KR20000032046A - Method for allocating spare area of optical recording media - Google Patents

Abstract

PURPOSE: A method for spare area of an optical recording media is provided to enable to extend supplementary spare area even when the supplementary spare area is less than a preset extendable area. CONSTITUTION: In a method for a spare area of an optical recording media, a size of an allowable supplementary spare area is first determined. Then, the supplementary spare area is variably assigned within a range of the size of the allowable supplementary area. The size of the allowable supplementary spare area is a size which can be managed within a defect managing area. The size of the is varied according to a condition of the defect managing area.

Description

Spare Area Allocation Method for Optical Recording Media

The present invention relates to a method for allocating a spare area of a rewritable optical record carrier.

In general, optical recording media are classified into three types, such as a read-only ROM type, a write once type Worm type, and a rewritable type that can be repeatedly recorded, depending on whether repeat recording is possible. Lose.

Among them, freely and repeatedly rewritable discs include a rewritable compact disc (CD-RW) and a rewritable digital versatile disc (DVD-RAM, DVD-RW).

In the case of such a rewritable optical recording medium, the recording / reproducing operation of information is repeatedly performed due to its use characteristics, and thus, the mixing ratio of the mixtures constituting the recording layer formed for recording information on the optical recording medium is increased. It becomes different from the mixing ratio and loses its characteristics, resulting in an error in recording / reproducing information.

This phenomenon is called deterioration, and the deteriorated area appears as a defect area when the format, recording, and reproducing command of the optical recording medium is executed.

In addition to the deterioration phenomenon, defect areas of the rewritable optical recording medium may be generated due to scratches on the surface, dust such as dust, errors in production, and the like.

Therefore, in order to prevent data from being recorded / reproduced in the defective areas formed due to the above reasons, it is necessary to manage the defective areas.

To this end, as shown in FIG. 1, a defect management area (hereinafter referred to as DMA) is provided in a lead-in area and a lead-out area of the optical recording medium. The defect area of the optical recording medium is managed. The data area is divided and managed by zones, and each zone is divided into a user area in which actual data is recorded and a spare area for use when a defect occurs in the user area.

In general, four DMAs exist in one disk (eg, a DVD-RAM), two DMAs exist in a lead-in area, and the other two DMAs exist in a lead-out area. Each DMA consists of two blocks, totaling 32 sectors.

Here, the first block of each DMA (called a DDS / PDL block) includes a Disc Definition Structure (DDS) and a Primary Defect List (PDL), and the second block of each DMA (called an SDL block) is an SDL (Secondary). Defect List).

In this case, PDL means main defect data storage, and SDL means defect data storage.

In general, the PDL stores entries created during the disc creation process and entries of all defective sectors that are identified during initializing, ie, initializing and re-initializing the disc. Here, each entry is composed of an entry type and a sector number corresponding to a defective sector as shown in Fig. 2A. The sector numbers are listed in a rising order. The entry type enumerates origins of defective sectors. For example, the entry type is classified into a P-list, a G ₁ -list, and a G ₂ -list.

That is, defective sectors defined by the disc manufacturer, such as those created during the disc creation process, are stored in a P-list, and defective sectors found during the certification process when the user formats the disc are stored in a G ₁ -list. Defect sectors transferred from the SDL without verification are stored in the G ₂ -list.

On the other hand, the SDL is listed in units of blocks, and stores entries of defective areas that occur after the format or defective areas that cannot be stored in the PDL during the format. Each SDL entry includes an area for storing the sector number of the first sector of the block in which the defective sector has occurred, an area for storing the sector number of the first sector of the replacement block as shown in FIG. 2B, and an unused area ( Reserved). Each entry is also assigned with one bit for Forced Reassignment Marking (FRM).

In this case, the defective areas (ie, defective sectors or defective blocks) in the data area should be replaced with normal areas, and there are a replacement method such as a slipping replacement method and a linear replacement method.

The sleeping replacement method is applied when a defective area is registered in the PDL. If a defective sector exists in a user area in which actual data is recorded as shown in FIG. 3A, the defective sector is skipped. Instead, it is replaced by a good sector following the defective sector to record data. Then, the user area in which data is recorded occupies a spare area as much as the defective sector skipped and eventually skipped. That is, the spare area is allocated to the user area by the skipped defective sectors. For example, the list PDL P- or G ₁ - if two defect sectors are registered in the list data is recorded pushed up to two sectors of the spare area. If a defective sector is recorded in the G ₂ -list of the PDL, the data is recorded by pushing up to 16 sectors (= 1 block) in the spare area.

In addition, the linear replacement method is applied when the defective area is registered in the SDL. When a defective block exists in the user area as illustrated in FIG. 3B, the replacement of the block unit allocated to the spare area ( replacement) field to record the data.

