JP2006202051A - Data processor and data processing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To perform optimum format processing in each of flash memories having respectively different characteristics. <P>SOLUTION: A data processor is provided with: a logical format means for logically formatting a file management area of a storage medium which utilizes a flash memory capable of electrically erasing/writing data; a data erasing means for electrically erasing data stored in a data area of the storage medium; an erasing time measuring means for measuring time required for electrically erasing a unit block of a prescribed size in the data area; and a format method selection means for selecting either the logical format to be executed by using only the logical format means or a logical/physical format for executing the logical format and the erasure of the data area together by using both of the logical format means and the data erasing means. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a data processing apparatus and a data processing method, and more particularly to a technique suitable for use in formatting a memory for storing image data taken by a digital camera or the like.

  Conventionally, flash memories such as compact flash (registered trademark) and SD (Secure Digital) memory cards have been widely used as recording media for digital cameras and the like. The flash memory is characterized by being non-volatile and capable of repeatedly erasing and writing data.

  Data erasure and writing in the flash memory are executed in units of a certain size called a block constituting the flash memory. For example, when rewriting data to a block in which data has already been written, the previous data is erased once for the block size, all data is electrically cleared, and then new data is written. Processing is in progress. On the other hand, if it is an erased block, it is only necessary to write new data for the block size.

  In addition, since the flash memory is used in various information devices such as a personal computer, a file system such as FAT (File Allocation Table) is generally constructed. Therefore, the flash memory can be logically distinguished into a management area for the file system and a data area where data actually exists.

  For this reason, as a method for logically formatting the flash memory with a digital camera or the like, there can be considered two methods: the case where the format target is only the management area, and the case where the data area is also performed in addition to the management area. As a matter of course, the former method that only initializes the management area can significantly reduce the time required for formatting compared to the latter method that erases the data area in addition to the initialization of the management area.

  On the other hand, as shown in Patent Document 1, writing to an erased block is faster than writing to a block where data has already been written, as much as erasing is not performed. Due to the nature of the flash memory, in the former method in which the data area is not erased, when data is already written in the data area, the time required for writing becomes disadvantageous compared to the latter. Further, it is known that the time required for erasing and writing varies depending on the flash memory product.

JP 2003-224809 A

  Conventional format processing is generally performed only by initializing the management area of the file system. On the other hand, due to the characteristics of the flash memory, if the physical format is performed on the remaining data area, there is a possibility that the writing in the subsequent operation will be superior in time. However, since the time required for each flash memory product differs, it is difficult to estimate the time when the physical formatting is performed. For this reason, if the data area is erased uniformly, the time required for formatting may become unexpectedly long in some cases.

  In view of the above-described problems, an object of the present invention is to enable optimum format processing for each flash memory having different characteristics.

  The data processing apparatus of the present invention includes a logical formatting means for logically formatting a file management area of a storage medium using a flash memory that can be electrically erased and written, and a data format recorded on the data area of the storage medium. A data erasing unit for electrically erasing data, an erasing time measuring unit for measuring a time required for the data erasing unit to electrically erase a unit block of a predetermined size in the data region, and the data region The time required for erasing the unit block is evaluated, and the logical format using only the logical formatting means, or using both the logical formatting means and the data erasing means, Select whether to perform logical or physical format that is executed together with erasure And having a formatting method selection means.

  The data processing method of the present invention includes a logical formatting step of logically formatting a file management area of a storage medium using a flash memory that can be electrically erased and written, and a data recording area of the storage medium. A data erasing step for electrically erasing data, an erasing time measuring step for measuring a time required for electrically erasing a unit block of a predetermined size in the data region in the data erasing step, and the data region The time required for erasing the unit block is evaluated, and only the logical formatting process is performed, or both the logical formatting process and the data erasing process are performed, and the logical formatting and the data area are Formatting method selection step for selecting whether to execute erasing together Characterized in that it.

  The computer program of the present invention is recorded in a logical formatting step for logically formatting a file management area of a storage medium using a flash memory that can be electrically erased and written, and in a data area of the storage medium. A data erasing step of electrically erasing data, an erasing time measuring step of measuring a time required for electrically erasing a unit block of a predetermined size in the data region in the data erasing step, Evaluating the time required for erasing the unit block, and erasing the logical format and the data area by performing only the logical formatting process or performing both the logical formatting process and the data erasing process. Format method selection to select whether to execute with Characterized in that to execute a data processing method in a computer having a degree.

