JP5521437B2 - Portable terminal device, software update method and program - Google Patents

Description

The present invention is a portable terminal device, a software update lateral Ho及 beauty program, and a software update method, especially rewriting rewriting target block of software that the difference data stored in the nonvolatile memory based on the software update.

  As shown in Patent Document 1, in a mobile terminal device such as a current mobile phone, a server connected to a network using a communication function is found when a problem is found in software (firmware) built into the mobile phone. Therefore, a technique and a mechanism for downloading difference data obtained by extracting differences between old and new program data of software and updating (difference rewriting) the software built in the device itself has been established. This is generally called FOTA (firmware over the air).

  Patent Document 2 describes that the control unit of the mobile terminal device downloads the difference data from the server and updates the software stored in the NOR flash memory of the mobile terminal device. When updating the software, when the control unit detects a defect in the rewrite target area (physical address A) of the memory, the control unit performs the update using the alternative area (physical address A ′) provided in advance in the memory, and the physical address A is assigned to the physical address A ′ as a logical address. As a result, even if the software program data is stored across discontinuous physical addresses, it appears to the control unit processor as continuous addresses.

  Patent Document 3 describes that the control unit of the mobile terminal device downloads the difference data from the server and updates the software stored in the NAND flash memory of the mobile terminal device. Here, the plurality of blocks constituting the NAND memory include a management area composed of at least one block, a code area composed of a plurality of blocks, a software area for storing software, a substitution area composed of a plurality of blocks, and a management area. It is assigned to an interference area composed of at least one block provided between the areas.

  When updating the software, if the control unit detects a defect in the block to be rewritten in the code area of the NAND memory, the control unit updates the block using the block in the replacement area, and displays correspondence information indicating that the replacement block replaces the defective block. Write to the management area. As a result, the continuity of memory addresses can be ensured as in Patent Document 2.

JP 2005-078502 A JP 2007-219883 A JP 2008-040701 A

  Patent Document 2 does not clearly indicate where information on a logical address assigned to an alternative area when a defect is detected is stored. On the other hand, in the technique described in Patent Document 3, a management area and an interference area are provided in the NAND flash memory for storing information indicating the correspondence between a defective block and an alternative block. However, in order to provide a management area and an interference area, a NAND flash memory block must be assigned to them.

  In addition, since the software size varies depending on the version, when executing the software, the entire area in the flash memory allocated in advance for storing the software is expanded in the RAM including the unused part of the area. There is a case. In this case, if there is a defective block in the unused portion, it is unused, so it is considered that there is no replacement block in the replacement area for the defective block. Therefore, if there is such an unused bad block, an error occurs and the software cannot be executed.

An object of the present invention is to solve the problems described above, a portable terminal device capable of effectively utilizing non-volatile memory for storing software, is to provide a software update lateral Ho及 beauty program.

Another object of the present invention is to solve the above-described problems, and to prevent an error from occurring even if there is a bad block in an unused part in the software storage area of the memory. It is to provide a Ho及 beauty program.

The portable terminal device according to the present invention includes a program area in which a part of a plurality of blocks constituting the own memory is allocated and software is stored, and an alternative in which a part of the plurality of blocks is allocated. Each of the plurality of blocks includes a main area for storing actual data (Main Area) and a spare area for storing spare data (Spare Area). The non-volatile memory in which the logical block number of the block is stored, and the correspondence between the physical block number and the logical block number of each block storing the software using only the program area and the alternative area Control means for accessing the non-volatile memory, said control means comprising: Based on the software differential data for updating in block units when rewriting of the software, if the rewriting target block of the program area is a defective block, writes the differential data into blocks of the spare area, the replacement write the logical block number of the rewrite target block in the spare area of the block in which the difference data is written in the area, said control means, said program area and the spare of the block respectively assigned to the replacement area The correspondence relationship is grasped based on the logical block number in the area, and the nonvolatile memory is accessed .

