JP2012118892A - Data storage device and data storage method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a data storage device and a data storage method that reduce the number of times of erasure by reducing the amount of data to be written each time the data is generated, and efficiently use a memory to which overwrite is impossible.SOLUTION: Each time data is generated, a CPU 2A stores the data while adding data types to the ending of the data generated in order from the head of a vacant area of the latest block. When there is no vacant area in the latest block, the CPU 2A erases all the data of other blocks except the latest block, then reads the data in order from the ending of the latest block, and extracts every predetermined number of pieces of data backward by the data types added to the ending of the data based upon the data types, and writes the extracted data in order from heads of other blocks.

Description

  The present invention relates to a data storage device and a data storage method, and more particularly to a data storage device and a data storage method for storing sequentially generated data in a memory that cannot be overwritten.

  For alarm devices such as gas leaks and fires, the setting data (eg gas concentration alarm value) set at the time of shipment from the factory, the alarm history at the time of alarm occurrence, the failure history at the time of failure occurrence, the energization time, etc. are recorded in EEPROM. ing. However, in order to store these data, it is necessary to increase the capacity of the EEPROM, which causes a problem in cost.

  Recently, it has been considered to use flash memory inside a microcomputer constituting an alarm device in place of EEPROM to store these data. This eliminates the need for an EEPROM and reduces costs.

  However, unlike the EEPROM, the flash memory cannot overwrite data. For this reason, conventionally, every time data is generated, all types of data (that is, setting data, energization time, alarm history, failure history) are added to the flash memory.

  This will be described in detail with reference to FIGS. That is, first, at the time of factory shipment, for example, when a shipment operation is performed, the CPU in the alarm device divides the flash memory area into two blocks B1 and B2 as shown in FIG. The data stored in both the blocks B1 and B2 are erased to make a free area.

  Next, as shown in FIG. 10B, the CPU in the alarm device writes the setting data received by communication from the outside at the head of the block B1. Next, the CPU in the alarm device writes in the block B1 in the order of energization time, alarm history 1 to 3, and failure history 1 to 3. Since it is the time of shipment at this time, 0 is written as the energization time. In addition, since no alarm or failure has occurred, empty data is written as the alarm histories 1 to 3 and the failure histories 1 to 3.

  Further, these energization times, alarm histories 1 to 3 and failure histories 1 to 3 all have the same data length, so that a data length adjustment area has a data length adjustment area shorter than the maximum data length. Is provided. For example, as the energization time, several tens of bytes are written together with long data such as alarm histories 1 to 3 and failure histories 1 to 3 where a few bytes can be written.

  After that, when an alarm is generated, the CPU in the alarm device moves the alarm history 2 to the alarm history 1, the alarm history 3 to the alarm history 2, and the new alarm history as the alarm history 3 as shown in FIG. All types of data (setting data, energization time data, alarm histories 1 to 3 and failure histories 1 to 3) are added.

  Thereafter, when a failure occurs, the CPU in the alarm unit moves the failure history 2 to the failure history 1 and the failure history 3 to the failure history 2 as shown in FIG. Append all types of data.

  Thereafter, when the clocking for each predetermined time is completed after the installation, the CPU in the alarm device adds all kinds of data with the new energization time obtained by adding the predetermined time as the energization time, as shown in FIG. . When writing to the end of the block B1, the CPU in the alarm device erases all the data stored in the block B2 to make an empty area as shown in FIG. Next, as shown in FIG. 14B, the CPU in the alarm device has the latest all types of data (that is, the first of all types of data stored in the block B1) at the head of the erased block B2. Write back all data types).

  When a setting device that reads data in the flash memory is connected to this alarm device, the alarm device determines whether or not data has been written from the area after block B2, and reaches the area to which data has been written. Then, the energizing time, the alarm history 1 to 3 and the data for each equal data length of the failure history 1 to 3 are set as the latest failure history 3-1, the latest alarm history 3-1, the latest energizing time, and the setting device. Send to.

  Thus, conventionally, every time data is generated, all types of data (that is, setting data, energization time, alarm history, failure history) are additionally written in the flash memory, so that the efficiency is low. Further, since the flash memory has a smaller number of erasable times than that of the EEPROM, it is necessary to reduce the number of times data is written, and there is a problem in use with an alarm device.