  The recording medium of the present invention records the computer program described above.

  According to the present invention, the time required for erasing the unit block is measured prior to the formatting process, and the physical format of the data area is selected according to the evaluation. Therefore, the optimum format according to the characteristics of the flash memory is selected. Processing can be performed.

(First embodiment)
Embodiments of the present invention will be described below with reference to the drawings.
FIG. 1 is a block diagram showing a configuration of an embodiment of a data processing apparatus of the present invention. In FIG. 1, reference numeral 100 denotes a digital camera.
Reference numeral 10 denotes a photographing lens, 12 denotes a shutter having a diaphragm function, 14 denotes an image sensor that converts an optical image into an electrical signal, and 16 denotes an A / D converter that converts an analog signal output from the image sensor 14 into a digital signal.

  A timing generation circuit 18 supplies a clock signal and a control signal to the image sensor 14, the A / D converter 16, and the D / A converter 26, and is controlled by the memory control circuit 22 and the system control circuit 50.

  An image processing circuit 20 performs predetermined pixel interpolation processing and color conversion processing on the data from the A / D converter 16 or the data from the memory control circuit 22. Further, the image processing circuit 20 performs predetermined calculation processing using the captured image data, and the system control circuit 50 controls the exposure control means 40 and the distance measurement control means 42 based on the obtained calculation result. TTL (through-the-lens) AF (autofocus) processing, AE (automatic exposure) processing, and EF (flash pre-flash) processing. Further, the image processing circuit 20 performs predetermined arithmetic processing using the captured image data, and also performs TTL AWB (auto white balance) processing based on the obtained arithmetic result.

  A memory control circuit 22 controls the A / D converter 16, the timing generation circuit 18, the image processing circuit 20, the image display memory 24, the D / A converter 26, the memory 30, and the compression / decompression circuit 32.

  The data of the A / D converter 16 is written into the image display memory 24 or the memory 30 via the image processing circuit 20 and the memory control circuit 22 or the data of the A / D converter 16 is directly passed through the memory control circuit 22. It is.

  Reference numeral 24 denotes an image display memory, 26 denotes a D / A converter, and 28 denotes an image display unit composed of a TFT LCD or the like. Display image data written in the image display memory 24 passes through the D / A converter 26. Displayed by the image display unit 28. If the image data captured using the image display unit 28 is sequentially displayed, the electronic viewfinder function can be realized. The image display unit 28 can arbitrarily turn on / off the display according to an instruction from the system control circuit 50. When the display is turned off, the power consumption of the digital camera 100 can be significantly reduced. it can.

  Reference numeral 30 denotes a memory for storing captured still images and moving images, and has a sufficient storage capacity to store a predetermined number of still images and a predetermined time of moving images. Thereby, even in the case of continuous shooting or panoramic shooting in which a plurality of still images are continuously shot, it is possible to write a large amount of images to the memory 30 at high speed. The memory 30 can also be used as a work area for the system control circuit 50.

  Reference numeral 32 denotes a compression / decompression circuit that compresses and decompresses image data by adaptive discrete cosine transform (ADCT) or the like, reads an image stored in the memory 30, performs compression processing or decompression processing, and stores the processed data in the memory 30. It has a function to write to.

Reference numeral 40 denotes an exposure control means for controlling the shutter 12 having a diaphragm function, and has a flash light control function in cooperation with the flash 48.
Reference numeral 42 denotes a distance measuring control means for controlling the focusing of the photographing lens 10, reference numeral 44 denotes a zoom control means for controlling zooming of the photographing lens 10, and reference numeral 46 denotes a barrier control means for controlling the operation of the protection means 102 as a barrier.

  A flash 48 has an AF auxiliary light projecting function and a flash light control function. The exposure control means 40 and the distance measurement control means 42 are controlled using the TTL method. Based on the calculation result obtained by calculating the captured image data by the image processing circuit 20, the system control circuit 50 performs the exposure control means 40 and the distance measurement. Control is performed on the control means 42.

A system control circuit 50 controls the entire digital camera 100, and a memory 52 stores constants, variables, programs, and the like for operation of the system control circuit 50.
Reference numeral 54 denotes a display unit such as a liquid crystal display device or a speaker that displays an operation state or a message using characters, images, sounds, or the like in accordance with execution of a program in the system control circuit 50, and an operation unit of the digital camera 100 One or a plurality of locations are installed in the vicinity where they can be easily seen, and are configured by a combination of, for example, an LCD, an LED, and a sounding element. The display unit 54 has a part of its function installed in the optical viewfinder 104.