A software update method according to the present invention is a software update method for a mobile terminal device, wherein a program area in which a part of a plurality of blocks constituting a self-memory is allocated to store software, and the plurality of blocks A plurality of blocks each including a main area for storing actual data and a spare area for storing spare data (Spare Area). In the nonvolatile memory in which the logical block number of the block is stored in the spare area of each block of the program area, the physical block number and logic of each block that stores the software using only the program area and the alternative area Control access based on the correspondence with block numbers It includes a step, wherein the controlling step, when rewriting of the software in blocks on the basis of the difference data for the software update, when rewriting target block of the program area is a defective block, the block of the substitution area the writes the differential data, look including the step of writing the logical block number of the rewrite target block in the spare area of the block in which the difference data of the replacement area is written to, the control step, the program area and the The nonvolatile memory is accessed by grasping the correspondence relationship based on the logical block number in the spare area of each of the blocks allocated to the alternative area .

A program according to the present invention is a program for causing a computer to execute a software updating method for a mobile terminal device, wherein a program area in which a part of a plurality of blocks constituting the own memory is allocated and software is stored; A plurality of blocks to which a part of the blocks is assigned, and each of the plurality of blocks includes a main area for storing actual data and a spare area for storing spare data (Spare Area). Each block that stores the software using only the program area and the alternative area in a non-volatile memory in which the logical block number of the block is stored in the spare area of each block of the program area Correspondence between block number and logical block number It grasps the includes a control process of access, the control process, when the rewriting of the software based on the difference data for updating the software in blocks, rewritten block of the program area is a defective block If the block alternative region writes the differential data, look including the process of writing the logical block number of the rewrite target block in the spare area of the block in which the difference data of the replacement area is written, the control process Is characterized in that the correspondence is grasped based on the logical block number in the spare area of each of the blocks allocated to the program area and the alternative area, and the nonvolatile memory is accessed .

  According to the present invention, it is possible to effectively use a nonvolatile memory that stores software.

  According to the present invention, it is possible to prevent an error from occurring even if a defective block exists in an unused portion in the software storage area of the memory.

It is a figure which shows schematic structure of the portable terminal device for demonstrating the principle of this invention. It is a figure which shows the structure of the portable terminal device by the 1st Embodiment of this invention. FIG. 3 is a diagram showing a memory configuration of the NAND flash memory of FIG. 2. FIG. 3 is a diagram showing a block configuration of the NAND flash memory of FIG. 2. It is a figure for demonstrating a mode that the difference data for a software update is produced | generated by comparing the program before the update of the software stored in the portable terminal device by the 1st Embodiment of this invention, and the program after the update. It is a flowchart which shows operation | movement of the portable terminal device by the 1st Embodiment of this invention. FIG. 6 is a diagram showing a memory configuration of the NAND flash memory of FIG. 2 for explaining an expansion processing operation to a RAM according to a second embodiment of the present invention. It is a flowchart which shows operation | movement of the portable terminal device by the 2nd Embodiment of this invention. It is a figure for demonstrating the software update operation | movement in the 3rd Embodiment of this invention. It is a flowchart which shows operation | movement of the portable terminal device by the 3rd Embodiment of this invention. It is a figure which shows the example which gives the information of the use size of a program for each program of FIG.

  Before describing embodiments of the present invention, the principle of the present invention will be described with reference to the drawings in order to help understanding of the present invention. FIG. 1 is a diagram showing a schematic configuration of a portable terminal device for explaining the principle of the present invention.

  The mobile terminal device shown in FIG. 1 has a program area in which a part of a plurality of blocks constituting the own memory 12 is allocated and stores software, and a part of the plurality of blocks is allocated. The plurality of blocks each include a main area (Main Area) for storing actual data and a spare area (Spare Area) for storing spare data, and the spare of each block of the program area A nonvolatile memory 12 in which the logical block number of the block is stored in the area is provided.

  Furthermore, the portable terminal device shown in FIG. 1 is configured to grasp the correspondence between the physical block number of each block and the logical block number based on the logical block number in the spare area of each of the plurality of blocks. 12 includes a control unit 11 that accesses the control unit 12. When the control unit 11 rewrites the software in units of blocks based on the difference data for software update, if the rewrite target block in the program area is a bad block, the control unit 11 writes the difference data in the block in the alternative area At the same time, the logical block number of the block to be rewritten is written in the spare area of the block in which the differential data in the alternative area is written.

  In this way, the control unit 11 writes the logical block number in the spare area of the alternative block when assigning the logical block number to the alternative block of the defective block at the time of software update. Therefore, it is not necessary to divide some of the blocks of the nonvolatile memory and provide a separate management area, so that the nonvolatile memory can be used effectively.

