KR100677640B1 - Optical data storage medium - Google Patents

Abstract

Disclosed is a disk having a free space for defect management and a free space allocation method. The present invention forms a plurality of regions into one group without predefining the relationship between regions and groups, and divides the allocation of free space into free spaces for skip substitution and linear substitution, and then frees space for skip substitution first. Allocate and allocate free space for linear replacement, depending on the amount of free space used for the remaining skip replacements and the purpose of the disk, and if there is not enough free space for linear replacement during use, linear replacement starts from the very end of the logical file space. Allocating additional free space for the system allows for more flexible and efficient allocation of free space.

Description

Optical data storage medium

FIG. 1A is a half plan view of a disc showing a user area, protection and free space, and FIG. 1B is a diagram showing a one-dimensional structure of a part of a DVD-RAM disc according to Specification Revision 1.0.

2 (a) and 2 (b) are diagrams for explaining the allocation of free space during initialization according to the present invention, and FIG. 2 (c) is a diagram for explaining the allocation of free space during use after initialization.

3 (a) and 3 (b) are diagrams showing discontinuities between regions of an ECC block due to a defective sector during skip substitution.

4 is a flowchart according to an embodiment of a method for allocating free space during initialization according to the present invention.

5 is a flowchart according to an embodiment of a method for allocating free space during use after initialization according to the present invention.

The present invention relates to the field of disks, and more particularly, to a disk having a free space for defect management and a free space allocation method.

As a general method of managing the defects of a recordable / rewritable disc, a skip replacement without using a logical sector number is used for defects that occur when the disc is initialized (“primary defects”). For defects that occur while using "(secondary defects)", use linear replacement that replaces the normal block in the free space with an error correction code ("ECC") block in the region where the error occurred. have.

That is, the skip replacement method means that a defective sector found during a certification process that checks a disk for defects when the disk is initialized is skipped without giving a logical sector number to the next sector of the defective sector. It is a method for minimizing the decrease in the recording or reproducing speed due to a defect by assigning a logical sector number to be used, i.e., skipping and skipping a sector in which a defect occurs during recording or reproduction. In this case, the actual physical sector number is pushed backward by the sector number specified by skipping. This rolling problem is solved by using as many sectors as defects in the free space located at the end of the recording area (group or region). Then, the defective sector position replaced by the skip replacement is prescribed to be recorded in the PDL (Primary Defect List) of the defect management area (DMA) of the disc.

If a defect occurs while using the disc, the skip replacement method cannot be used. This would violate the file system conventions if you skip over the faulty part, because there will be discontinuities in the logical sector numbers. Therefore, when a defect occurs while using a disc, a linear replacement method is used, which replaces an ECC block including a defective sector with an ECC block in a free space and replaces the defective block by linear replacement. The position is defined to be recorded in the secondary defect list (SDL) of the defect management area of the disc. However, there is no space in the logical sector number when using the linear replacement method, but in the case of a defect, the positions of the sectors on the disk are not contiguous and the actual data for the defective ECC block exists in the free space.

Meanwhile, as an example of a disc, a digital versatile disc random access memory (DVD-RAM) disc according to Specification Revision 1.0 is a plurality of groups having a constant user area and spare area for each zone. consist of. That is, FIG. 1A is a half plan view of a disk showing a user area, a guard area, and a free space, and FIG. 1B shows a partial area on the disk in one dimension. The area is in the order of a protected area, a user area, a free space, and a protected area.

The fact that the disk is divided into zones solves the problem of incorrect recording due to the change of spindle speed during recording, and ZCLV (Zone Constant) to improve the search speed than recording by the linear speed constant (CLV) method. Linear Velocity).

That is, in the case of managing defects by linear substitution, the linear substitution in the region where the defect occurs as much as possible has the advantage that the search speed is high because there is no change in the linear velocity of the disk. Therefore, in the DVD-RAM, a certain amount of free space is allocated to each region as shown in FIG.

As described above, the conventional defect management method forms a group for each region and allocates free space at the end of each group. Each group consists of one defect management area. In addition, since the start sector number of each group is determined in advance, the ECC block is also started at the start position of the region, which is a unit for physically dividing the region.