  Accordingly, the present invention provides a data storage device and a data storage method that can reduce the number of times of erasure by reducing the amount of data to be written each time data is generated, and can efficiently use a memory that cannot be overwritten. This is the issue.

  The invention according to claim 1 for solving the above-described problem is a data storage device for storing a plurality of types of data that are sequentially generated in a non-overwriteable memory, wherein a plurality of blocks are provided in the memory area, Latest block setting means for setting one of a plurality of blocks as the latest block, and each time the data is generated, the data type is added to the end of the generated data in order from the beginning of the empty area of the latest block and stored. Data storage means, free area determination means for determining whether or not there is an empty area in the latest block, and other blocks excluding the latest block when the empty area determination means determines that there is no empty area Erasing means for erasing all of the data, and after all erasing by the erasing means, the data is read in order from the back of the latest block, Data moving means for extracting a predetermined number of data from the back for each type based on the data type added at the end of the data, and writing the extracted data in order from the top of the other block, and In the data storage device, the latest block setting means sets the other block as the latest block after completion of writing by the data moving means.

  According to a second aspect of the present invention, in the data storage device for storing a plurality of types of data sequentially generated in a non-overwriteable memory, a plurality of blocks are provided in the area of the memory, and one of the plurality of blocks is updated. The latest block setting means for setting as a block, the data storage means for adding the data type to the end of the generated data in order from the beginning of the empty area of the latest block every time the data is generated, and the data A second data storage means for overwriting the generated data in a second memory that can be overwritten every time it occurs, and other blocks excluding the latest block when the free area determination means determines that there is no free area Erasing means for erasing all of the data, and after erasing all the data by the erasing means, the latest data stored in the second memory And a data moving unit for sequentially writing from the head of the block, wherein the latest block setting unit sets the other block as the latest block after the writing by the data moving unit is completed. .

  According to a third aspect of the present invention, in the data storage device in which energization time data is generated every predetermined time as the data, the energization time data stored at the head of each block is compared, and the maximum energization time data is obtained. The latest block determination means for determining the written block as the latest block, the data is read in order from the back of the latest block, and a predetermined number of data is read from the back for each type based on the data type added at the end of the data. The data storage device according to claim 1, further comprising reading means for reading data as latest data.

  According to a fourth aspect of the present invention, the reading means and the data moving means determine the data length from the data type added to the end of the data, and the data length determined from the area in which the data type is written 4. The data storage device according to claim 3, wherein it is determined that the data of the area up to minutes ago is the data of the data type.

  According to a fifth aspect of the present invention, in the data storage method for storing a plurality of types of data sequentially generated in a non-overwriteable memory, a plurality of blocks are provided in the memory area, and one of the plurality of blocks is set as a latest block. A newest block setting step for setting as the data block, a data storage step for adding the data type to the end of the generated data in order from the top of the empty area of the newest block every time the data is generated, An empty area determining step for determining whether or not there is an empty area; and an erasing process for erasing all data of other blocks except the latest block when the empty area determining means determines that there is no empty area; After all erasure in the erasing step, data is read sequentially from the back of the latest block, and the data added to the end of the data is read. A data movement step of extracting a predetermined piece of data from the back for each type based on the data type and writing the extracted data in order from the top of the other block, in the latest block setting step, In the data storage method, the other block is set as the latest block after completion of writing in the data movement step.

  According to a sixth aspect of the present invention, in the data storage method for storing a plurality of types of data sequentially generated in a memory that cannot be overwritten, a plurality of blocks are provided in the memory area, and one of the plurality of blocks is updated. A latest block setting step for setting as a block; a data storage step for adding and storing a data type at the end of the generated data in order from the beginning of the empty area of the latest block each time the data is generated; and A second data storage step of overwriting the generated data in a second memory that can be overwritten every time it occurs, and other blocks except the latest block when it is determined by the free space determination step that there is no free space An erasing process for erasing all data in the memory, and after erasing all the data in the erasing process, the latest data stored in the second memory A data movement step of sequentially writing from the head of the block, wherein the latest block setting step sets the other block as the latest block after the completion of writing by the data movement step. .

