JP2004326539A - Method for recording for recording medium - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To uniformize the number of times of rewriting in a recording area of a recording medium and consequently increase the durable number of times of writing on the recording medium by permitting the shift of a physical position, on the recording medium, of a specific area such as a management area for data in which information is frequently changed, without formatting the recording medium. <P>SOLUTION: Every time the power supply of equipment using a memory card is turned on, a FAT area allocated to the memory card is copied to an unused area of the memory card, and the contents of the FAT area of copy source are erased, turning the FAT area into an unused area. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a recording medium recording method, and more particularly to a technique for increasing the number of write endurances to a recording medium such as a memory card.
[0002]
[Prior art]
In general, when data is recorded on a recording medium such as a memory card, information for managing the arrangement of data areas in a logical space is recorded simultaneously with the data. As a method for managing the data area, there is a FAT (File Allocation Table) method, and the recording medium is managed by a “data area” for recording data and a “FAT area” for recording management information of the data area.
[0003]
When writing or erasing data on the recording medium, it is necessary to always change the contents of the FAT, and therefore the number of times of writing and erasing the FAT area is larger than that of the data area. A recording medium such as a NAND memory has an endurance limit on the number of times of writing. However, since the number of times of writing in the FAT area is extremely larger than that in the data area, the portion corresponding to the FAT area tends to be destroyed earlier.
[0004]
As a result, there is a problem that the recording medium itself cannot be used because the FAT area reaches the endurance limit in a short period of time even though most of the data area has a sufficient margin to reach the endurance limit.
[0005]
Conventionally, in order to solve the above-described problems, there is a recording medium formatting method in which when a recording medium format is rewritten, a management area allocated to the recording area of the recording medium is moved to uniformly use the recording medium (patent) Reference 1).
[0006]
[Patent Document 1]
Japanese Patent Laid-Open No. 8-329610
[Problems to be solved by the invention]
However, since the method described in Patent Document 1 moves the management area such as the FAT area allocated to the recording area of the recording medium when rewriting the format of the recording medium, the FAT area or the like unless the recording medium is formatted. There is a problem that the management area cannot be moved.
[0008]
For example, the recording medium may be formatted only when a new recording medium is used for the first time, and then the recording medium is not formatted by repeating data writing, erasing, etc. However, there is a problem that a management area such as a FAT area allocated to the recording area of the recording medium cannot be moved.
[0009]
The present invention has been made in view of such circumstances, and the physical position in the recording medium of a specific area where information is frequently changed, such as a data management area, is not formatted. It is an object of the present invention to provide a recording medium recording method that can make the number of rewrites in the recording area of the recording medium uniform and thereby increase the number of write endurances of the recording medium.
[0010]
[Means for Solving the Problems]
In order to achieve the above object, according to the recording medium recording method of the first aspect, the information that is physically assigned to the recording medium is frequently changed each time the device that uses the recording medium is turned on. The specific area is moved to an unused area of the recording medium.
[0011]
The recording method of the recording medium according to claim 2 counts the number of changes of the contents of a specific area where information is frequently changed physically allocated to the recording medium, and the counted number of changes reaches a specified number. Each time it reaches, the specific area is moved to an unused area of the recording medium.
[0012]
The recording medium recording method according to claim 3, wherein each time data is written to the recording medium, a specific area physically assigned to the recording medium is frequently changed to an unused area of the recording medium. It is characterized by being moved to.
[0013]
According to the recording medium recording method of the present invention, each time data in the recording medium is erased, a specific area that is frequently assigned to the recording medium and is frequently changed is designated as an unrecorded area of the recording medium. It is characterized by being moved to the use area.
[0014]
That is, according to the inventions according to claims 1 to 4, the physical position in the recording medium of the specific area where information is frequently changed is changed every time the device using the recording medium is turned on. The recording medium is moved to an unused area of the recording medium every time the content of the specific area is changed to the specified number of times, every time data is written to the recording medium, or every time data in the recording medium is erased. Thus, the specific area can be moved regularly or irregularly without formatting, thereby making it possible to equalize the number of rewrites in the recording area of the recording medium, and as a result, the number of endurance writing to the recording medium. Can be increased.
[0015]
According to a fifth aspect of the present invention, in the recording medium recording method according to any one of the first to fourth aspects, the specific area is a data management area of the recording medium. The contents of the data management area such as the FAT area are changed each time data is written or erased.
[0016]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, preferred embodiments of a recording medium recording method according to the present invention will be described in detail with reference to the accompanying drawings.
[0017]
FIG. 1 is a principal block diagram of an electronic apparatus to which a recording medium recording method according to the present invention is applied. The electronic device 10 is a device (for example, a digital camera, a personal computer, etc.) that reads / writes data from / to the memory card 12, and mainly includes a control circuit 14 and an internal memory 14 such as an SDRAM.
