JP2006163622A - Portable terminal device and data access method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a portable terminal device and a data access method which can use efficiently data stored in an external memory in a communication using a portable terminal. <P>SOLUTION: In the portable terminal device which is attachable/detachable at least and which has a rewritable external storage medium, the external memory 109 of the portable terminal device 100 is divided into a region for regular storage, and a physical access region used temporarily to be managed. When an application which uses a huge memory is performed, the physical access region 112 of the external memory 109 can be used. Utilization with the sufficient efficiency of the external memory 109 is attained by increasing the physical access region 112 according to circumstances. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a portable terminal device, and more particularly to a portable terminal device and a data access method that require a large-capacity temporary memory such as performing a multimedia function.

Conventionally, in a mobile terminal device, a built-in memory capacity is limited, and there is a possibility that an application cannot be executed due to insufficient memory capacity. As a solution to these problems, a method of solving the memory shortage by providing an interface of an external recording medium in the portable terminal device and storing the data in either the external storage medium or the internal memory is known ( For example, see Patent Document 1).
JP 2000-324255 A, page 9, FIG.

  However, the above prior art describes both a method for instructing which data is stored in both the external storage medium for the portable terminal device and the internal memory. The details of access and management methods are not described.

  Data includes data that is stored using a file system, such as still images and moving images, and data that requires a continuous area, such as temporary data. The prior art does not describe how to use the memory in consideration of such data.

  SUMMARY OF THE INVENTION An object of the present invention is to provide a mobile terminal device and a data access method that can efficiently use data stored in an external memory in communication using a mobile terminal.

  To achieve the above object, a portable terminal device according to the first aspect of the present invention is a portable terminal device including at least a detachable and rewritable external storage medium, wherein a first file system accesses the external storage medium with a file system. It comprises a setting means for creating an area and a second area to be accessed outside the file system, and setting the sizes of the first area and the second area.

  As a preferred mode, for example, as in claim 2, in the mobile terminal device according to claim 1, the external storage medium stores in advance an identification ID for identification with another external storage medium. Also good.

  Further, as a preferred aspect, for example, as in claim 3, in the portable terminal device according to claim 1, an identification ID generating means for generating an identification ID for identifying the external storage medium for each external storage medium is provided. And the external storage medium may have a third area for storing the identification ID.

  As a preferred aspect, for example, as in claim 4, in the mobile terminal device according to any one of claims 1 to 3, the identification ID, a start address and a size of the first area, and the first Management means for managing the start address and size of the two areas in association with each other may be provided.

  As a preferred mode, for example, as in claim 5, in the mobile terminal device according to any one of claims 1 to 4, when the first area has an empty area, the empty area is Control means that is temporarily used as part of the area 2 may be provided.

  Further, as a preferred aspect, for example, as in claim 6, in the mobile terminal device according to any one of claims 1 to 5, the control means is configured such that the free area of the first area is existing by deleting a file. When the gap area is generated between data, the existing data is moved so that the gap area becomes a continuous empty area, and the continuous empty area is temporarily used as a part of the second area. You may make it do.

  Moreover, as a preferable aspect, for example, as in claim 7, in the mobile terminal device according to claim 5 or 6, the management unit temporarily terminates a free area temporarily used as the second area. After that, the first area may be set again.

  In order to achieve the above object, a data access method according to an eighth aspect of the present invention is a data access method for an external storage medium that is at least detachable and rewritable. And a second area that is accessed outside the file system, and the respective sizes of the first area and the second area are set.

  Further, as a preferred aspect, for example, as in claim 9, in the data access method according to claim 8, the external storage medium stores an identification ID for identification with another external storage medium, and The identification ID, the start address and size of the first area, and the start address and size of the second area may be managed in association with each other.

  Moreover, as a preferable aspect, for example, as described in claim 10, in the data access method according to claim 8 or 9, when the first area includes an empty area, the empty area is changed to the second area. You may make it use temporarily as a part of.

  As a preferred mode, for example, as described in claim 11, in the data access method according to any one of claims 8 to 10, a free area in the first area is generated between existing data due to file deletion. If it is a gap area, the existing data is moved so that the gap area becomes a continuous empty area, and the continuous empty area is temporarily used as a part of the second area. Good.

  In addition, as a preferable aspect, for example, as in claim 12, in the data access method according to claim 10 or 11, a free area temporarily used as the second area is changed to the first after the temporary use ends. You may make it set to 1 area | region.

