JP5483930B2 - In-vehicle electronic device and control program - Google Patents

Description

  The present invention relates to an in-vehicle electronic device that has a storage device that distributes and stores a single file into a plurality of areas, and that is powered on / off by an external switch. The present invention relates to a technique for recovering data when it is blocked.

  In-vehicle electronic devices in recent years are required to have not only car navigation but also audio and visual functions. The in-vehicle electronic device requires a storage device for storing various content data such as map data, music data, and video data. These contents data have a large capacity and are required to be updated appropriately. Therefore, a hard disk device is used as a large capacity and rewritable storage device. Patent Document 1 describes a hard disk device that stores content data.

  A hard disk device generally stores a single file by dividing it into a plurality of areas (sectors). The hard disk device also divides the disk into a data area and a management area, and stores file data in the data area. Then, file entry information and link list information corresponding to the so-called table of contents of the file are stored in the management area. The file entry information has a start position (sector number) for each file. The link list information has a link order of sectors in which files are stored.

  In an in-vehicle electronic device, a file system controls reading / writing of a file with respect to a hard disk device. When reading data, the file system first reads file entry information and link list information in the management area. Then, the start sector number of the file and the link order of the sectors are acquired. Then, the sector in the data area is sequentially referred to from the start sector according to the link order to read the data, and the desired file is read. When writing a file, the file system acquires a writable sector number from the hard disk device. Then, the file entry information having the start sector number and the link list information having the sector link order are written to the management area, and the file data is written to the sector in the data area.

Japanese Patent No. 377922

  When writing a file, the hard disk device manages whether or not data writing is completed for each sector. In the sector where data writing has been completed, data can be read out at any time thereafter. However, in a sector where data writing is not completed, data cannot be read thereafter. Such a sector is hereinafter referred to as a bad sector.

  One cause of the occurrence of a bad sector is an instantaneous power interruption when data is being written to the hard disk device. Here, the in-vehicle electronic device is generally connected to the in-vehicle battery by an accessory switch, and the power is turned on / off. The accessory switch is configured to turn on / off power to other in-vehicle devices such as electrical components. Therefore, the user tends to collectively turn on and off power to the vehicle-mounted electronic device and other devices by opening and closing the accessory switch. For this reason, when compared with a general-purpose computer such as a personal computer, for example, the power supply is often shut down without going through a normal termination procedure of the in-vehicle electronic device. Then, a bad sector occurs in the hard disk device, and the probability of hindering subsequent file reading increases.

  In particular, when a bad sector occurs in the management area, the following problem occurs. For example, if a bad sector occurs in the link list information, the link order after the place where the bad sector occurs cannot be read, and the link of the sector is not traced. Then, the file itself cannot be read. Alternatively, when a bad sector occurs in the file entry information, it is impossible to read the start position of the file included in the directory where the bad sector occurs and the directory below it. As described above, there are cases where it is not possible to read not only the file that was being written but also the file that has been written and the file that has already been stored.

  In this regard, if it is a general-purpose computer, the history of data written to file entry information and link list information is stored in nonvolatile memory or a hard disk, or backup data of such information is created in the hard disk to prepare for recovery. A method has been proposed. However, since the former method requires a large-capacity memory or hard disk, it is not preferable for an in-vehicle electronic device that is strongly demanded for downsizing and cost reduction. In the latter method, it takes a certain amount of time to restore the backed up data to the file entry information or link list information in which a bad sector has occurred. Considering that restoration processing can occur more frequently in a vehicle-mounted electronic device than a general-purpose computer, long-time restoration processing is not preferable because it may impair user convenience.

  Accordingly, an object of the present invention made in view of the above is to provide an in-vehicle electronic device capable of recovering file entry information and link list information in a short time without increasing the cost.

  In order to achieve the above object, the in-vehicle electronic device according to the first aspect of the present invention has a storage device that distributes and stores a single file into a plurality of areas, and the power from the in-vehicle battery is turned on / off. And a memory capable of holding data even when the power is turned off. Then, the storage unit stores file entry information having a start position of the file when the file is stored in the storage device, and link list information having a link order of the area from the start position. When writing to the storage device, the link list information is written to a plurality of link list information writing positions in the storage device for each first writing unit as a part thereof. Further, the backup means stores the plurality of link list information write positions and data indicating the end of writing of the first write unit for the plurality of link list information write positions in the memory. Further, when the restoration means is turned on again after the power is turned off, writing of the first write unit to the first link list information writing position among the plurality of link list information writing positions is completed. If not, the data written in the second link list information write position is written in the first link list information write position.

  Further, in the in-vehicle electronic device according to the second aspect of the present invention, the writing means has file entry information having a start position of the file when the file is stored in the storage device, and the area from the start position. When the link list information having the link order is written to the storage device, the file entry information is written to a plurality of file entry information write positions in the storage device for each second write unit as a part thereof. Further, the backup means writes the first file entry information write position among the plurality of file entry information write positions to the storage device. When the restoration means is not turned on when the second file unit is written to the first file entry information write position when the power is turned off and then turned on again, the second means The data written in the file entry information write position is written in the first file entry information write position.

  Furthermore, in the vehicle-mounted electronic device according to the third aspect of the present invention, the writing means stores file entry information having a start position of the file when the file is stored in the storage device, and the area from the start position. When the link list information having the link order is written to the storage device, the file entry information is written to the file entry information write position in the storage device for each second write unit as a part thereof. The backup unit stores the second write unit and the file entry information write position in the memory. When the restoration means is not turned on when the second write unit stored in the memory with respect to the file entry information write position is finished when the power is turned off and then turned on again, The second writing unit is written in the file entry information writing position.

  According to the present invention, an in-vehicle electronic device capable of recovering link list information and file entry information in a short time without increasing costs is provided.