On the other hand, in order to increase the data recording capacity of the optical disk, a method of allocating a spare area having a capacity smaller than that of the spare area of FIG. 1 described above to only one zone of the data area or a portion of the data area is proposed. have.

One of them is a method of locating a spare area at the top of the data area, as shown in FIG. 4, and the spare area at this time is called a primary spare area (SA-pri). That is, the remaining data area except the main spare area becomes a user area.

The primary spare area is an area allocated during the initial formatting process, and is not assigned a logical sector number (LSN). That is, the primary spare area may be allocated when the disc manufacturer manufactures the optical disc or may be allocated when the user formats the blank disc for the first time.

At this time, the capacity of the main spare area may be variously allocated. For example, 26 MB (MB is Mega Byte) to set 4.7 GB (GB is Giga Byte) as the initial data recording capacity (that is, the first user area). You can allocate it, or you can allocate 145MB for 4.5GB.

Then, if defective sectors are registered in the PDL by initial or reformatting, data is not recorded in the defective sectors, thereby reducing the recording capacity. Therefore, the main spare area is slipped to the user area by the defective sectors registered in the PDL during formatting to maintain the initial data recording capacity. That is, the physical sector number (PSN) to which the logical start position LSN = 0 of the user area is given changes according to defective sectors registered in the PDL at the time of formatting. In this case, the main spare area is sleeped in reverse order. In addition, the assignment of spare blocks in the main spare area for linear replacement is performed in the reverse order.

On the other hand, when the main spare area is to be made full by sleeping replacement or linear replacement, a new spare area is allocated again near the end of the user area as shown in FIG. The spare area at this time is called a supplementary spare area (SA-sup). That is, since important data is copied at the end of the user area, the auxiliary spare area is allocated near the end, not the end of the user area.

In addition, when the auxiliary spare area is to be full, the auxiliary spare area may be expanded as shown in FIG.

In this case, when the auxiliary spare area is extended to a predetermined increment of a predetermined size (for example, 32 MB), the next expandable area may not be the predetermined increment. For example, an increase of a certain size may be set to 32MB, but a size of less than 32MB may remain an expandable area. This may occur when data is recorded in a part of the area to be expanded, i.e., the maximum allowable auxiliary spare area size, or the area not expanded within the maximum allowable auxiliary spare area may not be 32 MB.

As described above, when the auxiliary spare area needs to be expanded and is further extended, but the expandable area is smaller than a predetermined increment of a predetermined size, the auxiliary spare area may not be allocated. This can also be solved by utilities such as de-fragmentation. That is, the auxiliary spare area to be expanded can be secured by moving data in the area to be extended to the upper part of the user area or by finding and moving an empty area of the user area.

However, utilities such as the defragmentation described above are time consuming and complex and have a problem of degrading the performance of the system. In other words, large data (e.g. 4.7GB) data needs to be rewritten, which requires almost the same amount of time as full formatting. Also, the disk structure is almost changed by finding empty space and inserting data. It must be complicated.

In the related art, the size of the expandable auxiliary spare area is not determined. That is, when it is not determined how much to allow the auxiliary spare area size to be extended when managing the spare area through DMA, a problem may occur in system operation such as the spare area is infinitely extended.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and an object of the present invention is to provide a spare area allocation method for an optical recording medium which allocates an auxiliary spare area in increments of a variable size within an allowable size.

Another object of the present invention is to provide a method for allocating a spare area of an optical recording medium that extends to the auxiliary spare area even when the size of the auxiliary spare area to be extended when the auxiliary spare area is extended by a predetermined increase in size is smaller than the predetermined increase. Is in.

Another object of the present invention is to extend the expandable area to the auxiliary spare area at one time when the size of the auxiliary spare area to be expanded when the auxiliary spare area is extended by an increase of a predetermined predetermined size is smaller than twice the preset increase. A spare area allocation method of an optical record carrier is provided.

1 is a view showing the structure of a typical optical disk

Figure 2a shows a general PDL entry structure

2b shows a general SDL entry structure

Figure 3a shows a typical sleeping alternative method

3b illustrates a typical linear replacement method

4 illustrates an example in which a general spare area is allocated to a top position of a data area.

5A and 5B show a conventional example in which an auxiliary spare area is allocated to a disk having a main spare area as shown in FIG. 4, and the auxiliary spare area is extended in a predetermined increment of a predetermined size.