  As described above, according to the first aspect of the present invention, each time data is generated, the data storage means stores the generated data with the data type added to the end of the generated data in order from the beginning of the empty area of the latest block. After the data erasing unit is completely erased by the erasing unit, the data is read in order from the back of the latest block, and a predetermined number of data is extracted from the back for each type based on the data type added at the end of the data. Thus, the extracted data is written in order from the top of the other blocks. Therefore, by adding the data type to the end of the data, when data is generated, it is not necessary to add all types of data. It is possible to read predetermined data, that is, latest data. As a result, the amount of data to be written can be reduced each time data is generated, the number of erasures can be reduced, and a memory that cannot be overwritten efficiently can be used.

  According to the second aspect of the invention, the data storage means adds the data type to the end of the generated data in order from the top of the empty area of the latest block every time data is generated, and the data moving means After all erasure is performed by the erasing means, the latest data stored in the second memory is sequentially written from the top of the other blocks. Therefore, by adding the data type to the end of the data, when data is generated, it is not necessary to add all types of data. The latest data can be read. In addition, the latest data stored in the latest block can be moved to the head of another block without sequentially reading from the back of the latest block. As a result, the amount of data to be written can be reduced each time data is generated, the number of erasures can be reduced, and a memory that cannot be overwritten efficiently can be used.

  According to the invention described in claim 3, the latest block determination means compares the energization time data stored at the head of each block, determines the block in which the maximum energization time data is written as the latest block, The reading means reads the data in order from the back of the latest block, and reads predetermined data from the back as the latest data for each type based on the data type added at the end of the data. Even if not, it can be determined which of the blocks is the latest block.

  According to the fourth aspect of the present invention, the reading means and the data moving means determine the data length from the data type added to the end of the data, and the data length determined from the area where the data type is written. It is determined that the data in the previous area is data of the data type. Therefore, since the data can be specified without making the data length of each type of data the same, there is no need to provide a data length adjustment area for adjusting the data length of each type of data to be the same. Data is not stored in memory.

  According to the fifth aspect of the present invention, in the data storing step, every time data is generated, the data type is added to the end of the generated data in order from the beginning of the empty area of the latest block, and stored. After all erasure in the erasure process, the data is read sequentially from the back of the latest block, and a predetermined number of data is extracted from the back for each type based on the data type added at the end of the data, and extracted Data is written sequentially from the beginning of other blocks. Therefore, by adding the data type to the end of the data, when data is generated, it is not necessary to add all types of data. It is possible to read predetermined data, that is, latest data. As a result, the amount of data to be written can be reduced each time data is generated, the number of erasures can be reduced, and a memory that cannot be overwritten efficiently can be used.

  According to the sixth aspect of the present invention, in the data storing step, every time data is generated, the data type is added to the end of the generated data in order from the head of the empty area of the latest block, and stored. After all erasure is performed by the erasing process, the latest data stored in the second memory is sequentially written from the top of the other blocks. Therefore, by adding the data type to the end of the data, when data is generated, it is not necessary to add all types of data. The latest data can be read. As a result, the amount of data to be written can be reduced each time data is generated, the number of erasures can be reduced, and a memory that cannot be overwritten efficiently can be used.

It is a block diagram which shows one Embodiment of the alarm device incorporating the data storage apparatus of this invention. It is a figure which shows the structure of the electricity supply time written in the flash memory which comprises the data storage apparatus shown in FIG. 1, setting data, an alarm history, and a failure history. It is a flowchart which shows the process sequence in the data storage process of CPU which comprises the data storage apparatus shown in FIG. It is a figure which shows the data stored in the flash memory at the time of factory shipment of the alarm device shown in FIG. It is a figure which shows the data stored in the flash memory at the time of energization time writing of the alarm device shown in FIG. It is a figure which shows the data stored in the flash memory at the time of the alarm generation of the alarm device shown in FIG. It is a figure which shows the data stored in the flash memory at the time of failure occurrence of the alarm device shown in FIG. It is a figure which shows the data stored in the flash memory when writing to the last of the block B1 of the alarm device shown in FIG. It is explanatory drawing for demonstrating the operation | movement at the time of the reading of the alarm device shown in FIG. It is a figure which shows the data stored in the flash memory at the time of the conventional factory shipment. It is a figure which shows the data stored in the flash memory at the time of the conventional alarm generation. It is a figure which shows the data stored in the flash memory at the time of the conventional failure occurrence. It is a figure which shows the data stored in the flash memory at the time of the conventional energization time writing. It is a figure which shows the data stored in the flash memory when writing to the last of the conventional block B1.