It is a figure explaining the use condition of the vehicle-mounted electronic device in this embodiment. 2 is a block diagram illustrating a configuration of an in-vehicle electronic device 10. FIG. FIG. 4 is a diagram for explaining reading and writing of data with respect to a hard disk device 19. It is a figure explaining operation | movement of the file system 128a as a writing means and a backup means in recovery | restoration of link list information. It is a figure explaining the operation | movement as a recovery means of the file system 128a. It is a figure explaining the modification in the restoration method of link list information LL. The operation of the file system 128a as the writing unit and the backup unit in the restoration of the file entry information will be described. It is a figure explaining the operation | movement as a recovery means of the file system 128a. 3 is a diagram for explaining a method of creating backup data in a backup memory 18. FIG. FIG. 4 is a diagram for explaining data stored in a backup memory 18. FIG. 5 is a flowchart for explaining an operation procedure of the in-vehicle electronic device 10 when writing data to the hard disk device 19. It is a flowchart figure explaining the operation | movement procedure of the vehicle-mounted electronic device 10 when performing the recovery method. It is a flowchart figure explaining the procedure of a link list information restoration process. It is a flowchart figure explaining the procedure of a file entry information recovery process. It is a flowchart explaining another procedure of file entry information recovery processing.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. However, the technical scope of the present invention is not limited to these embodiments, but extends to the matters described in the claims and equivalents thereof.

  FIG. 1 is a diagram for explaining a usage state of an in-vehicle electronic device in the present embodiment. The in-vehicle electronic device 10 is an in-vehicle electronic device in which car navigation, audio, and visual functions are integrated. The in-vehicle electronic device 10 includes a hard disk device 19 for storing content data such as map data, music data, and video data. The in-vehicle electronic device 10 includes a read / write control unit 128 that controls reading / writing of content data with respect to the hard disk device 19. The in-vehicle electronic device 10 reads the map data stored in the hard disk device 19 by the read / write control unit 128 and performs a route search. The in-vehicle electronic device 10 reads out music data and video data stored in the hard disk device 19 by the read / write control unit 128 and reproduces and outputs the music and video.

  The in-vehicle electronic device 10 is configured to be connectable to the public communication network 50. The public communication network 50 is, for example, the Internet or a VICS (Vehicle Information and Communication System) communication network. The in-vehicle electronic device 10 connects to a content data provider server (not shown) via the public communication network 50 and downloads the content data. The downloaded content data is stored in the hard disk device 19. Such content data includes TOC (Table of Contents) of music CD, CDDB (CD Data Base), etc. in addition to the music data and video data as described above. Further, the in-vehicle electronic device 10 may receive content data transmitted by wireless broadcasting in addition to the public communication network 50.

  The in-vehicle electronic device 10 is configured to be connectable to an external storage medium 7. The storage medium 7 is, for example, a USB memory or an SD card. The in-vehicle electronic device 10 reads content data from the external storage medium 7 and stores it in the hard disk device 19. The user can transplant the content data to the in-vehicle electronic device 10 through the storage medium 7 by storing the content data in the storage medium 7 using a general-purpose computer or other information processing apparatus.

  In this way, the in-vehicle electronic device 10 can acquire new content data from the public communication network 50 or the storage medium 7 at any time according to the user's request. Therefore, the content data stored in the hard disk device 19 is updated as appropriate.

  Further, the in-vehicle electronic device 10 is connected by an in-vehicle battery 20 and an accessory (ACC) switch 22 outside the in-vehicle electronic device 10 to be turned on / off. The in-vehicle electronic device 10 operates by turning on the power when the ACC switch 22 is on. On the other hand, when the ACC switch 22 is off, the power is cut off and the operation is interrupted. The ACC switch 22 turns on / off the power from the in-vehicle battery 20 to devices such as electrical components mounted on the same vehicle. Therefore, when the user opens / closes the ACC switch 22, the power to the devices including the in-vehicle electronic device 10 may be turned on / off collectively.

  Here, if the power is turned off while the hard disk device 19 is writing data, a bad sector is generated in the hard disk. Then, when the read / write control unit 128 tries to read / write a bad sector, the hard disk device 19 notifies the read / write control unit 128 of an error. Therefore, the reading and writing of data will be hindered. In the present embodiment, the method described later enables subsequent data reading even when a defective sector occurs.

  FIG. 2 is a block diagram illustrating the configuration of the in-vehicle electronic device 10. In the in-vehicle electronic device 10, a CPU (Central Processing Unit) 12 executes various control programs and processing programs, and a system control unit 122, a navigation control unit 124, a main control unit 126, a read / write control unit 128, and a decoding unit. 140 is configured. A ROM (Read Only Memory) 14 stores a control program and a processing program executed by the CPU 12. A RAM (Random Access Memory) 16 temporarily stores data for various calculations when the CPU 12 operates, and is used as a work area.

  The system control unit 122 controls the overall operation of the in-vehicle electronic device 10. In addition, the navigation control unit 124, the main control unit 126, the read / write control unit 128, and the decoding unit 140 are activated upon detection of power-on to the in-vehicle electronic device 10.

  The navigation control unit 124 performs a route search process for car navigation based on the map data. The map data is stored in the hard disk device 19. In addition, an interface between the display unit 3 and the operation input unit 4 and other units is provided. That is, image data to be displayed on the display unit 3 is generated, or input from the operation input unit 4 is transferred to other units.

  The main control unit 126 performs control for realizing car audio and visual functions. The main control unit 126 receives a music reproduction instruction and a video reproduction instruction from the user from the operation input unit 4. Then, content data such as music data and video data is acquired via the read / write controller 128. The content data is stored in the storage medium 7 or the hard disk device 19 connected to the connection port 6. Alternatively, the main control unit 126 acquires content data from the audio deck 21. The audio deck 21 reads content data from a storage medium such as a CD or a DVD. Then, the main control unit 126 passes the content data to the decoding unit 140.

  The decoding unit 140 decodes the music data to generate an audio signal and outputs it to the speaker 8 mounted on the vehicle. Alternatively, the video data is decoded to generate a video signal, which is output to the display unit 3 via the navigation control unit 124.

