JP5485846B2 - Information recording device - Google Patents

Description

  The present invention relates to an information recording apparatus that records acquired information in a data file on a nonvolatile memory.

  When writing data to a storage medium with a relatively large storage capacity little by little, each time data writing is completed so that newer data is stored for a longer time, data written blocks are stored in a predetermined storage area. When the specific information is stored and data is written next time, the specific information is read from the storage area, the block on which data is to be written next is specified based on the read specific information, and the data is read from the block. It is necessary to resume writing. In order to facilitate access to the writing position, it is desirable to divide the storage area into a plurality of data files in advance and manage the data written blocks hierarchically.

  However, in a storage medium using a non-volatile storage element such as a flash memory, there is an upper limit on the number of times of writing. Therefore, when information in a specific area in the storage area of the storage medium is updated each time data is written, The upper limit of the number of times of writing of the memory element constituting the area is reached in a short time. Therefore, the specific information of the data written block is stored in a RAM (Random Access Memory) in the information storage device, and the specific information of the data written block stored in the RAM is always read. When data is written, it is conceivable to update specific information on the RAM.

Japanese Patent Laid-Open No. 6-12267

  However, the specific information on the RAM can be easily destroyed by the occurrence of an abnormality such as a momentary power interruption to the RAM. In this case, the specific information stored in the storage medium may be used to determine the block to which data is to be written next, but it is specified to reduce the number of times the area storing the specific information in the storage medium is written. When the frequency of writing information is reduced, the specific information stored in the storage medium often indicates a block for which data writing has been completed several times in the past. When the block to which the data is to be written is determined, there is a possibility that the latest written data may be lost due to overwriting because the writing target block actually goes back.

  Accordingly, an object is to provide an information storage device in which data stored in a storage medium is not lost due to overwriting even when an abnormality occurs in specific information on a RAM.

The information storage device according to the present invention is an information recording device for sequentially recording information to be recorded on a plurality of data files existing in a non-volatile memory. A volatile memory for storing specific information for specifying a block in which data has been written in the file, and a block in the data file to which data is to be written next are specified based on the specific information stored in the volatile memory. A control unit that executes a process for writing the recording target data to the nonvolatile memory, and the control unit performs the writing process on at least a current writing target in a setting file existing in the nonvolatile memory. Is performed in a state in which specific information for identifying the data file set as is recorded. When a failure is detected in the volatile memory, the setting file recorded in the non-volatile memory is read, and the data file next to the data file currently set in the setting file is read. Write processing is executed as a write target.

  With the configuration as described above, the control unit specifies the data file next to the data file specified by the specifying information stored in the volatile memory as a writing target. However, when an abnormality occurs in the volatile memory, the specific information stored on the volatile memory cannot be trusted. Therefore, the control unit updates the content of the specific information so that the data file next to the data file currently specified as a write target is set as a new write target. As a result, the control unit can recognize that the data file to be written is the next data file by referring to the specific information, and can write data to the next data file. As a result, the written data in the write target data file at the time of occurrence of an abnormality is prevented from being lost due to overwriting.

  According to the present configuration configured as described above, data stored in the storage medium is not lost due to overwriting even when abnormality occurs in specific information on the RAM.

The block diagram which shows schematic structure of the vehicle-mounted network system containing a data storage device Memory card format The figure which shows the data structural example of a FAT area | region A diagram showing an example of the data structure of the root directory area Diagram showing data structure example of data area Figure showing the contents of the configuration file Software configuration diagram showing various functions implemented by the microcomputer of the data storage device executing programs and various information on the RAM and memory card Data flow diagram showing the flow of data processing by each program CAN data format Format diagram of CAN data record storing vehicle information The flowchart which shows the process which a CAN communication control part performs Flow chart showing processing executed by recording data generation unit Flowchart showing processing executed by the memory manager during data transfer from the record storage buffer to the SD write buffer The flowchart which shows the process which a memory manager performs at the time of writing to the memory card 17 of the data stored in SD write buffer 14 is a flowchart showing a write request processing subroutine executed in S008 of FIG. Flow chart showing setting file read processing subroutine Flow chart showing processing executed by memory manager when power is turned on Flow chart showing processing executed by memory manager when ignition is ON Flowchart showing processing periodically executed by the memory manager to monitor RAM corruption Flow chart showing processing executed by memory manager when ignition is OFF Logical map of the data area indicating that an error occurred while writing data to the data file Logical map showing transition of data area state when an error occurs while writing data to data file

  Hereinafter, embodiments of the present invention will be exemplarily described based on the drawings. Embodiment shown below is an illustration and this invention is not limited to these.

