JP2001067796A - Method for transmitting data between plural lsis and dvd audio reproducing device using the method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a DVD audio reproducing device capable of preventing a digital signal just before it is inputted to a D/A conversion LSI from being illegally copied. SOLUTION: A digital signal processing LSI 6 and a D/A conversion LSI 7 are connected with each other through external busses 13 to 15. A scramble processing circuit 17 scrambling a digital signal to be outputted from a digital signal processing circuit 16 is provided in the inside of the digital signal processing LSI 6 and a descramble processing circuit 18 descrambling a scrambled digital signal to be transmitted through the external busses 13 to 15 is provide in the inside of the D/A conversion LSI 7.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for transmitting data between a plurality of LSIs connected to each other via an external bus, and more particularly, to a method for processing digital signals connected to each other via an external bus. LSI and D / A conversion L
The present invention relates to a method for transmitting a digital signal from a digital signal processing LSI to a D / A conversion LSI via an external bus in a DVD audio reproducing apparatus provided with an SI, and a DVD audio reproducing apparatus using the method.

[0002]

2. Description of the Related Art Recently, a DVD audio standard for realizing multi-channel reproduction of high-quality audio by mainly recording an audio signal on a DVD having a capacity of 4.7 GB in a single-sided single-layer system has been determined.
The development of DVD audio playback devices for playing audio discs is also underway. According to the DVD audio standard, it is possible to record and reproduce audio signals having various sampling frequencies, quantization bit numbers, and channel numbers. For example, the sampling frequency 192
An audio signal having a frequency of kHz, a quantization bit number of 24, and a channel number of 2 is recorded to reproduce stereo sound having a maximum frequency of 96 kHz, or a sampling frequency of 96 kHz, a quantization bit number of 24, and a channel number of 6
Record audio signal, the highest frequency is 48kHz
Or play multi-channel audio. Further, various recording and reproduction are possible, such as recording a video signal on a DVD and reproducing a video together with audio. The sampling frequencies of the audio signals are 192/96/48 kHz and 176.4 /
There are 88.2 / 44.1 kHz and the number of quantization bits is 24/20/16 bit.

FIG. 11 is a diagram showing a configuration of a part related to transmission of a digital signal from a digital signal processing LSI 6 to a D / A conversion LSI 7 in a conventional DVD audio reproducing apparatus. In FIG. 11, a digital signal processing LSI 6 and a D / A conversion LSI 7 are connected to an external bus 1.
They are connected to each other via 3 to 15. The digital signal processing LSI 6 processes an input digital signal (packet stream) to generate a digital signal. The D / A conversion LSI 7 is a digital signal processing LSI.
The digital signal output from 6 is D / A converted to generate an analog signal.

FIG. 12 shows the digital signal processing L of FIG.
6 is a timing chart showing a digital signal output from SI6 (in the case of two channels). In FIG. 12, a word clock is a clock signal indicating a timing at which a channel of serial data is switched, and is transmitted through the external bus 13 in FIG. Serial data is
Including data of two channels (ch1, ch2),
The data is transmitted through the external bus 14 (for example, when the number of channels is 4, another serial data including two channels (ch3 and ch4) is output in parallel with the serial data). The bit clock is a clock signal synchronized with the serial data, and is transmitted through the external bus 15. From these word clocks, serial data and bit clocks, the respective bit arrays {MS
B, 23, 22,..., 3, 2, LSB}.

[0005]

As described above, in the conventional DVD audio reproducing apparatus, the digital signal processing L
The SI 6 and the D / A conversion LSI 7 are provided on separate chips and are connected to each other via external buses 13 to 15. For this reason, there is a problem that digital signals can be taken out from the external buses 13 to 15 between the digital signal processing LSI 6 and the D / A conversion LSI 7 and copied illegally. From the digital signal just before being input to the D / A conversion LSI 7, the super-high-quality stereo sound and the high-quality multi-channel sound as described above can be easily reproduced (see FIG. 12).

The digital signal processing LSI 6 and D /
If the A-conversion LSI 7 is provided on a single chip, illegal copying of extracting digital signals from the external buses 13 to 15 can be prevented. However, in this case, noise or the like due to digital signal processing performed by the digital signal processing LSI 6 enters the analog circuit portion included in the D / A conversion LSI 7, and as a result, the analog output from the D / A conversion LSI 7 Another problem arises in that the signal quality is degraded. When playing DVD audio, (for example, C
Since high-speed digital signal processing is performed (compared with D reproduction), this quality deterioration is remarkable.

Therefore, an object of the present invention is to provide a DVD capable of taking out a digital signal immediately before being input to a D / A conversion LSI and preventing the digital signal from being illegally copied.
An object of the present invention is to provide an audio reproducing device.

[0008]

Means for Solving the Problems and Effects of the Invention A first invention is a first LS connected to each other via an external bus.
A method for transmitting data between the first LSI and the second LSI, wherein the data is scrambled inside the first LSI, and the scrambled data is transmitted from the first LSI to the second LSI.
, Through an external bus, and descrambles the scrambled data inside the second LSI.

In the first aspect of the present invention, since the signal transmitted through the external bus between the first LSI and the second LSI is scrambled, even if data is taken out from the external bus and illegally copied, , Can not play it.

A second invention is a digital signal processing LSI and a D / A converter L connected to each other via an external bus.
A method of transmitting a digital signal from a digital signal processing LSI to a D / A conversion LSI through an external bus in a DVD audio reproducing apparatus for reproducing a DVD audio disk provided with an SI, comprising the steps of: Processes the digital signal read from the DVD audio disk, scrambles the processed digital signal, and converts the scrambled digital signal from a digital signal processing LSI to a digital signal.
A / A conversion LSI transmits the signal through an external bus, descrambles the scrambled digital signal transmitted through the external bus inside the D / A conversion LSI, and D / A converts the digital signal after descrambling. It is characterized by.

