JP2009064394A - Access control device, access control method, access control program, storage medium, storage device, and image processing device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an access control device which assigns an appropriate storage medium to data in accordance with a data-rewriting frequency. <P>SOLUTION: The access control device includes: a FLASH ROM which memorizes a conversion table for correlating an outside address, an inside address of data in MLC, SLC, or FeRAM, and the number of rewriting times with each other; a determination section 601 which determines whether the number of rewriting times corresponding to an inside address exceeds a predetermined first threshold value or not when an inside address corresponding to an outside address designated for writing is an inside address of MLC or SLC; a transferring section 602 which transfers data stored in the inside addresses having the number of rewriting times exceeding the first threshold value to the inside addresses of SLC or FeRAM respectively; and a table renewal section 603 which renews the conversion table by substituting transfer destination inside addresses for the inside addresses corresponding to the outside addresses of the transferred data. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an access control device that controls access to a storage device, an access control method, an access control program, a recording medium, a storage device, and an image processing device such as a printer, a scanner, a FAX, a copier, and a multifunction peripheral. .

  A hard disk drive (HDD) is widely used as a storage device for storing data. Also, NAND flash memory (hereinafter referred to as NAND FLASH) and FeRAM (Ferroelectric Random Access Memory) are widely known as storage media used in a non-volatile storage device different from the HDD.

  NAND FLASH is mainly classified into two types, SLC (Single Level Cell) and MLC (Multi Level Cell). The upper limit of the number of times data can be rewritten and the manufacturing cost are different between SLC and MLC. For example, SLC and MLC can be rewritten approximately 100,000 times and approximately 10,000 times, respectively. Also, the manufacturing cost of MLC is lower than that of SLC.

  On the other hand, FeRAM can be rewritten 10 to 100 billion times, which is much larger than NAND FLASH. However, since FeRAM is not highly integrated, there is a drawback that the bit unit price is high.

  In Patent Document 1, file management information having a high rewrite frequency in the flash memory is written to the volatile memory when the power is turned on, the file management information is updated on the volatile memory, and the updated information is written to the flash memory when the power is shut off. Storage devices have been proposed. As a result, it is possible to extend the life of a storage device composed of a flash memory with a short access life.

JP 2006-252535 A

  In consideration of extending the life of the storage device, it is desirable to use an FeRAM with a large number of rewritable times, but there is a problem that the cost becomes very high. Therefore, a method of using MLC or SLC, which is lower in cost than FeRAM, together with FeRAM as a storage medium in the storage device is conceivable. This method uses a conversion table in which the address of data designated by the access request source is associated with the address of the storage medium that actually stores the data. Thereby, the access request source can recognize the data as one storage device without being aware of which storage medium stores the data.

  However, since the number of times that each storage medium can be rewritten is different, for example, if data with a high rewrite frequency is stored in an MLC with a small number of rewrites, the probability of occurrence of a defective block increases. In this case, even if wear leveling is performed and the number of rewrites is averaged in the storage device, there is a problem that the life of the entire storage device is shortened.

  The present invention has been made in view of the above, and an access control device, an access control method, an access control program, a recording medium, a storage device, and an image that can allocate an appropriate storage medium according to the data rewrite frequency An object is to provide a processing apparatus.

  In order to solve the above-described problems and achieve the object, the invention according to claim 1 is directed to an external device, first storage means for storing data accessed by the external device, the data stored, and the data An access control device connected to the second storage means having a rewritable number greater than that of the first storage means, the external address designated for accessing the data by the external device, and the first storage Table storage means for storing a conversion table in which an internal address indicating either the storage position of the data in the means or the storage position of the data in the second storage means and the number of times of rewriting the data are associated with each other Determining whether the internal address corresponding to the external address for which writing has been designated is the internal address of the first storage means; A determination means for determining whether or not the number of rewrites corresponding to the internal address exceeds a predetermined first threshold when the internal address is in a stage; and the number of rewrites exceeds the first threshold Move the data stored at the internal address of the first storage means to the internal address of the second storage means, and move the internal address corresponding to the external address of the moved data Table updating means for updating the conversion table by replacing with the previous internal address.

  The invention according to claim 2 further comprises calculation means for calculating the sum of the number of rewrites corresponding to the internal address of the second storage means in the invention according to claim 1, wherein the determination means further comprises: Determining whether or not the sum is a multiple of a predetermined value, and the moving means further includes the internal address of the second storage means when the sum is a multiple of the predetermined value. The data stored in the internal addresses in a predetermined ratio in ascending order of the number of rewrites is moved to the internal addresses of the first storage means.

  The invention according to claim 3 is the invention according to claim 2, wherein the table storage means determines whether or not the internal address of the second storage means is replaced with the internal address of the first storage means. The conversion table further correlating the change history information to be represented is stored, and the moving unit includes the internal address of the second storage unit, the internal address of the second storage unit, and the first storage unit of the first storage unit. The data of the internal address associated with the change history information indicating the replacement with the internal address does not move to the internal address of the first storage means.

  The invention according to claim 4 is the invention according to claim 1, further comprising transmission / reception means for transmitting / receiving the conversion table to / from the external device.

  According to a fifth aspect of the present invention, in the first aspect of the invention, the moving unit stores the data stored in the internal address of the first storage unit in which the number of rewrites exceeds the first threshold. The internal address of the second storage means moves to the internal address where the data is not written.

  The invention according to claim 6 is the invention according to claim 5, wherein the determination means further determines whether or not the internal address where the data is not written exists in the second storage means. The moving means stores the internal address of the first storage means in which the number of rewrites exceeds the first threshold when there is no internal address where the data is not written in the second storage means. The transferred data is moved to another internal address in which the data of the first storage means is not written.

  The invention according to claim 7 is the invention according to claim 6, wherein the table storage means replaces the internal address of the first storage means with another internal address of the first storage means. And storing the conversion table further associating movement information representing the above.

  The invention according to claim 8 is the invention according to claim 5, wherein the determination means further determines whether or not the internal address where the data is not written exists in the second storage means. The moving means, when there is no internal address in which the data is not written in the second storage means, the internal ratios of a predetermined ratio in ascending order of the number of rewrites corresponding to the second storage means Moving to one of the addresses.

