JP2008276647A - Data recording device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a data recording device, capable of automatically recording necessary data and using a small-capacity memory. <P>SOLUTION: The data recording device comprises a nonvolatile memory 10, and a control part 20 which performs writing processing of measurement data and order specification data to the nonvolatile memory 10. When at least one of data D1 of a first block written to a first storage area 11 of the nonvolatile memory 10 and data D2 of a second block written to a second storage area 12 thereof contains data of a value out of a predetermined range, the control part 20 writes new measurement data to the first storage area so that the data D1 and the order specification data assigned to D1 are not overwritten. When the data D1 and D2 do not contain the value out of the predetermined range, the control part 20 writes the new measurement data to the first storage area so that the data D1 and the order specification data assigned to D1 are overwritten. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a data recording apparatus.

  Data recording devices (data log devices) that continuously acquire and record data such as temperature, vibration, brightness, sound, and images are known. For example, food temperature management, drive recorders, flight recorders, Used for voice recorders, seismometers, etc.

In these data recording devices, when the value of the measured data exceeds a predetermined range, it can be determined that some event has occurred for the measurement target. And if the data acquired after the said data are analyzed, the state after the event occurrence of the measurement object can be known. In addition, if the data acquired within a certain period before the data is analyzed, the state of the measurement target before the occurrence of the event can be known.
JP 2005-259041 A

  In these data recording devices, if the time interval for measuring (storing) data is shortened, changes in data can be recorded accurately. However, since the number of data increases if the data measurement time interval is shortened, a large-capacity memory is required to record the data.

  On the other hand, if the time interval for measuring data is lengthened, the number of data decreases, so that a memory with a small capacity can be used. However, if the data measurement interval becomes long, it becomes difficult to record fine data changes.

  In order to know the state of the event occurrence, it is preferable to analyze the change in data before and after the event occurrence, but in order to reliably store the measurement data before and after the event occurrence, always record the data. It is necessary to store a large amount of memory.

  An object of the present invention is to provide a data recording apparatus capable of automatically recording necessary data and using a memory having a small capacity.

(1) A data recording apparatus according to the present invention comprises:
A data recording device that performs processing of writing a plurality of measurement data received in time series into a memory,
A nonvolatile memory including a plurality of storage areas in which the measurement data is written;
A predetermined number of measurement data as one block, each measurement data for one block is sequentially written in a given storage area of the nonvolatile memory, and then each measurement data for the next one block is stored in another storage area. A write control unit that repeatedly performs a sequential writing process,
The write control unit
In the storage area of the nonvolatile memory in which the measurement data of each block is written, the order specifying data for specifying the order in which each block is allocated and acquired is written in association with each block,
Whether one block last written in a given storage area of the non-volatile memory and the next one block acquired after the one block include measurement data having a value outside a predetermined range. If at least one of them contains, the measurement data for one block last written in the given storage area and the order specifying data assigned to the one block are not overwritten. , Writing each measurement data for one new block and the order specifying data assigned to the one block to the given storage area, and if none of them includes the measurement data and the order specifying data, In order to be overwritten, each measurement data for one new block and the sequence specifying data assigned to the one block are written in the given storage area. Characterized in that the writing.

  According to the data recording apparatus of the present invention, a predetermined number (N) of measurement data of one block written in a given storage area and a predetermined number (N) of measurement data acquired thereafter are recorded. It is determined whether or not 2N measurement data together with the data includes data having a value outside a predetermined range. Here, the value in the predetermined range is a value of measurement data that determines that the measurement target is normal. That is, if the measurement data is a value within a predetermined range, the measurement data indicates that the measurement target is in a normal state. Conversely, if the measurement data is a value outside the predetermined range, the measurement data indicates that an abnormality has occurred in the measurement target. In the present invention, when 2N measurement data includes data having a value outside the predetermined range, the N measurement data of one block last written in the given storage area is stored. It is determined that the data is necessary. On the other hand, if 2N measurement data are all data within a predetermined range, data that does not require storage of the N measurement data of one block last written in the given storage area. It is determined that

  For example, according to the present invention, if the next block obtained after the last block written to a given storage area contains measurement data indicating an abnormality, the last write to the given storage area is performed. The measured data for one block is stored. In addition, according to the present invention, even when one block last written in a given storage area includes measurement data indicating an abnormality, one block last written in the given storage area. Measurement data is saved.