The second invention (and the third invention described below)
Now, the digital signal processing LSI and D / A conversion LS
Since the digital signal transmitted on the external bus during I is scrambled, even if the digital signal is taken out from the external bus and copied illegally, it cannot be reproduced.

A third invention is a DVD audio reproducing apparatus for reproducing a DVD audio disk, comprising a digital signal processing LSI and a D / A conversion LSI connected to each other via an external bus. A digital signal processing means for processing a digital signal read from a DVD audio disk, and a scramble processing means for scrambling a digital signal output from the digital signal processing means; Includes descramble processing means for descrambling the scrambled digital signal transmitted via the external bus, and D / A conversion means for D / A converting the digital signal output from the descrambling processing means. I have.

[0013] In a fourth aspect based on the third aspect, the DV is the same as that of the third aspect.
Header reading means for reading attribute information of the digital signal described in the header of a packet constituting the digital signal read from the D audio disk, a header analyzing unit for analyzing the attribute information read by the header reading means, and The apparatus further includes a scramble / descramble control unit that controls the scramble processing unit and the descramble processing unit based on the analysis result of the header analysis unit.

In the fourth aspect, scrambling / descrambling according to the attribute of the digital signal is performed.

In a fifth aspect based on the fourth aspect, the attribute information includes information relating to the quality of a sound obtained by reproducing the digital signal (hereinafter, the quality of the digital signal). The scramble control unit controls the scramble processing unit and the descramble processing unit based on the quality of the digital signal indicated by the analysis result of the header analysis unit so that confidentiality corresponding to the quality of the digital signal is realized. It is characterized by.

[0016] In the fifth aspect, the scramble / scramble / reproduce method is implemented to realize confidentiality corresponding to the quality of the digital signal.
Perform descrambling (for example, higher confidentiality is realized for a higher quality signal). As a result, the efficiency of the scrambling / descrambling process is increased.

According to a sixth aspect based on the fifth aspect, the quality of the digital signal is a sampling frequency and / or the number of quantization bits of the digital signal.

In a seventh aspect based on the fifth aspect, the scramble / descramble control means comprises a plurality of predetermined levels of digital signal quality and a plurality of levels for realizing confidentiality corresponding to each quality. It has a table in which identifiers assigned to the scramble / descramble information are described in association with each other, and the plurality of scramble / descramble information. By referring to the table, the analysis result of the header analysis unit is obtained. By selecting the scramble / descrambling information corresponding to the quality of the digital signal indicated by the above and giving the selected scramble / descrambling information to the scrambling processing means and the descrambling processing means. Characterized by controlling There.

In an eighth aspect based on the seventh aspect, the scrambling / descrambling control means has a table, and by referring to the table, the quality of the digital signal indicated by the analysis result of the header analysis section is improved. A scramble / descramble information selection unit that selects corresponding scramble / descramble information and outputs an identifier of the selected scramble / descramble information, has a plurality of scramble information, and among the plurality of scramble information, It has a scramble control unit for providing scramble information corresponding to the identifier output from the descramble information selection unit to the scramble processing means, and a plurality of descramble information, and among the plurality of descramble information, the scramble / descramble information Selector A descrambling control unit for providing descrambling information corresponding to the output identifier to a descrambling processing unit, wherein the scrambling control unit is included inside the digital signal processing LSI, and the descrambling control unit performs D / A conversion. It is characterized in that it is included inside the LSI.

In the eighth invention, the scramble control section having a plurality of scramble information is a digital signal processing L.
Since the descrambling control section that is included inside the SI and has a plurality of descrambling information is included inside the D / A conversion LSI, the scrambling / descrambling information does not leak. As a result, there is no danger that an illegally copied digital signal can be reproduced.

In a ninth aspect based on the fourth aspect, the attribute information includes information indicating which position is a track boundary in the digital signal,
The descrambling control means has a plurality of pieces of scramble / descrambling information, and selects one of the plurality of pieces of scramble / descrambling information on a track basis in accordance with a user's instruction. It is characterized by giving to means.

In the ninth aspect, a boundary between a track (corresponding to one music piece) and a track is detected, and scramble / descrambling information is selected for each track in response to a user's instruction.

In a tenth aspect based on the fourth aspect, the attribute information includes information indicating which position is a group boundary in the digital signal, and the scramble / descramble control means includes It has scramble / descramble information and responds to user instructions,
One of the plurality of pieces of scramble / descramble information is selected in a group unit and is provided to the scramble processing means and the descramble processing means.

In the tenth aspect, a boundary between a group (corresponding to one album composed of a plurality of songs) and a group is detected, and scramble / descramble information is selected for each group in response to a user's instruction. .

In an eleventh aspect based on the third aspect, the scramble processing means scrambles the digital signal output from the digital signal processing means for each channel in units of sample points.

In a twelfth aspect based on the third aspect, the scramble processing means scrambles the digital signal output from the digital signal processing means for each channel in units of bytes.

In a thirteenth aspect based on the third aspect, the scramble processing means scrambles the digital signal output from the digital signal processing means between channels in units of sample points.

In a fourteenth aspect based on the third aspect, the scramble processing means scrambles the digital signal output from the digital signal processing means between channels in units of bytes.

[0029]

DESCRIPTION OF THE PREFERRED EMBODIMENTS (First Embodiment) FIG. 1 is a block diagram showing a configuration of a DVD audio playback device according to a first embodiment of the present invention. In FIG. 1, a DVD audio reproducing apparatus includes a pickup 1 and a driver 2
Servo circuit 3, error correction circuit 4, encryption / decryption circuit 5, digital signal processing LSI 6, D / A conversion L
An SI 7 and a system controller 8 are provided.