  The invention according to claim 9 is an external device, first storage means for storing data accessed by the external device, and the data stored therein, wherein the number of times the data can be rewritten is greater than that of the first storage means. An access control method in an access control device connected to a second storage means, wherein the access control device is an external address designated for accessing the data by the external device, and the first storage means. A table storage means for storing a conversion table in which an internal address indicating either the storage position of the data or the storage position of the data in the second storage means and the number of rewrites of the data are associated with each other; The internal address corresponding to the external address designated for writing by the judging means is the internal address of the first storage means. A determination step of determining whether or not the number of rewrites corresponding to the internal address exceeds a predetermined first threshold value when the internal address of the first storage means is determined; A moving step of moving, by moving means, the data stored at the internal address of the first storage means whose number of rewrites exceeds the first threshold to the internal address of the second storage means; And a table updating step of updating the conversion table by replacing the internal address corresponding to the external address of the moved data by the update means with the internal address of the transfer destination.

  The invention according to claim 10 is the invention according to claim 9, wherein the calculation means calculates the sum of the number of rewrites corresponding to the internal address of the second storage means, and the determination means. A second determination step of determining whether or not the sum is a multiple of a predetermined value; and the moving means further includes the second storage when the sum is a multiple of the predetermined value. A second movement step of moving the data stored in the internal addresses at a predetermined ratio in ascending order of the number of rewrites corresponding to the internal addresses of the means to the internal addresses of the first storage means; , Further comprising.

  The invention according to claim 11 is the invention according to claim 10, wherein the table storage means determines whether or not the internal address of the second storage means is replaced with the internal address of the first storage means. The conversion table further correlating the change history information to be expressed is stored, and the second moving step includes the first storage means from the internal address of the second storage means among the internal addresses of the second storage means. The data of the internal address associated with the change history information indicating the replacement with the internal address is not moved to the internal address of the first storage means.

  The invention according to claim 12 is the invention according to claim 9, further comprising a transmission / reception step of transmitting / receiving the conversion table to / from the external device by transmission / reception means.

  The invention according to claim 13 is the invention according to claim 9, wherein in the moving step, the data stored in the internal address of the first storage means in which the number of rewrites exceeds the first threshold is stored. The internal address of the second storage means moves to the internal address where the data is not written.

  The invention according to claim 14 is the invention according to claim 13, wherein the determining step further determines whether or not the internal address where the data is not written exists in the second storage means. The moving step stores the internal address of the first storage unit in which the number of rewrites exceeds the first threshold when there is no internal address where the data is not written in the second storage unit. The transferred data is moved to another internal address in which the data of the first storage means is not written.

  The invention according to claim 15 is the invention according to claim 14, wherein the table storage means replaces the internal address of the first storage means with another internal address of the first storage means. And storing the conversion table further associating movement information representing the above.

  According to a sixteenth aspect of the present invention, in the invention according to the thirteenth aspect, the determining step further determines whether or not the internal address where the data is not written exists in the second storage means. In the moving step, when the internal address where the data is not written in the second storage means does not exist, the internal ratio is set in a predetermined order in ascending order of the number of rewrites corresponding to the second storage means. Moving to one of the addresses.

  The invention according to claim 17 is an access control program for causing a computer to execute the access control method according to claim 9.

  The invention according to claim 18 is a computer-readable recording medium having recorded thereon the access control program according to claim 17 to be executed by a computer.

  According to a nineteenth aspect of the present invention, there is provided a first storage means for storing the data accessed by an external device, and a second storage means for storing the data, wherein the number of rewritable times of the data is greater than the first storage means. And an external address designated by the external device for accessing the data, and an internal address representing either the data storage position in the first storage means or the data storage position in the second storage means Table storage means for storing a conversion table in which an address is associated with the number of times of rewriting the data, and the internal address corresponding to the external address for which writing is specified is the internal address of the first storage means When the internal address of the first storage means is determined, the number of rewrites corresponding to the internal address is determined in advance. Determining means for determining whether or not the first threshold value exceeded, and the second storage means for storing the data stored at the internal address of the first storage means for which the number of rewrites exceeds the first threshold value. Moving means for moving to the internal address, and table updating means for updating the conversion table by replacing the internal address corresponding to the external address of the moved data with the internal address of the movement destination. It is characterized by that.

  According to a twentieth aspect of the present invention, there is provided an image processing apparatus that includes a printer unit or a scanner unit and processes input image data, the first storage unit storing the image data, and the image data stored therein. A second storage means having a number of rewritable times of the image data greater than the first storage means, an external address designated for accessing the image data, and a storage location of the image data in the first storage means Alternatively, a table storage means for storing a conversion table in which an internal address representing one of the storage positions of the image data in the second storage means and the number of rewrites of the image data are associated with each other, and writing is designated Determining whether the internal address corresponding to the external address is the internal address of the first storage means; In the case of an internal address, determination means for determining whether or not the number of rewrites corresponding to the internal address exceeds a predetermined first threshold; and the first that the number of rewrites exceeds the first threshold A moving means for moving the image data stored at the internal address of the storage means to the internal address of the second storage means, and an internal address corresponding to the external address of the moved image data, And table updating means for updating the conversion table by substituting the internal address.

  According to the present invention, there is an effect that an appropriate storage medium can be allocated according to the data rewrite frequency.

  Exemplary embodiments of an access control apparatus according to the present invention will be explained below in detail with reference to the accompanying drawings. In the following, the access control apparatus according to the present invention is a multi-function machine that is an image processing apparatus including devices such as an image forming unit that forms an image on an image carrier and a fixing unit that fixes the formed image on a recording sheet. An example applied to is described. Note that an applicable device is not limited to a multi-function device, and can be applied to any other electronic device such as a personal computer as long as the device stores data in a nonvolatile storage medium such as NAND FLASH.

(First embodiment)
The multifunction peripheral according to the first embodiment includes a storage device that includes a plurality of storage media having different upper limit values for the number of rewritable times, and when the number of times of rewriting for a storage medium with a lower upper limit value exceeds a predetermined threshold, The conversion table is updated so that a storage medium with a large upper limit value is substituted.

  FIG. 1 is a simplified diagram illustrating a configuration of a multifunction peripheral 100 according to the first embodiment. In the multifunction machine 100, the scanner unit 101 and the laser recording unit 102 form an image and print on paper, and the post-processing unit 103 performs output paper alignment, stapling, and punch hole processing.

  The scanner unit 101 includes a transparent glass platen 104, an automatic double-sided document feeder 105 (hereinafter referred to as RADF) for feeding a document on the top surface of the document table 104, and a document placed on the top surface of the document table 104. The scanner unit 106 reads an image.

  Image data read by the scanner unit 101 is output to the laser recording unit 102.