  Therefore, according to the present invention, each measurement data for one block including data indicating abnormality and each measurement data for one block acquired before that are stored. That is, according to the present invention, it is possible to save each measurement data for at least one block acquired before data indicating abnormality. Therefore, by analyzing this, it is possible to determine an event that has occurred in the measurement target in the process leading to the occurrence of an abnormality.

  Further, according to this data recording apparatus, the necessity of each measurement data for one block written at the end of a given storage area is determined using each measurement data for one block written in a different storage area. judge. Therefore, according to this data recording apparatus, control is performed so that new data is not written to the storage area until it is determined whether or not each block of measurement data written at the end of the given storage area is necessary. be able to. Then, after determining the necessity of each measurement data for one block written at the end of a given storage area, by setting the write address (write start address) of the storage area, It is possible to decide whether to overwrite the measurement data or to save the data of one block without overwriting. As a result, the memory addresses can be used without any gaps, so that the memory capacity can be used without waste.

  In addition, according to the present invention, order specifying data assigned to a block in order to specify the order in which the blocks that need to be stored are acquired are stored in association with the block. Therefore, when the stored measurement data is analyzed, the acquisition order of each stored block can be easily determined. In addition, since the number of non-stored blocks existing between stored blocks can be recognized, more accurate analysis can be performed.

  Note that the order specifying data may be data that can specify the order of each acquired block, such as a serial number and time. Further, for example, numbers in ascending order from 1 may be assigned in the order of acquired blocks, and the numbers may be stored as they are in association with blocks that need to be stored, or predetermined conversion may be performed to clearly distinguish the numbers from measurement data. You may make it preserve | save after giving. For example, when the number of measurement data per block and the address at which data is written are the same in each data recording, the address at which the order specifying data is written is the same every time, so there is no confusion with the measurement data. As in the former case, an ascending number may be written as the order specifying data. On the other hand, when the number of measurement data per block or the address at which data is written differs in each data recording, it is desirable to write the order specifying data so as not to cause confusion with the measurement data as in the latter case.

  Further, the order of the addresses for writing the measurement data for one block and the order specifying data is not limited. For example, the order specifying data may be written to the address next to the address where the last measurement data of one block is written, or the first measurement of one block starting from the address next to the address where the order specifying data is written. You may make it write in order from data.

(2) A data recording apparatus according to the present invention comprises:
The write control unit
It is determined whether or not one block acquired before the last block written in the given storage area includes measurement data having a value outside the predetermined range. Each measurement data of one block newly written in the given storage area and each of the measurement data of one block written in the storage area and the order specifying data assigned to the block are not overwritten. The order specifying data allocated to one block is written.

  According to this, the data acquired after the data indicating the occurrence of the event can be saved.

  For example, according to the present invention, when one block acquired before each measurement data for one block last written in a given storage area contains measurement data indicating an abnormality, the given storage area Each measurement data for one block written last is stored. That is, according to the present invention, each measurement data for at least one block acquired after the measurement data indicating abnormality can be stored. Therefore, by analyzing this, it becomes possible to analyze the state of the measurement target after the occurrence of an abnormality.

(3) A data recording apparatus according to the present invention comprises:
The nonvolatile memory is
3n (n is an integer of 1 or more) or more of the storage area,
The write control unit
Each block of measurement data is sequentially written in the k-th (k is an integer between 1 and 3n-1) storage area of the non-volatile memory, and then the next block is measured in the k + 1 storage area. After sequentially writing data and sequentially writing each measurement data for one block in the 3n storage area, the process of sequentially writing each measurement data for the next block in the first storage area is repeatedly performed. And

  According to this, when the block including the measurement data indicating abnormality and the blocks before and after the data are stored, the probability of using each storage area equally can be increased. As a result, the capacity of the memory can be used without waste.