  Among the display contents of the display unit 54, what is displayed on the LCD or the like includes single shot / continuous shooting display, self-timer display, compression rate display, number of recorded pixels, number of recorded pixels, number of remaining images that can be captured, shutter Speed display, Aperture display, Exposure compensation display, Flash display, Red-eye reduction display, Macro shooting display, Buzzer setting display, Clock battery level display, Battery level display, Error display, Multi-digit number information display, External There are an attachment / detachment state display of the recording medium 200, a communication I / F operation display, a date / time display, and the like.

  Among the display contents of the display unit 54, what is displayed in the optical viewfinder 104 includes in-focus display, camera shake warning display, flash charge display, shutter speed display, aperture value display, exposure correction display, and the like.

  Reference numeral 56 denotes an electrically erasable / recordable nonvolatile memory, such as an EEPROM. Reference numerals 60, 62, 64, 66, 68 and 70 are operation means for inputting various operation instructions of the system control circuit 50, and may be a single unit such as a switch, a dial, a touch panel, pointing by line-of-sight detection, a voice recognition device, or the like. Consists of multiple combinations.

  In the following, the operation means will be described in detail. Reference numeral 60 denotes a mode dial switch, such as power off, automatic shooting mode, shooting mode, panoramic shooting mode, playback mode, multi-screen playback / erase mode, PC connection mode, etc. Each function mode can be switched and set.

  Reference numeral 62 denotes a first shutter switch (SW1) which is turned ON during the operation of a shutter button (not shown), and AF (auto focus) processing, AE (auto exposure) processing, AWB (auto white balance) processing, EF (flash) Instructs the start of operations such as (pre-flash) processing.

  Reference numeral 64 denotes a second shutter switch (SW2), which is turned on when the operation of a shutter button (not shown) is completed, and a signal read from the image sensor 12 is transferred to the memory 30 via the A / D converter 16 and the memory control circuit 22. Exposure processing for writing image data, development processing using computations in the image processing circuit 20 and the memory control circuit 22, reading out the image data from the memory 30, compression in the compression / decompression circuit 32, and recording on the recording medium 200 or 210 It instructs the start of a series of processes called recording processes for writing data.

  Reference numeral 66 denotes an image display ON / OFF switch, which can set ON / OFF of the image display unit 28. With this function, when photographing using the optical viewfinder 104, it is possible to save power by cutting off the current supply to the image display unit including a TFT LCD or the like.

  Reference numeral 68 denotes a quick review ON / OFF switch, which sets a quick review function for automatically reproducing image data taken immediately after photographing. In the present embodiment, in particular, a function for setting a quick review function when the image display unit 28 is turned off is provided.

  70 is an operation unit composed of various buttons, a touch panel, etc., a menu button, a set button, a macro button, a multi-screen playback page break button, a flash setting button, a single shooting / continuous shooting / self-timer switching button, menu movement + (plus) Button, menu shift- (minus) button, playback image shift + (plus) button, playback image shift- (minus) button, shooting image quality selection button, exposure correction button, date / time setting button, and the like.

  80 is a power control means, which is composed of a battery detection circuit, a DC-DC converter, a switch circuit for switching a block to be energized, etc., and detects the presence / absence of a battery, the type of battery, the remaining battery level, and the detection result In addition, the DC-DC converter is controlled based on an instruction from the system control circuit 50, and a necessary voltage is supplied to each part including the recording medium for a necessary period.

  82 and 84 are connectors, 86 is a primary battery such as an alkaline battery or a lithium battery, a secondary battery such as a NiCd battery, NiMH battery or Li battery, an AC adapter, or the like. 90 is a card controller for transmitting and receiving data to and from an external recording medium such as a memory card, 91 is an interface with an external recording medium such as a memory card, 92 is a connector for connecting to an external recording medium such as a memory card, and 98 is a connector 92. The recording medium attachment / detachment detecting means detects whether or not the external recording medium 200 is attached to the recording medium. Reference numeral 110 denotes a communication means for performing communication, and 112 denotes a connector for connecting a communication antenna.

  In the present embodiment, a single or a plurality of interfaces and connectors for attaching a recording medium may be provided. Moreover, it is good also as a structure provided with combining the interface and connector of a different standard.