FIG. 1 is a block diagram showing a schematic configuration of an in-vehicle network system including a data storage device (corresponding to an information storage device) according to the present embodiment. As shown in FIG. 1, various ECUs (Electric Control Units) 2 for controlling each electronic component (actuator, meter, etc.) of the vehicle, and various sensors 3 for detecting the state of the vehicle, They are connected to each other by a kind of CAN (Controller Area Network). Here, various ECUs 2 include an engine control ECU, an ABS (Antilock Brake System) ECU,
Etc. are included. The various sensors include an acceleration sensor, an exhaust temperature sensor, an O ₂ sensor, various switches, and pedals. Each of these various ECUs 2 and various sensors 3 stores data addressed to other ECUs 2 in a predetermined format frame (FIG. 9), and sends them to the CAN. The frame sent to the CAN in this way (hereinafter referred to as “CAN data”) is taken in by the ECU 2 that requires it and used for control of the electronic components by the ECU 2. The data storage device 1 intercepts data including vehicle information (control information and status information) among the CAN data distributed on the CAN in this way, and prepares for an external memory card in preparation for failure inspection at a later date. Since it is an ECU for storing in 17, it is connected to CAN like the other ECUs 2. Here, CAN is a kind of in-vehicle network, but what in-vehicle network connects ECUs depends on a required data band and cost. Therefore, when there is an ECU connected to another type of in-vehicle network (for example, LIN [Local Interconnect Network], FlexRay [registered trademark of Daimler Co., Ltd.]), the data storage device 1 is connected to the other type. It is desirable to be connected to the in-vehicle network.

  The data storage device 1 includes a CAN transceiver 16 that interfaces with CAN, a microcomputer 14 that executes processing for CAN data, a memory card slot 15 as an external memory slot connected to the microcomputer 14, and a power source (battery ) The power supply circuit 12 for reducing the power supply voltage of 12V from 4 to supply the power supply voltage of 5V to the microcomputer and supplying the power supply voltage of 3.3V to the memory card slot 15 is incorporated.

  The CAN transceiver 16 is a device that terminates the physical layer of the CAN. The CAN transceiver 16 converts CAN data modulated by the two-wire operating voltage method on the CAN into a binary signal of H / L, and sends it to the microcomputer 14. introduce.

  As a hardware configuration, the microcomputer 14 includes a RAM 21, a ROM 22, a voltage power supply monitoring unit 24, and an input information monitoring unit 23 in addition to a processor (not shown) that executes a program.

Among these, the input information monitoring unit 23 monitors the state (ON / OFF) of an ignition signal input from the ignition switch 5 to another ECU, and inputs the inspection result to the processor. The power supply voltage monitoring unit 24 monitors the voltage of the power supply (battery) 4 while the processor is in the wake-up state, and inputs the monitoring result to the processor. Each of these functions is a function realized by the processor by executing a program.

  Since the data recording apparatus 1 is directly connected to the battery without passing through the ignition switch or the accessory switch, the power is supplied even while the ignition switch is OFF. This is mainly for holding the data in the RAM 21. The data recording process to the RAM 21 is performed only while the ignition switch is ON, and the standby state (power saving mode) is maintained while the ignition switch is OFF. However, it may be modified so that data can be recorded in the RAM 21 even while the ignition switch is OFF.

The ROM 22 stores various programs to be read and executed by the processor (FIG. 7) and defines the areas (reserved area, FAT area, root directory area, data area) in the FAT (File Allocation Table) file system. In addition, specific contents to be described in the FAT area and the root directory area are fixed.

  The RAM 21 (corresponding to a volatile memory) constructs various buffers by the processor executing processes according to the various programs, and temporarily stores data such as setting file information 45 and setting file number 43 described later. It is a work area.