(4) A data recording apparatus according to the present invention comprises:
The write control unit
The predetermined range is set to a predetermined value in advance.

(5) A data recording apparatus according to the present invention comprises:
The write control unit
The predetermined range is set based on measurement data.

(6) A data recording apparatus according to the present invention comprises:
The write control unit
A write stop process for determining whether or not the measurement data satisfies a predetermined write stop condition and performing control to stop writing data to the nonvolatile memory when the predetermined write stop condition is satisfied It is characterized by including a part.

  As a result, it is possible to prevent the loss of already stored data. In particular, the data recording apparatus of the present invention uses a non-volatile memory as the storage unit. Therefore, even when an unexpected situation occurs and the supply of power to the storage device is stopped, the loss of already stored data can be prevented.

(7) A data recording apparatus according to the present invention comprises:
The image processing apparatus further includes a detection unit that detects that the storage capacity of the unused area for each storage area falls below a predetermined value.

(8) A data recording apparatus according to the present invention comprises:
The write control unit
It is determined whether or not each measurement data for one block last written in the given storage area satisfies a predetermined acquisition condition, and when it is satisfied, 1 last written in the given storage area Each measurement data for one block and the order specification assigned to the one block are stored in the given storage area so that each measurement data for the block and the order specification data assigned to the one block are not overwritten. It is characterized by writing data.

  Here, the data satisfying the predetermined acquisition condition is, for example, measurement data acquired at L intervals (L is an integer larger than the number N of data of one block) among measurement data (or measurement data acquisition intervals) Measurement data obtained at a wider predetermined interval).

  According to this, since consecutive N pieces of measurement data are periodically stored, it can be confirmed that the data recording apparatus is operating normally.

(9) A data recording apparatus according to the present invention comprises:
The write control unit
When the write destination is switched from the other storage area to the given storage area, and each measurement data for one new block and the order specifying data assigned to the one block are written to the given storage area, By designating the highest address of the area corresponding to each measurement data for one block last written in the given storage area and the order specifying data assigned to the one block, the given data Control to overwrite each measurement data for one block last written in the storage area and the order specifying data assigned to the one block,
By designating a lower address than the lowest address of the area corresponding to each measurement data for one block last written in the given storage area and the order specifying data assigned to the one block The measurement data for one block and the order specifying data assigned to the one block are controlled so as not to be overwritten.

  For example, when the order specification data assigned to one block is written after the measurement data for one block is written, the address where the first measurement data of one block is written is specified as the write address of the new data. Thus, the measurement data for one block and the order specifying data are overwritten and deleted. Thereby, the storage capacity can be used without waste.

  Conversely, by specifying a lower address than the address where the measurement data and sequence specifying data for one block are written as the new data write address, the measurement data and sequence specifying data for that block are overwritten. Therefore, necessary data can be saved.

(10) A data recording apparatus according to the present invention comprises:
The nonvolatile memory is
A predetermined dedicated storage area not included in the plurality of storage areas;
The write control unit
At least one measurement data of each block sequentially written in a given storage area of the nonvolatile memory is sequentially written in the dedicated storage area of the nonvolatile memory.

  The dedicated storage area is provided separately from a block including measurement data indicating abnormality and a plurality of storage areas for storing blocks before and after the block, and is dedicated to the use of sequentially writing at least one measurement data of each block. is there. According to this, because at least one measurement data (data acquired at a predetermined interval longer than the measurement data acquisition interval) of each block is stored in the dedicated storage area regardless of whether or not an event has occurred, Long-term data changes can be confirmed. Since the dedicated storage area is periodically written, it is desirable to configure it as a ring buffer and use it while overwriting and erasing the old data in order. According to this, the number of data necessary for checking long-term data fluctuation can be efficiently stored with a relatively small memory capacity.

(11) A data recording apparatus according to the present invention comprises:
The nonvolatile memory is a ferroelectric memory.

  It is known that a ferroelectric memory generally has a large number of rewritable times and a short time required for rewriting. Therefore, by using a ferroelectric memory as the nonvolatile memory, it is possible to provide a data recording device with a small limit on the number of rewrites and a limit on the data acquisition time interval.