  Next, another portable terminal device according to the present invention will be described with reference to FIG. In FIG. 1, another portable terminal device according to the present invention includes a non-volatile memory 12 including a program area in which a part of a plurality of blocks constituting the own memory 12 is allocated and stores software, and the program area. When the software is read out from the program area, if the read target block in the program area is a bad block, a control unit 11 is provided which sets the data in the read target block as a predetermined fixed value.

  As described above, when the block to be read in the program area is a bad block, the control unit 11 replaces the data in the block to be read with a predetermined fixed value, so that an unused portion in the program area that is a software storage area is defective. It is possible to prevent an error even if a block exists.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  FIG. 2 is a diagram showing the configuration of the portable terminal device according to the first embodiment of the present invention. 2, the mobile terminal device according to the first embodiment of the present invention includes an antenna 21, a communication unit 22, a control unit 23, a NAND flash memory 24, and a RAM (Random Access Memory) 25. .

  FIG. 3 is a diagram showing a memory configuration of the NAND flash memory 24 of FIG. 2, and FIG. 4 is a diagram showing a block configuration of the NAND flash memory 24 of FIG. As shown in FIG. 3, the NAND flash memory 24 is composed of a plurality of blocks, and each block is composed of a plurality of pages as shown in FIG.

  Generally, a flash memory cannot be erased (erased) before new writing (program) can be performed. In FIG. 4, a block is an erase unit and a page is a program unit. The block is composed of a plurality of pages, that is, the erased block can be programmed a plurality of times for each page. Each page is composed of a main area (Main Area) and a spare area (Spare Area). The former stores actual data, and the latter includes ECC (Error Correcting Code) for detecting and correcting bit errors. Accompanying data (spare data) is stored.

  In the NAND flash memory, an error may occur during Erase or Program, and it is necessary to manage the block in which the error has occurred so that it is not used as a defective block (defective block). Some of these bad blocks already exist at the time of shipment from the factory of the memory, while others are generated while the user is using the memory. In both cases, management is required so that the memory is not used. .

  As shown in FIG. 4, a bad block marker (Invalid Block Marker) is provided at a specific position in the spare area. If this marker satisfies a predetermined condition, the block can be identified as a bad block. In addition, a logical block number can be stored at a specific position in the spare area. A logical block number is assigned in advance to each block in the program area of the NAND flash memory 24 to be described later, that is, a logical block number is stored in advance at a specific position in the spare area of each block in the program area.

  The NAND flash memory 24 includes a program area to which a plurality of blocks are assigned and an alternative area to which at least one block is assigned. In the example shown in FIG. 3, blocks with physical block numbers 0 to 6 are allocated to the program area, and blocks with physical block numbers N to N + 3 are allocated to the alternative area. Software is stored in the program area, and as described above, the logical block number of the block is stored in advance in the spare area of each block in the program area. In the example shown in FIG. 3, the physical block number = logical block number is set in a block that is not a bad block in the program area.

  On the other hand, no logical block number is assigned to each block in the alternative area, that is, no logical block number is stored in the spare area of each block in the alternative area. At the time of software update, when a defective block exists in the program area or newly occurs, the control unit 23 writes to the block in the alternative area and assigns a logical block number to this alternative block.

  FIG. 5 is a diagram for explaining how the difference data necessary for updating the software (old software) stored in the program area of FIG. 3 to new software is generated. FIG. 5 shows an example in which a difference occurs in the memory blocks 2, 4 and 5 in the old and new software. An image of the old and new software (binary file or hex file) is input to the difference generation tool, and the difference generation tool compares the two, and generates and outputs difference data including information indicating the memory block position where the difference has occurred. This difference data is placed on a server (not shown) connected to the network.

  The control unit 23 of the mobile terminal device according to the first embodiment of the present invention uses the antenna 21 and the communication unit 22 to access the server via the network and download the difference data. And the control part 23 can update to new software by rewriting software in a block unit using this difference data. The memory block numbers shown in FIG. 5 correspond to the logical block numbers in the NAND flash memory 24 shown in FIG.

  In FIG. 3, the block with the physical block number 4 is not recognized as a bad block before the software update, and the logical block number 4 is stored in advance at a specific position in the spare area of this block. It is assumed that the program data A to G of the old software are respectively stored in the physical block numbers 0 to 6 (logical block numbers 0 to 6) in FIG.

