JP2000243037A - Device and method for reproducing digital signal - Google Patents

Abstract

PROBLEM TO BE SOLVED: To lighten a burden to a microcomputer and software at the time of reproduction processing of a BCA digital signal by reproducing first data from a disk in which first data being a signal of a pulse state of RZ modulation, measuring the length of the first data and deciding pulse width, and detecting a synchronizing signal included in the first data. SOLUTION: A pulse width counting means 107 has a counter measuring the width of data, measures 'HIGH', 'LOW' of reproduced data by an internal counter, and a burden to a microcomputer is lightened by measuring pulse width by a pulse width discriminating means, a synchronizing signal detecting means, and a data converting means. Also, a burden to software processing is lightened by making only data transfer after temporary storage of a microcomputer, error correcting processing, and error code check processing as software processing. As pulse width is decided after it is confirmed that the length of reproduced data is a fixed time or more, erroneous detection caused by hazard can be prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to a reproducing apparatus and a method recorded on a medium such as an optical disk.

[0002]

2. Description of the Related Art DVD-ROM (Digital Video Disc)
-ROM) is recorded after the end of the disc manufacturing process, and records information about the disc. Inner circumference area B of the disk different from the area where main data is recorded
Digital signals are recorded in a CA (Burst Cutting Area). In order to reproduce this digital signal, the microcomputer determines the pulse width of the digital signal reproduced from the disk, detects the synchronization signal, performs data conversion,
All processing of error detection code check processing and error correction processing was performed by real-time software processing.

[0003]

When a microcomputer determines the pulse width of a digital signal reproduced from a disk, it is necessary to always monitor the width of the digital signal by the microcomputer, which causes a problem that the microcomputer is overloaded. . Performing all the processing including this processing by software processing causes a problem that the load of the software processing is large. Therefore, a means of partially hardening the processing may be considered. Here, taking a BCA digital signal recorded on a DVD-ROM as an example, a hardware processing method of a BCA digital signal reproducing method will be considered, and a distinction between software processing and hardware processing will be considered.

Accordingly, in the present invention, the load of the microcomputer and the software processing is reduced by examining the hardware processing method when performing the BCA digital signal reproduction processing recorded on the disk such as the DVD-ROM.
An object of the present invention is to reproduce a BCA digital signal recorded on a disk such as a ROM.

[0005]

According to the present invention, an area different from an area in which main data of a medium such as an optical disk is recorded (for example, an innermost area BCA of the disk).
In a device (or a digital signal processing LSI) for reproducing a digital signal recorded in a disc, a pulse width counting unit, a pulse width determination unit, a synchronization signal code detection unit, a data conversion unit,
Equipped with microcomputer temporary storage means, error correction means, error detection signal checking means, temporary storage means included in the playback device, and a microcomputer for control, and has an internal counter for measuring the pulse width of data read from the disk. , The synchronization signal is detected, the data is converted according to the format, the data is temporarily recorded in the buffer, and the combination of the BCA main data and the synchronization signal added thereto is used as one recording unit to temporarily store the microcomputer. By recording the data in the microcomputer, the handling of the data of the microcomputer becomes easy.

The above processing is performed by hardware processing. The error correction means and the error detection code check means perform the error correction processing and the error detection code check by software processing, so that the load of software processing is reduced and the BC recorded on a disc such as a DVD-ROM is
A digital signal reproduction processing is performed.

[0007]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a block diagram showing a configuration of a reproducing apparatus according to a first embodiment of the present invention. In FIG.
Denotes a medium such as an optical disk on which main digital data and a BCA digital signal are recorded; 102, a pickup for reading a signal recorded on the optical disk 101; 103, a preamplifier;
05 is a microcomputer for controlling this system, 106 is a control signal output from the microcomputer 105, 107 is a means for counting the pulse width of the reproduction data, 108 is a pulse width count result, 109 is a rising edge of the reproduction data, 110 is a rising edge of the reproduction data. Means for judging the pulse width of reproduced data from a disc, detecting a synchronization signal, and performing data conversion;
11 is a synchronization signal detection signal, 112 is a data signal, 113
Is a means for controlling data buffering timing; 114, 115, and 116 are buffer timing control signals; 117 is means for buffering input data; 118 is output data; 119 is microcomputer temporary storage means; BCA digital signal output to the means 121;
Reference numeral 22 denotes an error correction unit that performs error correction for an error that occurred during reading of a disk or recording of a storage unit. Reference numeral 123 denotes a unit that detects a data error. Reference numeral 124 denotes a block that performs processing of a BCA digital signal by hardware processing. This block performs processing of the BCA digital signal by software processing.