  According to the first aspect of the present invention, the setting unit creates a first area for accessing the external storage medium with a file system and a second area for accessing with a file system other than the file system, and the first area and Since the size of each of the second areas is set, a first area accessed by the file system and a second area directly accessed by a physical address can be created, whereby continuous data such as temporary data can be created. The required data can be stored in the second area of the external storage medium, and the settings of the first area and the second area can be changed according to the use situation of the user. The advantage that it can be used is obtained.

  According to the second aspect of the present invention, since the identification ID for identifying the external storage medium is stored in advance in the external storage medium, the identification can be performed even if the external storage medium is replaced. The advantage that it can be obtained.

  According to the third aspect of the present invention, the identification ID generating means generates an identification ID for identifying the external storage medium for each of the external storage media, and stores the identification ID in the third area of the external storage medium. Since the identification ID is stored, even when the external memory does not have the identification ID, an advantage is obtained that the identification can be performed even if the external storage medium is replaced.

  According to a fourth aspect of the invention, the management means associates and manages the identification ID, the start address and size of the first area, and the start address and size of the second area. Therefore, the setting information of the identification ID, the first area, and the second area can be managed for each external storage medium, and even if the external storage medium is replaced, the inserted external storage medium There is an advantage that the set first area and second area can be correctly recognized.

  According to claim 5, when there is an empty area in the first area by the control means, the empty area is temporarily used as a part of the second area. When the first area has a vacancy, an advantage is obtained in that the external storage medium can be efficiently used by accessing the vacant area as the second area.

  According to a sixth aspect of the present invention, when the empty area of the first area is a gap area generated between existing data due to file deletion by the control means, the gap area is continuously opened. Since the existing data is moved to become an area and the continuous empty area is temporarily used as a part of the second area, the empty area generated by deleting the file in the first area It is possible to increase the area that can be used as the second area by narrowing down and to obtain an advantage that the external storage medium can be used efficiently.

  According to the invention of claim 7, the management means sets the free area temporarily used as the second area to the first area again after the temporary use is completed. There is an advantage that the external storage medium can be used efficiently.

  According to an eighth aspect of the present invention, a first area for accessing the external storage medium with a file system and a second area for accessing with a file system other than the file system are created, and the first area and the first area are created. Since the size of each of the two areas is set, data that requires a continuous area such as temporary data can be stored in the second area of the external storage medium. Accordingly, the setting of the first region and the second region can be changed, and an advantage that efficient use can be obtained is obtained.

  According to the ninth aspect of the present invention, the identification ID for identifying the external storage medium, the start address and size of the first area, and the start address and size of the second area are obtained. Since it is managed in association with each other, it can be identified even if the external storage medium is replaced, and the setting information of the identification ID, the first area, and the second area can be managed for each external storage medium. Thus, even if the external storage medium is replaced, the first area and the second area set in the inserted external storage medium can be recognized correctly.

  According to a tenth aspect of the present invention, when the first area has an empty area, the empty area is temporarily used as a part of the second area. If there is a free space in this area, an advantage is obtained that the external storage medium can be used efficiently by accessing the free area as the second area.

  According to an eleventh aspect of the present invention, when the empty area of the first area is a gap area generated between existing data due to file deletion, the gap area becomes a continuous empty area. Since the existing data is moved and the continuous free area is temporarily used as a part of the second area, the free area generated by deleting the file in the first area can be reduced. The area that can be used as the second area can be increased, and there is an advantage that the external storage medium can be used efficiently.

  According to the twelfth aspect of the present invention, the empty area temporarily used as the second area is set as the first area again after the temporary use is completed. The advantage that it can be utilized automatically is obtained.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
A. First embodiment A-1. Configuration of First Embodiment FIG. 1 is a block diagram showing configurations of a mobile terminal device and an external memory according to a first embodiment of the present invention. In the figure, the mobile terminal device 100 includes a communication unit 101, a display unit 102, a data management unit 103, a data area setting unit 104, an internal memory 105, an external memory management unit 106, a file system 107, and a physical access unit 108. . The communication unit 101 performs a voice call, data communication, and the like. The display unit 102 displays various data. The data management unit 103 manages data storage destinations, access means selection, and the like.