  Next, the operation of the mobile terminal device according to the first embodiment of the present invention will be described. FIG. 6 is a flowchart showing the operation of the portable terminal device according to the first embodiment of the present invention. First, when the portable terminal device according to the first embodiment of the present invention is turned on, the control unit 23 searches for a spare area of each block of the NAND flash memory 24, and the physical block number and logical block number of each block. It is assumed that information indicating the correspondence relationship is stored in the RAM 25. As a result, the control unit 23 accesses the block of the NAND flash memory 24 corresponding to the logical block number based on the information in the RAM 25.

  In FIG. 6, at the time of software update, the control unit 23 starts writing to the block to be rewritten in the program area of the NAND flash memory 24 using the difference data downloaded from the server (step S1). Here, when the rewrite target block is not a bad block (step S2), the control unit 23 writes the data in the rewrite target block as it is (step S3), and proceeds to the process of step S7.

  On the other hand, when the block to be rewritten is a defective block or when it is newly found to be a defective block (step S2), the control unit 23 replaces the block to be rewritten with a block in the replacement area (for example, an unreplaced area block). Data is written to the first block of the used blocks (step S4). In addition, the control unit 23 writes the logical block number of the rewrite target block at a specific position in the spare area of this alternative block (step S5). Then, the control unit 23 updates the information in the RAM 25 so that the logical block number is associated with the physical block number of the alternative block instead of the physical block number of the rewrite target block (step S6).

  FIG. 3 shows a case where an error has occurred in Erase or Program for the block with physical block number 4 and a defect in the block with physical block number 4 is detected. In this case, as shown in FIG. 3, the control unit 23 writes the data E ′ in the block of the physical block number N in the alternative area, and writes the logical block number 4 in a specific position in the spare area of the alternative block. Normally, the maximum number of defective blocks that may occur in the entire memory is determined by the specification, and the number of blocks to be allocated to the alternative area is determined with respect to the number of blocks in the program area in consideration of this.

  Returning to FIG. 6, in step S7, if there is another block to be rewritten, the process returns to step S1, and if the writing is completed, the software update ends.

  As described above, in the first embodiment of the present invention, when software is updated, when detecting a defect in a rewrite target block, the control unit 23 writes to the replacement block and rewrites the replacement block. Since logical block numbers of blocks are assigned, continuity of memory addresses can be ensured.

  In the first embodiment of the present invention, the logical block number is assigned to the alternative block by writing the logical block number in the spare area of the alternative block. Therefore, it is not necessary to divide some of the blocks of the NAND flash memory 24 and provide a separate management area, so that the memory can be used effectively.

  In the first embodiment of the present invention, when the mobile terminal device is powered on, the control unit 23 searches the spare area of each block of the NAND flash memory 24, and the physical block number and logical block of each block. Information indicating the correspondence relationship with the number is stored in the RAM 25, but such an operation may not be performed. In this case, since the above information is not stored in the RAM 25, the control unit 23 searches the spare area of each block of the NAND flash memory 24 for each access and grasps the correspondence relationship. If the physical block number is equal to the logical block number in a block that is not a bad block in the program area, it is replaced to recognize the substitute block only when the bad block is detected and the corresponding substitute block is accessed. What is necessary is just to search the spare area | region of each block of an area | region.

  In the first embodiment of the present invention, the physical block number = logical block number in each block of the program area of the NAND flash memory 24, and the logical block number is stored in advance in the spare area of each block of the program area. It was said that However, when the physical block number is equal to the logical block number in this way, the correspondence between the physical block number and the logical block number can be obtained without referring to the spare area. Therefore, the logical block number is set in the spare area of each block in the program area. It is not necessary to store. However, even in this case, of course, it is necessary to write the logical block number in the spare area of the alternative block.

  Next, a second embodiment of the present invention will be described with reference to the drawings. The basic configuration and operation of the mobile terminal device according to the second embodiment of the present invention are the same as those of the mobile terminal device according to the first embodiment of the present invention, but in the second embodiment of the present invention. Furthermore, the operation when the software of the NAND flash memory 24 is read to be executed and expanded in the RAM 25 is devised.