6 (a) and 6 (b) show an example in which the auxiliary spare area is expanded by a variable size increase within an allowable size when the auxiliary spare area is allocated to the disk having the main spare area as shown in FIG. 4. Drawings

7 (a) to 7 (c) show an example in which the remaining area is extended to the auxiliary spare area when the expandable spare spare area is smaller than an increase of a predetermined size in the disk having the main spare area as shown in FIG. Drawing of the present invention

8 (a) and 8 (b) show the remaining spare area at once when the expandable spare spare area is smaller than twice the increment of a predetermined size in the disk having the main spare area as shown in FIG. Figures of the present invention showing an example extended to

The spare area allocation method of the optical recording medium according to the present invention for achieving the above object is to determine the allowable size of the auxiliary spare area when the spare area is allocated to the initial optical recording medium and the spare area needs to be expanded. And allocating an auxiliary spare area with a variable size within the allowable size determined in the step.

The allowable size of the step is characterized in that the size can be managed in the defect management area.

The allowable size of the step is characterized in that it depends on the conditions of the defect management area.

The auxiliary spare area allocating step may include allocating the auxiliary spare area only once within the determined allowable size.

The auxiliary spare area allocation step is characterized in that the auxiliary spare area is extended in increments of a variable size whenever necessary within the determined allowable size.

According to the present invention, a spare area allocation method for an optical recording medium includes: assigning a spare area to an initial optical recording medium and allocating the spare area in increments of a predetermined size when the spare area needs to be expanded. It is characterized in that the allocation to the auxiliary spare area even if less than the increase of the predetermined size.

The assignable auxiliary spare area may be configured to maximize a preset allowable size.

The spare area allocation method of the optical recording medium according to the present invention allocates an auxiliary spare area in increments of a predetermined size when a spare area is allocated to an initial optical recording medium and the spare area needs to be expanded. If it is less than the multiple of the increment of the predetermined size, it is characterized in that the assignable auxiliary spare area is allocated at one time.

Other objects, features and advantages of the present invention will become apparent from the following detailed description of embodiments taken in conjunction with the accompanying drawings.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

The present invention is to prevent fragmentation that occurs when the expandable auxiliary spare area is smaller than a predetermined increment of a predetermined size, and after determining the size of the allowable auxiliary spare area, the auxiliary auxiliary spare area is supported in increments of a variable size within an allowable size. A first embodiment of allocating a spare area and a second embodiment of extending the auxiliary spare area even when the size of the auxiliary spare area to be expanded when the auxiliary spare area is extended by a predetermined increment is set smaller than the predetermined increase. Can be divided.

First embodiment

That is, as shown in Figs. 6 (a) and 6 (b), the increment that expands within the allowable size is not made constant but variable. In this case, if necessary, the auxiliary spare area may be allocated only once or may be divided and expanded several times. In the case of extending multiple times, the extended area must be used first before the extended area becomes active. If the auxiliary spare area is allocated only once, the size of the auxiliary spare area will be the maximum allowable size. However, if data is recorded within the maximum allowable size, the size that can be allocated at one time can be as small as that.

At this time, the maximum allowable auxiliary spare area is, for example, about 120 MB. For example, the maximum defective area size that can be managed by the DMA and the maximum allowable size that can be used as the primary spare area and the sub spare area.

That is, there may occur a case in which a defective sector found during formatting cannot be registered as a PDL, an SDL cannot be converted into a PDL, or a defect block found during data recording / reproduction cannot be registered in the SDL. This is because the number of entries that can be registered in the DMA is limited by the following condition (1).

Here, S _PDL is the number of sectors used to hold the PDL entries, S _SDL is the number of sectors used to hold the SDL entries, E _PDL is the number of PDL entries, and E _SDL is the number of SDL entries. And, Denotes the largest integer not greater than P.

That is, the total number of sectors that can be used for the PDL and the SDL cannot exceed 16 sectors, and the PDL alone or the SDL alone cannot exceed 15 sectors.

At this time, according to the above equation 1, the defect area that can be managed by the DMA to the maximum becomes about 145MB (= 121MB + α). For example, since a defect area that SDL 1 sector can manage is 8 MB and a PDL 1 sector can be managed 1 MB, adding SDL 15 sectors (= 120 MB) to PDL 1 sector (= 1 MB) becomes 121 MB. In consideration of the defect in the spare area, α is added to 145MB. That's about 3% of 4.7GB. That is, up to about 3% of the spare area can be allocated.

Therefore, if the initial recording capacity of the user area is 4.7 GB and the primary spare area is allocated 26 MB, the auxiliary spare area can be allocated up to 119 MB.

In addition, when the DMA condition as shown in Equation 1 is changed, the maximum allowable auxiliary spare area may also vary. In addition, the maximum allowable size of the auxiliary spare area may vary according to the size of the primary spare area.

For example, if the maximum allowable spare spare area is 120 MB, in the first embodiment of the present invention, the spare spare area may be allocated only once as 120 MB once, or may be allocated only once with a size smaller than 120 MB. have.