FIG. 2 shows an optical disk medium such as a DVD. In the figure, reference numeral 201 denotes an area in which main data is recorded, 202 denotes an innermost peripheral area different from the area in which main data is recorded, and BCA (Burst C).
utting Area).

FIG. 3 shows an example of the structure of a BCA digital signal, which comprises a BCA preamble field, a BCA digital signal field, and a BCA postamble field. BCA-Sync-Byte 301 is BC
It is added before the A preamble field 302. Reference numeral 305 denotes an error detection code EDC, and 306 denotes an error correction code. The BCA-Resync 303 has information data 304, an error detection code EDC305,
All the fields are inserted before the error correction code 306. Reference numeral 307 denotes a BCA postamble field, which is a 4h of 55h sandwiched between two BCA-Resyncs.
Consists of bytes.

In FIG. 4, reference numeral 401 denotes a BCA-Sync before demodulation.
-Byte301 and BCA-Resync303, 16 recorded by RZ modulation composed of C15 to C0.
It is a fixed channel bit pattern of bits. Reference numeral 402 denotes a SyncCode (data bit) after demodulation.

A reference numeral 501 in FIG. 5 denotes B read from the pick.
This is a CA digital signal, and the time widths of a, b, c, and d are defined by 503. Reference numeral 502 denotes reproduced data input to the pulse width counting means 107, and the pulse width is defined by 504.

In FIG. 6, reference numeral 601 denotes a pulse width counting means 10;
7, reproduced data corresponding to the input channel bits, 602 is a reproduced data pulse width, 603 is a reproduced data pulse width, 604 is a data bit demodulated from the pulse width, 605 is a Sync / Resync code discrimination pattern, and 606 is a demodulated data bit. Previous Sync / Resync code,
607 is a demodulated BCA-Sync-Byte, 60
8 is a demodulated BCA-Resync.

In this embodiment, a case where data in accordance with the formats shown in FIGS. 3, 4 and 5 is input will be described as an example. Next, the flow of the signal processing of FIG. 1 will be described.

In FIG. 1, a pickup 102 reads a signal recorded on an optical disk 101, amplifies the signal by a preamplifier 103, and outputs the amplified signal to a pulse width counting means. The optical disk 101 by the pulse width counting means 107
Then, the rising edge of the signal read from is detected, and the pulse width until the next rising detection is counted by the master clock. At this time, in order to prevent erroneous detection of the pulse width due to the hazard of the input signal, the pulse width is measured after confirming that the period during which the input signal is low is longer than a predetermined time.

The measured count number 108 and the rising edge 109 of the reproduced data are input to a pulse width determination / synchronization signal detection / data converter 110. The pulse width determination / synchronization signal detection / code conversion means 110 determines the pulse width based on the pulse width count number, and determines Sync and Resyn.
The c code is detected. After the detection of the synchronization signal, data conversion is performed on the reproduced data according to a predetermined data format. The detected synchronization signal is sent to the timing control unit 113.
The converted data 112 is input to the data buffering means 117.

The timing control means 113 controls data buffering based on the input control signal.
The data buffering means 117 records data in the microcomputer temporary storage means 119 at a predetermined timing based on the control signal output from the controller 113. The data recorded in the microcomputer temporary storage unit 119 is transferred to a temporary storage unit of the reproducing apparatus in order to perform an error correction process and an error code check. An error in the recorded data is corrected by the error correction unit 122, and then the data error code check unit 123 checks the data error detection code. The error correction unit 122 checks the data that could not be corrected. Are recorded again in the temporary storage means of the playback device and then output.