  Hereinafter, a data storage device and a data storage method of the present invention will be described with reference to the drawings. FIG. 1 is a block diagram showing an embodiment of an alarm device incorporating the data storage device of the present invention. As shown in the figure, the alarm device 1 is connected to a microcomputer (hereinafter referred to as μCOM) 2 that controls the alarm device 1 as a whole, a sensor 3 that detects abnormalities such as gas leakage and fire, and a setting device 4 that will be described later. The input / output terminal 5 is provided.

  The μCOM 2 includes a CPU 2A that performs various processes according to a processing program, a ROM 2B that stores a program for processing performed by the CPU 2A, a work area that is used in various processes in the CPU 2A, a data storage area that stores various data, and the like. And a flash memory 2D, which is a non-overwritable non-volatile memory. The CPU 2A performs an alarm generation process for generating an alarm based on an output from the sensor 3, a failure detection process for detecting a failure, and the like.

  The flash memory 2D is provided with two blocks B1 and B2 in the memory area. In the flash memory 2D, data such as energization time, set value data, alarm history, and failure history are sequentially written. As shown in FIGS. 2A to 2D, the data such as energization time, setting data, alarm history, and failure history include an area in which a checksum is written at the beginning and a data type at the end (that is, energization time, setting). An area for writing data), and an area for writing the data itself between the checksum and the data type. These data have different data lengths depending on the data type, the longest setting data, the longest alarm history and failure history, and the shortest energization time.

  Next, the operation of the data storage device having the above-described configuration will be described with reference to FIGS. FIG. 3 is a flowchart showing a processing procedure in the data storage processing of the CPU 2A constituting the data storage device shown in FIG. FIG. 4 is a diagram showing data stored in the flash memory 2D when the alarm device 1 shown in FIG. 1 is shipped from the factory. FIG. 5 is a diagram showing data stored in the flash memory 2D at the time of writing the energization time of the alarm device 1 shown in FIG. FIG. 6 is a diagram showing data stored in the flash memory 2D when an alarm is generated by the alarm device 1 shown in FIG. FIG. 7 is a diagram showing data stored in the flash memory 2D at the time of failure of the alarm device 1 shown in FIG. FIG. 8 is a diagram showing data stored in the flash memory 2D when writing to the end of the block B1 of the alarm device 1 shown in FIG.

  First, the CPU 2A starts the data storage process in response to power-on. First, in the first step S1, the CPU 2A determines whether or not the alarm device 1 is in a shipping mode. If it is the shipping mode (Y in step S1), the CPU 2A erases all the data in both the blocks B1 and B2 in the flash memory 2D as shown in FIG. 4A to make a free area (step S2). .

  Next, the CPU 2A functions as the latest block setting means, and sets the block B1 as the latest block (step S3). This step S3 corresponds to the latest block setting step in the claims. Thereafter, as shown in FIG. 4B, the CPU 2A functions as data storage means, stores the energization time (energization time data) at the head of the block B1, and is obtained by communication from the outside such as the setting device 4 after that. The set data is stored (step S4). In step S4, the CPU 2A functions as a second data storage unit and stores the energization time in the RAM 2C. Here, 0 is written as the energization time. This step S4 corresponds to the data storage step and the second data storage step in the claims.

  Thereafter, the CPU 2A waits for the shipment mode to be canceled (N in step S5), and proceeds to the next step S6. When the shipping mode is canceled, the CPU 2A performs the alarm generation process and the failure detection process described above in parallel with the data storage process.

  In step S6, the CPU 2A functions as an empty area determination unit and determines whether or not the latest block is full. Specifically, the CPU 2A reads data from the end of the latest block, and determines whether or not empty data “1” continues for a predetermined byte or more. The CPU 2A determines that the latest block is full if empty data is not continuous for a predetermined byte or more from the end, and determines that the latest block is not full if empty data is continuous for a predetermined byte or more from the end. This step S6 corresponds to a free space determination step in the claims.

  If it is determined that the latest block is not full (N in step S6), then the CPU 2A determines whether or not the timing for every predetermined time started after the power is turned on (step S12). If it is determined that the time measurement for the predetermined time has ended (Y in step S12), the CPU 2A, as shown in FIG. 5, sets a predetermined current energization time at the beginning of the empty area of the latest block (block B1 in the example of FIG. 5). The new energization time 2 added with the time is written, and the energization time stored in the RAM 2C is overwritten with the new energization time (step S13), and the process proceeds to the next step S14. By step S13, the latest energization time is always stored in the RAM 2C. If the measurement of the predetermined time has not ended (N in step S12), the CPU 2A immediately proceeds to step 14 without proceeding to step S13.