  The memory card 17 (corresponding to a non-volatile memory) is a card-type removable storage medium in which a storage area is composed of a non-volatile storage element such as a flash memory having an upper limit on the number of writing. There are various standards for memory cards having such properties. One example is an SD memory card (a trademark of Panasonic Corporation, SanDisk Corporation, Toshiba Corporation). However, if a USB interface is provided in place of the memory card slot 15, a USB flash memory can be used in place of the memory card 17.

  As the file format of the memory card 17, FAT is usually used. As shown in FIG. 2, the storage area of the storage medium according to the FAT is divided into a reserved area, a FAT area, a root directory area, and a data area by initialization. Among these, the reserved area is an area for storing a boot parameter block, a disk label, a boot code, and the like.

  The FAT area is a collection of pointers indicating the position of the data area. That is, in FAT, a data area is allocated to each file in units of blocks (clusters). Therefore, as shown in FIG. 3, in the FAT area, for each block (cluster) constituting the data area, a block number or a mark indicating the end of the subsequent block (cluster) assigned to the same file, or A mark indicating that it is empty is described.

  Further, as shown in FIG. 4, the root directory area is attribute information such as the block number (initial data area) of the first block (cluster), file name, data size, etc. for each file stored in the data area. Is the area to be described.

As is clear from the above, the total of the information described in the FAT area and the information described in the root directory area is file management information, and the computer 14 accessing the memory card 17 can describe the description of these areas. By viewing, the position of one or a plurality of blocks (clusters) in the data area assigned to each file is recognized, and the data stored in these blocks (clusters) is read as a set of file data. For example, in the examples of FIGS. 3 and 4, two blocks (clusters) with block numbers 1 and 2 are assigned to the configuration file 46 (see FIG. 7) having the file name (ini1. ***). , Two blocks (clusters) with block numbers 2 and 4 are assigned to the setting file 46 (see FIG. 7) having the file name (ini2. ***), and block numbers 5, 6, 7, and 8 are assigned. Four blocks (clusters) are assigned to a data file having a file name (data1. ***), and four blocks (clusters) with block numbers 9, 10, 11, and 12 are assigned to the file name (data2. ***) is assigned to a data file with
It can be seen that four blocks (clusters) with block numbers 21, 22, 23, and 24 are assigned to the data file having the file name (datan. ***). In the example of FIG. 4, the value of the data size indicates the number of blocks (clusters). However, since the sector which is the minimum storage unit of the storage device is usually 512 bytes / sector, one block (cluster) is included. In the case of 1 sector, each setting file 46 (ini1. ***, ini2. ***) having a data size of 2 has 1024 bytes and each data file has a data size of 4 ( The number of bytes of data1. ***, data2. ***, ... datan. ***) is 2048 bytes.

In the present embodiment, as described above, the specific contents of the FAT area and the root directory area are fixedly prepared in advance in the ROM 22, and the memory card 17 is initialized when the memory card 17 is initialized. This is copied to the FAT area and the root directory area defined on the storage area, and these areas are not updated thereafter. The specific contents of the FAT area and the root directory area are two setting files 46 (ini1. ***, ini2. ***) having the same data size and n data files (data1) having the same size. . ***, data2. ***,... Datan. ***), all blocks (clusters) of the data area are allocated. Therefore, at the time of initialization of the memory card 17, two setting files 46 (ini1. ***, ini2. ***) and n data files (data1. ***, data2. ***, ... datan. ***) exist, and thereafter the file attributes of these files are not changed. As a result, no matter how many times each data file in the data area is updated, the number of writes to the FAT area and the root directory area cannot reach the upper limit, and the contents of the FAT area and the root directory area are described. And the attributes of each file in the data area do not occur, so if the memory card 17 is removed from the memory card slot 15 and connected to an inspection device (computer) outside the data storage device 1, the data area Each data file can be read out.

  Each setting file 46 is a file that is exclusively referred to by the microcomputer 14 and, as shown in FIG. 6, writes a data file number that identifies the data file currently being written, and the data file. This is a file in which a block number indicating the last one of blocks (clusters) into which data has been written after the time point determined as a target, the number of times of writing, and a checksum (SUM value) are stored. Among these, the combination of the data file number and the block number corresponds to “address information”.

