and modulation methods, and appropriate reception processing cannot be performed unless a digital audio signal of a sampling frequency and a modulation method suitable for a digital audio interface format is used. Will be gone.

[0004]

In the digital audio interface format, additional information such as a subcode and a channel status can be transmitted in addition to audio signal data. In this channel status, data indicating the nature of the data being transmitted is transmitted. Specifically, a type code, a copy prohibition code, and the like of the device that transmitted the audio signal are transmitted.

[0005] Here, if a device that has received data transmitted in the format of the digital audio interface cannot correctly determine the channel status such as a copy prohibition code, the device may malfunction, and in the worst case, copying may occur. It is conceivable that audio data can be copied (digitally copied) even though a code for prohibiting is added.

Therefore, the input of a digital audio signal,
In the case of a device capable of outputting, it was necessary to check whether or not to perform an operation conforming to the format of the digital audio interface.

Therefore, an object of the present invention is to provide a checking device that can easily check a digital audio interface of a digital audio device.

[0008]

According to the present invention, for example, as shown in FIG. 1, additional information of digital data to be transmitted is provided.
Setting means 8 for arbitrarily setting a status information signal
The status information signal set by the setting means 8 is received.
The output means 6, 9 for outputting to the measuring device and the device to be measured
Means for inputting the status information signal processed by
14, 17 and the steps input from the input means 14, 17
Demodulation means 26 for demodulating the status information signal;
Means for setting the status information signal demodulated by the
Device under measurement of the status information signal set by 8
Display means 27 for displaying the processing status in the computer so that it can be confirmed
It is characterized by having.

[0009]

With this configuration, the digital data output from the check device is supplied to the device under test (digital audio device), and the status information signal in the digital data output from the device under test is checked. The status of the returned status information signal is displayed, and it is possible to check whether the status information signal is correctly processed by the device under test.

[0010]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view showing a first embodiment of the present invention;

FIG. 1 is a diagram showing the overall configuration of a check apparatus according to the present embodiment. In FIG. 1, reference numeral 1 denotes an analog input terminal. A terminal to which an analog audio signal is supplied. And the analog input terminal 1
Is supplied to an analog / digital converter 3 via a buffer 2 and converted into a digital audio signal. At this time, the reference signal generator 4
Is the analog / digital converter 3
And the digital conversion is performed at a timing based on the reference clock. In this case, the reference signal generator 4
The reference clock output by the switch can be switched into three types under the control of the reference signal switch 5. This 3
By switching the type of reference clock, the sampling frequency of the digital audio signal converted by the analog / digital converter 3 becomes 48 kHz, 44.1 kHz, or 32 kHz.
Hz.

The digital audio signal output from the analog / digital converter 3 is converted to a digital processing circuit 6
To supply. In this digital processing circuit 6, analog /
The digital audio signal supplied from the digital converter 3 is converted into digital data in a digital audio interface format. At this time, the reference clock output from the reference signal generator 4 is supplied to the digital processing circuit 6 and a PLL circuit (phase locked loop circuit) 7 is connected to the digital processing circuit 6. The conversion process is performed at the timing based on the conversion.

In the figure, reference numeral 8 denotes a timing circuit. The timing circuit 8 includes thirteen switches S ₂ , S ₃ ,
_{S 8, S 9, S 10} , S 14, S 15, S 20, S 21, S 24, S
_25, S _28, S ₂₉ is is connected. These switches S _{2 to} S ₂₉ are connected to the second, third, eighth, ninth, and first bits of a channel status signal to be described later.
0th bit, 14th bit, 15th bit, 20th bit, 21st bit, 24th bit, 25th bit, 28
The switches corresponding to the data of the 29th bit and the 29th bit. The bit data of the corresponding channel status signal changes according to the switching of each switch.
3-bit channel status signal (parallel signal)
Is supplied to the serial data generation circuit 9.

The serial data generating circuit 9 converts the 13-bit channel status signal supplied from the timing circuit 8 into serial data. At this time, the data is converted into serial data at a clock rate based on the reference clock output from the reference signal generator 4. Then, the converted serial data is supplied to the digital processing circuit 6.
The digital processing circuit 6 converts digital data supplied from the analog / digital converter 3 into a digital audio interface format.
The serial data supplied from the serial data generation circuit 9 is added to the channel status signal included in this format.