  Embodiments to which the present invention is applied will be described below with reference to the drawings. However, the present invention is not limited to the following embodiments. Moreover, this invention shall include what combined the following content freely.

  FIG. 1A to FIG. 8 are diagrams for explaining a data recording apparatus (data log apparatus) according to an embodiment to which the present invention is applied.

(1) Configuration of Data Recording Device FIG. 1A is a functional block diagram of the data recording device 1 according to the present embodiment. FIG. 1B is a schematic diagram of a nonvolatile memory 10 applicable to this embodiment. Hereinafter, the configuration of the data recording apparatus 1 will be described with reference to FIGS. 1 (A) and 1 (B).

  The data recording apparatus 1 according to the present embodiment includes a nonvolatile memory 10 as shown in FIGS. 1 (A) and 1 (B). Here, the non-volatile memory is a storage device in which stored information is not lost even when the power is turned off, that is, a storage device that does not need to supply energy for holding information from the outside. If the nonvolatile memory is used, the acquired information can be held even when the power supply from the data recording apparatus 1 is stopped. The nonvolatile memory can be realized using, for example, a capacitor to which electrical hysteresis is applied.

  In the data recording apparatus 1 according to the present embodiment, a ferroelectric memory (FeRAM) may be used as the nonvolatile memory 10. That is, the nonvolatile memory 10 may have a structure including a capacitor having a ferroelectric substance (ferroelectric capacitor). The ferroelectric substance applicable to the ferroelectric capacitor is not particularly limited. For example, a PZT ferroelectric material made of an oxide containing Pb, Zr, and Ti as constituent elements may be used. Good. Alternatively, any material such as SBT, BST, BIT, or BLT may be applied as the ferroelectric substance. The ferroelectric capacitor may have a structure including a counter electrode and a ferroelectric substance provided between the counter electrodes.

  As shown in FIG. 1B, the nonvolatile memory 10 is divided into a plurality of storage areas. In the example shown in FIG. 1B, the nonvolatile memory 10 is divided into two storage areas, a first storage area 11 and a second storage area 12. However, in the present invention, the nonvolatile memory 10 may be divided into three or more storage areas. In the present invention, the nonvolatile memory 10 may include a dedicated storage area 13.

  The data recording apparatus 1 according to the present embodiment includes a write control unit 20. The write control unit 20 controls the writing operation (processing) of measurement data to the nonvolatile memory 10. The write control unit 20 designates an address for writing measurement data in the nonvolatile memory 10 and performs a data write operation to the nonvolatile memory 10. For example, the write control unit 20 may include a write address specifying unit 25 that specifies the write address of the nonvolatile memory 10. Then, the write control unit 20 writes the measurement data at the address specified by the write address specifying unit 25. The address generation procedure of the write address specifying unit 25 is not particularly limited. For example, the next write address is generated by adding (incrementing) the data size of the measurement data to the current write address. Also good.

  The write control unit 20 sequentially writes a predetermined number (N) of measurement data of one block to a given storage area (hereinafter referred to as “first storage area 11”) of the nonvolatile memory 10, and thereafter The control data is sequentially written in the storage area (hereinafter referred to as “second storage area 12”). For example, the write address designating unit 25 sequentially designates the address of the first storage area 11 and writes N data, and then designates the address of the second storage area 12 sequentially. This can be realized by performing a process of writing individual data. At this time, the write address specifying unit 25 may sequentially specify the addresses of the first and second storage areas 11 and 12 from the higher address to the lower address. When the nonvolatile memory 10 is divided into two storage areas, the write address specification unit 25 specifies the address of the second storage area 12 after specifying the address of the first storage area 11, and then Then, the address of the first storage area 11 is designated again. When the nonvolatile memory 10 has M storage areas (M is an integer of 3 or more), the write address designating unit 25 sequentially designates from the address of the first storage area to the address of the Mth storage area, and stores the Mth memory. After writing N data in the area, the address of the first storage area is designated again.