  As described above, each data file in the data area is generated at the time of initialization as having a fixed length. However, at the time of initialization, only the stack value is actually stored. The data can be additionally written in units of blocks (clusters). However, the range in which the substantial data written thereafter exists is unknown even if the FAT area and the root directory area are read. In addition, the microcomputer 14 cyclically designates each data file as a write target file so that new data is stored for a longer time, and as a write target block (cluster) in order from the top of each data file. It is necessary to specify and overwrite newly obtained data. For this reason, the setting file 46 for specifying the block (cluster) to which data is to be written next and the block (cluster) to which data is to be written next can be specified. Is stored.

  However, two setting files 46 are prepared in the data area. This is because the setting file 46 is alternately updated to halve the number of times of writing to the nonvolatile memory element of the block (cluster) to which each setting file 46 is assigned, and thereby the number of times of writing reaches the upper limit. This is in order to extend the period required for. In order to realize such an object, a file in which a setting file number 47 for designating which setting file 46 was last updated is stored in the data area. File number 43 is stored. The microcomputer 14 can recognize the setting file 46 to be updated next by referring mainly to the setting file number 43 on the RAM 21.

  Furthermore, in order to reduce the number of times of writing to the nonvolatile memory element of the block (cluster) to which each setting file 46 is assigned, in this embodiment, all items except for the number of times of writing are items to be written to the setting file 46. (Hereinafter referred to as “setting file information 45”) is stored on the RAM 21 and used for reference by the microcomputer 14. That is, the microcomputer 14 determines which block (cluster) in which data file should be written by reading the setting file information 45, and updates only the setting file information 45 after writing the data. To do.

  However, if the setting file 46 on the memory card 17 is not updated at all, when the setting file information 45 is lost for some reason, it becomes impossible to correct the discrepancy between the contents of the setting file 46 and the contents of the data area. Will do. Therefore, in the present embodiment, when the abnormality detection module 36, which will be described later, detects an abnormality occurrence such as a momentary battery interruption or reset (S301), the memory manager 34 (to be described later) sets the setting file information such as RAM corruption. When an abnormality is detected (S503), when the ignition signal OFF is detected based on the monitoring result of the input information monitoring unit 23 (S605), the setting file is updated according to the contents of the setting file information 45, respectively. (FIG. 16). In order to detect the above-mentioned garbled RAM, three setting file information (A to C) 45 having the same contents are stored in the RAM 21 independently of each other and updated at the same time. . When a defect is found in the contents of the three setting file information (A to C) 45, it is recognized that the RAM 21 has been garbled.

  FIG. 7 is a software configuration diagram showing each function realized by the processor executing the program stored in the ROM 22 and each information stored on the RAM 21 and the memory card 17. As shown in FIG. 7, the functions realized by the processor are roughly divided into an ECU system management unit 31, a CAN communication control unit 32, a recording data generation unit 33, and a memory manager 34.

  The ECU system management unit 31 is a function for controlling each circuit constituting the data storage device 1 and has a time information creation unit 35 and an abnormality detection unit 36 under control.

  The time information creation unit 35 is a software timer and notifies the recording data generation unit 33 of the current time.

  The abnormality detection unit 36 detects an instantaneous power supply interruption or a voltage drop due to attachment / detachment of the power supply (battery) 4, reset, or other causes based on the monitoring information from the power supply voltage monitoring unit 24, and also monitors input information Based on the monitoring result of the unit 23, the ignition signal ON is detected, and processing for notifying the memory manager 34 of the occurrence of these events is executed.

Further, the ECU system management unit 31 manages the transition between the wake-up state and the sleep state of the entire microcomputer 14, and if the monitoring result of the input information monitoring unit 23 is OFF of the ignition signal, another program After the necessary processing is completed, the entire microcomputer 14 is shifted to the sleep state. On the other hand, even if the microcomputer 14 is in the sleep state, the monitoring result of the input information monitoring unit 23 is checked, and if it indicates that the ignition signal is ON. The entire microcomputer 14 is changed to the wake-up state.

  The CAN communication control unit 32 uses the CAN driver 27 for the CAN data transmitted from the CAN transceiver 18 to perform processing for the logical layer of the CAN protocol.