Further, depending on the defect processing situation during data recording / reproducing, it can be variably expanded such as 30MB, 20MB, 50MB, ..., etc. within 120MB.

If data is recorded within the maximum allowable size, the last data recording position becomes the maximum size that can be extended to the auxiliary spare area, and in this case, the auxiliary spare area is expanded by an increase of the variable size within the maximum expandable size.

If the auxiliary spare area that can be allocated later is secured by deleting data, the data can be expanded again within the maximum allowable size.

Therefore, if data is recorded within the maximum allowable size or the maximum allowable size, all of the maximum expandable size can be allocated to the auxiliary spare area, thereby eliminating the need for defragmentation due to the remaining area of the small size.

Second embodiment

Meanwhile, according to the second embodiment of the present invention, if the auxiliary spare area is expanded by a predetermined increase of a predetermined size, the auxiliary spare area may be changed only when the expandable area is smaller than the increase of the predetermined size or smaller than twice the increase. It is to expand in size. At this time, the extension of the auxiliary spare area may be up to a predetermined maximum allowable size. The maximum allowable size here applies in the same manner as in Example 1 above.

If the data is recorded within the maximum allowable size, the last data recording position becomes the size that can be extended to the auxiliary spare area, and if the spare spare area that can be allocated later is secured, the data is expanded again within the maximum allowable size. can do.

For example, as shown in (a) to (c) of FIG. 7, if the predetermined increment is 32 MB, the auxiliary spare area is extended by 32 MB as needed. Then, if there is about 29MB of expandable space, and you need more spare spare space, you can expand 29MB to spare spare space instead of defragmenting it.

On the other hand, if the expandable area is smaller than twice the increment, the remaining area may be expanded at once.

For example, as shown in (a) and (b) of FIG. 8, if the predetermined increment of the predetermined size is 32 MB, the auxiliary spare area is extended by 32 MB as needed. Then, if there is about 61 MB of expandable area and you need more spare spare areas, you can extend 61 MB into the spare spare area at a time.

In other words, when the expandable area is 61MB, first, 32MB may be extended, and then 29MB may be extended, or 61MB may be extended at a time.

As in the first embodiment described above, if data is recorded within the maximum allowable size or the maximum allowable size, all of the maximum expandable size can be allocated to the auxiliary spare area, so that fragmentation due to the remaining area of the small size is unnecessary. do.

As described above, according to the method for allocating a spare area of an optical recording medium according to the present invention, after determining the maximum allowable auxiliary spare area, the auxiliary spare area is allocated in increments of a variable size within the maximum allowable size, or The auxiliary spare area to be extended by expanding the remaining area to the auxiliary spare area even when the size of the auxiliary spare area to be extended when the auxiliary spare area is expanded by a predetermined constant size is smaller than twice the increment or increase of the predetermined predetermined size. Even if the size of is smaller than a predetermined increment of size, there is no need for de_fragmentation that requires a lot of time and complexity. In addition, since the maximum size of the expandable auxiliary spare area is determined, there is no problem such that the spare area is extended indefinitely, thereby improving system performance.

Claims (10)

A method of separately allocating a spare area when a spare area is allocated to an initial optical recording medium and an extension of the spare area is required, Determining an allowable size of the auxiliary spare area; And allocating an auxiliary spare area in a variable size within the allowable size determined in the step. The method of claim 1 wherein the allowable size of the step is A spare area allocation method for an optical record carrier, characterized by a size that can be managed in a defect management area (DMA). The method of claim 1 wherein the allowable size of the step is A spare area allocation method for an optical record carrier, characterized in that it depends on the conditions of the defect management area. The method of claim 1 wherein the allowable size of the step is And a spare area allocation method according to the size of the initially allocated spare area. The method of claim 1 wherein the allowable size of the step is A spare area allocation method for an optical record carrier, characterized in that if data is recorded within the maximum allowable size, the data varies depending on the amount of data recorded. The method of claim 1, wherein the secondary spare area allocation step And allocating an auxiliary spare area only once within the determined allowable size. The method of claim 1, wherein the secondary spare area allocation step And extending the auxiliary spare area in increments of a variable size whenever necessary within the determined allowable size. A method for allocating a spare area in increments of a predetermined size when a spare area is allocated to an initial optical recording medium and the spare area needs to be expanded, And assigning an auxiliary spare area to the auxiliary spare area even if the assignable auxiliary spare area is smaller than the predetermined increment. 9. The method as claimed in claim 8, wherein the assignable auxiliary spare area maximizes a predetermined allowable size. A method for allocating a spare area in increments of a predetermined size when a spare area is allocated to an initial optical recording medium and the spare area needs to be expanded, And allocating said assignable auxiliary spare area at once if said assignable auxiliary spare area is smaller than a multiple of said predetermined size increment.