  The RADF 105 reverses the front and back surfaces of a document on which a single-sided image feed path from the document tray (not shown) to the discharge tray (not shown) via the document table 104 and the scanner unit 106 has read the image on one side again. It has a double-sided document feed path leading to the document table 104, and can handle both single-sided and double-sided documents.

  The scanner unit 106 irradiates a document with a lamp, and forms an image of reflected light of the document on a light receiving surface of a photoelectric conversion element with a lens, a mirror, or the like. The photoelectric conversion element converts the reflected light on the image surface of the document into an electrical signal and outputs it to the image processing unit 204 (described later in FIG. 2).

  The laser recording unit 102 includes a paper transport unit 107 that transports paper, a laser writing unit 108, and an electrophotographic process unit (image forming unit) 109.

  The paper transport unit 107 includes a sub transport path that reverses the front and back surfaces of the paper that has passed through the fixing roller and leads it to the electrophotographic process unit 109 again in the double-sided copying mode in which images are formed on both sides of the paper.

  The laser writing unit 108 is a semiconductor laser that irradiates laser light based on image data supplied from the image processing unit 204, and the surface of the photosensitive drum of the electrophotographic process unit 109 that passes the light irradiated from the semiconductor laser through a mirror or a lens. Light distribution. An electrostatic latent image is formed on the surface of the photosensitive drum, and the toner image is made visible by supplying toner from the developing device.

  The toner image is transferred onto the paper guided from the paper transport unit 107, and then heated and pressurized by the fixing roller, and the toner image is melted and fixed on the surface of the paper.

  After the writing on the sheet is completed in this way, a part of the output sheet is aligned in the post-processing unit 103, the staple and punch holes are processed, and the sheet is discharged to the tray.

  Next, a detailed configuration and function of the multifunction peripheral 100 will be described with reference to FIG. FIG. 2 is a block diagram illustrating a detailed configuration of the MFP 100 according to the first embodiment.

  As shown in FIG. 2, the multifunction peripheral 100 includes, as main hardware configurations, the post-processing unit 103, the RADF 105, the scanner unit 106, the paper transport unit 107, the laser writing unit 108, and the electrophotographic process unit 109 described above. In addition, a duplex unit 217 used for duplex printing, an operation panel 225, and a storage device 300 are provided.

  In addition, an operation panel board 228, a machine control board 231, a CCD board 210, and an image processing board 201 are provided as control units that control these units.

  The operation panel 225 includes an LCD (Liquid Crystal Display) 223 and operation keys 224 provided on the upper surface of the multifunction peripheral 100.

  The operation panel board 228 includes a RAM 227 that is a work area, and a CPU 226 that controls the operation panel 225 using the RAM 227.

  The machine control board 231 manages each device including the duplex unit 217, the post-processing unit 103, the RADF 105, the scanner unit 106, the paper transport unit 107, the laser writing unit 108, and the electrophotographic process unit 109. The machine control board 231 includes a RAM 229 that is a work area, and a CPU 230 that performs control for managing each device using the RAM 229.

  The post-processing unit 103 includes a CPU 222 that controls the operation of the post-processing unit 103. The RADF 105 also includes a CPU 221 that controls the operation of the RADF 105.

  The CCD board 210 includes a CCD 213 which is a photoelectric conversion element, and an A / D conversion unit 211, a CCD control unit 212, and an analog circuit 214 as peripheral components of the CCD 213.

  The image processing board 201 includes a CPU 202 that performs various kinds of image processing on image data, and RAM 203, an image processing unit 204, a laser control unit 207, an image accumulation control unit 205, and data accumulation as peripheral components of the CPU 202. A unit 206 and an I / F controller 208.

  In the MFP 100, the CPU 202 mounted on the image processing board 201 controls the devices configuring each unit in an integrated manner via the CPU mounted on each board arranged for each unit. The RAM 203 is also used as a work area for the CPU 202.

  Next, processing of image data in the copy mode in the multi function device 100 will be described.

  First, the image of the document fed to the document table 104 via the RADF 105 is sequentially read by the scanner unit 106.

  The CCD 213 on the CCD board 210 in the scanner unit 106 is driven by the CCD controller 212. The output signal of the CCD 213 is sent to the image processing board 201 as 8-bit image data from the A / D converter 211 after gain adjustment is performed by the analog circuit 214.

  The image data is subjected to predetermined image processing by the image processing unit 204 and then stored in the data storage unit 206 by the image storage control unit 205.

  The image data stored in the data storage unit 206 is stored in the storage device 300. These processes are executed for all documents set in the RADF 105.

  After the image reading is completed, the image accumulation control unit 205 repeats the process of reading the plurality of pieces of image data stored in the storage device 300 in the page order by the number of set copies. The image data is supplied to the laser writing unit 108 via the laser control unit 207 after predetermined image processing is executed by the image processing unit 204. Then, the laser writing unit 108 writes image data on the paper. After the image data is written, a part of the output paper is aligned by the post-processing unit 103, staple and punch holes are processed, and the paper is discharged to the discharge tray.

  Accordingly, even when a plurality of copies of each original image are formed, the reading operation for each original image need only be performed once.

  Next, the hardware configuration of the storage device 300 will be described with reference to FIG. As shown in FIG. 3, the storage device 300 includes, as main hardware configurations, an MLC NAND FLASH (hereinafter simply referred to as MLC301), an SLC NAND FLASH (hereinafter simply referred to as SLC302), an FeRAM 303, A NAND FLASH MLC controller 311 that controls the MLC 301, a NAND FLASH SLC controller 312 that controls the SLC 302, an FeRAM controller 313, and a control unit 320 are provided.

  As described above, the storage device 300 includes three storage media in which the number of rewritable times increases in the order of the MLC 301, the SLC 302, and the FeRAM 303. Note that the combination of storage media constituting the storage device 300 is not limited to the MLC 301, the SLC 302, and the FeRAM 303. As long as a plurality of storage media having different rewritable times are combined, the storage device 300 can be configured by any combination of storage media.

  For example, a plurality of MLC NAND FLASHs having different multi-value levels such as 4-value (2 bits) or 16-value (4 bits) may be combined.

  Next, the hardware configuration of the control unit 320 will be described. As illustrated in FIG. 3, the control unit 320 includes a CPU 321, a RAM 322, a FLASH ROM 323, and an I / F controller 324 as main hardware configurations.