  The data area setting unit 104 sets the occupation ratios of the file system access area 111 and the physical access area 112, or the sizes thereof, in the external memory 109 described later. The internal memory 105 stores programs and various data. The external memory management unit 106 manages the start address, size, identification ID, and the like of the file system access area 111 and the physical access area 112 in the external memory 109 described later. The file system 107 rewrites data in the file system access area 111 of the external memory 109. The physical access unit 108 rewrites data in the physical access area 112 of the external memory 109.

  The external memory 109 is a storage medium that can be attached to and detached from the mobile terminal device 100. The external memory 109 has an identification ID storage area 110, a file system access area 111, and a physical access area 112 in which identification IDs that do not overlap are stored in advance, enabling identification with other external memories. .

A-2. Operation of First Embodiment Next, the operation of the first embodiment described above will be described. FIG. 2 is a flowchart for explaining the setting operation of the file system area and the physical access area of the external memory in the second embodiment. In the first embodiment, it is assumed that the external memory 109 is used for the first time and no data is stored therein. Further, it is assumed that the external memory 109 is attached to the portable terminal device 100 and can be used.

  First, the data area setting unit 104 designates the occupation ratio of the file system access area 111 and the physical access area 112, or the size of each (step S10). Next, an identification ID is acquired from the external memory 109 (step S12). Next, the acquired identification ID and the set information (occupation ratio or size) of the file system access area 111 and the physical access area 112 are associated with each other and stored in the external memory management unit 106 (step S14).

  As described above, in the first embodiment, the file system area 111 and the physical access area 112 can be set and managed for each external memory 109. Further, by managing the identification ID, the file system area 111, and the physical access area 112 in association with each external memory 109, the external memory 109 can be identified, and even if the external memory 109 is replaced, the external memory 109 is assigned to the external memory 109. Since the file system access area 111 and the physical access area 112 are correctly identified, writing beyond the respective areas does not occur.

  Next, the flow of data writing in the first embodiment will be described with reference to the flowchart of FIG. Here, FIG. 3 is a flowchart for explaining the flow of data writing in the first embodiment. First, data writing of the mobile terminal device 100 occurs (step S20). For example, there is data storage such as still images and moving images by menus or creation of temporary data for Web display.

  Next, the data management control unit 103 determines whether the data to be written is for data storage or temporary for application operation (step S22). If it is determined that the data is to be stored, the data is stored in the file system access area 111 of the external memory 109 via the file system 107 (step S24).

  On the other hand, if it is determined that the data is not stored, the external memory management unit 106 is searched, and whether there is a physical access area 112 capable of storing temporary data to be stored in the external memory 109 currently inserted. It is determined whether or not (step S26). If there is a physical access area 112 that can be stored in the external memory 109, temporary data is stored in the physical access area 112 of the external memory 109 via the physical access unit 108 (step S28). On the other hand, when the data cannot be stored in the external memory 109, the application software issues a message or stops the operation of the software, as in the case of the conventional mobile terminal device.

  According to the first embodiment described above, by using the physical access area 112 provided in the external memory 109, it is possible to store continuous temporary data separately from the data to be stored in the external memory 109. The malfunction of the application program due to the lack of memory is reduced. In the first embodiment, two areas of the file system access area 111 and the physical access area 112 are created in the external memory 109. For example, if all the external memories 109 are made into the physical access area 112, more physical accesses are made. The area can be used, and an application that uses a large amount of the physical access area can also operate.

  In addition, the external memory management unit 106 stores the information (occupation ratio or size) of the file system access area 111 and the physical access area 112 set in the external memory 109 and the identification ID 110 in association with each other, and stores the information. When the memory 109 is replaced with another external memory, the external memory after replacement is determined from the identification ID of the replaced external memory 109 and the information (occupancy ratio or size) held in the external memory management unit 106. And the external memory 109 before replacement can be discriminated.

B. Second Embodiment Next, a second embodiment of the present invention will be described.
B-1. Configuration of Second Embodiment FIG. 4 is a block diagram showing configurations of a mobile terminal device and an external memory according to the second embodiment. It should be noted that portions corresponding to those in FIG. The identification ID generation unit 400 generates an identification ID for identifying the external memory 109. The second embodiment assumes a case where the external memory 109 does not have an identification ID that can be distinguished from other external memories.

  Here, FIG. 5 is a conceptual diagram showing a mapping example of the external memory 109 according to the second embodiment. In the external memory 109, an ID storage area 110 for identification is arranged at the recordable head address, and then a file system access area 111 and a physical access area 112 are sequentially arranged. However, this arrangement is only an example, and the second embodiment is effective for other arrangements. The identification ID storage area 110 is not recognized by the user as an area that is not included in the area set by the data area setting unit 104.