Since the starting logical sector number of each group is designated as described above, when the defect is managed by the skip substitution, the restriction that the skip substitution should occur only in the corresponding group occurs. The number of sectors that can be skipped by a defective sector is only possible within the number of available sectors of the free space in the group when it is desired to replace the defect by skipping a defect occurring in the group. Therefore, due to the constraint that large-size defects occurring in one group must be handled only in the group, the maximum size of defects that can be skipped is limited.

If the defect caused by the skip substitution is larger than the size of the free space of the group, the free space in the other group should be used by using the linear substitution. However, in the case of linear substitution, defect management is performed not in sectors but in ECC block units, that is, in 16 sector units, so that 16 sectors of free space are required to process a single defect sector, thereby reducing efficiency of defect management. There was a problem.

In addition, the size of the free space for defect management is also determined as a standard, so even in applications where defect management using linear substitution cannot be applied, such as real-time recording, the same amount of free space must be allocated. There was a problem that the efficiency of utilization is poor.

In order to solve the above problems, an object of the present invention is to create a plurality of regions in one group, have a free space for skip substitution for the group allocated first, and free space for a linear substitution allocated later Branch is to provide a disk.

Another object of the present invention is to create a plurality of regions in one group, to allocate the free space for the skip substitution first, and to allocate the free space for the linear replacement later, a more flexible and efficient method of allocating the free space To provide.

In order to achieve the above object, the disk according to the present invention, upon initialization, creates a plurality of regions on the disk including the user data area into one group, and creates a primary free space allocated for the generated one group. It is characterized by having.

In order to achieve the above object, the free space allocation method according to the present invention is a free space allocation method for a disc recording and / or reproducing apparatus which allocates free space for disc defect management. And generating a plurality of regions on the disk including a group, and allocating primary free space for skip substitution for the generated group.

Hereinafter, with reference to the accompanying drawings will be described a preferred embodiment of the disk having a free space for the defect management and the free space allocation method according to the present invention.

 The allocation of free space on the disk for defect management according to the present invention is classified into a primary spare area, a secondary spare area, and an additional spare area, and are defined as follows. .

The primary free space is the first free space to be allocated when the disk is initialized for the replacement of a defect, and is used first for the skip replacement, and the remaining free space can be used as the secondary free space for linear replacement. Secondary free space is a space for linear replacement of a defect occurring during the use of a disk, and refers to free space remaining or separately allocated free space used by a skip replacement among the first free spaces at the time of initialization. The additional free space is a free space for linearly replacing a defect that occurs while using a disk, and means additional free space allocated during use after initialization.

That is, in the present invention, as shown in FIG. Space ”) first. This skip replacement can improve the utilization of free space because it is replaced by sectors, but it is not used after the initializing of the disk because the defective space is not simply used but is continuously recorded from the next normal sector. none.

The primary free space allocated at initialization allocates the maximum free space required for skip substitution, but the remaining free space after skip substitution can be used as the secondary free space for linear substitution. In addition, when it is determined that the linear replacement cannot be sufficiently performed only with the secondary free space allocated in the primary free space after the skip replacement is completed, the secondary free space for linear replacement is shown in FIG. As shown in (b) of FIG. 2, the second free space is not given a logical sector number, and the second free space allocation information is stored and managed in the defect management area (DMA). Secondary free space allocated at initialization is by default placed at the end of the region, which does not mean that all space should be allocated. This not only has the advantage of easy management by allocating the free space for linear substitution at the end of the area, but also has the advantage of easily finding the free space of the nearest area by managing by area unit. It has the advantage of being able to manage with few modifications.

In addition, this secondary free space can be placed in front of the protected area, which is the last part of the area, and if the secondary free space is arranged in each area, the size of the secondary free space is determined by a formula (for example, 3% of each area). It can be predefined as a magnitude or an absolute magnitude.

If there is not enough free space for linear permutation allocated on a local basis during use after initialization, additional free space for linear permutation is determined from the rear end of the logical file space on the file system as shown in FIG. Allocate by increasing the free space gradually in size, but in the case of linear substitution, the logical file space discontinuity can be solved by using the reverse order from the rear of the logical file space.