  The FLASH ROM 323 stores an access control program that executes access control processing, a conversion table, and the like. The CPU 321 controls each part of the multifunction peripheral 100 according to a program in the FLASH ROM 323. The RAM 322 stores various data necessary for controlling the multifunction peripheral 100.

  The I / F controller 324 executes access control to the storage device 300. For example, the I / F controller 324 receives an access command transmitted from the image processing board 201 and stores it in the RAM 322. The I / F controller 324 can be realized, for example, as an ATA controller that can control an access command based on the ATA standard.

  The type of the I / F controller is not limited to this, but is Serial ATA, USB (Universal Serial Bus), IEEE (Institute of Electrical and Electronic Engineers) 1394, SPI (Serial Peripheral Interface), I2C (Inter-Integrated Circuit). ), DRAM BUS, and any interface standard such as an interface used in a storage medium such as SRAM using signals such as CS, WE, OE, ADDRESS, and DATA.

  Note that commands issued from a host such as the image processing board 201 connected to the storage device 300 are temporarily stored in the RAM 322 via the I / F controller 324. The CPU 321 refers to the conversion table using an LBA (Logical Block Address) in the command stored in the RAM 322 as a key, and specifies a storage medium and an address to be accessed. The control unit 320 also converts access units for the storage medium. For example, the control unit 320 accesses the MLC 301, the SLC 302, and the FeRAM 303 with the access unit aligned to 512 bytes.

  Here, the configuration of the conversion table stored in the FLASH ROM 323 will be described. FIG. 4 is an explanatory diagram illustrating an example of the data structure of the conversion table according to the first embodiment. As shown in FIG. 4, the conversion table stores a host LBA, an assigned device, a device LBA, a used / unused flag, and the number of rewrites in association with each other.

  The host LBA is an address (external address) designated by the host side such as the image processing board 201 connected to the storage device 300 for accessing data. As described above, in the storage device 300, access is controlled by an LBA having a sector (512 bytes) as one unit, like a generally used HDD. Note that the unit of LBA is not limited to 512 bytes. Also, the conversion table may be configured to manage the number of rewrites in units of blocks in which the host LBAs are further grouped.

  The allocation device sets the type (MLC, SLC, or FeRAM) of a storage medium (device) to be allocated as a data storage area specified by the host LBA. The device LBA sets an address (internal address) of data in the assigned device. The used / unused flag is a flag indicating whether or not data is written in an area specified by the device LBA of the assigned device. “Unused” is set when data is not written in the area, and “used” is set when data is written. The number of rewrites sets the number of times data is written to the area specified by the device LBA.

  By referring to such a conversion table, the host side can access data without being aware of the storage medium in the storage device 300. Even if the storage medium for storing the data is changed according to the frequency of access to the data, the host can change the storage medium without being aware of the change of the storage medium simply by updating the conversion table accordingly. You can access the data in the same way as before.

  The conversion table is created in advance according to the combination of storage media constituting the storage device 300 and the respective capacities, and is stored in the FLASH ROM 323.

  Next, an example of address assignment for the storage medium constituting the storage device 300 will be described. FIG. 5 is a diagram illustrating an example of an address map of the storage device 300.

  In the figure, an example is shown in which LBA (host LBA) = 0 to 2097151 is assigned to the MLC 301, LBA = 2097152 to 3145727 is assigned to the SLC 302, and LBA = 3145728 to 3670015 is assigned to the FeRAM 303.

  Further, in the example of the figure, the address of the FLASH ROM 323 storing the conversion table is assigned to LBA = 3670016. Accordingly, the transmission / reception unit 604 described later can transmit / receive the conversion table to / from the external device.

  Next, the software configuration of the control unit 320 in FIG. 3 will be described. FIG. 6 is a functional block diagram for explaining the software configuration of the control unit 320. As illustrated in FIG. 6, the control unit 320 includes a determination unit 601, a moving unit 602, a table updating unit 603, and a transmission / reception unit 604 as main software configurations.

  The determination unit 601 determines whether to move data to a device having a large number of rewritable times. Specifically, the determination unit 601 is a device in which the allocation device corresponding to the host LBA designated from the host side is smaller in the number of rewritable times than other devices, and the number of rewritable times corresponding to the host LBA is a predetermined threshold value. Judge whether or not

  When the number of rewrites exceeds a predetermined threshold, the moving unit 602 moves the device storing the corresponding data to a device with a larger number of rewrites. The moving unit 602 refers to the used / unused flag of the conversion table, specifies an unused address in the device having a large number of rewritable times, and moves data to any of the unused addresses. It should be noted that if the number of rewrites is 0, it can be determined that it is not used, but if a used / unused flag is used, it can be more easily determined whether it is unused.

  When there is no unused address, the moving unit 602 specifies a predetermined ratio of addresses in ascending order of rewrites, and moves data using any of the specified addresses as a transfer destination. Further, the moving unit 602 may be configured to move data to an address having the smallest number of rewrites.

  The table update unit 603 updates the conversion table. For example, when the data is moved by the moving unit 602, the table updating unit 603 updates the conversion table accordingly. More specifically, the table update unit 603 changes the device assigned to the host LBA of the moved data from the source device to the destination device. Further, the table update unit 603 changes the allocation device for the host LBA associated with the migration destination device to the migration source device. Further, the table updating unit 603 updates the conversion table by exchanging the values of the device LBA, the used / unused flag, and the number of rewrites in accordance with such replacement of the allocated devices.

For example, it is assumed that the change table before movement is set as follows.
(1) Host LBA = 0, assigned device = MLC, device LBA = 0
(2) Host LBA = 2097153, Allocated device = SLC, Device LBA = 1

When the data corresponding to each of the host LBAs of (1) and (2) above are replaced, the table update unit 603 changes the conversion table as follows.
(1 ′) Host LBA = 0, assigned device = SLC, device LBA = 1
(2 ′) Host LBA = 2097153, Allocated device = MLC, Device LBA = 0

  The transmission / reception unit 604 transmits / receives a conversion table between the host and the storage device 300. For example, when the I / F controller 324 conforms to the ATA standard, the transmission / reception unit 604 converts the LBA conversion table in response to the READ command issued to the conversion table LBA (= 3670016) in FIG. Is sent to the command issuer. Further, according to the WRITE command issued to the LBA, the transmission / reception unit 604 updates the conversion table of the LBA with the conversion table received from the command issuer.

  The access control program of the first embodiment is a computer-readable recording medium such as a CD-ROM, a floppy (registered trademark) disk (FD), a DVD or the like in an installable or executable file. May be recorded and provided.