  The interface and the connector may be configured using a PCMCIA card, a CF (Compact Flash (registered trademark)) card, or the like that conforms to a standard. Furthermore, when the interface 91 and the connector 92 are configured using a PCMCIA card, a CF (Compact Flash (registered trademark)) card, or the like, a LAN card, modem card, USB card, IEEE1394 card, P1284 card By connecting various communication cards such as SCSI cards, communication cards such as PHS, etc., image data and management information attached to the image data can be transferred to and from other computers and peripheral devices such as printers. it can.

  Reference numeral 102 denotes protection means that is a barrier that prevents the imaging unit from being soiled or damaged by covering the imaging unit including the lens 10 of the digital camera 100. Reference numeral 104 denotes an optical viewfinder, which can take an image using only the optical viewfinder without using the electronic viewfinder function of the image display unit 28.

  In the optical viewfinder 104, some functions of the display unit 54, for example, a focus display, a camera shake warning display, a flash charge display, a shutter speed display, an aperture value display, an exposure correction display, and the like are installed. Reference numeral 200 denotes an external recording medium such as a memory card. The overall system configuration of the digital camera 100 has been described above.

FIG. 2 is a diagram schematically showing a logical configuration of a file system constructed in the external recording medium 200 in the present embodiment.
As shown in FIG. 2, the storage area of the external recording medium 200 is divided into a file system management area 210 and a data area 220. The management area 210 includes a master boot record (MBR) 211, a boot sector 212, a fat (FAT: file allocation table) 213, and a root directory entry 214.

  In the master boot record 211, a partition table is described. The partition table is a table showing logical areas called partitions, such as the position of the boot sector 212 and the size of the data area 220.

  The boot sector 212 describes basic information for handling data in which the file system is placed in the data area 220, such as the cluster size and the size of the fat 213. A cluster is a logical minimum size for handling data in the data area 220.

  Finally, the fat 213 is a table indicating the position of the file in the data area 220 with the cluster as a reference. By analyzing the fat 213, which cluster forms the file in which order, and which cluster is unused (entry cleared with “0” in the table) ) Can be known.

  In general, when a normal (logical) format is executed for such an external recording medium 200, the operation of the file system includes the master boot record 211 and the boot sector 212 from the device information of the external recording medium 200. After reconfiguring and writing, the area of the fat 213 and the root directory entry are cleared to “0” to make the external recording medium 200 apparently unused.

  In the present embodiment, such a format is referred to as a logical format. In this logical format, as described above, only the management area 210 of the file system is rewritten, and the data written in the data area 220 is written as it is without being rewritten.

  On the other hand, there is a format called a physical format. The physical format is a format that not only rewrites the management area 210 of the file system but also clears the value for the data area 220.

  On the other hand, means for erasing the designated area using electrical means is called a physical format. In this embodiment, since the external storage medium 200 uses a flash memory, in the physical format in this embodiment, instead of clearing the value of the data area 220, the data in the data area 220 is erased. To do.

  In the digital camera 100 according to the present embodiment, the format of the external recording medium 200 can be executed, and when a format is selected, a format menu is displayed on the display unit 54 as shown in FIG.

  FIG. 4 shows the processing when “OK” is selected in the format menu of FIG. If “Cancel” is selected, no processing is performed, the formatting menu on the display unit 54 is deleted, and the normal operation is resumed.

Hereinafter, the process shown in FIG. 4 will be described in detail.
In step S401, it is determined whether there is a record of performing physical format time measurement for the unit block of the data area 220 for the external recording medium 200. In the present embodiment, when the measurement time has been performed before, the measurement time storage means for storing the measurement time in an arbitrary area of the memory 30 is provided, which is stored by the measurement time storage means. This is done with or without measurement time.

  The result of the physical format time measurement is cleared when the power of the digital camera 100 is turned off or when the recording medium attachment / detachment detection 98 determines that the external storage medium 200 is removed. Here, if it is determined that there is a measurement result, the process of the next step S402 is skipped.

  In step S402, an arbitrary block (unit block) of the external recording medium 200 is physically formatted, and the time required for it is measured. The time measured here is stored in an arbitrary area of the memory 30.

  In step S403, a logical format is executed. As described above, the logical format is realized by reconstructing the MBR and the boot sector from the device information of the external recording medium 200 and clearing the FAT area 213 and the root directory entry 214. In the present embodiment, during the formatting period, the display unit 54 displays that formatting is in progress.