The pickup 1 reads a digital signal from the DVD audio disk 12. Driver 2
Drives the pickup 1. The servo circuit 3 keeps the movement of the driver 2 stable. The error correction circuit 4 corrects an error in the digital signal output from the pickup 1. The encryption / decryption circuit 5 decodes a previously encrypted digital signal output from the error correction circuit 4. The digital signal processing LSI 6 processes a digital signal output from the encryption / decryption circuit 5. D / A conversion LSI7
Converts the digital signal output from the digital signal processing LSI 6 from digital to analog. System controller 8
Includes a CPU 9, a RAM 10, a ROM 11, and the like, and controls the digital signal processing LSI 6 and the D / A conversion LSI 7. Note that each of the above circuits (3 to 5) may be implemented as software.

The outline of the operation of the DVD audio reproducing apparatus configured as described above will be described below. FIG.
In, when the DVD audio disk 12 is set in the DVD audio reproducing apparatus and a PLAY button (not shown) is pressed, the disk 12 starts rotating by being driven by a motor (not shown). Meanwhile, pickup 1
Receives digital signals from the rotating disk 12 while moving in the radial direction of the disk 12 in response to the driving of the driver 2. Thus, while the digital signal is being read from the disk 12, the movement of the driver 2 is kept stable by the servo circuit 3.

The error correction circuit 4 receives a digital signal output from the pickup 1, and corrects an error in the digital signal. The encryption / decryption circuit 5 receives a previously encrypted digital signal output from the error correction circuit 44 and decodes the digital signal. It should be noted that error correction and encryption / decryption are not directly related to the gist of the present invention, and thus description thereof is omitted. Digital signal processing L
The SI 6 processes the digital signal output from the encryption / decryption circuit 5 under the control of the system controller 8,
Generate a digital audio signal and a digital video signal (although the latter signal is not required).

Here, a specific example of the processing performed by the digital signal processing LSI 6 will be described. FIG. 2 is a schematic diagram showing the contents and structure of a digital signal input to the digital signal processing LSI 6 of FIG. In FIG. 2A,
The digital signal is divided into a plurality of groups, and the groups are further divided into a plurality of tracks. Here, the “track” corresponds to each song, and the “group” corresponds to an album including a plurality of songs.

As shown in FIG. 2B, the digital signal having the above content has a packet stream structure in which a plurality of packets are serially connected. The packet is composed of a header part and a data part. The data section stores a digital audio signal (or a digital video signal), and the header section describes attribute information of the signal.

As the above attribute information, for example, (1)
Information indicating whether the digital signal stored in the data section is audio or video, or (2) when the digital signal stored in the data section is audio, the sampling frequency, the number of quantization bits, and the channel number (ie, For example, if the number of channels is 6, first to sixth
information indicating which channel signal of the channel)
(3) There is information indicating that the digital signal stored in the data section is that at the beginning or end of a group or track.

When a digital signal having the above structure is input to the digital signal processing LSI 6,
The digital signal processing LSI 6 first reads (α) the contents of the header of each packet (the above attribute information), then (β) sorts the digital signal into audio and video, and then (γ) A process of generating an audio signal (and a digital video signal) is performed.

The attribute information read from the header in the process (α) is notified from the digital signal processing LSI 6 to the system controller 8. The system controller 8 controls the digital signal processing LSI 6 based on the notified attribute information.
The processing of the above (β) and (γ) is realized in SI6.

The digital video signal generated by the digital signal processing LSI 6 is sent to a video processing circuit (not shown). On the other hand, the digital audio signal is transmitted to the D / A conversion LSI 7 through the external buses 13 to 15. Since the digital video signal is not directly related to the gist of the present invention, the description is omitted, and the digital audio signal is hereinafter simply referred to as "digital signal".

The D / A conversion LSI 7 performs a D / A conversion process on the transmitted digital signal.
The conversion LSI 7 outputs an analog signal. At this time, the system controller 8 executes the digital signal processing LS
D / A conversion LS based on the attribute information notified from I6
I7, thereby controlling the D / A conversion LSI
7, the D / A conversion process according to the number of channels, the sampling frequency, and the number of quantization bits of the digital signal is realized. The above is the outline of the operation of the DVD audio playback device of FIG.

Next, transmission of a digital signal from the digital signal processing LSI 6 to the D / A conversion LSI 7, which is a feature of the present invention, will be described in detail. FIG.
FIG. 2 is a diagram illustrating a configuration example of a portion related to transmission of a digital signal from a digital signal processing LSI 6 to a D / A conversion LSI 7 in the VD audio reproduction device. In FIG. 3, a digital signal processing LSI 6 and a D / A conversion LS
I7 is connected to each other via external buses 13 to 15. The digital signal processing LSI 6 includes a digital signal processing circuit 16 and a scramble processing circuit 17. The D / A conversion LSI 7 is a descramble processing circuit 1
8 and a D / A conversion circuit 19. Note that the above circuits (16 to 19) may be implemented as software.

FIG. 4 is a flow chart showing an operation example of a part related to the transmission of a digital signal from the digital signal processing LSI 6 to the D / A conversion LSI 7 in the DVD audio reproducing apparatus of FIG. In FIG. 4, first, in the digital signal processing LSI 6, the digital signal processing circuit 16 processes the input digital signal (the specific example is described above) (step S).
1). Next, the scramble processing circuit 17 scrambles the digital signal output from the digital signal processing circuit 16 (step S2).

Then, the digital signal scrambled in step S2 is output from the digital signal processing LSI 6 to D
The data is transmitted to the / A conversion LSI 7 through the external buses 13 to 15 (step S3).