  In step S <b> 14, the CPU 2 </ b> A determines whether data to be stored in the flash memory 2 </ b> D is generated due to an alarm or failure, a setting data update request from the setting device 4, or the like. If there is no data to be stored in the flash memory 2D (N in step S14), the CPU 2A immediately returns to step S1.

  On the other hand, if data to be stored in the flash memory 2D has occurred (Y in step S14), the CPU 2A writes the generated data at the head of the empty area of the latest block (step S15), and then returns to step S1. .

  The details of step S15 will be described. For example, when an alarm is generated, the CPU 2A writes the new alarm history 2 to the head of the free area of the latest block (block B1 in the example shown in FIG. 6) as shown in FIG. . When a failure occurs, the CPU 2A writes a new failure history 3 at the head of the empty area of the latest block (block B1 in the example shown in FIG. 7) as shown in FIG.

  In steps S12 to S15 described above, the CPU 2A functions as data storage means. Steps S12 to S15 correspond to the data storage step in the claims.

  On the other hand, if it is determined that the latest block is full (Y in step S6), then, as shown in FIG. 8A, the CPU 2A functions as an erasing unit, and other blocks excluding the latest block. The data stored in (block B2 in the example of FIG. 8) is completely erased to make a free area (step S7). This step S7 corresponds to an erasing process in the claims. Next, the CPU 2A writes the latest energization time stored in the RAM 2C at the head of another block (step S8).

  Next, as shown in FIG. 8B, the CPU 2A searches the setting data stored in the latest block among the setting data stored in the latest block and writes it after the energization time (step S9). . Thereafter, as shown in FIG. 8C, the CPU 2A searches for the third to third alarm histories out of the alarm histories stored in the latest block, writes them to the back of the setting data, and thereafter, FIG. As shown in (D), after searching for the third failure history from the failure history stored in the latest block and writing it after the alarm history (step S10), the process proceeds to step S11.

  The above search will be described in detail. First, the CPU 2A starts reading from the end of the latest block (block B1). The CPU 2A stores the data type added to the end of the data at the end. The CPU 2A determines the type of data written at the end of the block B1 from this data type. In the example shown in FIG. 8C, the CPU 2A determines that the alarm history 7 is written at the end of the latest block. The CPU 2A determines the data length of the data from the determined data type, and determines that the data in the area before the determined data length from the area where the data type is written is the data of that data type.

  In the example shown in FIG. 8C, the data in the area from the tail to the previous data length of the alarm history is determined as the alarm history 7. Further, the CPU 2A reads the data toward the head of the latest block, and determines the type of data written before the alarm history 7 from the data type stored in the area before the alarm history 7. In the example illustrated in FIG. 8C, it is determined that the alarm history 6 is written before the alarm history 7. As described above, the CPU 2A sequentially reads data from the back to the front, and searches the alarm history stored in the latest block from the back to the third.

  In the example shown in FIG. 8C, the alarm histories 7, 6, and 5 are searched as the third to third alarm histories from the alarm histories stored in the latest block. The CPU 2A sequentially writes the three alarm histories 7, 6, and 5 in the block B2 from the front. That is, the alarm history 5 is moved to the alarm history 1, the alarm history 6 is moved to the alarm history 2, and the alarm history 7 is moved to the alarm history 3.

  In the example shown in FIG. 8D, the failure histories 6, 5, and 4 are searched as the third failure history from the failure history stored in the latest block. The CPU 2A writes to the block B2 in order from the earliest of these three failure histories 6, 5, and 4. That is, the failure history 4 is moved to the failure history 1, the failure history 5 is moved to the failure history 2, and the failure history 6 is moved to the failure history 3 to be additionally recorded.

  In steps S8 to S10 described above, the CPU 2A functions as a data moving unit. Steps S8 to S10 correspond to the data movement step in the claims.

  In step S11, the CPU 2A functions as the latest block setting means, sets the other block (block B2 in the example shown in FIG. 8) as the latest block, and proceeds to the next step S12. This step S11 corresponds to the latest block setting step in the claims.