  The main control unit 126 receives a content data download instruction from the operation input unit 4 by the user. Then, it connects to the public communication network 50 via the communication unit 19 and connects to the server of the content data provider via the public communication network 50. The communication unit 19 is configured to be connectable to the public communication network 50 by wireless communication. The main control unit 126 then downloads content data from the server. Then, the downloaded content data is stored in the hard disk device 19 via the read / write control unit 128. Alternatively, the communication unit 19 may receive content data transmitted by wireless broadcasting.

  The main control unit 126 receives a content data transfer instruction from the operation input unit 4 by the user. Then, content data is acquired from the storage medium 7 via the read / write controller 128. Then, the acquired content data is stored in the hard disk device 19 via the read / write control unit 128.

  The read / write control unit 128 reads and writes content data from and to the storage medium 7 and the hard disk device 19 connected to the connection port 6. The read / write control unit 128 includes a device driver 128b and a file system 128a. The device driver 128b delivers the content data reading / writing position and the content data to the storage medium 7 and the hard disk device 19. The file system 128a instructs the device driver 128b to read / write the content data as a file and deliver the content data. The operation will be described in detail later.

  The hard disk device 19 includes a hard disk 19a coated with a magnetic material, a magnetic head for writing data on the hard disk 19a, a drive mechanism thereof, and a control circuit for the magnetic head. The hard disk has a management area and a data area. The hard disk device 19 stores data in units of sectors in the management area and the data area. At this time, a single file is distributed and stored in a plurality of sectors. The hard disk device 19 operates when the power is turned on when the ACC switch 22 is on. When the ACC switch 22 is off, the power is cut off and the operation is interrupted.

  The in-vehicle electronic device 10 includes a backup memory 18 in addition to the ROM 14 and the RAM 16. The backup memory 18 is configured to retain stored data even when the power from the in-vehicle battery 20 is cut off by the ACC switch 22. For example, it is composed of DRAM (Dynamic RAM) or SDRAM (Synchronous DRAM) having a backup power source. Alternatively, a rewritable nonvolatile memory such as an EEPROM (Electrically Erasable and Programmable ROM) may be used. In this embodiment, the backup memory 18 holds data necessary for recovery of files stored in the hard disk device 19. Details thereof will be described later.

  FIG. 3 is a diagram for explaining reading and writing of data with respect to the hard disk device 19. The hard disk 19a of the hard disk device 19 has a management area MA and a data area DA. The hard disk device 19 stores file entry information FE and link list information LL in the management area MA, and stores a data file in the data area DA. The hard disk device 19 stores data in units of sectors in the management area MA and the data area DA.

  The file entry information FE has file names “File — 001”, “File — 002”, “File — 003”, and so on, and a start sector number that is the start position of the file. The file entry information FE further has a data capacity for each file, although not shown. The link list information LL has a link order of sectors in which files are stored. The link list information LL is, for example, FAT (File Allocation Table). In the case of FAT, a plurality of sectors are handled as one cluster, and the sector link order is provided in cluster units. However, here, for convenience, the link list information LL will be described as having a link order in units of sectors.

  First, file writing will be described by taking the file “File_001” as an example.

  The hard disk device 19 stores the file “File_001” in the sector SEC according to the availability of the data area DA. Here, the sector SEC has sector numbers “001”, “008”, “010”, “003”, and “020”, respectively. The sectors SEC are linked in this order. Here, the start sector number of the file “File_001” is “001”.

  The file system 128 a receives each sector number from the hard disk device 19. Then, the file name “File — 001” and the start sector number “001” are written in the file entry information FE (arrow F1).

  Then, the file system 128a writes the sector link order in the link list information LL. The index number of the link list information LL corresponds to the sector number. Each index number is registered in association with the next sector number. Therefore, the link order of the sector of the file “File_001” can be traced as “001”, “008”, “010”, “003”, “020 (END)” according to the index number.

  Next, file reading will be described. When reading the file “File — 001” written as described above, the file system 128 a first searches the file entry information FE for the file name “File — 001” and its start sector position “001”. Then, the link order of the sector SEC is acquired from the link list information LL. That is, the index numbers “001”, “008”, “010”, “003”, and “020 (END)” are searched. Then, the stored data is read by referring to the sectors SEC in the data area DA in that order. In this way, the file “File_001” is read.

  When the file once written is updated, the file system 128a sequentially writes the update data to the sector SEC in the link order searched as described above.

  Here, when the power source of the in-vehicle electronic device 10 is cut off when the file entry information FE and the link list information LL are written and a defective sector is generated in the management area MA, the subsequent file reading is hindered. In such a case, in order to recover the file entry information FE and the link list information LL, the file system 128a executes the following processing. In the present embodiment, the file system 128a that performs recovery processing of the file entry information FE and link list information LL described below corresponds to the “writing unit”, “backup unit”, and “recovery unit” in the present invention. .

  For convenience of explanation, a method for restoring the link list information LL will be described first. Next, a method for restoring the file entry information FE will be described.

[1] Method for Restoring Link List Information LL FIGS. 4 and 5 are diagrams illustrating a method for restoring the link list information LL. In the present embodiment, the file system 128a creates backup data of the link list information LL in the management area MA of the hard disk 19a. By doing so, data is made redundant so that a bad sector is prepared. According to the FAT specification, the management area MA can be provided with areas for storing two FATs. Hereinafter, the link list information LL1 and the link list information LL2 of the backup data will be described as an example.

  First, referring to FIG. 4, the operation of the file system 128a as a writing unit and a backup unit will be described. When writing the link list information LL1 and LL2 to the hard disk device 19 as writing means, the file system 128 creates part of the link list information LL1 and LL2 for each predetermined write unit WU and stores it in the RAM (S1). ). Here, the write unit WU is, for example, 512 bytes of data corresponding to one sector.

  Then, the file system 128a stores, as backup means, the position where the write unit WU is written and flag data indicating the end of writing (hereinafter, write flag) in the backup memory 18. Here, the position where the write unit WU is written is the sector number or its address. At this time, the file system 128a stores the write positions WP1 and WP2 and the write flags WF1 and WF2 in the backup memory 18 for each of the link list information LL1 and LL2 (S2). Here, the write positions WP1 and WP2 correspond to the “link list information write position”. In the following, the values “ON” of the write flags WF1 and WF2 indicate a state where the writing is not completed, and “OFF” indicates the completion of writing. The write flags WP1 and WP2 are written with “OFF” as an initial value.