  FIG. 5 is a diagram illustrating an example of a screen display displayed on the display unit 54 in order to indicate to the user that the formatting process is in progress. In FIG. 5, reference numeral 501 denotes a progress bar that visually notifies the user of the progress of processing. Reference numeral 502 denotes a remaining time display section that displays the time required for completion of formatting. The remaining time and progress bar are updated at appropriate time intervals while the formatting process is in progress.

  In step S404, the time measured when the unit block is physically formatted in step S402 is evaluated. If this time is equal to or less than the “predetermined time value T”, a physical format of the data area 220 that can be temporally superior in the subsequent writing process is performed. On the other hand, if it is determined that the measured time is greater than the “predetermined time value T”, the formatting process is terminated to shorten the formatting time. Here, the “predetermined time value T” serving as a determination criterion is a design value.

  In step S405, the time required for erasing performed in step S406 is predicted from the number of areas to be physically formatted and the time measured in step S403. Then, as shown in FIG. 5, the prediction result is displayed on the remaining time display unit 502 on the display unit 54.

  In step S406, the physical format of the data area 220 is actually performed. At this time, the display states of the remaining time display unit 502 and the progress bar 501 are updated at appropriate intervals. When all the operations are finished, the display unit 54 is returned to the normal operation, and the formatting process is finished.

  By performing the above processing operations, appropriate format processing can be executed for each flash memory, so even if the time required for physical formatting differs for each flash memory product, the time required for physical formatting is expected. The inconvenience of being excessively large outside can be prevented.

(Another embodiment according to the present invention)
The time value T in step S404 can be set to the most preferable value for the user after statistically calculating the unit block erase time for each flash memory having a plurality of different characteristics in advance. This is not a limitation. For example, an upper limit waiting time W (for example, 3 minutes) for the user or the apparatus is set, and the product of the unit block erasing time and the number of format target areas (time required for erasing) exceeds this waiting time W. Only if there is not, the process may proceed to step S405.

  Further, the determination in step S404 may be performed before the logical format in step S403, or the logical format in step S403 may be performed after step S405.

  Each means constituting the data processing apparatus and each step of the data processing method in the embodiment of the present invention described above can be realized by operating a program stored in a RAM or ROM of a computer. This program and a computer-readable recording medium recording the program are included in the present invention.

  Further, the present invention can be implemented as, for example, a system, apparatus, method, program, or storage medium, and can be applied to a system composed of a plurality of devices. Moreover, you may apply to the apparatus which consists of one apparatus.

  In the present invention, a software program (in the embodiment, a program corresponding to the flowchart shown in FIG. 4) for realizing the functions of the above-described embodiment is directly or remotely supplied to a system or apparatus, and the system Or the case where it is achieved also by the computer of the apparatus reading and executing the supplied program code is included.

  Accordingly, since the functions of the present invention are implemented by computer, the program code installed in the computer also implements the present invention. In other words, the present invention includes a computer program itself for realizing the functional processing of the present invention.

  In that case, as long as it has the function of a program, it may be in the form of object code, a program executed by an interpreter, script data supplied to the OS, or the like.

  As a recording medium for supplying the program, for example, floppy (registered trademark) disk, hard disk, optical disk, magneto-optical disk, MO, CD-ROM, CD-R, CD-RW, magnetic tape, nonvolatile memory card ROM, DVD (DVD-ROM, DVD-R) and the like.

  As another program supply method, a client computer browser is used to connect to an Internet homepage, and the computer program itself of the present invention or a compressed file including an automatic installation function is downloaded from the homepage to a recording medium such as a hard disk. Can also be supplied.

  It can also be realized by dividing the program code constituting the program of the present invention into a plurality of files and downloading each file from a different homepage. That is, a WWW server that allows a plurality of users to download a program file for realizing the functional processing of the present invention on a computer is also included in the present invention.

  In addition, the program of the present invention is encrypted, stored in a storage medium such as a CD-ROM, distributed to users, and key information for decryption is downloaded from a homepage via the Internet to users who have cleared predetermined conditions. It is also possible to execute the encrypted program by using the key information and install the program on a computer.

  In addition to the functions of the above-described embodiments being realized by the computer executing the read program, the OS running on the computer based on the instructions of the program is used for the actual processing. The functions of the above-described embodiment can be realized by performing some or all of the processes.