[0018]
The control circuit 14 performs overall control of the memory card 12, the internal memory 16, and the like. When data is input from the outside, the data is recorded in the memory card 12, and when a read command is received, the data is read from the memory card 12. When the data is output and an instruction to initialize the memory card 12 or erase data is received, the memory card 12 is initialized or the data to be erased is erased.
[0019]
Next, a recording method according to the present invention when data is written to or erased from the memory card 12 by the control circuit 14 will be described with reference to FIGS.
[First Embodiment]
FIG. 2 is a flowchart showing a first embodiment of a recording medium recording method according to the present invention.
[0020]
In general, when data is recorded on a memory card, a physical recording area is arranged in a logical space to enable efficient data operation. As a method of associating a physical area with a logical space, a method of assigning a logical address for each physical structural unit (A, B, C,...) Of a memory card as shown in FIG.
[0021]
The recording area of the memory card is divided into physically small pages (for example, 512 bytes), and further divided into a plurality of continuous physical pages, each block having an address (physical address) in physical space. ) Is assigned. Note that data is read from and written to the memory card in units of pages, and erasure is performed in units of blocks.
[0022]
In FIG. 2, when the electronic device 10 using the memory card 12 is powered on (step S10), the logical address is read from each physical recording area (each block) of the memory card 12, and the read logical address A logical / physical address conversion table for converting the address into a physical address is created (steps S11 and S12). Based on this logical / physical address conversion table, each recording area in the physical space is arranged in the logical space, and a set recorded discontinuously in the physical space is made continuous in the virtual space, and data in the logical space is recorded. Reading, writing, erasing, etc. are performed. FIG. 4A shows an example of the usage state of each recording area in the memory card 12 at this time.
[0023]
Subsequently, in step S13 of FIG. 2, the contents of the area corresponding to the FAT area are read and copied to the unused area (see FIG. 4B). Next, in step S14, the contents of the copy source FAT area are erased (see FIG. 4C).
[0024]
Thereafter, the logical / physical address conversion table is updated (step S16), and the same FAT area is accessed until the electronic device 10 is powered off.
[Second Embodiment]
FIG. 5 is a flowchart showing a second embodiment of the recording method of the recording medium according to the present invention.
[0025]
In the figure, when the electronic device 10 that uses the memory card 12 is powered on (step S20), the logical address is read from each physical recording area of the memory card 12, and the read logical address is used as the physical address. A logical / physical address conversion table to be converted is created (steps S21 and S22). FIG. 6A shows an example of the usage state of each recording area in the memory card 12 at this time.
[0026]
Next, it is determined whether or not there is an operation for writing data and an unused area in which data can be written exists in the memory card 12 (step S23). If an unused area where data can be written exists, new data is written to the unused area as shown in FIG. 6B, and the contents of the FAT area are updated (steps S24 and S25). ). Subsequently, the logical / physical address conversion table is updated (step S26).
[0027]
Further, it is determined whether or not an operation for erasing data has been performed (step S27). If there is an operation for erasing data, the data in the area to be erased is erased as shown in FIG. As a result, the contents of the FAT area are updated (steps S28 and S29). Subsequently, the logical / physical address conversion table is updated (step S30).
[0028]
The number of updates of the contents of the FAT area in step S25 or step S29 is counted, and it is determined whether or not the counted number of changes reaches a specified number and there is an unused area where FAT copying is possible (step). S31). When this condition is satisfied, the contents of the FAT area are copied to the unused area as shown in FIG. 6D, and the contents of the FAT area as the copy source are erased as shown in FIG. 6E. (Step S32). Thereafter, the logical / physical address conversion table is updated (step S33).
[0029]
Then, the processing from step S23 to step S33 is repeatedly executed until the electronic device 10 is turned off (step S34).
[Third Embodiment]
FIG. 7 is a flowchart showing a third embodiment of the recording method of the recording medium according to the present invention.
[0030]
In the figure, when the power of the electronic device 10 using the memory card 12 is turned on (step S40), the logical address is read from each physical recording area of the memory card 12, and the read logical address is used as the physical address. A logical / physical address conversion table to be converted is created (steps S41 and S42). FIG. 8A shows an example of the usage state of each recording area in the memory card 12 at this time.
[0031]
Next, it is determined whether or not there is an operation for writing data and an unused area in which data can be written exists in the memory card 12 (step S43). If an unused area where data can be written exists, new data is written to the unused area as shown in FIG. 8B (step S44).
[0032]
Subsequently, as shown in FIG. 8C, the updated FAT related to the writing of new data is written in the unused area, and the contents of the original FAT area are erased as shown in FIG. Step S45). Thereafter, the logical / physical address conversion table is updated (step S46).