  In this case, the access control program is loaded onto the CPU 321 by being read from the recording medium and executed by the multi-function device 100, and each unit described in the software configuration is generated on the CPU 321.

  Further, the access control program of the present embodiment may be provided by being stored on a computer connected to a network such as the Internet and downloaded via the network.

  Next, an access control process performed by the MFP 100 according to the first embodiment configured as described above will be described. FIG. 7 is a flowchart showing an overall flow of access control processing in the first embodiment.

  First, the control unit 320 determines whether the access request is a write access according to the type of command received (step S701). If the access is not write access, that is, read access (step S701: NO), the control unit 320 executes read access processing for reading data from the designated host LBA (step S702).

  In the case of write access (step S701: YES), the control unit 320 executes a write access process for writing the designated data to the designated host LBA (step S703).

  Next, the control unit 320 obtains an allocation device, a device LBA (hereinafter referred to as DA1), and a rewrite count (hereinafter referred to as WC1) corresponding to the accessed host LBA (hereinafter referred to as HA1) from the conversion table (step S704). ).

  Next, the table update unit 603 adds 1 to the acquired WC1 (step S705). Next, the determination unit 601 determines whether the assigned device is an MLC and WC1 has exceeded a threshold value 1 (for example, 5,000 times) indicating the upper limit of the number of rewrites predetermined for the MLC 301. (Step S706).

  When allocation device = MLC and WC1> threshold 1 (step S706: YES), conversion table update processing is executed in which data is moved to SLC302 whose upper limit of the number of rewritable times is larger than MLC301 and the conversion table is updated. (Step S707). Details of the conversion table update process will be described later.

  If it is determined in step S706 that the assigned device = MLC and WC1> threshold 1 is not satisfied (step S706: NO), the determining unit 601 determines that the assigned device is SLC and WC1 is predetermined for SLC302. It is further determined whether or not a threshold value 2 (for example, 50,000 times) representing the upper limit of the number of rewrites exceeded has been exceeded (step S708).

  When allocation device = SLC and WC1> threshold 2 (step S708: YES), conversion table update processing is executed in which data is moved to FeRAM 303 whose upper limit of the number of rewritable times is larger than SLC302, and the conversion table is updated. (Step S709). Note that the conversion table update processing in this case is different only in the migration destination device and the migration source device, and the processing content is the same as the conversion table update processing in step S707 (described later).

  After executing the conversion table update process in step S707 or S709, the host LBA of the migration destination device is set as the accessed host LBA, and the process returns to step S704 to repeat the process.

  If it is determined in step S708 that the assigned device = SLC and WC1> threshold 2 is not satisfied (step S708: NO), and after the read access is executed in step S702, the control unit 320 ends the access control process.

  Next, details of the conversion table update processing in steps S707 and S709 will be described. FIG. 8 is a flowchart showing the overall flow of the conversion table update process in the first embodiment.

  First, the migration unit 602 searches the conversion table for a host LBA (hereinafter referred to as HA2) whose assigned device matches the destination device and is unused or has the smallest number of rewrites (step S801). In addition, the moving unit 602 acquires a device LBA (hereinafter referred to as DA2) corresponding to HA2 and the number of rewrites (hereinafter referred to as WC2) (step S802).

  Next, the table update unit 603 changes the assigned device corresponding to HA1 to the movement destination device (step S803). In addition, the table update unit 603 changes the device LBA corresponding to HA1 from DA1 to DA2 (step S804). DA1 means the device LBA of the source device, that is, the device LBA acquired in step S704 in FIG. Further, the table update unit 603 changes the number of rewrites corresponding to HA1 from WC1 to WC2 (step S805).

  Similarly, the table updating unit 603 executes the following processing in order to update each item corresponding to HA2 that is the migration destination host LBA with each item corresponding to HA1 (from step S806 to step S808). .

  That is, first, the table update unit 603 changes the allocation device corresponding to HA2 to the migration source device (step S806). Further, the table update unit 603 changes the device LBA corresponding to HA2 from DA2 to DA1 (step S807). Further, the table updating unit 603 changes the number of rewrites corresponding to HA2 from WC2 to WC1 (step S808).

  The conversion table need not be updated for each item as described above. For example, a plurality of items corresponding to one host LBA may be updated collectively.

  Next, the migration unit 602 reads the data of the device LBA = DA1 (hereinafter referred to as DDA1) of the migration source device into the RAM 322 (step S809).

  Next, the determination unit 601 determines whether or not WC2 = 0 (step S810). This means that the determination unit 601 determines whether data is written in DA2 that is the address of the destination device. This is because the data written in the destination device needs to be moved to the source device.

  If WC2 = 0 is not satisfied (step S810: NO), the moving unit 602 reads the data of the device LBA = DA2 (hereinafter referred to as DDA2) of the movement destination device into the RAM 322 (step S811). Then, the migration unit 602 reads DDA2 from the RAM 322 and writes it to the device LBA = DA1 of the migration source device (step S812).

  After writing DDA2 in step S812 or if it is determined in step S810 that WC2 = 0 (step S810: YES), the moving unit 602 reads DDA1 from the RAM 322, and the device LBA = DA2 of the destination device (Step S813).

  In the above description, the threshold value used for the determination of the number of rewrites is a half value (MLC: 5,000 times, SLC: 50,000 times) of the upper limit value of rewriteable times (MLC: 10,000 times, SLC: 100,000 times). However, the threshold value may be any value as long as it is within the upper limit range.

  As described above, in the access control device according to the first embodiment, it is determined whether or not the number of rewrites exceeds the threshold value determined for each type of storage medium. The data can be copied to a larger storage medium and the conversion table can be updated. That is, an optimal storage medium can be allocated according to the data rewrite frequency, and the occurrence probability of defective blocks can be reduced. Thereby, the reliability of the storage device can be improved. Further, it is possible to realize a low-cost and long-life storage device without using only a high-cost storage medium having a large number of rewritable times.

  In the access control device according to the first embodiment, the optimized conversion table can be transferred to the outside, so that it is possible to create a copy of the storage device that has learned the optimal configuration. . Further, by analyzing the contents of the conversion table, it is possible to perform biasing of the storage medium being used, life prediction, and the like.

(Second Embodiment)
In the first embodiment, the occurrence of defects is avoided by moving data from a storage medium having a small upper limit of the number of rewritable times to a storage medium having a large upper limit. On the other hand, among the data stored in the storage medium with a large upper limit value, the data with a small number of write accesses is considered to have a low probability of occurrence of a defect even if it is replaced with a storage medium with a small upper limit value.