In this case, since linear substitution is processed in units of ECC blocks, even if one sector is defective, the free space of the ECC block is used, and the defective block is replaced with free space in a physically separated location. Therefore, when searching for a region where a defect has occurred, there is a disadvantage that the search speed is slowed down. However, since it can cope with a defect that occurs during use, a linear substitution is used for a secondary defect that occurs during use.

Also, allocate additional free space only as contiguous, empty space behind the logical file space. The maximum amount of this additional free space must be smaller than the final area. Here, the logical file space means a logical space capable of recording / reproducing user data files among all the spaces used in the file system.

In the case of 80 mm diameter discs, the user data area should be within the radius of 38 mm as much as possible, because of disc ejection, etc., the diameter of 80 mm discs is affected by abrupt birefringence from around 38 mm radius.

On the other hand, when forming a plurality of regions proposed in the present invention as a group to allocate free space for skip replacement at the end of the disk, 7679 items (for 15 sectors), which is the maximum number of defects that can be processed by PDL The maximum amount of free space to be handled by the group, and the ECC block does not start at the beginning of the region due to the rolling of logical sector numbers due to skip substitution in the border region between regions. You must allocate more free space (“free space for block position control”) to prevent it from being turned on.

For example, if the disk to be applied to the present invention is a 1.46 GB (Giga Bytes) DVD-RAM, the primary free space may process 8 sectors of PDL items and 64 SDL items, thus insufficient primary free space immediately after formatting. To avoid warnings. Here, a warning level occurs when the free space is less than 32 ECC blocks. Therefore, the total initial free space is allocated to have a margin of 3% or more in consideration of the number of defects occurring in the free space and the free space for preventing discontinuity of ECC blocks in each region.

PDL items that can be processed by the primary free space range from a minimum of 1 sector to a maximum of 8 sectors, and SDL items range from a minimum of 1 sector to a maximum of 8 sectors, and free space for processing PDL items (S _PDL). ) And free space (S _SDL ) for processing SDL items can be represented as follows.

1 = S_PDL <= 8, ~~ 1 <= S_SDL <= 8

Next, a description will be made of FIG. 3 (a) and (b) in connection with the rolling phenomenon of the logical sector number due to skip substitution that may occur in the boundary region.

As proposed in the present invention, when a plurality of regions are formed as a group, as shown in (a) of FIG. 3, when a defective sector exists in region #n, one ECC block unit is skipped by skipping substitution. If the remaining sectors do not exist at the end of the region, and if data is written to the remaining sectors that do not become one ECC block unit, the logical sector number may be pushed out due to skip substitution in the boundary region. As shown in (b), discontinuity of ECC blocks may occur at the boundary location of each region. That is, one ECC block may be located over two regions. In this case, not only do you need to drive the disks at different speeds to read or write one ECC block, but also the user area and the protection area (a buffered area to prevent drive instability due to the difference in rotational speed between regions). Physical sector numbers are contiguous, however, such problems may arise.

Therefore, in the present invention, if a sector is left less than the number of sectors (16 sectors) of one ECC block at the end of the region due to a defective sector, it is skipped without using it, and a logical sector by skip substitution that may occur in such a boundary region is skipped. A free space for block position control for controlling the ECC block to start at the start position of the region in response to the rolling of numbers should be allocated as given in Equation 2 below.

In the case of a DVD-RAM disc, the number of sectors per ECC block is 16, so the maximum number of ECC blocks that can remain at the end of a region without remaining at the start of the region is 15 sectors. In order to match the starting position of the ECC block at the start of the region, the extra space is needed because the remaining sectors cannot be formed at the end of each region. The area where the region is connected is the number of regions minus one. In other words, if there are two regions, one region is connected, and if there are three regions, two regions are connected. It is enough to allocate free space for block position control corresponding to one ECC block per region.

Therefore, it is preferable that one disk has only one group for skip substitution, and in case of only one group, the free space for skip substitution is the number of items that can be processed by PDL and SDL at the end of the disk. It may be allocated in consideration of a free space for controlling the block position (here, up to 32 ECC blocks) for adjusting the starting position of the ECC block in the boundary region.