Here, the format of the digital audio interface will be described. In this format, as shown in FIG. 2A, one frame is composed of left channel (L channel) data and right channel (R channel) data. Divided into two subframes,
Data of this frame structure is continuously transmitted. Each sub-frame is composed of 32 bits as shown in FIG. 2B, and includes 4 bits of synchronization bits, 20 bits of audio data, 1 bit of a validity flag (V bit), and 1 bit of user data ( U bit), channel status (C bit), parity bit (P bit)
Etc.

As shown in FIG. 3, the channel status assigned to one bit in one frame is composed of 192 frames from the 0th frame to the 191st frame, and one unit of data is formed. The type code is transmitted using data of a total of 4 bits of the 10th, 10th, and 15th bits.

Table 1 shows an example of this type code.

[0018]

[Table 1]

Since the 11th to 14th bits are all "0" signals, there is no need to set them when transmitting the type code. Actually, the eighth, ninth, tenth, and fifteenth bits are used. The type code can be transmitted by the instruction of the 4th bit data. SCMS by type
The corresponding DAT-P is a DAT corresponding to the serial copy management system (SCMS). The SCMS-compatible DAT is a system in which the number of digital copies is limited, and the conventional DAT is Shows those that do not employ this system.

The digital data in the format of the digital audio interface to which the channel status thus formed is added is supplied from the digital processing circuit 6 to the coaxial digital output terminal 11 via the buffer 10 and the buffer 10 To the optical digital output terminal 13 through the photoelectric conversion circuit 12,
Output is made from the respective output terminals 11 and 13.

In the figure, reference numeral 14 denotes an optical digital input terminal. Digital data obtained at the optical digital input terminal 14 is supplied to a buffer 16 via a photoelectric conversion circuit 15 and further supplied to a coaxial digital input terminal 17. The supplied digital data is supplied to the buffer 16. In this case, the digital data obtained at the respective input terminals 14 and 17 is digital data in the format of a digital audio interface. Then, each digital data obtained in the buffer 16 is supplied to the digital processing circuit 6, and the digital processing circuit 6 extracts only audio data from the format of the digital audio interface. Then, the extracted left channel audio data is supplied to the left channel digital / analog converter 19L via the digital filter 18, and the right channel audio data is supplied to the right channel digital / analog converter 19R. .

Then, each digital / analog converter 19
The analog audio signal of each channel converted by L, 19R is supplied to left and right analog output terminals 20L, 20R. Each digital / analog converter 19L,
The analog audio signal of each channel converted by the 19R is supplied to the left and right headphone output terminals 23L and R via the left and right regulators 21L and 21R and the headphone amplifiers 22L and 22R.

In this embodiment, digital data obtained at the optical digital input terminal 14 and the coaxial digital input terminal 17 is supplied to the first decoder 24 via the buffer 16 and is included in the digital data by the decoder 24. Decodes various control data (channel status) and outputs the decoded data to a digital data output terminal
25.

Furthermore, the digital data obtained in the optical digital input terminal 14 and the coaxial digital input terminal 17 is supplied to the second decoder 26 via the buffer 16, decodes the channel status in the second decoder 26 , And supplies the decoded channel status data to the display 27 . The display 27 includes, for example, a plurality of light emitting diodes, and displays the decoded channel status. That is, a light emitting diode is prepared for each type shown in Table 1 described above, and the light emitting diode corresponding to the type determined by decoding and emitting light is emitted.

Next, a description will be given of the operation of checking a digital audio device using the checking device having the above-described configuration. For example, when checking a DAT, the coaxial digital output terminal 1 of the checking device is used.
1 or the optical digital output terminal 13 is connected to a digital input terminal of a DAT to be checked with a coaxial cable or an optical fiber cable, and the digital output terminal of the DAT is further connected to an optical digital input terminal 14 of the check device with an optical fiber cable or a coaxial cable. Connect to coaxial digital input terminal 17. Also, an audio signal output terminal of any audio device (such as a tape deck) that outputs an analog audio signal is connected to the analog input terminal 1, and an analog audio signal output from the analog audio device is supplied to the check device.