  Therefore, in the multi-function peripheral according to the second embodiment, among the data stored in the storage medium having the large upper limit value of the rewritable number, the data having the smaller rewritable number is transferred to the storage medium having the smaller upper limit value of the rewritable number. It is something that moves.

  Next, a detailed configuration and function of the multifunction machine 900 according to the second embodiment will be described with reference to FIG. FIG. 9 is a block diagram illustrating a detailed configuration of the MFP 900 according to the second embodiment.

  In the second embodiment, only the configuration of the storage device 930 is different from that of the first embodiment. Other configurations and functions are the same as those in FIG. 2 which is a block diagram showing the configuration of the multi-function device 100 according to the first embodiment, and thus are denoted by the same reference numerals and description thereof is omitted here.

  The storage device 930 of the second embodiment is different from the storage device 300 of the first embodiment only in the function of the control unit 920 (described later in FIG. 10) and the configuration of the conversion table. That is, since the hardware configuration of the storage device 930 is the same as that of FIG. 3 which is the hardware configuration of the storage device 300 of the first embodiment, the description thereof is omitted.

  Next, the data structure of the conversion table in the second embodiment will be described with reference to FIG. As shown in FIG. 10, the conversion table further stores a device change history in association with the host LBA, the assigned device, the device LBA, the used / unused flag, and the number of rewrites.

  As the device change history, a history in which data is moved from a storage medium having a large upper limit of the number of rewrites to a storage medium having a small upper limit is set. Specifically, “Yes” is set in the device change history when data is moved from the FeRAM 303 to the SLC 302 or from the SLC 302 to the MLC 301 and the conversion table is updated by a method described later. In the device change history, “none” is set by default.

  The device change history is used to avoid the occurrence of a data movement loop. For example, since the number of times of rewriting of the MLC 301 has reached the threshold value, it may be replaced with the SLC 302, and it may be determined that the number of write accesses is small by a method described later, and replaced with the MLC 301 again. Furthermore, in this case, there is a possibility that a loop of substitution processing may occur such that the number of rewrites reaches the threshold value and substitution is made for the SLC 302. Therefore, in the present embodiment, the device change history is referred to, and control is performed so as not to move again when it has been moved to a storage medium having a small upper limit value in the past.

  Next, a software configuration of the control unit 920 in the storage device 930 according to the second embodiment will be described. FIG. 11 is a functional block diagram for explaining the software configuration of the control unit 920. As illustrated in FIG. 11, the control unit 920 includes a determination unit 901, a moving unit 902, a table update unit 903, a transmission / reception unit 604, and a calculation unit 905 as main software configurations.

  The configuration and function of the transmission / reception unit 604 are the same as those in FIG. 6, which is a block diagram showing the software configuration of the multifunction peripheral 100 according to the first embodiment. .

  The calculation unit 905 calculates the sum of the number of rewrites corresponding to the device LBA of the SLC 302 and the FeRAM 303.

  The determination unit 901 is different from the determination unit 601 of the first embodiment in that a function for further determining whether or not the calculated sum has reached a multiple of a predetermined specified value is added.

  When the calculated sum reaches a multiple of the specified value, the moving unit 902 specifies device LBAs having a predetermined ratio (for example, 10% of the total) with a small number of rewrites for each of the SLC 302 and the FeRAM 303, and specifies the specified device LBA This is different from the moving unit 602 of the first embodiment in that a function for moving the data is transferred to the MLC 301 and the SLC 302, respectively.

  The table update unit 903 is different from the table update unit 603 according to the first embodiment in that device update history update processing is added.

  Next, an access control process performed by the MFP 900 according to the second embodiment configured as described above will be described. FIG. 12 is a flowchart showing an overall flow of the access control process in the second embodiment.

  In the second embodiment, a process of moving data from a storage medium having a small upper limit of the number of rewritable times to a storage medium having a large upper limit is executed as in the first embodiment. That is, the access type determination process and the conversion table update process from step S1201 to step S1209 are the same as the process from step S701 to step S709 in the multi-function device 100 according to the first embodiment, and thus description thereof is omitted. .

  Next, the calculation unit 905 calculates the sum of the number of rewrites for the FeRAM 303 with reference to the conversion table (step S1210).

  Next, the determination unit 901 determines whether or not the calculated sum is a multiple of a predetermined specified value (for example, 5,000 times) (step S1211). If it is a multiple (step S1211: YES), a process of moving data from the FeRAM 303 to the SLC 302 and updating the conversion table (hereinafter referred to as conversion table update process 2) is executed (step S1212). Details of the conversion table update process 2 will be described later.

  In step S1211, when it is determined that the sum is not a multiple of the specified value (step S1211: NO) or after the conversion table update process 2 (step S1212), the calculation unit 905 further refers to the conversion table. The sum of the number of rewrites for the SLC 302 is calculated (step S1213).

  Next, the determination unit 901 determines whether or not the calculated sum is a multiple of a predetermined specified value (for example, 5,000 times) (step S1214). If it is a multiple (step S1214: YES), conversion table update processing 2 for moving data from the SLC 302 to the MLC 301 is executed (step S1215).

  If it is determined in step S1214 that the sum is not a multiple of the specified value (step S1214: NO), or after the conversion table update process 2 (step S1215), the access control process ends.

  Note that the method for determining the execution timing of the conversion table update process 2 is not limited to the method of referring to the number of rewrites of the conversion table, and the conversion table update process 2 is executed when a predetermined standard is reached. Any method can be applied if possible.

  For example, when a counter for counting the number of rewrites is used in each of the FeRAM 303 and the SLC 302 and the counter value reaches a threshold value determined for each storage medium, the conversion table update processing 2 is performed only for that storage medium. It may be configured to execute. In this case, the counter value is stored in a non-volatile storage medium such as the FLASH ROM 323, and is initialized to 0 after the conversion table update process 2 is executed.

  Next, details of the conversion table update process 2 in steps S1212 and S1213 will be described. FIG. 13 is a flowchart showing an overall flow of the conversion table update processing 2 in the second embodiment.

  First, the migration unit 902 acquires a predetermined percentage of host LBAs (hereinafter referred to as migration target LBAs) from the conversion table in ascending order of the number of rewrites, where the assigned device is the migration source device (step S1301).

  Next, the moving unit 902 acquires a device change history corresponding to the movement target LBA from the conversion table (step S1302). Next, the moving unit 902 determines whether or not the acquired device change history is “Yes” (step S1303).