  Since the program code stored in the NAND flash memory cannot be directly executed on the same memory, the program stored in the built-in ROM of the CPU normally operates to expand the program code of the NAND flash memory into the RAM and store it in the RAM. The CPU executes the expanded program code. A program for executing the expansion process to the RAM is generally called a boot loader.

  In the second embodiment of the present invention, when the control unit 23 of FIG. 2 develops the program of the NAND flash memory 24 in the RAM 25 according to a boot loader (not shown), there is a defective block in the program area of the NAND flash memory 24. In this case, the data written in the alternative block in the alternative area of the NAND flash memory 24 is expanded in the RAM 25 instead. Here, when a substitute block for the bad block does not exist in the substitute area, that is, when it is considered that a bad block exists in the unused part of the program area of the NAND flash memory 24, the data of the bad block is set to a predetermined fixed value. The data is expanded in the RAM 25. This fixed value is, for example, a value indicating that the block is an unused block (initialized state). This is generally all 0xFF, which is a state after block erasure of the flash memory.

  FIG. 7 is a diagram showing a memory configuration of the NAND flash memory 24 of FIG. 2 for explaining the expansion processing operation to the RAM 25 in the second embodiment of the present invention. In FIG. 7, the NAND flash memory 24 includes a program area 101 to which blocks with physical block numbers 0 to 6 are allocated and an alternative area 201 to which blocks with physical block numbers N to N + 3 are allocated.

  The program area 101 stores software program data A to D. However, since the block with the physical block number 2 is a defective block, the block with the physical block number N of the alternative area 201 which is an alternative block for the defective block. It is assumed that program data C is stored in. Further, it is assumed that the block with the physical block number 4 is a defective block, and no replacement block for the defective block exists in the replacement area 201.

  When the control unit 23 develops the software in the program area 101 in the RAM 25, for example, for the block having the physical block number 0, the program data A in the block is read and developed in the RAM 25. Further, since the block with the physical block number 2 is a defective block and there is an alternative block (physical block number N), the control unit 23 reads the program data C in the alternative block and develops it in the RAM 25. .

  For the block of physical block number 5 which is an unused block, the control unit 23 reads all 0xFF data in this block and develops it in the RAM 25. Then, for the bad block with physical block number 4 for which no alternative block exists, the control unit 23 develops the data of this bad block in the RAM 25 as all 0xFF data.

  FIG. 8 is a flowchart showing the operation of the portable terminal device according to the second embodiment of the present invention. In FIG. 8, the control unit 23 reads the data of the development target block in the program area 101 (step S11). If the expansion target block is a bad block and there is no replacement block for the expansion target block in the replacement area 201 (step S12), the control unit 23 converts the data of the expansion target block to all 0xFF data. To the RAM 25 (step S13).

  In step S12, otherwise, the control unit 23 reads the data from the corresponding block as described above and expands it in the RAM 25 (step S14). In step S15, if there is still another development target block in the program area 101, the process returns to step S11.

  As described above, in the second embodiment of the present invention, when there is no alternative block for a defective block, the control unit 23 handles the data of the defective block by replacing it with all 0xFF data. Therefore, even when there is a bad block in an unused part in the program area 101 and no alternative block for it exists in the alternative area 201, the boot process can be continued without causing an error. This is effective, for example, when the entire program area 101 including the unused part is always expanded in the RAM 25 in the boot loader because the used area in the program area 101 changes depending on the software version.

  Even if a substitute block for a bad block disappears for some reason, the boot process can be continued without causing an error if the contents contained in the block are not used.

  Next, a third embodiment of the present invention will be described with reference to the drawings. The basic configuration and operation of the mobile terminal device according to the third embodiment of the present invention are the same as those of the mobile terminal device according to the first embodiment of the present invention, but the third embodiment of the present invention is When a software update is performed, if a bad block exists in an unused part in the program area and a replacement block for the block does not exist in the replacement area, the data of the bad block is handled as a predetermined fixed value (all 0xFF). This is different from the first embodiment of the present invention.

  FIG. 9 is a diagram for explaining an operation of updating software (old software) stored in the program area 101 to new software in the third embodiment of the present invention. As shown in FIG. 9, the NAND flash memory 24 includes program areas 101 to 103, and the program X in the program area 101 is updated to a program X '. Although not shown in FIG. 9, the NAND flash memory 24 naturally includes an alternative area as in the first embodiment of the present invention.