  Next, the file system 128a writes the write unit WU to the hard disk device 19 as a writing means. At this time, first, the write flag WF1 is set to “ON”, and the write unit WU is written to the link list information LL1 (S3). At this time, the write unit WU is written in the sector SEC_WP1 corresponding to the write position WP1. When the writing of the write unit WU to the link list information LL1 is completed, the file system 128a sets the write flag WF1 to “OFF” as backup means (S3 ′). Next, the file system 128a sets the write flag WF2 to “ON” and writes the write unit WU to the link list information LL2 (S4). At this time, the write unit WU is written in the sector SEC_WP2 corresponding to the write position WP2. When the writing of the writing unit to the link list information LL2 is completed, the writing flag WF2 is set to “OFF” (S4 ′).

  By repeating such an operation, the link list information LL1, LL2 is written in the management area MA. At this time, the write positions WP1 and WP2 stored in the backup memory 18 are overwritten for each write unit WU. The initial values of the write flags WP1 and WP2 are set to “OFF” each time.

  In the above processing, for example, if the power is shut down while writing unit WU is written in link list information LL1, write flag WF1 is held in backup memory 18 with "ON" and write flag WF2 being "OFF". Is done. Further, when the power is shut off while writing the write unit in the link list information LL2, the write flag WF1 is held in the backup memory 18 in a state of “OFF” and the write flag WF2 is “ON”.

  Therefore, after the power is restored, the file system 128a first reads the write flags WF1 and WF2 as a recovery means, and detects which of the link list information LL1 and LL2 is being written when the power is shut off.

  Next, the operation of the file system 128a as a recovery unit will be described with reference to FIG. First, for convenience of explanation, a case where the power is shut off while the link list information LL2 is being written will be described with reference to FIG. In this case, the write flag WF1 is stored in the backup memory 18 in a state of “OFF” and the write flag WF2 is “ON”. Therefore, at this time, it can be determined that a bad sector has occurred in the sectors constituting the link list information LL2. The position corresponds to the position where writing was performed at the time of power-off, that is, the writing position WP2 of the link list information LL2 stored in the backup memory 18.

  Therefore, the file system 128a reads the write position WP2 from the backup memory 18 (S5). Then, the writing position corresponding to the writing position WP2, that is, the writing position WP1 is read (S6). Then, data is read from the sector SEC_WP1 of the link list information LL1 at the write position WP1 (S7). At this time, the writing of the write unit WU to the link list information LL1 has already been completed, and the data is stored in the sector SEC_WP1. Therefore, the file system 128a writes the read data to the sector SEC_WP2 corresponding to the write position WP2 of the link list information LL2 (S8). In this way, the data of sector SEC_WP2 is determined. Therefore, when the sector SEC_WP2 is a bad sector, this can be solved, and the link list information LL2 can be recovered together with it.

  Next, with reference to FIG. 5B, a case where the power is shut off while the link list information LL1 is being written will be described. In this case, the write flag WF1 is stored in the backup memory 18 in a state of “ON” and the write flag WF2 is “OFF”. Therefore, at this time, it can be determined that a bad sector has occurred in the sectors constituting the link list information LL1. The position corresponds to the position where writing was performed at the time of power-off, that is, the writing position WP 1 stored in the backup memory 18.

  Therefore, the file system 128a reads the write position WP1 from the backup memory 18 (S15). Then, the writing position corresponding to the writing position WP1, that is, the writing position WP2 is read (S16). Then, data is read from the sector SEC_WP2 of the link list information LL2 at the write position WP2 (S17). At this time, since the link list information LL2 is in a state before writing, past data is read out. Then, the file system 128a writes the read data to the sector SEC_WP1 of the link list information LL1 corresponding to the write position WP1 (S18). In this way, the data of sector SEC_WP1 is determined. Therefore, when the sector SEC_WP1 is a bad sector, this is solved. As described above, the data written in the sector SEC_WP2 is the data of the past link list information. However, the subsequent reading can be enabled by eliminating the defective sector. Therefore, the content data can be written again.

  In this way, the link list information LL1 and LL2 can be restored. The backup memory 18 does not store the entire write unit WU (512 bytes), but stores the write positions WP1 and WP2 and the write flags WF1 and WF2. Therefore, the link list information LL1 and LL2 can be restored by using the minimum capacity (for example, 4 bytes) of the backup memory 18. In particular, as the capacity of the content data file increases, the data capacity of the link list information LL1 and LL2 increases accordingly. However, in this way, the link list information LL1 and LL2 can be restored only by using a certain capacity of the backup memory 18 regardless of the capacity of the content data file. And since the capacity | capacitance of the backup memory 18 can be made into the minimum, the circuit scale can be reduced as the vehicle-mounted electronic device 10 whole, and cost reduction is attained.

  Further, the entire data of one of the link list information LL1 and LL2 is not written to the other, but the data for the defective sector is written. Therefore, it is possible to minimize the time required for the restoration process, and the convenience for the user can be improved.

[2] Modified Example of Link List Information Restoration Method As described above, the backup memory 18 is configured to hold the stored data even when the ACC switch 22 is turned off. For this purpose, for example, a rewritable non-volatile memory such as an EEPROM can be used, but more preferably, a DRAM or SDRAM having a backup power source is used. Since SDRAM and DRAM have a faster read / write speed than EEPROM, processing can be speeded up, and writing can be performed in units of small capacity compared to EEPROM, so that hardware resources can be optimally used.

  As a backup power source, it is possible to provide a battery separately from the in-vehicle battery 20 or to receive power supply from the in-vehicle battery 20 in a separate system from the ACC switch 22. Here, in the latter case, the data in the backup memory 18 may be lost by disconnecting the connection with the in-vehicle battery 20. For example, this is a case where the in-vehicle electronic device 10 is removed from the vehicle body for the purpose of inspection or the like.