Here, the characteristics of the BCA digital signal will be described. Unlike the main data, the BCA digital signal does not need to be processed in real time because the product information of the disk is recorded, so it can be read once and all the necessary information can be obtained, and it is not necessary to read it many times. Have. Since the BCA digital signal is composed of the data format shown in FIG. 3, that is, the BCA main data, the synchronization signal added thereto, the error detection code, and the error correction code, the BCA digital data is reproduced. For this purpose, it is necessary to store all of these data except for the synchronization signal in the temporary storage means, and to perform error correction processing and error code check processing.

However, since the bus width is limited when transferring data between the microcomputer temporary storage means and the temporary storage means of the reproducing apparatus, it takes time to record all reproduced BCA digital signals. Therefore, it can be understood that the place where the software processing takes the longest time is the place where the demodulated data is recorded in the storage means and the data error correction processing and the data error code check processing are performed. Also BCA
One frame is composed of the main data and the synchronization signal added thereto.

The problem to be solved by the present invention is that when a microcomputer determines the pulse width of a digital signal reproduced from a disk, the signal width must always be monitored by the microcomputer, which places a load on the microcomputer. In addition, there is a problem in that the software processing burden is increased due to performing all processing of BCA digital signal reproduction by software processing.

Therefore, in the present invention, the BCA digital data does not need to be processed in real time because the product information of the disc is recorded, so that all the necessary information can be obtained by reading once, and it is necessary to read many times. Noting the feature that there is no, and the fact that it takes time to perform data error correction processing and data error code check processing,
It is an object of the present invention to reduce the burden of a microcomputer and software processing by hardening a part of the processing and to perform a BCA digital signal reproduction processing recorded on a disk such as a DVD-ROM.

Based on the above, an explanation for solving the problem will be further added with reference to FIGS.

First, a pulse width counting means 107 is provided to determine the pulse width of a digital signal reproduced from a disk. The pulse width counting means has a counter for measuring the width of the data using the edge of the master clock, and “High” and “Lo” of the reproduced data 501.
w "is measured by an internal counter, and 1T to 4T (1T is shown in FIG.
504) is determined. Accordingly, the provision of the pulse width counting means having the counter eliminates the need for the microcomputer to determine the pulse width, thereby eliminating the problem of imposing a load on the microcomputer. Also, at the time of this pulse width determination, even if the reproduced data becomes a hazard signal, the pulse width is determined by confirming that the length of the reproduced data is equal to or longer than a predetermined time, so that an erroneous detection due to the hazard of the reproduced data is performed. Can be prevented.

Next, consideration will be given to the large burden of software processing due to performing all processing of BCA digital signal reproduction by software processing. As described above, it is not necessary to perform all processing on a BCA digital signal in real time, and it is necessary to perform real-time processing for data buffering, data error correction processing, and data error code checking processing that require time for processing. There is no. Therefore, the data reproduced from the disc is input to the pulse width counting means and counted by the counter, and the pulse width is determined by the counter, the synchronization signal is detected, the pulse width is determined by the data conversion means, the synchronization signal is detected, and the data is converted according to the format. The timing control signal generated by the timing control means is stored in the data buffering means and recorded in the microcomputer temporary storage means. Data transfer to temporary storage means, error correction processing,
The error code check processing is performed by software processing to reduce the load of software processing.

Here, a data transfer format at the time of recording from the data buffering means to the microcomputer temporary storage means will be considered with reference to FIG. Data error correction processing,
The data necessary for performing the data error code check processing is the BCA main data 302, 304, and 307, the error detection code 305, and the error correction code 306. Therefore, there is no need to transfer the synchronization signals 301 and 303 to the microcomputer temporary storage means.

However, since the BCA digital signal records the BCA main data and the synchronization signal added thereto as one frame, the BCA main data and one line of the synchronization signal in FIG. As soon as the transfer preparation is completed,
When handling the CA main data, it is easier for the microcomputer to handle the data when performing the data mapping if the synchronization signal added to each BCA main data is added.

Therefore, in the present invention, 5 bytes are provided as an area in the microcomputer temporary storage means where BCA data can be used, and one line (4 bytes) of BCA main data and a synchronization signal (1 byte) added to the data are provided. Is used as one recording unit, thereby making it easier to handle data of the microcomputer.