B-2. Operation of the Second Embodiment Next, the operation of the second embodiment described above will be described. FIG. 6 is a flowchart for explaining the setting operation of the file system area and the physical access area of the external memory in the second embodiment. In the second embodiment, it is assumed that the external memory 109 is used for the first time and no data is stored therein. Further, it is assumed that the external memory 109 is attached to the portable terminal device 100 and can be used.

  First, the occupation ratio of the file system access area 111 and the physical access area 112 or their sizes are designated by the data area setting unit 104 (step S30). Next, the identification ID generation unit 400 generates an identification ID for the external memory 109 (step S32). Next, the generated identification ID is stored in the identification ID storage area 110 in the external memory 109 (step S34). Then, the identification ID and the set information (occupancy ratio or size) of the file system access area 111 and the physical access area 112 are associated with each other and stored in the external memory management unit 106 (step S36).

  As described above, in the first embodiment, the identification ID generated by the identification ID generation unit 400 is stored in the identification ID storage area 110 in the external memory 109, and this identification ID is stored in the file in the external memory 109. Since each external memory 109 is managed by the external memory management unit 106 in association with information (occupation ratio or size) of the system access area 111 and the physical access area 112, each external memory 109 is replaced with an external memory 109 having no identification ID. The file system access area 111 and the physical access area 112 of the memory can be managed.

  Next, the flow of data writing in the second embodiment will be described with reference to the flowchart of FIG. Here, FIG. 7 is a flowchart for explaining the flow of data writing in the second embodiment. First, data writing occurs in the mobile terminal device 100 (step S40). For example, there is data storage such as still images and moving images by menus or creation of temporary data for Web display.

  Next, the data management control unit 103 determines whether the data to be written is for data storage or temporary for application operation (step S22). If it is determined that the data is to be stored, the data is stored in the file system access area 111 of the external memory 109 via the file system 107 (step S24).

  On the other hand, if it is determined that the data is not stored, the external memory management unit 106 is searched, and whether there is a physical access area 112 capable of storing temporary data to be stored in the external memory 109 currently inserted. It is determined whether or not (step S26). If there is a physical access area 112 that can be stored in the external memory 109, temporary data is stored in the physical access area 112 of the external memory 109 via the physical access unit 108 (step S28). On the other hand, when the data cannot be stored in the external memory 109, the application software issues a message or stops the operation of the software, as in the case of the conventional mobile terminal device.

  According to the second embodiment described above, by using the physical access area 112 provided in the external memory 109, the malfunction of the application program due to the shortage of the physical access area on the mobile terminal device 100 side is reduced. In the second embodiment, the two areas of the file system access area 111 and the physical access area 112 are created in the external memory 109. For example, if all the external memories 109 are the physical access areas 112, more physical access areas Can be used, and even applications that use a lot of physical access areas can operate.

  According to the second embodiment, even when the external memory 109 does not have a unique identification ID, the external memory 109 can be identified by having the external memory 109 have the identification ID created by the mobile terminal device 100. It becomes possible to manage the information of the created physical access area 111 and file system access area 112 in association with each external memory 109.

C. Third Embodiment Next, a third embodiment of the present invention will be described. The mobile terminal device according to the third embodiment is the same as the configuration shown in FIG. 1 or FIG. Below, it demonstrates as a structure similar to FIG.

  In the third embodiment, data storage by the file system has already occurred in the external memory 109 before the physical access area 112 is created. The file system access area 111 is not managed by the data management control unit 103. Therefore, in order to create the physical access area 111, it is necessary to create it in an area excluding the file system access area 112.

  The flow of setting a physical access area for the external memory 109 will be described below. It is assumed that the external memory 109 is attached to the mobile terminal device 100 and can be used. Here, FIG. 8 is a flowchart for explaining the operation of the mobile terminal device according to the third embodiment. The data area setting unit 104 in FIG. 1 notifies the user of the currently set size of the file system access area 111 (step S50). Next, the user designates the size of the physical access area 112 based on the size of the file system access area 111 notified by the data area setting unit 104 of FIG. 1 (step S52). Here, when setting a file system access area larger than the currently set file system access area, the file system access area 111 is also designated again.