  Next, an operation when a history reading request is made by the setting device 4 will be described. First, the CPU 2A functions as the latest block determination means, compares the energization times written at the heads of the blocks B1 and B2, and determines the block in which the maximum value is written as the latest block. After that, the CPU 2A functions as a reading unit, reads from the back of the latest block, the first energization time found first is the latest energization time, the first setting data found is the latest setting data, the alarm history up to the third from the back, failure The history is transmitted to the setting device 4 as the latest alarm history and the latest failure history.

  In the example shown in FIG. 9, the CPU 2A determines that the block B2 is the latest block, the energization time 3 is the latest energization time, the setting data 2 is the latest setting data, the alarm histories 4, 3, and 2 are the latest alarm history, and the failure history 3 2 and 1 are transmitted to the setting device 4 as the latest failure history.

  According to the above-described embodiment, the CPU 2A provides the two blocks B1 and B2 in the area of the flash memory 2D, sets one of the two blocks B1 and B2 as the latest block, and stores data (energization time, setting data, Each time an alarm history (failure history) is generated, a data type is added to the end of the data generated in order from the top of the empty area of the latest block and stored. Further, the CPU 2A determines whether or not there is an empty area in the latest block, and when it is determined that there is no empty area, after erasing data of other blocks excluding the latest block, the data is read sequentially from the back of the latest block. Based on the data type added to the end of the data, one or three pieces of data are extracted from the back for each type, and the extracted data is written in order from the top of the other blocks. Thereafter, the CPU 2A sets other blocks as the latest blocks after the writing is completed.

  As described above, when data is generated by adding the data type to the end of the data, all types of data (energization time, setting data, alarm history 1 to 3, failure history 1 to 3) are provided as in the conventional example. Even if only the generated data is added after the data, it is possible to read three pieces of data from the latest for each type, that is, the latest data. As a result, the amount of data to be written can be reduced each time data is generated, the number of erasures can be reduced, and a memory that cannot be overwritten efficiently can be used.

  Further, according to the above-described embodiment, the CPU 2A overwrites and saves the energization time in the RAM 2C, and after all erasure is performed, the latest energization time stored in the RAM 2C is sequentially written from the top of the other blocks. As a result, the latest energization time stored in the latest block can be moved to the head of another block without sequentially reading from the back of the latest block.

  Further, according to the embodiment described above, the CPU 2A compares the energization times stored at the heads of the blocks B1 and B2, determines the block in which the maximum energization time is written as the latest block, and determines the latest block. The data is read in order from the back, and based on the data type added at the end of the data, one from the back for each type (in the case of energization time and setting data), or three (in the case of alarm history and failure history) ) As the latest data, it is possible to determine which of the blocks is the latest block without having information on the latest block.

  According to the above-described embodiment, the CPU 2A determines the data length from the data type added at the end of the data, and the data in the area up to the data length determined from the area where the data type is written. The data type is determined to be data. Therefore, since the data can be specified without making the data length of the energization time, the alarm history, and the failure history the same as before, the data length for adjusting the data length of each type of data to the same There is no need to provide an adjustment area, and useless data is not stored in the flash memory 2D.

  According to the above-described embodiment, the CPU 2A has the function of determining the data length from the data type added at the end of the data, and the data length of the energization time, the setting data, the alarm history, and the failure history is set. Although each is variable, the present invention is not limited to this. For example, if a data length adjustment area is provided in the same manner as in the past and the data lengths of energization time, setting data, alarm history, and failure history are the same, the CPU 2A must have a function for determining the data length. There is no.

  Further, according to the above-described embodiment, the CPU 2A determines the latest block from the energization time stored at the head of each of the blocks B1 and B2 at the time of reading by the setting device 4, but the present invention is not limited to this. Not a thing. For example, an area indicating the latest block may be provided in an area different from the blocks B1 and B2 of the flash memory 2D, and the block stored in the area may be determined as the latest block. In this case, when the latest block is full, it is not necessary to write the energization time at the beginning of the other blocks.

  Further, according to the embodiment described above, the flash memory 2D is provided with the two blocks B1 and B2. However, the present invention is not limited to this. As the block, two or more blocks may be provided, and three or four blocks may be provided.