  Therefore, when the data in the backup memory 18 is lost, the file system 128a in the modified example restores the link list information LL1 and LL2 by the following method.

  FIG. 6 is a diagram illustrating a modification of the link list information LL restoration method. First, referring to FIG. 6A, a case where a bad sector is included in the link list information LL2 stored in the management area MA of the hard disk 19a will be described. The file system 128a first refers to the write positions WP1 and WP2 stored in the backup memory 18 as recovery means. However, at this time, the write positions WP1 and WP2 have disappeared. Alternatively, for example, as will be described later, when the check code stored in advance in the backup memory 18 is lost, it may be determined that the write positions WP1 and WP2 are lost. At this time, it is unknown which of the link list information LL1 and LL2 contains the defective sector.

  Therefore, the file system 128a first reads out data for each of the sectors SEC1_1, 2,..., N sequentially from the start position of the link list information LL1. Then, the read data is sequentially written in the sectors SEC2_1, 2,..., N of the link list information LL2 (S20). Here, if reading of all sectors in the link list information LL1 is completed, there is a high probability that the link list information LL2 includes a defective sector. However, at this time, the link list information LL2 can be restored by transplanting the data of the link list information LL1.

  Next, a case where a bad sector is included in the link list information LL1 will be described with reference to FIG. If the sector SEC1_N in the link list information LL1 is a bad sector during the operation of FIG. 6A, an error is notified from the hard disk device 19, and reading cannot be performed at that position. Then, the file system 128a once stops reading the link list information LL1. Then, the data of the sector SEC2_N of the link list information LL2 corresponding to the sector SEC1_N that cannot be read is read. Then, the read data is written in the sector SEC1_N of the link list information LL1 (S22). Then, data reading is resumed from the subsequent sector SEC1_N + 1 in the link list information LL1, and the read data is written from the sector SEC2_N + 1 in the link list information LL2 (S24).

  In this way, the link list information LL1 can be restored. In this case, the link list information LL2 is not the latest information data because it is in a state before writing. However, the subsequent reading can be made possible by eliminating the defective sector. Therefore, the content data can be written again.

[3] First Method for Restoring File Entry Information Next, a method for restoring the file entry information FE will be described. In this embodiment, when the file system 128a writes the file entry information FE to the hard disk 19a, data is made redundant by two methods to prepare for recovery. The first method is to create backup data of file entry information in the hard disk 19a. The second method is a method of storing the write unit when writing to the hard disk 19 a in the backup memory 18. Next, the first method will be described first, and then the second method will be described.

  7 and 8 are diagrams for explaining a method of restoring the file entry information FE by creating backup data of the file entry information FE on the hard disk 19a. Here, the file entry information FE1 and the file entry information FE2 of the backup data will be described as an example.

  First, the operation of the file system 128a as a writing unit and a backup unit will be described with reference to FIG. When creating the file entry information FE2 of the backup data of the file entry information FE1 as writing means, the file system 128a creates part of the file entry information for each predetermined writing unit fWU and stores it in the RAM (S101). ). The write unit fWU is, for example, 512 bytes of data corresponding to one sector. Then, the file system 128 a writes the write unit fWU to the hard disk device 19. At this time, the write unit fWU is first written to the file entry information FE1 (S103). At this time, the write unit fWU is written in the sector SEC_fWP1 corresponding to the write position fWP1. Here, the write position fWP1 corresponds to the “file entry information write position”.

  Next, the file system 128a writes the write unit fWU to the file entry information FE2 as backup means (S104). At this time, the file entry information FE2 is written not in the management area MA but in the fixed unused area DA1. Further, the write unit fWU is written in the sector SEC_fWP2 corresponding to the write position fWP2. Then, the file system 128a stores the write position fWP1 in the fixed unused area DA1 of the hard disk device 19 (S105).

  By repeating such an operation, the file entry information FE1 is written in the management area MA of the hard disk 19a, and the file entry information FE2 is written in the fixed unused area DA1. However, the present embodiment is not limited by the area for storing the file entry information. The write position fWP1 is also written in the fixed unused area DA1, but the write position fWP1 is overwritten for each write unit fWU.

  FIG. 8 is a diagram for explaining the operation as the recovery means of the file system 128a. Here, a case will be described in which the power is shut off while writing to the file entry information FE1.

  The file system 128a reads the write position fWP1 from the fixed unused area DA1 of the hard disk device 19 as a recovery means (S115). Then, data is read from the write position corresponding to the write position fWP1 in the file entry information FE2, that is, the sector SEC_fWP2 at the write position fWP2 (S116), and the read data is read into the sector SEC_fWP1 of the file entry information FE1 corresponding to the write position fWP1. Is written (S118). In this way, when the sector SEC_fWP1 is a bad sector, this is solved. At this time, since the file entry information FE2 is in a state before writing, it is not the latest information data, but it can be read later by eliminating the defective sector. Therefore, the content data can be written again.

  In this way, the file entry information FE1 can be recovered. Since the write position fWP1 is stored in the unused area DA1 of the hard disk device 19, the capacity of the hard disk device 19 is not increased, and the file entry information FE1 can be restored by using the minimum capacity. Become. Further, it is not necessary to increase the capacity of the backup RAM 18. Therefore, the circuit scale of the in-vehicle electronic device 10 as a whole can be reduced, and the cost can be reduced.

  Furthermore, since the entire data of the file entry information FE2 is not written to the file entry information FE1, but data for bad sectors is written, it is possible to minimize the time required for the recovery process, Convenience can be improved.

[4] Second Method for Restoring File Entry Information FIG. 9 is a diagram for explaining a method for creating backup data in the backup memory 18. First, when writing the file entry information FE into the management area MA of the hard disk 19, the file system 128a generates a part of the data of the file entry information FE for each predetermined writing unit fWU and stores it in the RAM 16 as writing means. (S201). Here, the write unit fWU is, for example, 512 bytes corresponding to one sector.

  Then, the file system 128a stores, as backup means, the position fWP at which the write unit is written and the data of the write unit fWU in the backup memory 18 (S202, S203).