[0033]
Further, it is determined whether or not there has been an operation for erasing data (step S47). If there has been an operation for erasing data, the data in the area to be erased is erased to become an unused area, The contents of the FAT area are updated (steps S48 and S49). Subsequently, the logical / physical address conversion table is updated (step S50).
[0034]
Then, the processing from step S43 to step S50 is repeatedly executed until the electronic device 10 is turned off (step S51).
[Fourth Embodiment]
FIG. 9 is a flowchart showing a fourth embodiment of the recording method of the recording medium according to the present invention.
[0035]
In the third embodiment shown in the flowchart of FIG. 7, the FAT area is moved to an unused area when the contents of the FAT area are updated when new data is written, and when the contents of the FAT area are updated when data is erased. Although the FAT area is not moved, in the following fourth embodiment, contrary to the third embodiment, the FAT area is moved when the contents of the FAT area are updated when new data is written. Instead, the FAT area is moved to an unused area when the contents of the FAT area are updated when data is erased.
[0036]
That is, in FIG. 9, when the electronic device 10 that uses the memory card 12 is turned on (step S60), the logical address is read from each physical recording area of the memory card 12, and the read logical address is physically read. A logical / physical address conversion table to be converted into addresses is created (steps S61 and S62).
[0037]
Next, it is determined whether or not there is an operation for writing data and an unused area in which data can be written exists in the memory card 12 (step S63). If there is an unused area in which data can be written, new data is written in the unused area, and then the contents of the FAT area are updated (steps S64 and S65). Subsequently, the logical / physical address conversion table is updated (step S66). FIG. 10A shows an example of the usage state of each recording area in the memory card 12 at this time.
[0038]
Further, it is determined whether or not an operation for erasing data has been performed (step S67). If there is an operation for erasing data, the data in the area to be erased is erased as shown in FIG. Thus, an unused area is set (step S68). Subsequently, as shown in FIG. 10C, the updated FAT related to the data erasure is written in the unused area, and the contents of the original FAT area are erased as shown in FIG. S69). Thereafter, the logical / physical address conversion table is updated (step S70).
[0039]
Then, the processing from step S63 to step S70 is repeatedly executed until the electronic device 10 is turned off (step S71).
[0040]
In this embodiment, the FAT area in the memory card is moved. However, the FAT area is not limited to the FAT area. For example, the directory area in which information of the root directory is recorded, or both the FAT area and the directory area may be used. In short, any area may be used as long as information is frequently changed.
[0041]
【The invention's effect】
As described above, according to the present invention, the physical position in the recording medium of a specific area where information is frequently changed, such as a data management area, is turned on to a device that uses the recording medium. Every time the number of changes in the contents of a specific area reaches the specified number, every time data is written to the recording medium, or every time data in the recording medium is erased, it is moved to an unused area on the recording medium. The specific area can be moved regularly or irregularly without formatting the recording medium, whereby the number of rewrites in the recording area of the recording medium can be made uniform. The number of write endurances can be increased.
[Brief description of the drawings]
FIG. 1 is a block diagram of an essential part of an electronic apparatus to which a recording medium recording method according to the present invention is applied. FIG. 2 is a flowchart showing a first embodiment of a recording medium recording method according to the present invention. FIG. 4 is a diagram showing an arrangement of recording areas from a physical space to a logical space using logical addresses. FIG. 4 is a diagram showing a state of moving a FAT area used for explaining the first embodiment. 6 is a flowchart showing a second embodiment of a recording medium recording method according to the present invention. FIG. 6 is a diagram showing a state of moving a FAT area used to explain the second embodiment. 8 is a flowchart showing a third embodiment of the recording method of the recording medium according to the invention. FIG. 8 is a diagram showing a state of moving the FAT area used to explain the third embodiment. 4 shows a recording medium recording method according to a fourth embodiment of the invention Flow [10] Figure [EXPLANATION OF SYMBOLS] showing a movement of the FAT area used for explaining the fourth embodiment
DESCRIPTION OF SYMBOLS 10 ... Electronic device, 12 ... Memory card, 14 ... Control circuit, 16 ... Internal memory

Claims (5)

Each time a device that uses a recording medium is turned on, a specific area that is physically assigned to the recording medium and frequently changes information is moved to an unused area of the recording medium. A recording method of a recording medium. The number of changes in the contents of a specific area where information is frequently changed physically allocated to the recording medium is counted. A recording method for a recording medium, wherein the recording medium is moved to an unused area. Recording of a recording medium, characterized in that each time data is written to the recording medium, a specific area that is physically assigned to the recording medium is frequently moved to an unused area of the recording medium. Method. A recording medium characterized in that, every time data in a recording medium is erased, a specific area that is physically assigned to the recording medium and whose information is frequently changed is moved to an unused area of the recording medium. Recording method. 5. The recording medium recording method according to claim 1, wherein the specific area is a data management area of the recording medium.

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