  Furthermore, after the program read from the recording medium is written in a memory provided in a function expansion board inserted into the computer or a function expansion unit connected to the computer, the function expansion board or The CPU or the like provided in the function expansion unit performs part or all of the actual processing, and the functions of the above-described embodiments are realized by the processing.

It is a block diagram which shows an example of the system of the digital camera in this Embodiment. It is a figure which shows the logical structure in the external recording medium in this Embodiment. It is a figure which shows an example of the screen displayed at the time of the format menu in this Embodiment. It is a flowchart which shows an example of the process by the format menu in this Embodiment. It is a figure which shows an example of the screen displayed at the time of the format in this Embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Shooting lens 12 Shutter 14 Image pick-up element 16 A / D converter 18 Timing generation circuit 20 Image processing circuit 22 Memory control circuit 24 Image display memory 26 D / A converter 28 Image display part 30 Memory 32 Image compression / expansion circuit 40 Exposure Control means 42 Distance control means 44 Zoom control means 46 Barrier control means 48 Flash 50 System control circuit 52 Memory 54 Display unit 56 Non-volatile memory 60 Mode dial switch 62 First shutter switch (SW1)
64 Second shutter switch (SW2)
66 Image display ON / OFF switch 68 Quick review ON / OFF switch 70 Operation unit 80 Power supply control means 82 Connector 84 Connector 86 Power supply means 90 Card controller 91 Interface 92 Connector 98 Recording medium attachment / detachment detection means 100 Digital camera 102 Protection means 104 Optical viewfinder 200 External recording media

Claims (10)

Logical formatting means for logically formatting a file management area of a storage medium using a flash memory that can be electrically erased and written;
Data erasing means for electrically erasing data recorded in the data area of the storage medium;
An erasing time measuring means for measuring a time required for the data erasing means to electrically erase a unit block of a predetermined size in the data area;
Evaluating the time required for erasing the unit block of the data area, and using only the logical formatting means, or using both the logical formatting means and the data erasing means, A data processing apparatus comprising: a format method selecting means for selecting which of logical and physical formats to be executed in combination with erasure of a data area.   The processing time predicting means for predicting the time required for formatting the entire storage medium based on the time required for erasing the unit block of the data area measured by the erasing time measuring means. Item 4. The data processing device according to Item 1.   3. The data processing apparatus according to claim 2, further comprising a processing progress display unit that calculates a time until completion of formatting based on a prediction result by the processing time prediction unit and displays the calculated result on a display unit. .   The data processing apparatus according to claim 3, wherein the processing progress display unit displays the time until the formatting is completed on the display unit while updating the period. Measurement time storage means for storing the measurement result by the erasure time measurement means in an internal storage medium,
5. The data processing apparatus according to claim 1, wherein when the measurement time is stored in the internal storage medium, the measurement by the erasure time measurement unit is omitted.   The record of time measurement of the physical format stored in the internal storage medium is cleared when power supply is cut off or when the storage medium targeted for formatting is removed. 5. The data processing device according to 5. A logical formatting step for logically formatting a file management area of a storage medium using a flash memory that can be electrically erased and written;
A data erasing step for electrically erasing data recorded in the data area of the storage medium;
An erasing time measuring step of measuring a time required for electrically erasing a unit block of a predetermined size in the data area in the data erasing step;
Evaluating the time required for erasing the unit block of the data area, performing the logical format only the logical format process, or performing both the logical format process and the data erasing process, the logical format and the A data processing method comprising: a formatting method selection step for selecting whether to execute erasure of a data area.   And a processing time predicting step for predicting a time required for formatting the entire storage medium based on the time required for erasing the unit block of the data area measured by the erasing time measuring step. Item 8. The data processing method according to Item 7. A logical formatting step for logically formatting a file management area of a storage medium using a flash memory that can be electrically erased and written;
A data erasing step for electrically erasing data recorded in the data area of the storage medium;
An erasing time measuring step of measuring a time required for electrically erasing a unit block of a predetermined size in the data area in the data erasing step;
Evaluating the time required for erasing the unit block of the data area, performing the logical format only the logical format process, or performing both the logical format process and the data erasing process, the logical format and the A computer program for causing a computer to execute a data processing method including a formatting method selection step for selecting whether to execute data area erasing together.   10. A computer-readable recording medium on which the computer program according to claim 9 is recorded.

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