  Then, the file system 128a writes the write unit fWU to the hard disk device 19 as writing means (S204). By repeating such an operation, the file entry information FE is written in the management area MA. At this time, the write unit fWU and the write position fWP stored in the backup memory 18 are overwritten for each write unit.

  In the above processing, the power is shut off when the write unit fWU is written in the file entry information FE. After the power is restored, the file system 128a first confirms the data at the write position fWP in the file entry information FE as a recovery means. If this cannot be read, it can be determined that a bad sector has occurred in the file entry information FE. Therefore, the write unit fWU stored in the backup memory 18 is written to the sector SEC_fWP corresponding to the write position fWP (S210). By doing so, defective sectors can be eliminated and data can be recovered.

  In this way, the file entry information FE can be recovered. According to this method, since the backup memory 18 reads and writes faster than the hard disk device 19, the processing when writing the write unit fWU is speeded up. In the case of the link list information LL, the data capacity increases as the file capacity increases as described above. In the case of the file entry information FE, the data capacity depends on the file capacity as the link list information LL. do not do. Therefore, the method of storing the write unit fWU in the backup memory 18 is a preferable aspect for speeding up the processing.

  In the above description, the recovery method of the link list information LL and the file entry information FE has been shown. The present embodiment includes a case where both the restoration of the link list information LL and the restoration of the file entry information FE are performed, and the case where only one of them is performed.

[5] Modification for Ensuring Accuracy of Data Held in Backup Memory 18 In the above-described second recovery method of link list information LL and file entry information FE, data stored in backup memory 18 Recovery is performed based on this. Therefore, the accuracy of the data stored in the backup memory 18 is required. Here, a modified example for ensuring the accuracy of the data stored in the backup memory 18 will be described.

  The present modification can be applied to both the link list information LL and the file entry information FE recovery method. In this modification, the file system 128a stores the following data in the backup memory 18 as backup means. Thereby, the accuracy of the data can be confirmed when the data in the backup memory 18 is read out as the recovery means.

  FIG. 10 is a diagram for explaining data stored in the backup memory 18. The backup check code bCH is predetermined data (for example, a character string) written when the in-vehicle electronic device 10 is initialized. When the file system 128a can read the backup check code bCH, it can confirm that the data of the entire backup memory 18 is not lost.

  The write position WP of the link list information LL, the write flag WF of the link list information LL, the write position fWP of the file entry information FE, and the write unit fWU of the file entry information FE are as described above. Here, a case where both the link list information LL and the file entry information FE are restored is shown, but in the case of only one of them, necessary data is written in each. In the case of the first method for creating backup data of the file entry information FE in the hard disk device 19, the writing unit fWU of the file entry information FE can be omitted.

  The write unit check code fCH of the file entry information FE is predetermined data (for example, a character string) written at the end of a predetermined area of the backup memory 18, for example, an area reserved in advance for 512 bytes. The file system 128a writes the write unit check code fCH at initialization. When the write unit fWU of the file entry information FE is normally written in this predetermined area, the write unit check code fCH is overwritten. Therefore, the file system 128a can confirm that the write unit fWU has been normally written when the write unit check code fCH cannot be read.

  Furthermore, the file system 128a stores the checksum CSM of the write unit fWU of the file entry information FE2 in order to confirm the accuracy of the write unit fWU written in the file entry information FE2. The file system 128a reads the write unit fWU from the hard disk device 19, calculates its checksum, and confirms that the write unit written in the file entry information FE2 is correct if it matches the stored checksum CSM. it can.

[6] Operation Procedure of In-Vehicle Electronic Device 10 in the Present Embodiment Next, the operation procedure of the in-vehicle electronic device 10 in the present embodiment will be described with reference to FIGS.

  FIG. 11 is a flowchart for explaining the operation procedure of the in-vehicle electronic device 10 when the link list information LL1, LL2 and the file entry information FE1, FE2 are written in the hard disk device 19. The procedure in FIG. 11A is executed when the content data is stored in the hard disk device 19 in response to an instruction input from the user, for example, in a state where the power is turned on. The procedure in FIG. 11A is a procedure executed by the file system 128a.

  The file system 128a first executes writing of link list information in a loop until all corresponding sectors are completed (S100, S110). That is, the file system 128a stores the write position WP1 in the backup memory 18 for each write unit WU (S101). Then, the write flag WF1 is changed from the initial value “OFF” to “ON” (S102). Then, the write unit WU is written in the write position WP1 of the link list information LL1 (S103). When the writing to the writing position WP1 is completed, the value of the writing flag WF1 is changed from “ON” to “OFF” (S104).

  Next, the file system 128a stores the write position WP2 of the link list information LL2 in the backup memory 18 (S105). Then, the write flag WF2 is changed from the initial value “OFF” to “ON” (S106). Then, the write unit WU is written in the write position WP2 of the link list information LL2 (S107). When the writing to the writing position WP2 is completed, the value of the writing flag WF2 is changed from “ON” to “OFF” (S108). As described above, the file system 128a repeats steps S102 to S108 until data is written in all sectors corresponding to the link list information LL1 and LL2.

  Next, the file system 128a executes the writing of the file entry information in a loop until all the corresponding sectors are completed (S112, S122). Here, as an example, a case where the file entry information FE1 and FE2 are written in the hard disk device 19 is shown.

  The file system 128a writes the write unit fWU to the file entry information FE2 of the fixed unused area DA1 (S118), and further writes the write position WP1 (S119). Then, the write unit fWU is written in the write position fWP1 of the file entry information FE1 (S120). As described above, the file system 128a repeats the steps S112 to S122 until all the sectors corresponding to the file entry information FE1 and FE2 are written.

  When the write unit fWU is stored in the backup memory 18, the write unit fWU and the write position WP are stored in the backup memory 18 as shown in FIG. 11B instead of steps S118 to S120 (S113). ), The writing unit fWU is written in the file entry information FE (S115).

  Although not shown here, in addition to the above procedure, the file system 128a writes a content data file to the data area DA of the hard disk 19a.