By setting up multiple regions as one group and allocating free space for skipping substitution at the end of the group, when a plurality of regions are included in a plurality of regions, the size is large due to the small allocated free space of each group. It is possible to reduce the occurrence of a problem that the ability to respond to the defects that occur continuously due to the defects is inferior.

500섹터는 건너뛰기 치환을 할 수 없게 되어 선형 치환을 하게 된다. 이 경우에는 대략 400

500개의 ECC 블록의 여유 공간이 필요할 뿐만 아니라 해당 결함이 발생한 지역에서 디스크의 성능이 크게 저하되는 단점이 있다. 그러나, 본 발명에서 제안하는 것과 같이 디스크 전체에 대해 하나의 큰 여유 공간을 건너뛰기 치환을 위해 할당한 경우에는 상기와 같은 크기가 큰 결함에 대해서도 건너뛰기 치환을 할 수 있다는 장점이 있다.For example, in the case of a disk having a capacity of about 4.7 GB with one group in each region, as shown in FIG. 1 (a), one group is composed of about 1600 tracks, and a physical disk The width of the bed is about 1 mm. At this time, if a wound larger than 1mm occurs in the radial direction, there are about 1600 defective sectors. However, if free space is grouped by region according to the capacity of the disk and allocated at a constant ratio, the inner circumference of the disk Only about 1100 sectors can be skipped, so the remaining 400

500 sectors cannot be skipped, resulting in linear substitution. In this case approximately 400

In addition to the need for 500 ECC blocks of free space, there is a disadvantage in that the performance of the disk is significantly degraded in the region where the defect occurs. However, when one large free space is allocated for the skip replacement of the entire disk as proposed in the present invention, there is an advantage that the skip replacement can be performed even for the above-described large defect.

4 is a flowchart according to an embodiment of a method for allocating free space of a disc at initialization according to the present invention. In FIG. 4, when an initialization command is input (step S101), one group is formed by using the plurality of regions of the disk by the initialization command, and the primary free space is allocated to the last part of the group (step S102). . That is, the primary free space for skip substitution is the free space for defect management of 7679 data sectors (480 ECC blocks), which is the maximum number of defect management items that can be processed by the PDL, and the start of ECC blocks in each boundary region. It is a free space for controlling the position of the block for adjusting the position (here up to 32 ECC blocks).

On the other hand, if the disk is a 1.46GB DVD-RAM, the primary free space can handle 8 sectors of PDL items and 64 SDL items, and is allocated in consideration of the free space for block position control.

When the primary free space is allocated, a defect generated by determining whether or not the entire disk area is defective is replaced by a skip replacement method using the primary free space allocated at the end of the group (step S103). In this case, if the primary free space allocated during the replacement of the defect by the skip replacement method is insufficient, the disk may be determined to be bad, and the disk may be further disabled by generating an initialization error message.

When the skip substitution is completed in step S103, the primary free space that is not used during the skip substitution is allocated as the secondary free space for the linear replacement, and the linear replacement is performed only with the secondary free space in the primary free space. If it is determined that it is insufficient, the second free space is further allocated on a local basis (step S104). The allocation information of the secondary free space for linear replacement allocated in this area unit is stored in the defect management area (DMA) of the disk. After the allocation of the first free space and the second free space for linear substitution, the initialization is terminated. Here, the reverse order from the rear of the free space in order to unify the management method of the additional free space for the linear replacement even for the second free space in the primary free space used for linear replacement and the second free space allocated by region unit It is preferable to use as.

FIG. 5 is a flowchart illustrating a method of allocating free space while using a disk after initialization, and additionally linear replacement is performed when there is insufficient secondary free space for linear replacement allocated during initialization for a defect occurring during use after initialization. Allocate free space for

In Fig. 5, it is determined whether additional free space for linear replacement is required while using the disk (step S201), and if it is determined that additional free space is needed, it is determined whether there is sufficient contiguous free space behind the logical file space. Determine (step S202). If there is sufficient contiguous free space at the rear of the logical file space at step S202, the additional free space for linear replacement is allocated to a constant size from the rear of the logical file space and the flow proceeds to step S201 to determine whether additional free space is needed. (Step S203).