  The recording data generation unit 33 compiles the vehicle information passed from the CAN communication control unit 32 and the time information passed from the time information creation unit 35 into a predetermined format and passes them to the memory manager 34.

  The memory manager 34 accesses the memory card 17 using the memory card driver 42, manages each area on the memory card 17, writes data to each data file, and updates each setting file.

  Hereinafter, specific processing contents for the CAN data by each function described above will be described with reference to the data flow diagram of FIG. 8, the format diagrams of FIGS. 9 and 10, and the flowcharts of FIGS. 11 to 14.

  First, as shown in the schematic format diagram of FIG. 9, the CAN data describes a “CANID” field for storing CANID, a “data” field for storing distribution target data, and a byte length of the “data” field. “DLC” field, and a “time stamp” field in which the CAN data issue time is described.

  Then, the CAN communication control unit 32 stores the CAN data transmitted from the CAN transceiver 18 in the reception buffer 47 as needed using the CAN driver 37. On the other hand, as shown in FIG. 11, the CAN communication control unit 32 periodically checks whether or not CAN data is stored in the reception buffer 47 (S001), and only when CAN data exists in the reception buffer. The CAN data in the reception buffer 47 is transferred to the recording data generation unit 33 (S002).

  The diagnosis information notified by the abnormality detection unit 36 to the recording data generation unit 40 includes a flag indicating whether the operation of the CAN transceiver 16, the memory card 17, or the microcomputer 14 itself is abnormal, or whether the operation is normal, and the cause of the abnormality It contains information that identifies

  As shown in FIG. 12, the recording data generation unit 33 acquires time information from the time information creation unit 35 every time it receives CAN data transferred from the CAN communication control unit 32 (S003), and receives the received CAN data. And the time information acquired in S003, recording data is created and transferred to the memory manager 34 (S004).

  As shown in the format diagram of FIG. 10, the recording data includes an “identifier (CANID)” field in which CANID is stored, a “time information” field in which time information is stored, and distribution target data in the CAN data. A 12-byte record consisting of a “data” field and a “SUM” field in which a checksum value is stored.

  Each time the recording data is transferred from the recording data generating unit 33, the memory manager 34 cyclically stores the received recording data in a record storage buffer 48 that can store N 12-byte records in a ring format. Store (overwrite) in order.

  Further, as shown in FIG. 13, the memory manager 34 periodically exceeds a predetermined amount, that is, the maximum data amount (512 bytes) that the memory card driver 42 can write to the memory card 17 by one writing process. Whether or not the data is stored in the record storage buffer 48 (S005), and only when the data of the predetermined amount (512 bytes) or more is stored, the data of the predetermined amount (512 bytes) Are transferred to the SD write buffer 49 (S006).

  The predetermined capacity is set depending on how much capacity of the memory (RAM 21) of the microcomputer is sufficient, but the microcomputer used for in-vehicle use is more than a general computer that performs recording processing on a memory card. Since the memory capacity is small, the predetermined capacity, which is the amount of data written at one time, is relatively small, and therefore the frequency of writing to the memory card is also relatively large.

  Further, as shown in FIG. 14, the memory manager 34 periodically checks whether data is stored in the SD write buffer 49 (S007), and only when data is stored in the SD write buffer 49. Then, write request processing is executed for the predetermined amount (512 bytes) of data stored in the SD write buffer 49 (S008).

  FIG. 15 shows a write request processing subroutine executed in S008. In the first step S101 after entering this subroutine, the memory manager 34 reads the three setting file information (A to C) 45 on the RAM 21.

  In the next S102, the memory manager 34 sets the setting file information (A to C) based on whether or not the contents of the three setting file information (A to C) 45 read in S101 match each other. Check whether 45 is normal or abnormal. If the contents of the three setting file information (A to C) 45 match each other, the memory manager 34 determines that each setting file information (A to C) 45 is normal. , The process proceeds to S104.