  In FIG. 9, when a bad block exists in an unused part of the program area 101 before software update (during old software), data is not written to this block before software update. There appears to be no alternative block for the block. In such a state, when updating (differential rewriting) to new software (program X ′) that will also use the unused part of the program area 101, the unused part of the program area 101 is also subject to differential rewriting. Become.

  In the third embodiment of the present invention, at the time of updating, the defective block data existing in this unused portion is treated as all 0xFF, and the all 0xFF data and difference data are used to replace the defective block. Thus, differential rewriting can be performed on blocks in the alternative area.

  FIG. 10 is a flowchart showing the operation of the portable terminal device according to the third embodiment of the present invention, and the processing operations in steps S1 to S7 in FIG. 10 are the same as those in FIG. In FIG. 10, the control unit 23 reads data from the rewrite target block in the program area 101 (step S21). Here, when the rewrite target block is a bad block and there is no replacement block for the rewrite target block in the replacement area (step S22), the control unit 23 sets the data of the rewrite target block as all 0xFF data. (Step S23).

  In step S22, if the rewrite target block is not a bad block, or if it is a bad block but there is a replacement block, the control unit 23 reads data from the rewrite target block or the replacement block (step S24). And the process after step S1 is performed based on the data and difference data which were obtained in step S23 or S24.

  As a result, even when there is no substitute block for the defective block, it is possible to execute the differential rewriting of the software in units of blocks without treating it as an error. Further, even if a substitute block for a bad block disappears for some reason, if the contents included in the block are not used, differential rewriting can be executed without treating it as an error.

  FIG. 11 is a diagram showing an example in which program size information is provided for each program in FIG. The usage size (data size) varies depending on the software version. As shown in FIG. 11, when the information on the used size is stored at the head of each program area, for example, the control unit 23 reads the size information in order to read the software and execute it in the RAM 25. Based on this, the number of blocks developed in the RAM 25 can be grasped.

  Therefore, in this case, it is not necessary to expand the entire program area in the RAM 25, that is, it is not necessary to expand the unused part of the program area in the RAM 25. Therefore, even if there is a bad block in the unused portion and there is no substitute block, no error occurs in the boot process.

  However, at the time of updating from the old software to the new software (difference rewriting), there is a case where such information is not stored as shown in FIG. Similarly, the unused portion is also subject to differential rewriting, and an error may occur when there is a bad block in the unused portion. The occurrence of such an error can be prevented by applying the third embodiment of the present invention also to the case as shown in FIG.

  The processing operation of the portable terminal device according to the flowcharts shown in FIGS. 6, 8, and 10 is such that a program stored in advance in a storage medium such as a ROM is read by a computer serving as a CPU (control unit) in the device. Of course, it can be realized by executing the command.

  The embodiment of the present invention is applicable to all mobile terminal devices including mobile phones, PHS (Personal Handyphone System), and PDA (Personal Data Assistance, Personal Digital Assistants).

11, 23 Control unit 12 Non-volatile memory 21 Antenna 22 Communication unit 24 NAND flash memory 25 RAM

Claims (15)

