JPS62298058A - Decoding method for multiplex writing data - Google Patents

Abstract

PURPOSE:To simplify a processing, and to reduce the burden of a hardware by executing a decision by majority before a decoding processing. CONSTITUTION:Each one data DSL, ESL is selected by reproducing each unit UT1-UT3 brought to multiplex writing, and executing a decision by majority with regard to parts of each data D1-D3, E1-E3. Subsequently, one new unit is constituted by coupling the data DSL, ESL obtained in such way, and read of a data is executed by performing a decoding processing such as prescribed error detection and error correction to this unit.

Description

[Detailed Description of the Invention] 3. Detailed Description of the Invention A. Field of Industrial Application The present invention is directed to a recording medium in which data such as an address and an error detection code or an error correction code are multiplexed and recorded on a recording medium such as an optical disk. This invention relates to a method for decoding multiplexed data.

B0 Summary of the Invention The present invention provides a recording unit in which an error detection or correction code is added to data such as an address, such as the identification part of each sector of an optical disk, and the recording unit is n-overwritten (n is an integer of 2 or more). When playing back what has been recorded on a recording medium,
A majority vote is taken only on each data part of the reproduced signal of n units that have been overwritten, and a majority vote is taken only on each error detection or correction code part, and these selected data and codes are combined to create a new By performing error detection or correction processing on this combined unit and reading the data, address reproduction with high reliability is possible with simple signal processing.

C0 Prior Art In recent years, recording media with extremely high recording densities, such as optical recording media such as optical disks and optical cards, have been put into practical use. The frequency of burst errors and random errors is also high, so especially important data such as the address data of each sector of an optical disk, the user registration number or PIN number of an optical card, etc. It is common practice to overwrite multiple files over and over again.

That is, concentric or spiral tracks are formed on a disk-shaped optical recording medium such as an optical disk or a magneto-optical disk, and one track is divided into a plurality of sectors. Further, in a card-shaped recording medium such as an optical card, for example, a strip-shaped recording area is divided into a plurality of recording tracks. Each predetermined position of each recording processor such as each sector and each recording track, for example, the first position 1, is used for so-called formatting processing prior to the start of use of a new disc, or by the supplier of the disc or card. Due to the so-called preformatting process or the like, addresses and error detection or error correction codes Mi (units serving as recording units) are recorded in multiple writing, for example, triple writing.

D1 Problems to be Solved by the Invention By the way, the above units (sets of data such as addresses and error detection or correction codes) are generally recorded in such a recording medium in n-multiple writing (n is an integer of 2 or more). When reproducing and reading, decoding processing such as error detection and error correction is performed for each reproduced signal of each n-overwritten unit, and error detection and correction processing for all units is performed. After that, valid data must be determined by majority logic, which complicates the decoding algorithm and hardware, increases the time required for arithmetic processing, and may impede high-speed access.

The present invention has been made in view of the above circumstances, and aims to provide a method for decoding multiplexed data that can simplify decoding processing such as error detection and error correction without deteriorating reliability. .

Means for Solving the E0 Problem In order to solve the above-mentioned problem, the decoding method for multiplexed data according to the present invention performs n-multiplex writing of units consisting of data and error detection or correction codes on a recording medium ( n is an integer greater than or equal to 2)), a majority vote of each data is taken for the reproduced signal for n units obtained by reproducing the n overwritten units. A new unit is constructed by combining the data selected by this method with a code selected by taking a majority vote of each error detection or correction code, and error detection or correction is performed on this combined unit. It is characterized by processing and reading data.

F9 effect It is only necessary to perform error detection or correction processing on the new unit obtained by the above combination, and there is no need to perform error detection or correction processing on each unit individually, which degrades reliability. Signal processing can be simplified and processing time can be shortened.

G. Embodiment Next, the basic principle of the reproducing operation of the signal reproducing method according to the embodiment of the present invention will be explained with reference to FIG.

- One unit as a recording unit that is overwritten n times (n is an integer of 2 or more) in C is obtained by, for example, important data such as address data and error detection encoding or error correction encoding of this data. In the example shown in FIG. 1, for example, n=3 (triple writing), and one unit of data and code are both equal to 24 bits.

That is, the first unit UTI consists of 24-bit data D1 such as the above address and a 24-bit error detection or correction code E1, and similarly, UT2 consists of D2 and E2, and UT3 consists of D3 and E3. There is. Three such triple-written units UTI, U
T2 and UT3 are reproduced, a majority vote is taken for each data D1, D2, and D3, and one data D$L is selected.