  Next, the identification ID of the external memory 109 is acquired (step S54). Then, the acquired identification ID, the set file system access area 111 and the information (occupancy ratio or size) of the physical access area 112 are associated with each other and stored in the external memory management unit 106 in FIG. 1 (step S56).

  According to the third embodiment described above, the physical access area 112 can be added to the external memory 109 in which only the file system access area 111 has already been created. In addition, when writing to the physical access area 112 occurs when there is a free area in the file system access area 111, the free area of the file system access area 111 is temporarily managed as a part of the physical access area 112. As a result, the external memory 109 can be used efficiently.

D. Fourth Embodiment Next, a mapping state of an external memory in a mobile terminal device according to a fourth embodiment of the present invention will be described. FIG. 9A is a conceptual diagram showing an example of mapping between the file system area 111 and the physical access area 112 set in the external memory 109. In the state divided as shown in FIG. 9A, files 1 to 5 are stored in the file system access area 111, and there is a free area (unrecorded area) after that. When an application that uses a large amount of the physical access area 112 is executed in this state, the free area of the file system access area 111 is temporarily used as a part of the physical access area 112.

  Based on the configuration according to the above-described first embodiment (FIG. 1), when a large amount of physical access area 112 is required in the above state, for example, when used as a buffer for streaming video playback, etc. 1 instructs the data management control unit 103 in FIG. 1 to temporarily change the start addresses, sizes, and the like of the file system access area 111 and the physical access area 112 managed by the external memory management unit 106.

  The external memory management unit 106 saves the start addresses and sizes of the file system access area 111 and the physical access area 112 of the current external memory 109, and accesses the file system so that the configuration shown in FIG. 9B is configured. The start address and size of the area 111 and the physical access area 112 are changed. Therefore, the physical access area 112 of the external memory 109 to which the application writes data is as shown in FIG.

  When the application is finished and the use of the physical access area 112 is no longer necessary, the external memory management unit 106 returns the saved file system access area 111 and the physical access area 112 to the start addresses and sizes.

  In the above-described fourth embodiment, when a large amount of physical access area 112 is required, the external memory 109 is efficiently used by temporarily using the free area of the file system access area 111 as the physical access area 112. Can do.

  In the above description, the configuration of FIG. 1 has been described, but the same effect can be obtained with the configuration shown in FIG. 4 (second embodiment). In FIGS. 9A and 9B and the above description, the identification ID and the identification ID storage area 110 are omitted for the sake of simplicity.

E. Fifth Embodiment Next, the mapping state of the external memory in the fifth embodiment of the present invention will be described. FIGS. 10A to 10D are conceptual diagrams showing mapping examples of file system areas and physical access areas set in the external memory according to the fifth embodiment. In the state divided as shown in FIG. 10A, the file system access area 111 stores files 1 to 7 and there is no free area thereafter. FIG. 10B shows the mapping of the external memory in a state where the files 2 and 7 are deleted from this state. In this state, even if the fourth embodiment described above is performed, only the file 7 can be used as the physical access area 112, and the efficiency is poor.

  Therefore, in this fifth embodiment, when an application that uses a large amount of the physical access area 112 in this state is executed, the gap in the file system access area 111 is reduced, and the empty area is temporarily stored. Used as part of the physical access area 112.

  Based on the configuration according to the above-described first embodiment (FIG. 1), when a large amount of physical access area 112 is required in the above state, for example, when used as a buffer for streaming video playback, etc. The data management control unit 103 in FIG. 1 performs processing (defragmentation processing) for filling the gap in the file system access area 111 by the file system 107 for accessing the file system access area 111 in the external memory 109.

  Thereafter, an instruction is given to temporarily change the start address, size, and the like of the file system access area 111 and the physical access area 112 managed by the external memory management unit 106. The external memory management unit 106 saves the start addresses and sizes of the file system access area 111 and the physical access area 112 of the current external memory 109, and accesses the file system so that the configuration shown in FIG. 10C is configured. The start address and size of the area 111 and the physical access area 112 are changed. Therefore, the physical access area 112 of the external memory 109 to which the application writes data is the area shown in FIG.

  When the application is finished and the use of the physical access area 112 is no longer necessary, the external memory management unit 106 returns the saved file system access area 111 and the physical access area 112 to the start addresses and sizes. However, at this time, the file system access area 111 packed by the process of filling the gap is not moved so as to return to the original position, and the mapping shown in FIG.