In the D / A conversion LSI 7, the descramble processing circuit 18 descrambles the digital signal transmitted in step S3 (ie, the digital signal scrambled by the scramble processing circuit 17) (step S4). Next, the D / A conversion circuit 19
Converts the digital signal output from the descramble processing circuit 18 (that is, the descrambled digital signal) from digital to analog (step S5). The above is an operation example of a portion related to transmission of a digital signal from the digital signal processing LSI 6 to the D / A conversion LSI 7.

In the above description, the digital signal output from the digital signal processing LSI 6 is shown in the timing chart of FIG. 12 (see the prior art). Hereinafter, specific examples of the scramble processing and the descrambling processing will be described.

FIGS. 5 to 7 illustrate specific examples (first to third specific examples) of the scramble processing and the descrambling processing performed in the scramble processing circuit 17 and the descrambling processing circuit 18 of FIG. FIG.
5A to FIG. 7A, a digital signal output from the digital signal processing circuit 16 is shown in FIG.
(B) shows a digital signal output from the scramble processing circuit 17, and (c) shows a digital signal output from the descramble processing circuit 18.

The process shown in FIG. 5 is an example of a scramble process in which a digital signal is scrambled for each channel in units of sample points, that is, in one channel, the sample points are exchanged on the time axis. . In FIG. 5, the digital signal (a) output from the digital signal processing circuit 16 is
It consists of two channels, ch1 and ch2. ch
1 has n sample points {L1, L2, L3,
.., Ln} are included in this order. Similarly, ch2 has n sample points {R1, R2, R3,.
Rn} are included in this order.

When the digital signal (a) is input to the scramble processing circuit 17, the scramble processing circuit 17 performs scramble processing for rearranging the sample points included in the signal in accordance with a predetermined rule. Here, it is assumed that four consecutive sample points are regarded as one group, and scramble processing is performed in each group in which the second sample point and the third sample point are exchanged with each other. .

Therefore, the digital signal (b) output from the scramble processing circuit 17 is such that ch1 is {L1, L
3, L2, L4, ..., L2n-1, L2n + 1, L2
n, L2n + 2}, and ch2 becomes {R1, R3, R
2, R4,..., R2n-1, R2n + 1, R2n, R2
n + 2}.

When the digital signal (b) is input to the descrambling circuit 18, the descrambling circuit 18 rearranges the sample points included in the signal in accordance with a rule reverse to that on the scramble side. A descrambling process is performed (here, one by one).
In each of the groups, the second sample point and the third sample point may be replaced with each other again). Thus, the same digital signal (c) as the digital signal (a) output from the digital signal processing circuit 16 is output from the descramble processing circuit 18.

The process shown in FIG. 6 is an example of a scramble process in which a digital signal is scrambled in units of bytes for each channel, that is, in one channel, bytes are replaced on the time axis. In FIG. 6, each sample point constituting digital signal (a) output from digital signal processing circuit 16 has 24 bits {MS
B, 23, 22, 21,..., 3, 2, LSB} are included in this order. Of these 24 bits, the first 8 bits (MSB, 23, 22,... 17) are the first byte, and the next 8 bits are (16, 15, 14,.
9) into the second byte, the last eight bits (8, 7, 6,
.., LSB) are referred to as a third byte.

When the digital signal of (a) is input to the scramble processing circuit 17, the scramble processing circuit 17 performs scramble processing for rearranging the bytes constituting the signal according to a certain rule. Here, it is assumed that a scramble process in which the first byte and the third byte are exchanged with each other at each sample point.

Therefore, in the digital signal (b) output from the scramble processing circuit 17, each sample point is represented by {(8, 7, 6,..., LSB), (16, 1).
5, 14, ..., 9), (MSB, 23, 22, ..., 1
7) It becomes like｝.

When the digital signal (b) is input to the descrambling circuit 18, the descrambling circuit 18 converts the bytes included in the signal into
A descrambling process of rearranging according to the rule opposite to that on the scramble side is performed (here, at each sample point, the first byte and the third byte may be replaced with each other again). Thus, the same digital signal (c) as the digital signal (a) output from the digital signal processing circuit 16 is output from the descramble processing circuit 18. 5 and 6
In the example of scrambling for each channel shown in (1), scrambling is performed in units of sample points and bytes, but scrambling may be performed in units of other data sets.

The processing shown in FIG. 7 scrambles a digital signal between channels in units of sample points, that is, scrambles a signal by exchanging sample points between one channel and another channel. It is an example of a scramble process. In FIG. 7, the digital signal processing circuit 16
The digital signal (a) output from is composed of two channels, ch1 and ch2. ch1 includes n sample points {L1, L2, L3,..., Ln} in this order. Similarly, ch2 includes n sample points {R1, R2, R3,..., Rn} in this order.

When the digital signal of (a) is input to the scramble processing circuit 17, the scramble processing circuit 17 sets a sample point on the ch1 side of the signal,
A scramble process for exchanging the sample points on the ch2 side according to a certain rule is performed. Here, ch
2nd, 4th, 6th,... Of 1 and ch2
It is assumed that a scramble process for exchanging the n-th sample point with each other is performed.

Therefore, the digital signal (b) output from the scramble processing circuit 17 is such that the ch1 is {L1, R
2, L3,..., Ln−1, Rn}, and ch2 is {R
1, L2, R3,..., Rn-1, Ln}. In addition,
In the example of scrambling between channels shown in FIG. 7, scrambling is performed in units of sample points, but scrambling may be performed in units of bytes or in units of other data sets. .

When the digital signal (b) is input to the descrambling circuit 18, the descrambling circuit 18 sets the sample points on the ch1 and ch2 sides of the signal to the scramble side. , A descrambling process of rearranging according to the reverse rule is performed (here, the second, fourth, sixth,..., N-th sample points of ch1 and ch2 may be replaced with each other again). Thus, the same digital signal (c) as the digital signal (a) output from the digital signal processing circuit 16 is output from the descramble processing circuit 18.