  If the device change history is “Yes” (step S1303: YES), the migration unit 902 excludes the corresponding host LBA from the migration target LBA (step S1304). As a result, the occurrence of a data movement loop can be avoided.

  If it is determined in step S1303 that the device change history is not “Yes”, that is, “No” (step S1303: NO), or after removing the host LBA whose device change history is “Yes” (step S1304) The moving unit 902 moves the data of the movement target LBA to an unused area of the movement destination device (step S1305). Note that the data of the unused area address of the movement destination device moves to the address of the area used by the movement source device.

  Also, the table update unit 903 rewrites the conversion table corresponding to the moved data (step S1306). The details of the data movement process and the table update process are the same as those in FIG. 8 which is the flowchart of the conversion table update process of the first embodiment, and a description thereof will be omitted.

  Finally, the table update unit 903 updates the device change history corresponding to the migration target LBA to “Yes” (step S1307), and ends the conversion table update process 2.

  As described above, in the access control apparatus according to the second embodiment, the number of write accesses of data stored in a storage medium having a large upper limit of the number of rewrites can be totaled, and data with a small number of write accesses can be rewritten. It is possible to move to a storage medium having a smaller upper limit value. As a result, the cost of the storage device can be reduced without causing problems.

(Modification)
In the above embodiment, referring to the used / unused flag in the conversion table, the unused area of the destination device is specified, and the data is moved to the unused area. When there is no unused area in the destination device, the destination device has moved to an area where the number of rewrites is small.

  On the other hand, when there is no unused area in the movement destination device, the unused area may be specified in the same device as the movement source, and the data may be moved to the specified unused area. Thereby, even when the capacity of the storage medium having a large number of rewritable times for replacement is insufficient, the operation as the storage device can be continued.

  Further, when configured in this way, information indicating that data has been moved in the same storage medium may be configured to remain in the conversion table. FIG. 14 is a diagram illustrating an example of the data structure of the conversion table configured as described above.

  As shown in FIG. 14, in addition to the host LBA, the assigned device, the device LBA, the used / unused flag, the number of rewrites, and the device change history, the conversion table further stores the movement history in the same kind of memory in association with each other. Yes.

  The movement history in the same kind of memory sets “Yes” when data is moved to an unused area in the same device with the above-described configuration. Note that “none” is set as the default in the movement history in the same kind of memory.

  In this way, by leaving a record substituted in the same type of storage medium in the conversion table, it becomes possible to determine that a memory shortage becomes obvious and that a memory needs to be added. That is, for example, if there are many addresses in the MLC 301 with the same-type memory movement history = “present”, it can be determined that the capacity of the SLC 302 is insufficient. Then, by repeating the operation by adding a memory, it is possible to obtain an optimal memory type capacity distribution that meets the system usage conditions, and to create a low-cost storage device.

  As described above, the access control device, the access control method, the access control program, the recording medium, the storage device, and the image processing device according to the present invention use a storage device that includes a plurality of types of storage media, or the storage device. Suitable for equipment.

1 is a simplified diagram illustrating a configuration of a multifunction machine. 1 is a block diagram illustrating a detailed configuration of a multifunction machine according to a first embodiment. It is a figure which shows the hardware constitutions of the memory | storage device of 1st Embodiment. It is explanatory drawing which shows an example of the data structure of the conversion table in 1st Embodiment. It is a figure which shows an example of the address map of a memory | storage device. It is a functional block diagram for demonstrating the software configuration of the control part of 1st Embodiment. It is a flowchart which shows the whole flow of the access control process in 1st Embodiment. It is a flowchart which shows the whole flow of the conversion table update process in 1st Embodiment. It is a block diagram which shows the detailed structure of the multifunctional device concerning 2nd Embodiment. It is explanatory drawing which shows an example of the data structure of the conversion table in 2nd Embodiment. It is a functional block diagram for demonstrating the software configuration of the control part of 2nd Embodiment. It is a flowchart which shows the whole flow of the access control process in 2nd Embodiment. It is a flowchart which shows the whole flow of the conversion table update process 2 in 2nd Embodiment. It is explanatory drawing which shows an example of the data structure of the conversion table in a modification.

Explanation of symbols

100, 900 MFP 101 Scanner unit 102 Laser recording unit 103 Post-processing unit 104 Document table 105 RADF
DESCRIPTION OF SYMBOLS 106 Scanner unit 107 Paper conveyance part 108 Laser writing unit 109 Electrophotographic process part 201 Image processing board 202 CPU
203 RAM
204 Image processing unit 205 Image storage control unit 206 Data storage unit 207 Laser control unit 208 I / F controller 210 CCD board 211 A / D conversion unit 212 CCD control unit 213 CCD
214 Analog Circuit 217 Duplex Unit 221 and 222 CPU
223 LCD
224 operation keys 225 operation panel 226 CPU
227 RAM
228 Operation panel board 229 RAM
230 CPU
231 Machine control board 300, 930 Storage device 301 MLC
302 SLC
303 FeRAM
311 NAND FLASH MLC controller 312 NAND FLASH SLC controller 313 FeRAM controller 320, 920 Control unit 321 CPU
322 RAM
323 FLASH ROM
324 I / F controller 601, 901 determining unit 602, 902 moving unit 603, 903 table updating unit 604 transmitting / receiving unit 905 calculating unit

Claims (20)