  In S104, the memory manager 34 reads the setting file information (A to C) 45 stored in the RAM 21, and the range of the data file to which data is to be written and the block (cluster) into which the data has been written in the data file. Recognize Then, the memory manager 34 checks whether the data amount in the data file to be written is equal to or larger than the upper limit (132 Mbytes) of the file capacity based on the recognized information. If the amount of data is less than the upper limit (132 Mbytes), the data on the SD write buffer 49 can be added to the data file. Therefore, in S105, the memory manager 34 sets the setting file information ( (A to C) After the number of the written block (cluster) in 45 is advanced by one, in S108, the block (cluster) corresponding to the number in the data file to be written is transferred to the SD write buffer 49. After the data is written, the process is returned to the main routine of FIG.

On the other hand, if it is determined in S104 that the data amount is equal to or greater than the upper limit (132 Mbytes), the data on the SD write buffer 49 cannot be added to the data file. The value of the setting file number 47 in the memory card 17 is changed to the other value, and the value of the file number of the writing target data file recorded in the writing target data file 46 indicated by the changed setting file number 47 Is rewritten to a value indicating the next data file of the data file designated by the value of the current file number, and the block number of the written block (cluster) is rewritten to 0. In the next S107, the memory manager 34 changes the value of the setting file number 43 on the RAM 21 to the other value, and sets the value of the file number of the write target data file in each setting file information (A to C) 45 as follows. The value of the current file number is rewritten to a value indicating the next data file of the specified data file, and the block number of the written block (cluster) is rewritten to 0. Thereafter, in S108, the memory manager 34 writes the data on the SD write buffer 49 to the block (cluster) corresponding to the number in the data file to be written, and then the process is performed in the main routine of FIG. To return to the end of all processing.

  In this case, the writing process does not use the FAT file system, but directly specifies the address of the data file and block to be written, which are specified by the information of the FAT area and the root directory area recorded in the memory card 17. This is done by specifying and writing.

  On the other hand, in the check in S102, if there is a defect in part of the contents of the three setting file information (A to C) 45, the microcomputer 14 determines that the setting file information (A ~ C) 45 is regarded as abnormal and the contents of the setting file information (A ~ C) 45 are regarded as unreliable, and the process proceeds to S103.

  In S103, the memory manager 34 executes setting file reading processing. FIG. 16 is a flowchart showing a setting file read processing subroutine executed in S103. In the first step S201 after entering this subroutine, the memory manager 34 reads the two setting files 46 from the data area of the memory card 17.

  In the next S202, the memory manager 34 checks whether the content of the target setting file 46 is normal or abnormal among the two setting files 46 read in S201. Here, the target setting file 46 is the setting file 46 indicated by the setting file number 47 stored in the data area of the memory card 17 when S202 is first executed after the subroutine is started. . When S202 is executed after S206, the setting file 46 is not the setting file 46 indicated by the setting file number 47.

  If the contents of the setting file 46 are normal, the memory manager 34 changes the value of the setting file number 47 in the data area of the memory card 17 to the other value in S203, and the changed setting file number The file number value of the write target data file recorded in the write target data file 46 indicated by 47 is rewritten to a value indicating the next data file of the data file specified by the current file number value and written. The block number of a completed block (cluster) is rewritten to 0. In the next S204, the memory manager 34 changes the value of the setting file number 43 on the RAM 21 to the other value, and sets the value of the file number of the write target data file in each setting file information (A to C) 45 as follows. The value of the current file number is rewritten to a value indicating the next data file of the specified data file, and the block number of the written block (cluster) is rewritten to 0. Thereafter, the memory manager 34 returns the processing to the original routine.

  On the other hand, if it is determined in S202 that the contents of the setting file 46 are abnormal (including the case where the information of the predetermined item is not included), the memory manager 34 in S205, in S201. It is checked whether or not all the setting files 46 read are abnormal. If the setting file 46 that is not the setting file 46 to be processed in S202 is normal, the memory manager 34 changes the target setting file 46 in S206, and returns the process to S201. . On the other hand, if all the setting files 46 read in S201 are abnormal, the memory manager 34 advances the process to S207.

In S207, the memory manager 34 initializes all setting files 46 in the data area of the memory card 17. That is, the content that the first data file (data1. *** in the example of FIG. 5) is to be written and that there is no written block (cluster) is read from the ROM 22 and written to each setting file 46. .