When it is considered that the data recorded in the microcomputer temporary storage means is sequentially stored in the storage means of the reproducing apparatus, this one-line unit (5 bytes) is read from the disk.
Comparing the time required to read out the data from the microcomputer register with the time required to read out the data from the microcomputer register, the time required for the former to read out 5 bytes is calculated from Figs. 5 and 6, and 5 bytes → 10T → 8.89 * 10 + 1.50 (us) → 90.4 (u
On the other hand, in the latter case, the reading of the microcomputer register is on the order of a multiple of the master clock, that is, on the order of nanometers, especially when there is no interrupt element to the microcomputer, and when the master clock is of the mega order. Therefore, since the latter method has a sufficiently high read speed, data from the disk can be stored in the storage means without waiting time.

As described above, in order to determine the pulse width of the digital signal reproduced from the disk, the pulse width counting means is provided, and the data recorded in the microcomputer temporary storage means is stored in the storage means of the reproducing apparatus. When B
One line (4 bytes) of the CA main data and the synchronization signal (1 byte) added to the data are used as one recording unit, and by recording the data, the processing load on the microcomputer is reduced.
In the digital signal reproduction procedure, the data is recorded in the microcomputer temporary storage means.
The data transfer from the remaining microcomputer temporary storage means to the temporary storage means of the reproducing apparatus, the error correction processing, and the error code check processing are performed by software processing to reduce the load of software processing.

As described above, when performing a BCA digital signal reproduction process recorded on a disc such as a DVD-ROM,
Hardening part of the processing and characterizing the data recorded in the microcomputer temporary storage means reduce the burden on the microcomputer and software processing, and reproduce the BCA digital signal recorded on a disk such as a DVD-ROM. Was realized.

[0031]

As described above, according to the present invention, an apparatus for reproducing a BCA digital signal recorded in an area other than the area where main data of a medium such as an optical disk is recorded and which does not need to be processed in real time. At
Count of the pulse width of the data reproduced from the disc,
The pulse width determination, synchronization signal code detection, and data conversion are performed by hardware processing, error detection code checking,
The error correction processing is performed by software processing to reduce the burden of software processing, and by characterizing the recording unit in the microcomputer temporary storage means, is recorded on a disk such as a DVD-ROM without placing a burden on the microcomputer. A BCA digital signal reproduction process has been realized.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of a means for reproducing a BCA digital signal according to the present invention.

FIG. 2 is a diagram of a medium such as an optical disc.

FIG. 3 is a structural diagram of a BCA digital signal.

FIG. 4 is a fixed channel bit pattern diagram.

FIG. 5 is a diagram showing an example of a BCA digital signal format.

FIG. 6 is a diagram showing an example of conversion from channel bit data to data bit data.

[Explanation of symbols]

101: Main digital data, 102: Pickup, 103: Preamplifier, 104: Reproduced reproduction data, 105: Microcomputer for controlling the system, 106 ...
Control signal 107, means for counting pulse width, 10
8 ... Pulse width count result 109 ... Rising edge of reproduced data 110 ... Data conversion means 11
1: Synchronous signal detection signal, 112: Data signal, 113:
Means for controlling the timing of buffering, 114 ...
Buffer timing control signal, 115 ... buffer timing control signal, 116 ... buffer timing control signal,
117: means for buffering data, 118: output data, 119: microcomputer temporary storage means, 120: B
CA digital signal, 121, 122... Temporary storage means of the reproducing apparatus, 123... Data error detecting means,
124, a block for processing the BCA digital signal by hardware processing; 125, a block for processing the BCA digital signal by software; 201, an area where main data is recorded; 202, a main data is recorded Inner circumference area different from the area, 301 ... BC
A-Sync-Byte, 302 ... BCA preamble field, 303 ... BCA-Resync, 304 ...
Information data, 305: Error detection code EDC, 306: Error correction code, 307: BCA postamble field, 401: BCA-Sync-Byte 30 before demodulation
1 and BCA-Resync 303, 402... SyncCode (data bit) after demodulation, 501... BCA digital signal read from pick, 502... Reproduced data, 503.
01 ... reproduced data input to the pulse width counting means 107, 602 ... reproduced data for the input channel bits, 603 ... pulse width of the reproduced data, 604 ... data bits demodulated from the pulse width, 605 ... Sync,
Resync code discrimination pattern, 606... S before demodulation
sync / Resync code, 607 ... BC demodulated
A-Sync-Byte, 608... Demodulated BCA-
Resync.

