Error detection/correction and fault detection/recovery – Data processing system error or fault handling – Reliability and availability
Reexamination Certificate
1998-11-06
2001-06-19
Iqbal, Nadeem (Department: 2184)
Error detection/correction and fault detection/recovery
Data processing system error or fault handling
Reliability and availability
C711S112000
Reexamination Certificate
active
06249884
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to recording media, and more particularly, to an apparatus and method for searching for defective addresses of recording media.
2. Description of the Related Art
With a recent trend to high-capacity recording media, many efforts have been made to utilize a structure in which defective recording locations are replaced by other recording locations. The recording medium is comprised of sectors which store and record data on their surfaces, and defects of the sectors are tested while manufacturing the recording medium.
Defective sectors cannot store data. The list for defective sectors is called a “primary defect list” (hereinafter called PDL). The PDL is stored at a predetermined location on a disk.
The recording medium is provided with additional sectors to replace the defective sectors. Defects of these extra sectors are called “secondary defects”, and extra sectors with such defects are classified in a “secondary defect list” (hereinafter called SDL).
When a driver having recording media is powered up, the PDL and SDL are read out and stored in a random access memory (RAM). A controller such as a microprocessor prevents data from being recorded on the defective sectors, using information on the PDL and SDL.
A recording medium such as a digital versatile disc (DVD) RAM, which repeatedly records and reproduces, first searches the defect list before recording or reproducing data. However, the defect list is very large, typically on the order of about 64 Kbytes. Accordingly, it takes much time to search the entire defect list and recover from defects.
SUMMARY OF THE INVENTION
To solve the above problem, it is an object of the present invention to provide an apparatus and method for effectively searching for defective addresses in a recording medium.
Accordingly, to achieve the above and other objects, there is provided an apparatus and method of searching for defective addresses of a recording medium which has a main data storage unit and a defective data management unit having at least one defect management area including first and second defect lists, and repeatedly records and reproduces. The method includes the steps of (a) performing correction of defects by searching for a defect-correctable defect management area of the defective data management unit; (b) recording data in the defect-correctable defect management area which was searched for; © calculating a temporary physical address by inputting the position of data whose real address is to be searched for, as a logical block address; (d) searching for the first and second defect lists of the defect management area recorded in the step (a), setting the first and second defect lists as input information, and calculating a real physical address by one-half dividing the temporary physical address calculated in the step (c); and (e) calculating a real data address from the real physical address.
In one embodiment, step (d) comprises the substeps of: (d1) calculating a first preliminary address by adding the total number of data units of a replaced group to the number of data addresses in an auxiliary area of the second defect list; (d2) comparing the first preliminary address to the temporary physical address; (d3) searching for the second defect list and obtaining the real physical address using a one-half dividing method, when the first preliminary address is greater than or equal to the temporary physical address; and (d4) searching for the first defect list and obtaining the real physical address using a one-half dividing method, when the first preliminary address is smaller than the temporary physical address.
In one embodiment, the step (d3) comprises the substeps of: (d3a) determining whether the first preliminary address is larger than the temporary physical address; (d3b) tracking a replacement address equal to the temporary physical address, using the consecutive one-half dividing method, when the first preliminary address is larger than the temporary physical address; and (d3c) tracking a real physical address corresponding to the replacement address, wherein when the first preliminary address is smaller than or equal to the temporary physical address, the first preliminary address becomes the replacement address.
Under another aspect of the invention, there is provided another method of searching for defective addresses of a recording medium which has a main data storage unit and a defective data management unit having at least one defect management area including first and second defect lists, and repeatedly records and reproduces. The method includes the steps of: (a) searching for a defect-correctable defect management area of the defective data management unit, performing correction of defects, and writing a defect map table showing the number of data units and the number of accumulated data units in the first and second defect lists of each group; (b) recording data in the defect-correctable defect management area which was searched for; © calculating a temporary physical address by inputting the position of data whose real address is to be searched for, as a logical block address; (d) determining a corresponding group using the temporary physical address and determining the range of a searching address of the corresponding group in the defect map table; (e) searching for the first and second defect lists of the defect management area recorded in the step (a), setting the first and second defect lists as input information, and calculating a real physical address by one-half dividing the temporary physical address calculated in the step (c); and (f) calculating a real data address from the real physical address.
In accordance with another aspect of the invention, there is provided a processor for controlling a recording medium having a main data storage unit and a defect data management unit for recording already-generated defects, comprising: a memory management unit for recording and storing data in the main data storage unit; a defect management unit having first and second defect lists for managing defects of the main data storage unit; a defect check unit which can communicate with the memory management unit, for checking the defects of main data of the main data storage unit via the first and second defect lists of the defect management unit; and a data sensing unit for processing data of the recording medium and communicating with the memory management unit and the defect management unit, wherein the defect check unit obtains a temporary physical address by receiving a logical block address at the position of data whose real physical address is to be searched for, and calculates a real physical address by setting the first and second defect lists as input information and performing a one-half dividing method on the temporary physical address.
In accordance with still another aspect of the invention, there is provided another processor for controlling a recording medium having a main data storage unit and a defect data management unit for recording defects which are already generated, comprising: a memory management unit for recording and storing data in the main data storage unit; a defect management unit having first and second defect lists for managing defects of the main data storage unit; a defect check unit which can communicate with the memory management unit, for checking a corresponding area to search for the defects of main data of the main data storage unit via a defect map table showing the first and second defect lists of the defect management unit, the number of data units in the first and second defect lists in each group, and the number of accumulated data units; and a data sensing unit for processing data of the recording medium and communicating with the memory management unit and the defect management unit, wherein the defect check unit obtains a temporary physical address by receiving a logical block address at the position of data whose real address is to be searched for, and calculates a real physica
Iqbal Nadeem
Mills & Onello LLP
Samsung Electronics Co,. Ltd.
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