  Further, according to the above-described embodiment, the energization time is also overwritten in the RAM 2C, and when the latest block is full, the latest energization time stored in the RAM 2C is set to the head of another block. However, the present invention is not limited to this. For example, the alarm history and failure history are also overwritten in the RAM 2C, and when the latest block is full, the latest alarm history and failure history stored in the RAM 2C is moved to the head of another block. May be.

  Further, the above-described embodiments are merely representative forms of the present invention, and the present invention is not limited to the embodiments. That is, various modifications can be made without departing from the scope of the present invention.

1 Alarm (Data storage device)
2A CPU (latest block setting means, data storage means, free space determination means, erasure means, data movement means, latest block determination means, reading means)
2D flash memory (memory)
B1 block B2 block

Claims (6)

In a data storage device for storing a plurality of types of data that occur sequentially in a memory that cannot be overwritten,
A plurality of blocks in the area of the memory, and a latest block setting means for setting one of the plurality of blocks as a latest block;
Data storage means for adding and storing a data type at the end of the generated data in order from the beginning of the empty area of the latest block every time the data is generated;
Free space determination means for determining whether or not there is a free space in the latest block;
If it is determined by the free area determination means that there is no free area, erasing means for erasing all data of other blocks except the latest block;
After all erasure by the erasing means, data is read in order from the back of the latest block, based on the data type added at the end of the data, a predetermined piece of data is extracted from the back for each type, Data moving means for sequentially writing the extracted data from the top of the other block,
The data storage device, wherein the latest block setting means sets the other block as the latest block after completion of writing by the data moving means. In a data storage device for storing a plurality of types of data that occur sequentially in a memory that cannot be overwritten,
A plurality of blocks in the area of the memory, and a latest block setting means for setting one of the plurality of blocks as a latest block;
Data storage means for adding and storing a data type at the end of the generated data in order from the beginning of the empty area of the latest block every time the data is generated;
Second data storage means for overwriting the generated data in a second memory that can be overwritten each time the data is generated;
If it is determined by the free area determination means that there is no free area, erasing means for erasing all data of other blocks except the latest block;
Data moving means for sequentially writing the latest data stored in the second memory in order from the head of the other block after being completely erased by the erasing means,
The data storage device, wherein the latest block setting means sets the other block as the latest block after completion of writing by the data moving means. In the data storage device in which energization time data is generated every predetermined time as the data,
Latest block determination means for comparing the energization time data stored at the head of each block and determining the block in which the maximum energization time data is written as the latest block;
Reading means sequentially reading from the back of the latest block, based on the data type added at the end of the data, reading means for reading a predetermined piece of data from the back for each type as the latest data,
The data storage device according to claim 1, further comprising: The reading means and the data moving means determine the data length from the data type added at the end of the data, and the data in the area up to the data length determined from the area where the data type is written. The data storage device according to claim 3, wherein the data storage device is determined to be data of the data type. In a data storage method for storing multiple types of data that occur sequentially in a memory that cannot be overwritten,
Providing a plurality of blocks in the memory area, and setting one of the plurality of blocks as a latest block;
A data storing step of adding and storing a data type at the end of the generated data in order from the beginning of the empty area of the latest block every time the data is generated,
A free space determination step of determining whether there is a free space in the latest block;
If it is determined by the free area determination means that there is no free area, an erasing step of erasing all data of other blocks except the latest block;
After all erasure in the erasing step, read data sequentially from the back of the latest block, based on the data type added at the end of the data, extract a predetermined piece of data from the back for each type, A data movement step of sequentially writing the extracted data from the top of the other block,
In the latest block setting step, after completion of writing in the data movement step, the other block is set as the latest block. In a data storage method for storing multiple types of data that occur sequentially in a memory that cannot be overwritten,
A latest block setting step of providing a plurality of blocks in the area of the memory and setting one of the plurality of blocks as a latest block;
A data storing step of adding and storing a data type at the end of the generated data in order from the beginning of the empty area of the latest block every time the data is generated,
A second data storing step of overwriting the generated data in a second memory that can be overwritten each time the data is generated;
When it is determined that there is no free space in the free space determination step, an erasing step of erasing all data of other blocks except the latest block;
A data movement step of sequentially writing the latest data stored in the second memory in order from the beginning of the other block after being completely erased by the erasing step,
In the data storage method, the latest block setting step sets the other block as the latest block after completion of writing by the data movement step.

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