As described above, the DV according to the first embodiment
In a D audio reproducing apparatus, a digital signal processing LSI
6 and the external buses 13 to 15 between the D / A conversion LSI 7
Is scrambled, so that even if a digital signal is taken out from the external buses 13 to 15 and copied illegally, it cannot be reproduced.

(Second Embodiment) The overall configuration of a DVD audio reproducing apparatus according to a second embodiment of the present invention is as follows.
Therefore, the block diagram of FIG. 1 is also used in the following description. Also, the outline of the operation of the DVD audio playback device is the same as that of the first embodiment, and the description is omitted.

FIG. 8 is a diagram showing a configuration example of a portion related to digital signal transmission between the digital signal processing LSI 6 and the D / A conversion LSI 7 in the DVD audio reproducing apparatus of FIG. In FIG. 8, a digital signal processing LSI 6 and a D / A conversion LSI 7 are connected to an external bus 1.
They are connected to each other via 3 to 15. The digital signal processing LSI 6 includes a header reading circuit 20, a digital signal processing circuit 16, and a scramble processing circuit 17. The D / A conversion LSI 7 includes a descrambling processing circuit 18 and a D / A conversion circuit 19. The system controller 8 includes a header analysis unit 21 and a scramble / descramble control unit 22. In the present embodiment, the header reading circuit 20 performs the digital signal processing L
Although provided inside the SI 6, it may be provided outside the LSI 6.

The header reading circuit 20 reads attribute information (see the first embodiment) described in the header (see FIG. 2) of the digital signal input to the digital signal processing LSI 6, and reads the information into the system controller. 8
Notify. The digital signal processing circuit 16 processes a digital signal (see the first embodiment). The scramble processing circuit 17 scrambles the digital signal output from the digital signal processing circuit 16 under the control of the system controller 8.

The descrambling processing circuit 18 is controlled by the system controller 8 to
7. The digital signal scrambled by 7 is descrambled. The D / A conversion circuit 19 D / A converts the digital signal output from the descrambling processing circuit 18.

In the system controller 8, the header analysis section 21 analyzes the attribute information notified from the header reading circuit 20, and performs the scrambling / descrambling control section 2.
2 receives the analysis result of the header analysis unit 21 and gives scramble information and descramble information to the scramble processing circuit 17 and the descramble processing circuit 18, respectively. The header analysis unit 21 and the scramble / descramble control unit 22 are realized by the operation of the CPU 9 according to a program stored in the ROM 11 in FIG. The scramble information and descramble information to be given to the scramble processing circuit 17 and the descramble processing circuit 18 are also stored in the ROM 11 in advance.

Here, the above-mentioned scramble / descramble information is information describing a procedure for performing scramble / descramble. For example, in a case where the processing shown in FIG. 5 is performed by the scramble processing circuit 17 and the descrambling processing circuit 18, the scramble information includes "4 consecutive sample points as one group and 1
In each group, the second sample point and the third sample point are exchanged with each other. " In this case, the descramble information is also
This may be the same as the scramble information.

Scramble / descramble control unit 22
Holds a plurality of sets of scramble / descramble information having different procedure complexity and a table for selecting any one set of the scramble / descramble information from the sets. Upon receiving the analysis result, referring to this table, any one set of scramble / descrambling information is selected and given to the scramble processing circuit 17 and descrambling processing circuit 18, respectively.

Scramble / descramble control unit 22
The scrambling / descrambling information and table held by are, for example, as follows. FIG.
FIG. 9 is a diagram showing a part of the contents of a scramble / descramble information and a table held by a scramble / descramble control unit 22 of FIG. 8. In FIG. 9, the column of attribute information in the table contains 192 kHz / 24 bi.
t, 96kHz / 24bit, 48kHz / 24bi
t,... are listed, and in the column of scramble / descramble information, an identifier (hereinafter, I) is associated with each attribute information.
D) # 1, # 2, # 3,... # 1, #
.. Correspond to the first scramble / descramble information, the second scramble / descramble information, the third scramble / descramble information, respectively.

The first scramble / descramble information is information whose scramble / descramble procedure is the most complicated, and the second scramble / descramble information is the next most complicated information. Third scramble /
The descrambling information is the simplest information among these three.

That is, in the table, the scramble / descramble procedure is performed in order from the digital signal (in the example shown in FIG. 9, the signal having the highest sampling frequency) from which the highest quality reproduced sound is obtained. Complex scrambling / descrambling information (thus achieving higher confidentiality) is associated with the information. Although not shown, when the sampling frequency is the same, more complex scramble / descramble information is associated with a digital signal having a larger number of quantization bits.

The scramble / descramble control unit 22, which holds the entity of the scramble / descramble information and the table as described above, stores the result of the analysis by the header analysis unit 21, that is, in the packet to which the header is attached. When the attribute information (sampling frequency or the like) of the digital signal is received, the table is referred to and the scramble / descrambling information corresponding to the attribute information is selected. And the selected scramble /
The substance of the descrambling information is given to the scramble processing circuit 17 and the descrambling processing circuit 18, respectively.

The scramble processing circuit 17 scrambles the digital signal output from the digital signal processing circuit 16 (for each packet) based on the scramble information provided from the scramble / descramble control unit 22. The descramble processing circuit 18 descrambles the digital signal scrambled by the scramble processing circuit 17 (for each packet) based on the descramble information provided from the scramble / descramble control unit 22. Each of the above circuits (16 to
19, 20) may be realized by software.

As described above, the DV according to the second embodiment
In a D audio reproducing apparatus, a digital signal processing LSI
6 and the external buses 13 to 15 between the D / A conversion LSI 7
Is scrambled, so that even if a digital signal is taken out from the external buses 13 to 15 and copied illegally, it cannot be reproduced.