In the next S208, the memory manager 34 initializes each setting file information (A to C) 45 on the RAM 21. That is, the contents that the first data file (data1. *** in the example of FIG. 5) is to be written and there is no written block (cluster) are read from the ROM 22 and each setting file information (A To C) 45. Thereafter, the memory manager 34 returns the processing to the original routine.

  Upon receiving notification from the above-described ECU system management unit 31 that the power supply [battery] 4 has been replaced, reset, or the like, resulting in the addition of the power supply voltage after an instantaneous power interruption, the memory manager 34 executes the processing shown in FIG. In S301, a setting file reading process is executed. That is, the memory manager 34 executes processing in accordance with the setting file reading processing subroutine shown in FIG.

  When the ignition signal is turned on, the microcomputer 14 returns from the power saving mode such as the sleep mode. When the microcomputer 14 receives the ignition signal ON notification from the ECU system management unit 31 described above, the memory manager 34, in S401, The setting file information is based on whether or not the contents of the three setting file information (A to C) 45 on the RAM 21 held by the power being supplied while the switch is OFF match each other. (AC) Check whether 45 is normal or abnormal. If the contents of the three setting file information (A to C) 45 are inconsistent with each other, the memory manager 34 determines that each setting file information (A to C) 45 is abnormal. The process proceeds to S402.

  On the other hand, if the contents of the three setting file information (A to C) 45 match each other, the memory manager 34 indicates that each setting file information (A to C) 45 is normal. Judgment is made and the process is terminated.

  In S402, the memory manager 34 executes a setting file reading process. That is, the memory manager 34 executes processing in accordance with the setting file reading processing subroutine shown in FIG.

  In the next S403, the memory manager 34 writes (overwrites) the three setting file information (A to C) 45 having the same contents as the contents of the setting file 46 read in S402 (S201) to the RAM 21. Further, the microcomputer 14 overwrites the setting file number 43 on the RAM 21 with the setting file number 47 in the data area of the memory card 17.

  The memory manager 34 periodically executes the process of FIG. 19 in order to monitor abnormalities of RAM corruption in parallel with the data writing to the data file as described above.

  In FIG. 19, in the first S501, three setting file information (A to C) 45 on the RAM 21 are read.

In next step S502, the memory manager 34 determines whether the setting file information is normal based on whether or not the contents of the three setting file information (A to C) 45 read in S501 match each other. Check for abnormalities. If the contents of the three setting file information (A to C) 45 match each other, it is determined that each setting file information (A to C) 45 is normal, and the process is terminated. To do.

  On the other hand, if there is a defect in some of the contents of the three setting file information (A to C) 45, the memory manager 34 determines that the setting file information (A to C) due to the garbled RAM. It is assumed that an abnormality has occurred in 45 and the content of the setting file information (A to C) 45 has become untrustworthy, and the process proceeds to S503.

  In S503, the memory manager 34 executes a setting file reading process. That is, the memory manager 34 executes a setting file read processing subroutine shown in FIG.

  Next, when the input information monitoring unit 23 detects that the ignition signal is OFF, the memory manager 34 performs the process of FIG. 20 in order to save the contents of the setting file information (A to C) 45 on the RAM 21 to the setting file. Run.

  The memory manager 34 reads the setting file information (A to C) 45 on the RAM 21 in the first S601 of FIG.

  In next step S602, the microcomputer 14 determines whether the setting file information is normal based on whether or not the contents of the three setting file information (A to C) 45 read in step S601 match each other. Check for abnormalities. If some of the contents of the three setting file information (A to C) 45 are flawed, the memory manager 34 has an abnormality in the setting file information (A to C) 45, and the setting file information (A to C) Assuming that the contents of 45 cannot be trusted, a setting file reading process is executed in S605. That is, the memory manager 34 executes a setting file read processing subroutine shown in FIG.

  On the other hand, if the contents of the three setting file information (A to C) 45 match each other, the memory manager 34 indicates that each setting file information (A to C) 45 is normal. Judgment is made and the process proceeds from S602 to S603. In S603, the memory manager changes the value of the setting file number 47 in the memory card 17 to the other value, and the written block recorded in the write target data file 46 indicated by the changed setting file number 47 Advance the (cluster) block number by one. In the next S604, the memory manager 34 changes the value of the setting file number 43 on the RAM 21 to the other value, and the written block (cluster) recorded in each setting file information (A to C) 45 is changed. Advance the block number by one.