Including a program area in which a part of a plurality of blocks constituting the own memory is allocated and storing software, and an alternative area to which a part of the plurality of blocks is allocated, Each block includes a main area for storing actual data (Main Area) and a spare area for storing spare data (Spare Area), and the logical block number of the block is stored in the spare area of each block in the program area. A NAND type flash memory in which the physical block number and the logical block number of each block of the program area are equal, and the logical block number of the block is not stored in the spare area of each block of the alternative area ;
Control means for grasping a correspondence relationship between a physical block number and a logical block number of each block storing the software by using only the program area and the alternative area, and accessing the NAND flash memory,
When rewriting the software on a block basis based on the difference data for updating the software, when the rewrite target block in the program area is a bad block, the control means includes the difference data in the block in the alternative area. And writing the logical block number of the block to be rewritten in the spare area of the block in which the differential data of the alternative area is written,
The control means grasps the correspondence relationship based on a logical block number in the spare area of each of the blocks allocated to the program area and the alternative area, and accesses the NAND flash memory. Mobile terminal device. A second memory;
The control means stores the correspondence relationship in the second memory, and when the logical block number of the rewrite target block is written in the spare area of the block in which the differential data of the alternative area is written, The mobile terminal apparatus according to claim 1, wherein the correspondence relationship in the second memory is updated. The second memory is a volatile memory;
3. The portable terminal device according to claim 2, wherein the control unit creates the correspondence relationship when the portable terminal device is turned on and stores the correspondence relationship in the second memory.   The mobile terminal device according to any one of claims 1 to 3, wherein the blocks in the alternative area are used in order from the first block in the alternative area. When rewriting the software, when the rewrite target block is a bad block and there is no block in the replacement area to which the logical block number of the rewrite target block is assigned, the control means the portable terminal device of the data given the claim 1-4, wherein one of and writes the differential data into blocks of the substitution area as a fixed value. 6. The portable terminal device according to claim 5 , wherein the predetermined fixed value is a value indicating an unused block. A software update method for a mobile terminal device,
Including a program area in which a part of a plurality of blocks constituting the own memory is allocated and storing software, and an alternative area to which a part of the plurality of blocks is allocated, Each block includes a main area for storing actual data (Main Area) and a spare area for storing spare data (Spare Area), and the logical block number of the block is stored in the spare area of each block in the program area. In the NAND flash memory, the physical block number and the logical block number of each block of the program area are equal, and the spare area of each block of the alternative area does not store the logical block number of the block. Using only the area and the alternative area Includes a control step of accessing to grasp the correspondence between the physical block number and the logical block number of each block for storing software,
In the control step, when rewriting the software on a block basis based on the difference data for updating the software, if the rewrite target block in the program area is a bad block, the difference data is transferred to the block in the alternative area. And writing the logical block number of the block to be rewritten in the spare area of the block in which the differential data of the alternative area is written,
The control step grasps the correspondence relationship based on a logical block number in the spare area of each of the blocks allocated to the program area and the alternative area, and accesses the NAND flash memory. How to update software. The control step includes the step of storing the correspondence relationship in a second memory, and when the logical block number of the rewrite target block is written in the spare area of the block in which the differential data of the alternative area is written, The software update method according to claim 7 , further comprising the step of updating the correspondence relationship in the second memory. The second memory is a volatile memory;
Wherein the step of storing a correspondence relationship in the second memory, the portable terminal device of software according to claim 8, wherein said creating a correspondence relation when the power is turned, characterized in that stored in the second memory updating Method. The software update method according to claim 7 , wherein the blocks in the alternative area are used in order from the first block in the alternative area. When rewriting the software, if the block to be rewritten is a bad block and there is no block in the substitution area to which the logical block number of the block to be rewritten is assigned, the data of the block to be rewritten is a predetermined data The software update method according to claim 7 , wherein the difference data is written as a fixed value in the block of the alternative area. Said predetermined fixed value, a method of software update claim 1 1, wherein the a value indicating the unused block. A program for causing a computer to execute a software update method for a mobile terminal device,
Including a program area in which a part of a plurality of blocks constituting the own memory is allocated and storing software, and an alternative area to which a part of the plurality of blocks is allocated, Each block includes a main area for storing actual data (Main Area) and a spare area for storing spare data (Spare Area), and the logical block number of the block is stored in the spare area of each block in the program area. In the NAND flash memory, the physical block number and the logical block number of each block of the program area are equal, and the spare area of each block of the alternative area does not store the logical block number of the block. Using only the area and the alternative area Includes a control process of accessing to grasp the correspondence between the physical block number and the logical block number of each block for storing software,
When the control process rewrites the software in block units based on the difference data for updating the software, if the block to be rewritten in the program area is a bad block, the difference data is transferred to the block in the alternative area. And writing the logical block number of the block to be rewritten in the spare area of the block in which the differential data of the alternative area is written,
The control process is characterized in that the correspondence relationship is grasped based on a logical block number in the spare area of each of the blocks allocated to the program area and the alternative area, and the NAND flash memory is accessed. Program to do. When rewriting the software, if the block to be rewritten is a bad block and there is no block in the substitution area to which the logical block number of the block to be rewritten is assigned, the data of the block to be rewritten is a predetermined data It claims 1 to 3, wherein the program and writes the differential data into blocks of the alternate area as a fixed value. It said predetermined fixed value, according to claim 1 4, wherein the program, which is a value indicating the unused block.

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