Further, as scramble / descramble information for scrambling / descrambling, a plurality of types of scramble information having different complexity (in other words, a plurality of scramble information having different degrees of concealment realized) are prepared in advance. In addition, since the scramble information to be used is changed according to the quality of the transmitted digital signal, an efficient scramble / decryption process corresponding to the quality of the digital signal is realized, for example, a higher quality signal realizes higher confidentiality.
Can descramble.

As for the quality of the digital signal,
In the digital signal processing LSI 6, the determination is made by referring to the contents of the header attached to each packet constituting the input digital signal. In other words, the header describes the quality of the digital signal stored in the packet to which the header is attached (such as the level of the sampling frequency and the size of the number of quantization bits). Can be performed.

[0091] To supplement this, in the case of DVD audio, a group (album) is stored in one disc.
Alternatively, the quality of the digital signal can be set for each track (song). Therefore, if the scramble / descramble information is selected based on the quality of the digital signal as in the present embodiment, the used scramble / descramble information is automatically switched for each group or track.

As described above, instead of the DVD audio reproducing apparatus automatically selecting the scramble / descramble information according to the quality of the digital signal, the scramble / descramble information is not
The user may arbitrarily specify the descrambling information.
In other words, the DVD audio reproducing apparatus uses a boundary between tracks (or a boundary between groups).
Automatically detected and group or track units,
Any scramble / descramble information may be selected in accordance with a user's instruction. The boundary between tracks (or the boundary between groups) can be detected based on the attribute information (3) described in the header section of FIG. Note that the attribute information (3) is information indicating that the digital signal stored in the data portion is that at the beginning or end of a group or track.

(Third Embodiment) The overall configuration of a DVD audio reproducing apparatus according to a third embodiment of the present invention is as follows.
Therefore, the block diagram of FIG. 1 is also used in the following description. Also, the outline of the operation of the DVD audio playback device is the same as that of the first embodiment, and the description is omitted.

FIG. 10 shows a digital signal processing LSI 6 and a D / A in the DVD audio reproducing apparatus of FIG.
FIG. 3 is a diagram illustrating a configuration example of a portion related to digital signal transmission between conversion LSIs 7; In FIG. 10, the digital signal processing LSI 6 and the D / A conversion LSI 7 are connected to each other via external buses 13 to 15. The digital signal processing LSI 6 includes a header reading circuit 20, a digital signal processing circuit 16, and a scramble processing circuit 1.
7 and a scramble control unit 23. D / A conversion L
The SI 7 includes a descrambling processing circuit 18, a descrambling control unit 24, and a D / A conversion circuit 19. The system controller 8 includes a header analysis unit 21 and a scramble / descramble information selection unit 25.

The header reading circuit 20 reads the attribute information (see the first embodiment) described in the header (see FIG. 2) of the digital signal input to the digital signal processing LSI 6, and stores the information in the system controller. 8
Notify. The digital signal processing circuit 16 processes a digital signal (see the first embodiment). The scramble processing circuit 17 scrambles the digital signal output from the digital signal processing circuit 16 under the control of the scramble control unit 23. Scramble control unit 2
3 gives scramble information to the scramble processing circuit 17.

The above-described scramble control section 23 operates according to a program stored in a ROM (not shown) also provided in the LSI 6 by a CPU (not shown) provided in the digital signal processing LSI 6. This is achieved by: The scramble information to be given to the scramble processing circuit 17 is also stored in this ROM in advance.

Under the control of the descrambling control section 24, the descrambling circuit 18 descrambles the digital signal scrambled by the scrambling circuit 17. The descrambling control section 24 gives the descrambling processing circuit 18 the descrambling information.
The D / A conversion circuit 19 D / A converts the digital signal output from the descrambling processing circuit 18.

The descrambling control unit 24 described above uses D /
The CPU provided in the A-conversion LSI 7 is
7 is realized by operating according to the program stored in the ROM provided in the memory 7. The descramble information to be given to the descramble processing circuit 18 is also stored in the RO
M is stored in advance in M.

In the system controller 8, the header analysis unit 21 analyzes the attribute information notified from the header reading circuit 20, and the scramble / descramble information selection unit 25 receives the analysis result of the header analysis unit 21, / Scramble control section 23, descramble control section 2
4 is notified of the ID of the selected scramble / descramble information.

The header analysis section 21 and the scramble / descramble information selection section 25 are provided in the ROM 11 of FIG.
This is realized by the operation of the CPU 9 according to a program stored in advance in the CPU 9. Here, the scramble / descramble information is information describing a procedure for performing scramble / descramble similar to that described in the second embodiment.

This embodiment is different from the second embodiment in the following points. That is, in the second embodiment,
The system controller 8 determines the substance of a plurality of sets of scramble / descramble information and any one of them.
And a table for selecting a set of scramble / descramble information (see FIG. 9). On the other hand, in the present embodiment, the system controller 8
Only the same table as in the embodiment is held. The substance of the scramble information is the digital signal processing L
The entity of the descrambling information held in SI6 is D
It is held in the / A conversion LSI 7.

In the system controller 8, the scramble / descramble information selector 25 holds a table. Upon receiving the analysis result of the header analysis unit 21, that is, the attribute information (sampling frequency and the like) of the digital signal stored in the packet to which the header is attached, the scramble / descramble information selection unit 25
Refers to the table and selects a set of scramble / descramble information corresponding to the attribute information (for each packet). Then, the IDs of the selected scramble / descramble information are respectively assigned to the scramble control unit 23 in the digital signal processing LSI 6 and the D / A conversion L
This is notified to the descrambling control unit 24 in the SI 7.