  Next, recovery processing when the power is turned off and turned on again when the procedure of FIG. 11 is executed will be described with reference to FIG.

  FIG. 12 is a flowchart for explaining the operation procedure of the in-vehicle electronic device 10 when the above-described recovery method is executed. The procedure of FIG. 12 is a procedure executed by the file system 128a as part of the initialization operation of the in-vehicle electronic device 10 as a whole when the power is turned on. The file system 128a first executes link list information recovery processing (S1000). Then, the file entry information recovery process is executed (S1002). Only one of the link list information recovery process (S1000) and the file entry information recovery process (S1002) may be used.

  FIG. 13 is a flowchart for explaining the procedure of the link list information restoration process. The procedure of FIG. 13 corresponds to the subroutine of procedure S1000 in FIG. The procedure of FIG. 13 is executed by the file system 128a as a recovery means.

  First, the file system 128a checks whether data is stored in the backup memory 18 (S1010). At this time, when the backup check code bCH shown in FIG. 10 is read, it is confirmed that data is stored. If it is stored (YES in S1010), it is determined which of the link list information LL1 and LL2 has a bad sector based on the write flags WF1 and WF2 (S1014). If it is determined that the link list information is LL2 (“LL2” in S1014), the link list information LL1 is written to the link list information LL2 (S1018), and the process is terminated. On the other hand, if it is determined that the link list information is LL1 (“LL1” in S1014), the link list information LL2 is written into the link list information LL1 (S1016), and the process is terminated.

  If no data is stored in the backup memory 18 (NO in S1010), the file system 128a writes all the data in the link list information LL11 to the link list information LL2 (S1018). Until writing of all sectors is completed, a process of writing data from the link list information LL1 to the link list information LL2 is executed (NO in S1024). Then, when the writing of all sectors is completed (YES in S1024), the process ends. At this time, if there is a bad sector in the link list information LL1 (YES in S1020), the data of that sector in the link list information LL2 is written in the link list information LL1 (S1022), and the process is terminated.

  According to such a procedure, the link list information LL1 and LL2 can be restored in a short time. Even if the data in the backup memory 18 is lost, the link list information LL1 and LL2 can be recovered.

  FIG. 14 is a flowchart for explaining the procedure of the file entry information recovery process. The procedure of FIG. 14 corresponds to the subroutine of procedure S1002 in FIG. The procedure of FIG. 14 is a procedure executed by the file system 128a as a recovery means. This procedure corresponds to the first method for creating backup data of file entry information in the hard disk device 19.

  First, the file system 128a reads the write unit WU of the file entry information FE2 from the hard disk device 19 (S1119), calculates its checksum, and confirms whether it matches the write unit checksum CSM shown in FIG. (S1120). If they match (OK in S1120), it can be determined that the writing to the file entry information FE2 has been completed normally. Then, the file system 128a reads and reads the write position WP of the file entry information FE1 (S1122). If not read, it is determined that a bad sector has occurred in the file entry information FE1 (YES in S1124), the file entry information FE2 is written to the file entry information FE1 (S1126), and the process is terminated. When the checksum obtained from the write unit WU of the file entry information FE2 does not match the write unit checksum CSM (NG of S1120), or when it is determined that no bad sector has occurred in the information FE1 (NO of S1124) Then, the process ends.

  According to such a procedure, the file entry information FE1 can be recovered in a short time.

  FIG. 15 is a flowchart for explaining another procedure of the file entry information recovery process. The procedure of FIG. 15 corresponds to a second method of creating backup data in units of writing file entry information in the backup memory 18. That is, this procedure is executed by the file system 128a as a recovery means instead of the procedure of FIG. 14 as a subroutine of step S1002 in FIG.

  First, the file system 128a checks whether data is stored in the backup memory 18 (S1130). Specifically, if the backup check code bCH shown in FIG. 10 is read, it can be determined that it is stored. If it is stored (YES in S1130), it is confirmed whether the data is accurate (S1132). Specifically, if the write unit check code fCH shown in FIG. 10 is read, it can be determined that it is accurate. If it is correct (YES in S1132), the write position WP is read (S133), and it is determined whether a bad sector has occurred in the file entry information (S1134). If it cannot be read and it is determined that a bad sector has occurred (YES in S1134), a part of the file entry information stored in the backup memory 18, that is, the write unit fWU is stored in the file in the management area MA of the hard disk 19a. The entry information FE is written (S1136), and the process is terminated.

  If no data is stored in the backup memory 18 (NO in S1130) or if the data is not accurate (NO in S1132), the process ends without performing the recovery process.

  According to such a procedure, the file entry information FE can be recovered in a short time. Furthermore, even if the data in the backup memory 18 is lost or partially destroyed, the file entry information FE can be recovered.

  In the above description, the hard disk device 19 is shown as an example of a storage device. However, the present embodiment can also be applied to a storage device such as an EEPROM that stores one file in a plurality of areas. In addition, the link list information has been described as an example in which a link order is provided for each sector. However, even if the sector link order is in cluster units such as FAT, it is included in the scope of the present embodiment. Furthermore, in the above description, the write unit corresponding to the capacity of the sector has been described as an example of the write unit for the link list information and the file entry information. However, the size of the writing unit is not limited to this, and may be, for example, a cluster unit. Further, when the storage device is composed of an EEPROM, one or a plurality of block units may be used.

  In addition, an in-vehicle electronic device has been described as an example of an electronic device whose power is turned on / off by an external switch. However, the present embodiment can be applied to other electronic devices as long as the electronic device has such a configuration. .

  As described above, according to the present embodiment, file entry information and link list information can be quickly restored at low cost.