The analog audio signal obtained at the analog input terminal 1 is converted into digital data and supplied to a digital processing circuit 6, which converts the serial data supplied from the serial data generation circuit 9 into a channel status signal. To the format of the digital audio interface added.
At this time, the data set by switching the switches S ₈ , S ₉ , S ₁₀ , and S ₁₅ connected to the timing circuit 8 becomes the type code of the channel status to be added (any of the types shown in Table 1). .

The digital data in the format of the digital audio interface to which the channel status is added is supplied from the coaxial digital output terminal 11 or the optical digital output terminal 13 to the DAT to be checked. On the DAT side, when receiving the digital data in the format of the digital audio interface, processing such as recording of the digital data is performed, and the recording state and the like can be checked. However, when the checking device of this example is used, the reception is performed. The digital data obtained is supplied again to the optical digital input terminal 14 or the coaxial digital input terminal 17 of the check device as digital data in the format of the digital audio interface by the circuit in the DAT. Then, the channel status in the digital data returned to the checking device is stored in the second decoder 2.
6 , and the decoded result is displayed on the display 27 .

The result of decoding the data processed in this way is displayed on the display 27 , so that the processing status of the channel status of the digital audio interface format in the DAT, which is the device under test, is determined. it can. That is, for example, DAT-P (SCMS
(Corresponding) type code is supplied as a channel status from the checking device to the DAT which is the device under test, and the same DAT-P type code is returned from the DAT and displayed on the display.
When displayed at 27 , it can be determined that the DAT is a device that can correctly process the channel status. When another type code is returned from the DAT and displayed on the display 27 , it can be determined that the DAT cannot correctly process the channel status (ie, malfunction).

By being able to check the processing status of the channel status in this way, it is possible to check whether the process (copy prohibition, etc.) given by the channel status is executed correctly. In particular, in this example, the serial copy management system DA
Since the type code corresponding to T can be output, the copy prohibition operation can be confirmed.

The audio data returned to the check device is output to audio equipment or headphone output terminals 23L, 2L connected to analog output terminals 20L, 20R.
Can be played from headphones connected to 3R,
The processing state of the audio signal can be checked from the reproduced sound.

In the above embodiment, the display 27
In the above, a light emitting diode is prepared for each type, and the light emitting diode corresponding to the type determined by decoding is made to emit light. However, the decoded bit data may be directly displayed by a plurality of light emitting diodes. . For example, when the type code of DAT-P is received, since this code is [11000001] (see Table 1), only three light emitting diodes corresponding to the "1" signal out of eight light emitting diodes are used. You may make it light and display it.

In the above embodiment, the channel status is added to the digital audio data obtained by converting the analog audio signal obtained at the analog input terminal 1, but the channel status is added to the audio signal obtained at the other input terminal. May be added. Alternatively, the audio signal may not be supplied to any terminal, and only the channel status may be added to the silent data as audio data.

Further, the present invention is not limited to the above-described embodiment, but may take various other configurations.

[0034]

[Effect of the Invention] According to the checking device of the present invention, it is possible to easily check whether a status information signal or the like is correctly processed in a device under test, and to easily search for a product whose operation state is defective based on the status information signal. it can.

[Brief description of the drawings]

FIG. 1 is a configuration diagram showing an embodiment of the present invention.

FIG. 2 is an explanatory diagram showing a format of a digital audio interface to which an embodiment is applied;

FIG. 3 is an explanatory diagram showing a channel status to which an embodiment is applied;

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 analog input terminal 3 analog / digital converter 4 reference signal generator 5 reference signal switch 6 digital processing circuit 8 timing circuit 9 serial data generation circuit 11 coaxial digital output terminal 13 optical digital output terminal 14 optical digital input terminal 17 coaxial digital Input terminal 26 Second decoder 27 Indicator

Claims (2)

(57) [Scope of request for utility model registration] 1. Additional information of digital data transmitted
Setting means for setting a certain status information signals arbitrarily, the status information signal set by said setting means
Output means for outputting to the device under test, and a status information signal processed by the device under test
Input means for inputting the status information signal input from the input means.
Demodulation means for demodulating, and a status information signal demodulated by the demodulation means
The status information signal set by the setting means.
Number so that the processing status of the device under test can be confirmed.
A check device comprising: a display unit for displaying the information . 2. The status information signal according to claim 1 , wherein
The type code of the device under test or the copy prohibition code
The checking device according to claim 1, wherein