In this case, since the additional free space allocation corresponds to the redistribution of the logical file space occurring after initialization, the file system needs help. In this case, the free space for the additional allocated linear replacement does not occur on a local basis, but at the end of the logical file space, that is, from the region with the highest logical sector number in the logical file space where the file can be written for user data. Free space can be allocated by increasing the logical sector number in the lower direction by size. If the secondary replacement occurs by using the additional free space allocated and linear substitution, the search speed may be slowed slightly, but the logical sector number area is not available to the file system in the logical file space. Discontinuity can be prevented.

In addition, in the conventional defect management method for linear replacement, the defective ECC block is replaced using the first normal ECC block which is not used among the ECC blocks in the free space. This is to use the free space from the front in order to skip over the free space where the defect occurs, while preventing the defective block in the free space from managing the defect. However, in the case of blocks of additional free space, when using sequentially from front to back as in the conventional method, a problem occurs when additional free space needs to be increased, that is, each additional free space increases. There is a problem that needs to be managed separately. To solve this problem, blocks of additional free space are used in reverse order from the rear. This has the advantage that if you only know the two sector numbers, the largest sector number and the smallest sector number where the additional free space starts, you can manage the entire additional free space continuously. In other words, the recording and / or reproducing apparatus does not need to know how many times the additional free space has been additionally allocated to a predetermined size, but can be managed only by knowing the start position and the end position. However, the maximum amount of this additional free space must be smaller than the final area.

If it is determined in step S202 that there is not enough contiguous free space at the back of the file system space, the free space is cleaned by the file system or the application (step S204). If it is determined (step S205), if there is contiguous free space, the process proceeds to step S203 in which additional free space is allocated. (Step S206). If no additional free space is required even in step S201, the process ends.

On the other hand, free space for defect management can be allocated less for special applications, such as real-time recording, and only limited linear replacement for secondary defects occurs. In the case of real time recording, it is desirable to process the secondary defect in the file system or the application program in order to ensure the minimum transmission speed required for the application.

Even in such a case, the recording and / or reproducing apparatus needs to detect a defect and to manage a minimum of the detected defect. In this case, the minimum management means managing whether or not the defect at the position where the defect occurs has been linearly replaced by using the SDL.

For example, for a defect that occurs while using a disc on which defect management information is recorded that does not use defect management by linear substitution for real-time recording, for example, the start of a block in which a defect occurs in the secondary defect list (SDL). Record only the sector number, record information indicating that the defective block is not replaced in the FRM (Forced Reallocating Masking) bit of the SDL item indicating whether or not the defective block has been replaced, and start sector number of the replacement block of the SDL item. Record information indicating no substitution. For a method of storing and managing defect management information indicating whether linear substitution is used for real-time recording, refer to Korean Patent Application No. 98-35847, filed by the same applicant, for "Record storing defect management information for recording real-time data." Media and its defect management method ".

Even when secondary defects are managed in the file system or application, the reason for defect management in the recording and / or playback device is that the defects processed by the file system or application when the disk is reinitialized for other purposes Since the recording and / or reproducing apparatus is not known, it may be possible to ignore and reinitialize the generated defect. Accordingly, the secondary defect (stored as an SDL item) is simply replaced with a PDL item and processed as a skip replacement. This is because fast formatting cannot be performed. Therefore, it is necessary to manage the occurrence of a defect in any case using SDL regardless of the linear substitution and the presence or absence of free space for the linear substitution.

As described above, the present invention is able to escape from the limitation of the maximum defect size that skip substitution is possible due to the constraint that the large size defects occurring in the group must be dealt with only within the group, thereby enabling more efficient skip substitution. According to the application purpose, the size of the free space can be adjusted appropriately, which has the advantage of more effective utilization of the disk space.

Claims (2)

A user data area in which user data is stored; And At least one spare data area for replacing a defective unit of the user data area, And said at least one spare data area is allocated in reverse order from the back of said user data area. The optical data storage medium of claim 1, wherein the spare data area is used from the rearmost end to replace a defective unit of the user data area.

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