In the digital signal processing LSI 6, the scramble control unit 23 holds a plurality of pieces of scramble information. The scramble control unit 23 gives the scramble information corresponding to the ID notified from the scramble / descramble information selection unit 25 of the system controller 8 to the scramble processing circuit 17 among the plurality of pieces of scramble information. The scramble processing circuit 17 scrambles the digital signal output from the digital signal processing circuit 16 (for each packet) based on the scramble information provided from the scramble control unit 23.

In the D / A conversion LSI 7, the descrambling control section 24 holds a plurality of pieces of descrambling information. The descramble control unit 24 gives the descramble information corresponding to the ID notified from the scramble / descramble information selection unit 25 of the system controller 8 to the descramble processing circuit 18 among the plurality of descramble information. The descramble processing circuit 18
The digital signal scrambled by the scramble processing circuit 17 based on the descrambling information given from the descrambling control unit 24 (for each packet)
Descramble. The above circuits (16 to 1)
9, 20) may be realized by software.

As described above, the DV according to the third embodiment
In a D audio reproducing apparatus, a digital signal processing LSI
6 and the external buses 13 to 15 between the D / A conversion LSI 7
Is scrambled, so that even if a digital signal is taken out from the external buses 13 to 15 and copied illegally, it cannot be reproduced.

Further, as scramble / descramble information for scrambling / descrambling, a plurality of types of scramble information having different complexity (in other words, a plurality of scramble information having different degrees of concealment realized) are prepared in advance. In addition, since the scramble information to be used is changed according to the quality of the transmitted digital signal, an efficient scramble / decryption process corresponding to the quality of the digital signal is realized, for example, a higher quality signal realizes higher confidentiality.
Can descramble.

Regarding the quality of the digital signal,
In the digital signal processing LSI 6, the determination is made by referring to the contents of the header attached to each packet constituting the input digital signal. In other words, the header describes the quality of the digital signal stored in the packet to which the header is attached (such as the level of the sampling frequency and the size of the number of quantization bits). Can be performed.

The digital signal processing LSIs 6, D /
A substance of the scramble information and a substance of the descrambling information are held in the A-conversion LSI 7, respectively.
Since only the ID of the information to be used is notified to the D / A conversion LSI 7, there is no danger that the scramble / descramble information is leaked and the digital signal copied illegally can be reproduced (the second one). In the embodiment, since the substance of the scramble / descramble information is notified from the system controller 8 to the digital signal processing LSI 6 and the D / A conversion LSI 7, the scramble / descramble information may be leaked.)

In the first to third embodiments, in particular,
In the DVD audio reproducing apparatus, external buses 13 to 1
5 digital signal processing LSIs connected to each other
6 and the digital signal transmitted between the D / A conversion LSI 7 are scrambled. Because D / A conversion LS
This is because if the digital signal immediately before being input to I7 is copied, ultra-high quality stereo sound or the like can be easily reproduced from the copied signal. That is, the above first to first
As in the third embodiment, in the DVD audio reproducing apparatus, by scrambling the digital signal immediately before being input to the D / A conversion LSI 7, it can be said that a particularly high illegal copy preventing effect is exhibited.

In addition, for example, in a CD player,
By scrambling the digital signal immediately before being input to the D / A conversion LSI, it can be said that a high illegal copy prevention effect can be exhibited.

More generally, the data transmitted between a plurality of LSIs connected to each other via an external bus is scrambled, so that the data is not fixed as in the first to third embodiments. It can be said that an illegal copy prevention effect is obtained.

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating a configuration of a DVD audio playback device according to a first embodiment of the present invention (second and third embodiments);
Also used in the embodiment).

FIG. 2 is a schematic diagram showing the contents and structure of a digital signal input to a digital signal processing LSI 6 of FIG.

FIG. 3 is a diagram showing a configuration example of a portion related to transmission of a digital signal from a digital signal processing LSI 6 to a D / A conversion LSI 7 in the DVD audio reproducing device of FIG.

FIG. 4 is a flowchart showing an operation example of a part related to transmission of a digital signal from the digital signal processing LSI 6 to the D / A conversion LSI 7 in the DVD audio reproducing device of FIG.

FIG. 5 is a diagram for explaining a first specific example of scramble processing and descrambling processing performed in the scramble processing circuit 17 and descrambling processing circuit 18 of FIG. 3;

6 is a diagram for explaining a second specific example of the scrambling process and the descrambling process performed in the scrambling process circuit 17 and the descrambling process circuit 18 in FIG. 3;

FIG. 7 is a diagram for explaining a third specific example of the scrambling process and the descrambling process performed in the scrambling process circuit 17 and the descrambling process circuit 18 in FIG. 3;

8 is a block diagram showing a digital signal processing LSI 6 and a digital signal processing LSI 6 in the DVD audio reproducing apparatus (second embodiment) shown in FIG.
FIG. 3 is a diagram illustrating a configuration example of a portion related to digital signal transmission between an / A conversion LSI 7;

9 is a scramble / descramble control unit 2 shown in FIG. 8;
2 is a diagram illustrating a part of the contents of a table and scramble / descrambling information held by the second embodiment; FIG.

FIG. 10 is a diagram showing a configuration example of a portion related to digital signal transmission between a digital signal processing LSI 6 and a D / A conversion LSI 7 in the DVD audio reproduction device (third embodiment) of FIG.

FIG. 11 shows a conventional DVD audio reproducing apparatus;
FIG. 2 is a diagram showing a configuration of a part related to transmission of a digital signal from a digital signal processing LSI 6 to a D / A conversion LSI 7;

12 is a timing chart showing a digital signal output from the digital signal processing LSI 6 of FIG. 11 (when the number of channels is two).