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Kenji Akahoshi 292 Yoshida-cho, Totsuka-ku, Yokohama-shi, Kanagawa Prefecture Inside the Multimedia Systems Development Division of Hitachi, Ltd. (72) Inventor Takanobu Nishio Yoshida-cho, Totsuka-ku, Yokohama-shi, Kanagawa 292 F-term in Hitachi Image Information System Co., Ltd. (Reference) 5D044 BC03 CC04 DE03 DE32 FG09 FG10 GL10 GM11 GM26 5D090 AA01 BB02 CC04 EE15 GG26

Claims (11)

[Claims] 1. A disk is recorded in a continuous stripe shape on the inner periphery of a disk, which constitutes one frame by a synchronization signal and main data. The main data is a first signal which is a pulse signal of RZ (Retutn to Zero) modulation. A disk reproducing apparatus for reproducing first data from a disk on which the data is recorded, a pulse width counting means for measuring the length of the first data, and a pulse width determining means for determining a pulse width from the measurement result Synchronizing signal detecting means for detecting a synchronizing signal included in the first data; data buffering means for temporarily storing the first data; a microcomputer for controlling the disk device; A digital signal reproducing device comprising: 2. A digital signal reproducing apparatus according to claim 1, wherein the transfer from the data buffering means to the temporary storage means of the microcomputer is performed on a frame-by-frame basis. 3. The data buffering means according to claim 1,
A digital signal reproducing device having an area in which data for one frame can be recorded. 4. The pulse width counting means according to claim 1, wherein:
A digital signal reproducing apparatus for measuring the length from the edge of a pulse to the next edge of the data using the operation clock of the means. 5. The digital signal processing method according to claim 1, wherein the pulse width determining means confirms that the measurement result of the pulse width counting means is equal to or more than a predetermined value, and determines the pulse width from the measurement result. Signal playback device. 6. A disk reproducing apparatus according to claim 1, wherein after recording one frame in the temporary storage means of the microcomputer, recording from the temporary storage means of the microcomputer to the temporary storage means of the reproduction apparatus, error correction processing, error correction, A digital signal reproducing apparatus characterized in that detection code check processing is performed by software for controlling a control microcomputer. 7. The temporary storage means of the microcomputer according to claim 1, wherein at least information indicating the end of transfer of the data for one frame and the first data recorded in the temporary storage means of the microcomputer is provided. A digital signal reproducing device having an area in which data of second data having information indicating the end of transfer of the first frame of the first data can be recorded. 8. The synchronization signal detecting means according to claim 1, wherein said data buffering means outputs a synchronization signal / main data discrimination signal when said one frame is transferred to said microcomputer temporary storage means.
A digital signal reproducing device for outputting in synchronization with a frame. 9. A continuous stripe is recorded on the inner circumference of the disk, which forms one frame by a synchronizing signal and main data, and the main data is a first pulse which is a pulse signal of RZ (Retutn to Zero) modulation. A disk reproducing method for reproducing first data from a disk on which the data is recorded, wherein the length of the first data is measured using a master clock, and the pulse width is determined from the measurement result. Digital signal reproduction method. 10. A ninth digital signal reproducing method according to the first
A digital signal reproducing method characterized by confirming that the measurement result of the data is equal to or more than a predetermined value and determining a pulse width from the measurement result to prevent erroneous detection of the first data due to a hazard. 11. A digital signal reproducing method according to claim 9,
After recording one frame in the temporary storage device of the microcomputer, the recording from the temporary storage device of the microcomputer to the temporary storage device of the playback device, error correction processing, and error detection code check processing are performed by software for controlling the control microcomputer. A digital signal reproduction method characterized by the above-mentioned.