  In the fifth embodiment described above, the external memory 109 is efficiently used by temporarily using the free area of the file system access area 111 as the physical access area 112 when a large amount of physical access area 112 is required. Can do.

  In the fifth embodiment, the description has been made in units of continuous files to simplify the description. However, when accessing with the file system 107, the file is actually accessed in units of sectors, and the file is deleted. If the writing is repeated, the file may not be continuous and may be segmented into sectors. Even in such a case, the same effect as in the fifth embodiment can be obtained by narrowing the gap in units of sectors.

  In the above description, the description is made with the configuration of FIG. 1, but the same effect can be obtained with the configuration of FIG. Also, in FIGS. 10A to 10D and the above description, the identification ID and the identification ID storage area 110 are omitted for the sake of simplicity.

  In the first to fifth embodiments described above, when a portable device capable of executing an application having a large memory usage such as multimedia has an external memory, the external memory is used to compensate for the insufficient memory amount, thereby improving the user's convenience. It can be used in a device that improves the performance.

It is a block diagram which shows the structure of the portable terminal device and external memory by 1st Embodiment of this invention. It is a flowchart for demonstrating the setting operation | movement of the file system area | region and physical access area | region of an external memory in this 2nd Embodiment. It is a flowchart explaining the flow of data writing in the first embodiment. It is a block diagram which shows the structure of the portable terminal device and external memory by this 2nd Embodiment. It is a conceptual diagram which shows the example of a mapping of the external memory 109 by this 2nd Embodiment. It is a flowchart for demonstrating the setting operation | movement of the file system area | region and physical access area | region of an external memory in this 2nd Embodiment. It is a flowchart explaining the flow of data writing in the second embodiment. It is a flowchart for demonstrating operation | movement of the portable terminal device by this 3rd Embodiment. It is a conceptual diagram which shows the mapping state of the external memory by 4th Embodiment of this invention. It is a conceptual diagram which shows the example of a mapping of the file system area | region and physical access area which were set to the external memory by this 5th Embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 100 Portable terminal device 101 Communication part 102 Display part 103 Data management control part (control means)
104 Data area setting section (setting means)
105 Internal memory 106 External memory management unit (management means)
107 File System 108 Physical Access Unit 109 External Memory (External Storage Medium)
110 ID area for identification (third area)
111 File system access area (first area)
112 Physical access area (second area)
400 ID generation part for identification (ID generation means for identification)

Claims (12)

In a mobile terminal device including an external storage medium that is detachable and rewritable at least,
Setting means for creating a first area for accessing the external storage medium with a file system and a second area for accessing with a file system other than the file system, and setting the sizes of the first area and the second area, respectively. A portable terminal device comprising:   The portable terminal device according to claim 1, wherein the external storage medium stores in advance an identification ID for identification with another external storage medium. An identification ID generating means for generating an identification ID for identifying the external storage medium for each external storage medium;
The portable terminal device according to claim 1, wherein the external storage medium has a third area for storing the identification ID.   4. A management unit that manages the identification ID, the start address and size of the first area, and the start address and size of the second area in association with each other. A portable terminal device according to any one of the above.   5. The control unit according to claim 1, further comprising a control unit that temporarily uses the empty area as a part of the second area when the first area has an empty area. The portable terminal device described.   The control means moves the existing data so that the gap area becomes a continuous empty area when the empty area of the first area is a gap area generated between existing data due to file deletion, 6. The portable terminal device according to claim 1, wherein the continuous empty area is temporarily used as a part of the second area.   The mobile terminal device according to claim 5 or 6, wherein the management unit sets a free area temporarily used as the second area to the first area again after the temporary use ends. In a data access method for an external storage medium that is at least removable and rewritable,
Creating a first area for accessing the external storage medium with a file system and a second area for accessing with a file system other than the file system, and setting each size of the first area and the second area; A featured data access method. The external storage medium stores an identification ID for identification from other external storage media,
9. The data access method according to claim 8, wherein the identification ID, the start address and size of the first area, and the start address and size of the second area are managed in association with each other.   10. The data access method according to claim 8, wherein when the first area has an empty area, the empty area is temporarily used as a part of the second area.   When the empty area of the first area is a gap area generated between existing data due to file deletion, the existing data is moved so that the gap area becomes a continuous empty area, and the continuous empty area The data access method according to claim 8, wherein: is temporarily used as a part of the second area.   12. The data access method according to claim 10, wherein a free area temporarily used as the second area is set as the first area again after the temporary use ends.

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