Connected to an external device, a first storage means for storing data accessed by the external device, and a second storage means for storing the data and having a rewritable number of times greater than that of the first storage means An access control device comprising:
An external address designated by the external device for accessing the data, and an internal address indicating either the storage location of the data in the first storage means or the storage location of the data in the second storage means Table storage means for storing a conversion table in which the number of rewrites of the data is associated with each other;
It is determined whether or not the internal address corresponding to the external address for which writing is specified is the internal address of the first storage means, and when the internal address is the internal address of the first storage means, the internal address Determining means for determining whether or not the number of rewrites corresponding to the number exceeds a predetermined first threshold;
Moving means for moving the data stored at the internal address of the first storage means whose number of rewrites exceeds the first threshold to the internal address of the second storage means;
Table updating means for updating the conversion table by replacing the internal address corresponding to the external address of the moved data with the internal address of the movement destination;
An access control device comprising: A calculation unit that calculates a sum of the number of rewrites corresponding to the internal address of the second storage unit;
The determination means further determines whether or not the sum is a multiple of a predetermined specified value,
Further, when the sum is a multiple of the specified value, the moving means further sets the internal addresses of the second storage means to the internal addresses having a predetermined ratio in ascending order of the number of rewrites corresponding to the internal addresses. Moving the stored data to the internal address of the first storage means;
The access control apparatus according to claim 1. The table storage means stores the conversion table further associated with change history information indicating whether or not the internal address of the second storage means is replaced with the internal address of the first storage means,
The movement means is associated with the change history information indicating that the internal address of the second storage means is replaced with the internal address of the first storage means from the internal address of the second storage means. The data of the internal address is not moved to the internal address of the first storage means;
The access control apparatus according to claim 2. Further comprising transmission / reception means for transmitting / receiving the conversion table to / from the external device;
The access control apparatus according to claim 1. The moving unit writes the data stored in the internal address of the first storage unit in which the number of rewrites exceeds the first threshold, and the data is written out of the internal address of the second storage unit. Not moving to the internal address,
The access control apparatus according to claim 1. The determination means further determines whether or not there is the internal address where the data is not written in the second storage means,
The moving means is stored in the internal address of the first storage means in which the number of rewrites exceeds the first threshold when there is no internal address in which the data is not written in the second storage means. Moving the data to another internal address in which the data of the first storage means is not written,
The access control apparatus according to claim 5. The table storage means stores the conversion table further associating movement information indicating whether or not the internal address of the first storage means is replaced with another internal address of the first storage means;
The access control apparatus according to claim 6. The determination means further determines whether or not there is the internal address where the data is not written in the second storage means,
The moving means has a predetermined ratio of the internal addresses in ascending order of the number of rewrites corresponding to the second storage means when there is no internal address in which the data is not written in the second storage means. Moving to one of the
The access control apparatus according to claim 5. Connected to an external device, a first storage means for storing data accessed by the external device, and a second storage means for storing the data and having a rewritable number of times greater than that of the first storage means An access control method in an access control device, comprising:
The access control device
An external address designated by the external device for accessing the data, and an internal address indicating either the storage location of the data in the first storage means or the storage location of the data in the second storage means And a table storage means for storing a conversion table in which the number of rewrites of the data is associated with each other,
When the determination unit determines whether the internal address corresponding to the external address designated for writing is the internal address of the first storage unit, and is the internal address of the first storage unit A determination step of determining whether or not the number of rewrites corresponding to the internal address exceeds a predetermined first threshold;
A moving step of moving, by moving means, the data stored at the internal address of the first storage means whose number of rewrites exceeds the first threshold to the internal address of the second storage means;
A table updating step of updating the conversion table by replacing the internal address corresponding to the external address of the moved data with the internal address of the destination by table update means;
An access control method comprising: A calculation step of calculating a sum of the number of rewrites corresponding to the internal address of the second storage unit by a calculation unit;
A second determination step of determining by the determination means whether the sum is a multiple of a predetermined value;
Further, when the sum is a multiple of the prescribed value, the moving means sets the internal addresses of the second storage means to the internal addresses at a predetermined ratio in ascending order of the number of rewrites corresponding to the internal addresses. A second movement step of moving the stored data to the internal address of the first storage means;
The access control method according to claim 9. The table storage means stores the conversion table further associated with change history information indicating whether or not the internal address of the second storage means is replaced with the internal address of the first storage means,
The second movement step corresponds to the change history information indicating that the internal address of the second storage unit is replaced with the internal address of the first storage unit from the internal address of the second storage unit. The data of the attached internal address does not move to the internal address of the first storage means;
The access control method according to claim 10. A transmission / reception step of transmitting / receiving the conversion table to / from the external device by transmission / reception means;
The access control method according to claim 9. In the moving step, the data stored in the internal address of the first storage unit in which the number of rewrites exceeds the first threshold is written in the internal address of the second storage unit. Not moving to the internal address,
The access control method according to claim 9. The determining step further determines whether or not there is the internal address where the data is not written in the second storage means;
The moving step is stored in the internal address of the first storage means in which the number of rewrites exceeds the first threshold when there is no internal address in which the data is not written in the second storage means. Moving the data to another internal address in which the data of the first storage means is not written,
The access control method according to claim 13. The table storage means stores the conversion table further associating movement information indicating whether or not the internal address of the first storage means is replaced with another internal address of the first storage means;
The access control method according to claim 14. The determining step further determines whether or not there is the internal address where the data is not written in the second storage means;
In the moving step, when there is no internal address in which the data is not written in the second storage means, the internal addresses in a predetermined ratio in ascending order of the number of rewrites corresponding to the second storage means Moving to one of the
The access control method according to claim 13.   An access control program for causing a computer to execute the access control method according to claim 9.   A computer-readable recording medium having recorded thereon the access control program according to claim 17 to be executed by a computer. First storage means for storing the data accessed by the external device;
Storing the data, a second storage means having a rewritable number of times larger than the first storage means;
An external address designated by the external device for accessing the data, and an internal address indicating either the storage location of the data in the first storage means or the storage location of the data in the second storage means Table storage means for storing a conversion table in which the number of rewrites of the data is associated with each other;
It is determined whether or not the internal address corresponding to the external address for which writing is specified is the internal address of the first storage means, and when the internal address is the internal address of the first storage means, the internal address Determining means for determining whether or not the number of rewrites corresponding to the number exceeds a predetermined first threshold;
Moving means for moving the data stored at the internal address of the first storage means whose number of rewrites exceeds the first threshold to the internal address of the second storage means;
Table updating means for updating the conversion table by replacing the internal address corresponding to the external address of the moved data with the internal address of the movement destination;
A storage device comprising: An image processing apparatus that includes a printer unit or a scanner unit and processes input image data,
First storage means for storing the image data;
Storing the image data, a second storage means having a rewritable number of times of the image data larger than the first storage means;
An external address designated for accessing the image data, and an internal address representing either the storage position of the image data in the first storage means or the storage position of the image data in the second storage means Table storage means for storing a conversion table in which the number of rewrites of the image data is associated with each other;
It is determined whether or not the internal address corresponding to the external address for which writing is specified is the internal address of the first storage means, and when the internal address is the internal address of the first storage means, the internal address Determining means for determining whether or not the number of rewrites corresponding to the number exceeds a predetermined first threshold;
Moving means for moving the image data stored at the internal address of the first storage means whose number of rewrites exceeds the first threshold to the internal address of the second storage means;
Table updating means for updating the conversion table by replacing the internal address corresponding to the external address of the moved image data with the internal address of the movement destination;
An image processing apparatus comprising:

Images