The majority decision at this time may be based on the coincidence of the data values themselves, or may be based on the data focus of each data.
, E3 as well, one code ESL is selected by majority vote. The data DSL and the code ESL obtained in this way are combined to form a new unit, and this unit is subjected to a predetermined error detection or error correction decoding process (decoding process) to convert the data. I'm trying to read it.

Incidentally, the above-mentioned multiple writing data includes, for example, address data of each sector of an optical disk, and a specific example of a decoding method for this address data will be explained with reference to FIG. 2.

That is, FIG. 2 is a diagram for explaining a specific example of a signal recording format on an optical disk as an example of an optical recording medium. In FIG. 2, one trunk on the optical disk is drawn out linearly, and the identification part (so-called ID part) of one sector is schematically shown enlarged.

One trunk is made up of a plurality of sectors, and one sector is made up of, for example, a preformatted identification part IDR and a data part DTP as an area in which sector data of -i is recorded. At the beginning position of the identification part IDR, a recording part of a synchronization signal (PLO sink) PLO3 for stabilizing the operation of the clock generation PLL circuit etc. when reading data is placed at the beginning. Units UT, which are one recording unit of sector identification address information, are successively arranged in triple writing (n=3). In other words, three units with the same content, which are recording units of sector identification address information) UT 1, UT 2,
UT3 are arranged sequentially following the synchronization signal PLO3, and each recording unit or unit IT has an address mark SPA of a sync pattern at the beginning, and an address AD consisting of a trunk address TA and a sector address SA.
is placed, and then a CRC error detection code or, for example, a BC
An error correction code ECC consisting of an H code is arranged.

Here, as an example of the number of bits in each part, the address AD has a total of 24 bits, including 16 bits for the trunk address TA and 8 bits for the sector address SA, and the length of the error detection or correction code ECC is It is equal to AD and has 24 bits. An error correction code is used as this code ECC, and a 24-pin address A
When D is encoded with an extended BCH code of (48, 24), error correction of up to 5 bits is possible.

Conventionally, when reading the identification part (CID part) of each sector of such a recording format and reproducing the address signal, each address AD of each UNISO) UTI to UT3 is detected or detected by error detection or correction code ECC, respectively. After the correction processing, valid ones of these processed address values are compared with each other, and if these valid address values are different, the address value that matches the most (in the case of triple writing, the address value that matches the most) is selected by majority logic. (two of the two address values match) are used. However, this method requires decoding processing for all the addresses of each multiplexed unit, and requires complex decoding processing successively for each multiplexed unit, which also imposes a heavy burden on the hardware. .

Therefore, in the embodiment of the present invention, one address AD, L is selected by taking a majority vote for each address ADI to AD3 of the reproduced signal of each multiplexed unit, and a majority vote is taken for each code ECC1 to ECC5. te1
After selecting one code ECC3L, these AD3L and code ECC5t are combined to form one new unit, and by performing decoding processing only on this one unit, the number of decoding processing times is reduced from the conventional three times ( Generally, in the case of n-overwriting, the number of times is reduced from n times to one time.

That is, by taking a majority vote before decoding, the processing is simplified and the hardware load can be reduced. The error detection or correction ability in this case is
This is approximately the same as the conventional case in which each unit is decoded and then a majority vote is taken, and there is no deterioration in reliability.

Note that the present invention is not limited to the above-mentioned embodiments, and can be easily applied to recording media such as magneto-optical disks and optical cards in addition to optical disks. In addition to addresses, data that is multiplexed includes important data such as registration numbers, passwords, and directory information.

H1 Effects of the Invention According to the method for decoding multiplexed data of the present invention, the number of decoding processes (decoding processes) for n multiplexed data can be significantly reduced without deteriorating reliability, and processing time can be shortened. In addition, the hardware load can be reduced and the configuration can be simplified.

[Brief explanation of the drawing]

FIG. 1 is a diagram for explaining the principle of data signal reproducing operation according to an embodiment of the present invention, and FIG. 2 is a diagram showing an example of a signal recording format on an optical disk used in the present invention.

Claims (1)

[Claims] In a signal reproducing method for reproducing a recording medium in which units consisting of data and error detection or correction codes are written n times (n is an integer of 2 or more) and recorded, One piece of data selected by majority vote for each of the above data parts and each error detection or correction code part of the reproduced signal for n units obtained by playing back the and one code selected by taking a majority vote to form a new unit, and this combined unit is subjected to error detection or correction decoding processing. How to decode multiplexed data.