[Explanation of symbols]

 6 Digital signal processing LSI 7 D / A conversion LSI 8 System controller 12 DVD audio disk 13-15 External bus 16 Digital signal processing circuit 17 Scramble processing circuit 18 Descramble processing circuit 19 D / A conversion circuit 20 header reading circuit 20 21 header analysis unit 22 scramble / descramble control unit 23 scramble control unit 24 descramble control unit 25 scramble / descramble information selection unit

Claims (14)

[Claims] A first bus connected to the first bus via an external bus;
Transmitting data between the first LSI and the second LSI, wherein the data is scrambled inside the first LSI, and the scrambled data is transmitted from the first LSI to the second LSI.
A data transmission method, wherein the data is transmitted to an SI via an external bus, and the scrambled data is descrambled inside a second LSI. 2. A DV for reproducing a DVD audio disk, comprising a digital signal processing LSI and a D / A conversion LSI connected to each other via an external bus.
In the D audio reproducing apparatus, the digital signal processing L
A method for transmitting a digital signal from an SI to a D / A conversion LSI via an external bus, wherein the digital signal read from the DVD audio disk is processed inside the digital signal processing LSI, and the digital signal after the processing is processed. A signal is scrambled, and a scrambled digital signal is transmitted from the digital signal processing LSI to the D / A conversion LSI through the external bus. A scramble transmitted through the external bus inside the D / A conversion LSI A descrambled digital signal, and D / A conversion of the descrambled digital signal. 3. A DVD audio reproducing apparatus for reproducing a DVD audio disk, comprising: a digital signal processing LSI and a D / A conversion LSI connected to each other via an external bus. A digital signal processing means for processing a digital signal read from the DVD audio disk, and a scrambling processing means for scrambling the digital signal output from the digital signal processing means; Inside the device, descramble processing means for descrambling the scrambled digital signal transmitted through the external bus, and D / A conversion means for D / A converting the digital signal output from the descrambling processing means. Including DVD audio Oh reproducing apparatus. 4. A header reading means for reading attribute information of a digital signal described in a header of a packet constituting a digital signal read from the DVD audio disk, wherein the attribute information read by the header reading means is read. 4. The DVD according to claim 3, further comprising: a header analysis unit for analyzing, and a scramble / descramble control unit for controlling the scramble processing unit and the descramble processing unit based on an analysis result of the header analysis unit.
Audio playback device. 5. The attribute information includes information related to the quality of a sound obtained by reproducing the digital signal (hereinafter, the quality of a digital signal). The scramble / descramble control unit includes: Controlling the scrambling processing means and the descrambling processing means based on the quality of the digital signal indicated by the analysis result of the analysis unit so that confidentiality corresponding to the quality of the digital signal is realized. The DVD audio playback device according to claim 4, which performs the operation. 6. The digital signal according to claim 5, wherein the quality of the digital signal is a sampling frequency and / or the number of quantization bits of the digital signal.
VD audio playback device. 7. The scrambling / descrambling control means is provided for a plurality of predetermined levels of quality of the digital signal and a plurality of scrambling / descrambling information for realizing confidentiality corresponding to each quality. And a plurality of scramble / descrambling information. The table includes a plurality of pieces of scramble / descrambling information. By referring to the table, the quality of the digital signal indicated by the analysis result of the header analysis unit. And selecting the corresponding scramble / descrambling information and providing the selected scramble / descramble information to the scramble processing means and the descrambling processing means, thereby controlling the scrambling processing means and the descrambling processing means. Features, claims Item 6. A DVD audio playback device according to item 5. 8. The scrambling / descrambling control means has the table, and refers to the table, whereby the scrambling / descrambling corresponding to the quality of the digital signal indicated by the analysis result of the header analyzing unit. A scrambling / descrambling information selecting unit for selecting information and outputting an identifier of the selected scrambling / descrambling information, having a plurality of the scrambling information, and selecting the scrambling / descrambling information among the plurality of scrambling information A scramble control unit that gives the scramble information corresponding to the identifier output from the unit to the scramble processing unit, and the plurality of descramble information, and among the plurality of descramble information,
A descrambling control unit for providing descrambling information corresponding to the identifier output from the scrambling / descrambling information selecting unit to the descrambling processing means, wherein the scrambling control unit performs the digital signal processing LS
8. The DVD audio playback device according to claim 7, wherein the DVD audio playback device is included inside the D / A conversion LSI, and the descrambling control unit is included inside the D / A conversion LSI. 9. The attribute information includes information indicating which position is a track boundary in the digital signal, and the scramble / descramble control means has a plurality of pieces of scramble / descramble information. 5. The apparatus according to claim 4, wherein any one of the plurality of pieces of scramble / descramble information is selected for each track in response to a user instruction, and is provided to the scramble processing means and the descramble processing means. The DVD audio playback device according to the above. 10. The attribute information includes information indicating which position is a group boundary in the digital signal, and the scramble / descramble control means has a plurality of pieces of scramble / descramble information. And selecting one of the plurality of pieces of scramble / descrambling information in a group unit according to a user's instruction and providing the selected scramble / descramble information to the scramble processing means and the descramble processing means. The DVD audio playback device according to the above. 11. The DVD according to claim 3, wherein the scramble processing means scrambles the digital signal output from the digital signal processing means in units of sample points for each channel.
Audio playback device. 12. The DVD audio reproducing apparatus according to claim 3, wherein the scramble processing means scrambles the digital signal output from the digital signal processing means in units of bytes for each channel. 13. The DV according to claim 3, wherein the scramble processing means scrambles the digital signal output from the digital signal processing means between channels in units of sample points.
D audio playback device. 14. The DVD audio reproducing apparatus according to claim 3, wherein the scramble processing means scrambles the digital signal output from the digital signal processing means between channels in units of bytes.