10: vehicle-mounted electronic device, 18: backup memory, 19: hard disk device, 128: read / write controller, 128a: file system, LL1, LL2: link list information, FE1, FE2: file entry information

Claims (12)

In-vehicle electronic equipment that has a storage device that distributes and stores a single file into multiple areas, and that is powered on and off from the in-vehicle battery,
A memory capable of holding data even when the power is turned off;
When the file entry information having the start position of the file when storing the file in the storage device and the link list information having the link order of the area from the start position are written to the storage device, the link Writing means for writing the list information to a plurality of linked list information writing positions in the storage device for each first writing unit that is part of the list information;
For each of the first write unit, wherein a plurality of linked list information writing position, and backup means for storing the data in the memory indicating the write end of the first write unit for the plurality of linked list information writing position ,
When the first write unit writing to the first link list information writing position among the plurality of link list information writing positions is not completed when the power is turned off and then turned on again, A vehicle-mounted electronic device comprising: a recovery unit that writes data written at a second link list information writing position to the first link list information writing position. In claim 1,
The writing means further writes the file entry information to a plurality of file entry information writing positions in the storage device for each second writing unit that is a part of the file entry information.
The backup means further writes a first file entry information write position among the plurality of file entry information write positions to the storage device,
When the power is turned off and then turned on again, the recovery means further stores the second file if the writing of the second writing unit to the first file entry information writing position is not completed. An in-vehicle electronic device, wherein data written at an entry information writing position is written into the first file entry information writing position. In claim 1,
If the check code stored in advance in the memory is not in a predetermined state when the power is turned on again, the recovery means is one link among the plurality of link list information stored in the storage device. An in-vehicle electronic device characterized by writing list information into other linked list information. In claim 1,
The restoration means, when data is not stored in the memory when the power is turned on again, sets one link list information among a plurality of link list information stored in the storage device to another An in-vehicle electronic device characterized by writing in link list information. In claim 1,
The on-vehicle electronic device characterized in that the memory has a predetermined capacity regardless of the number or capacity of the files. In-vehicle electronic equipment that has a storage device that distributes and stores a single file into multiple areas, and that is powered on and off from the in-vehicle battery,
A memory capable of holding data even when the power is turned off;
The file entry information having the start position of the file when the file is stored in the storage device and the link list information having the link order of the area from the start position are written to the storage device. Writing means for writing entry information to a plurality of file entry information writing positions in the storage device for each second writing unit that is a part of the entry information;
Backup means for writing the first file entry information write position among the plurality of file entry information write positions to the storage device for each second write unit ;
If the writing of the second writing unit to the first file entry information writing position is not completed when the power is turned off and then turned on again, the second file entry information writing position is set. A vehicle-mounted electronic device comprising: a recovery unit that writes the written data to the first file entry information writing position. In-vehicle electronic equipment that has a storage device that distributes and stores a single file into multiple areas, and that is powered on and off from the in-vehicle battery,
A memory capable of holding data even when the power is turned off;
The file entry information having the start position of the file when the file is stored in the storage device and the link list information having the link order of the area from the start position are written to the storage device. Writing means for writing entry information to a file entry information writing position in the storage device for each second writing unit that is a part of the entry information;
Backup means for storing the second write unit and the file entry information write position in the memory for each second write unit;
When writing of the second write unit stored in the memory for the file entry information write position is not completed when the power is turned off and then turned on again, the second write unit is set to An in-vehicle electronic device comprising: a recovery unit that writes to the file entry information writing position. In any one of Claims 1 thru | or 7,
An in-vehicle electronic device characterized in that a power source from the in-vehicle battery is further turned on and off to other in-vehicle devices. An in-vehicle electronic device having a storage device that distributes and stores a single file into a plurality of areas, has a memory that can hold data even when the power from the on-vehicle battery is turned on and off, and even when the power is turned off A control program,
When the file entry information having the start position of the file when storing the file in the storage device and the link list information having the link order of the area from the start position are written to the storage device, the link A first writing step of writing list information to a plurality of linked list information writing positions in the storage device for each first writing unit that is part of the list information;
A first backup step of storing, in the memory, the plurality of linked list information writing positions and data indicating completion of writing to the plurality of linked list information writing positions for each first writing unit ;
When the first write unit writing to the first link list information writing position among the plurality of link list information writing positions is not completed when the power is turned off and then turned on again, A control program for causing the in-vehicle electronic device to execute a first restoration step of writing data written at a second link list information writing position to the first link list information writing position. In claim 9,
A second writing step of writing the file entry information to a plurality of file entry information writing positions in the storage device for each second writing unit that is a part of the file entry information;
A second backup step of writing a first file entry information write position among the plurality of file entry information write positions to the storage device;
If the writing of the second writing unit to the first file entry information writing position is not completed when the power is turned off and then turned on again, the second file entry information writing position is set. A control program for causing the in-vehicle electronic device to further execute a second restoration step of writing the written data to the first file entry information writing position. An in-vehicle electronic device having a storage device that distributes and stores a single file into a plurality of areas, has a memory that can hold data even when the power from the on-vehicle battery is turned on and off, and even when the power is turned off A control program,
The file entry information having the start position of the file when the file is stored in the storage device and the link list information having the link order of the area from the start position are written to the storage device. A writing step of writing entry information to a plurality of file entry information writing positions in the storage device for each second writing unit that is a part of the entry information;
A backup step of writing a first file entry information write position among the plurality of file entry information write positions to the storage device for each second write unit ;
If the writing of the second writing unit to the first file entry information writing position is not completed when the power is turned off and then turned on again, the second file entry information writing position is set. A control program for causing the in-vehicle electronic device to execute a recovery step of writing the written data to the first file entry information writing position. An in-vehicle electronic device having a storage device that distributes and stores a single file into a plurality of areas, has a memory that can hold data even when the power from the on-vehicle battery is turned on and off, and even when the power is turned off A control program,
The file entry information having the start position of the file when the file is stored in the storage device and the link list information having the link order of the area from the start position are written to the storage device. A writing step of writing entry information to a file entry information writing position in the storage device for each second writing unit that is a part of the entry information;
A backup step for storing the second write unit and the file entry information write position in the memory for each second write unit;
When writing of the second write unit stored in the memory for the file entry information write position is not completed when the power is turned off and then turned on again, the second write unit is set to A control program for causing the in-vehicle electronic device to execute a restoration step of writing to the file entry information writing position.

Images