  The microcomputer 14 shifts to a power saving mode such as a sleep mode when the ignition signal is turned off. In addition, when it is necessary to receive and record CAN data even when the ignition signal is OFF, the normal mode can be configured without shifting to the power saving mode.

  According to the present embodiment described above, as described above, since it is not necessary to update the FAT area and the root directory area of the memory card 17, the life of the memory card 17 is reached when the number of times of writing in the area reaches the upper limit. There is no problem of running out in a short period of time.

Further, according to the present embodiment, up to which block (cluster) of which data file data has been written is managed by the setting file 46 stored in the data area of the memory card 17, Since two files 46 are prepared in advance and the setting files 46 are alternately updated, the number of times of writing of the block (cluster) in which each setting file 46 is recorded can be halved. The time until the upper limit of the number of writing times is reached can be extended.

Further, according to the present embodiment, the processing of FIG. 16 is executed in S103 of FIG. 15, S301 of FIG. 17, S503 of FIG. 19, S605 of FIG. 20, and as shown in FIG. The setting file information (A to C) 45 on the RAM 21 is trusted due to the occurrence of an abnormality (reset, garbled RAM, ignition OFF, etc.) when data is written to the middle block of data1. ***). Even if it is insufficient, as shown in FIG. 22, the write target data file in the next data write is switched to the next data file (data2. ***) (S204), and the head Data writing can be resumed from

Further, by switching the write target data file at the time of occurrence of the abnormality in this way, it is possible to prevent the data written up to the time of occurrence of the abnormality from being overwritten and lost by data writing immediately after the occurrence of the abnormality. Therefore, although garbage data may remain in a block (cluster) other than the block (cluster) in which data has been written up to the time of occurrence of the abnormality, if the memory card 17 is loaded into the inspection device (computer), Since the data file (data1. ***) is targeted for data writing, data written up to the time of occurrence of an abnormality can be read.

1 Data storage device 14 Microcomputer 15 Memory card slot 17 Memory card 21 RAM
22 ROM
23 Input Information Monitoring Unit 24 Power Supply Voltage Monitoring Unit 31 ECU System Management Unit 32 CAN Communication Control Unit 34 Memory Manager 35 Time Information Creation Unit 36 Abnormality Detection Unit 33 Record Data Generation Unit 45 Setting File Information

Claims (5)

An information recording apparatus for recording information in order for a plurality of data files existing in a nonvolatile memory,
Volatile memory that stores specific information that identifies the data file that is currently set as the write target and the data-written block in the data file;
Based on the specific information stored in the volatile memory, a control unit that specifies a block in the data file to which data is to be written next, and executes a process of writing the recording target data to the nonvolatile memory; With
The control unit performs the writing process in a state where recording information specifying at least a data file currently set as a writing target is recorded in a setting file existing in the nonvolatile memory, and the volatile When a failure is detected in the volatile memory, the setting file recorded in the non-volatile memory is read, and the data file next to the data file currently set in the setting file is read. An information recording apparatus characterized by executing a writing process as a writing target. When there is no change in the data file to be written since the previous execution of the write process, the control unit identifies a block in the data file where data has been written in the setting file existing in the nonvolatile memory. The information recording apparatus according to claim 1, wherein the writing process is executed without recording the latest specific information. The control unit, when a change has occurred in the data file to be written from the time of the previous write processing execution, based on the latest specific information on the volatile memory in the setting file present in the nonvolatile memory, 2. The information recording apparatus according to claim 1, wherein a process of recording specific information for specifying a data file currently set as a write target and a data-written block in the data file is executed. When the power to be turned on is turned off, the control unit sets the current configuration target file in the nonvolatile memory as a current writing target based on the latest specific information on the volatile memory. 2. The information recording apparatus according to claim 1, wherein a process of recording specific information for identifying a data file and a data-written block in the data file is executed.   5. The abnormality of the volatile memory is at least one of a voltage drop of a power source supplied to the volatile memory and a data abnormality of data stored in the volatile memory. The information recording device according to any one of the above.

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