  Further, the write control unit 20 performs control so that at least one measurement data of each block sequentially written in the first storage area 11 or the second storage area 12 is sequentially written in the dedicated storage area 13 of the nonvolatile memory 10. May be. For example, the write control unit 20 may perform control so that only the first measurement data of each block is sequentially written in the dedicated storage area 13. For example, this control is performed only when the top data is written when the write address designating unit 25 sequentially designates the addresses of the first storage area 11 or the second storage area 12 and writes N data. Further, it can be realized by performing a process of writing the leading data in the dedicated storage area 13. At this time, the write address designating unit 25 may sequentially designate the address of the dedicated storage area 13 from the upper address to the lower address.

  The data recording apparatus 1 according to the present embodiment may include an order specifying data generation unit 30. The order specifying data generation unit 30 may be included in the write control unit 20 as shown in FIG. The order specifying data generation unit 30 generates order specifying data for specifying the order in which each block is assigned to each block written in the nonvolatile memory 10. The order specifying data generation unit 30 may generate the order specifying data by incrementing a counter each time measurement data for one block is written in one storage area. Then, the write control unit 20 may perform control to write the order specifying data to the next address of the storage area after writing the measurement data for one block in one storage area. After writing the order specifying data, control for writing each block of measurement data from the next address of the storage area may be performed.

  The data recording apparatus 1 according to the present embodiment may include a write stop processing unit 35. The write stop processing unit 35 may be included in the write control unit 20 as shown in FIG. The write stop processing unit 35 stops writing measurement data to the nonvolatile memory 10. The write stop processing unit 35 determines whether the measurement data satisfies a predetermined write stop condition, and stops writing data to the nonvolatile memory 10 when the write stop condition is satisfied. The write stop processing unit 35 may stop the write operation immediately after obtaining data that satisfies the write stop condition. Alternatively, the write stop processing unit 35 may stop writing data after a predetermined time has elapsed after acquiring data that satisfies the write stop condition.

  The data recording apparatus 1 may include a detection unit that detects that the storage capacity of the unused area for each storage area has fallen below a predetermined value. At this time, the write address designating unit 25 may control the designated address based on the detection signal from the detection unit. The data recording apparatus 1 may also include a writing number measuring unit that measures the number of data writing (rewriting) for each address. In addition, the data recording apparatus 1 may use the nonvolatile memory 10 (first and second storage areas 11 and 12) in a circulating manner as a ring buffer.

  Next, a specific apparatus configuration of the data recording apparatus 1 according to the present embodiment will be described. FIG. 2 is a block diagram showing an example of a specific device configuration of the data recording device 1.

  The data recording apparatus 1 has a CPU 100. The CPU 100 controls the operation of the data recording device 1. For example, the CPU 100 determines a write address of the FeRAM 110 (a ferroelectric memory as an example of the nonvolatile memory 10), sequentially designates the write address, and causes measurement data to be written to the designated write address. That is, the CPU 100 may function as the write control unit 20. Further, the CPU 100 may control the operation of the measuring device and set the data measurement interval (measurement data acquisition interval). The FeRAM 110 functions as the nonvolatile memory 10.

  The CPU 100 may control the operation of the data recording device 1 based on a control program read from the ROM 120. The CPU 100 may also control the operation of the data recording device 1 based on the measurement parameters stored in the RAM 130. Here, the measurement parameter may be, for example, information that is keyed and stored in the RAM 130. The function of the RAM 130 may be realized by a rewritable ROM such as an EEPROM or an FeRAM.

  In the data recording device 1, the CPU 100, the FeRAM 110, the ROM 120, the RAM 130, and the I / O may be configured as one integrated circuit device (for example, a semiconductor chip). Then, the data recording apparatus 1 may perform control for controlling the measuring device and generating display image data for displaying an image on the display by the integrated circuit device.

(2) Operation of Data Recording Device 1 Hereinafter, the operation of the data recording device 1 according to the present embodiment will be described. FIG. 3 is a flowchart for explaining the operation of the data recording apparatus 1.

  First, an initial value is set (step S10). Here, the initial value is, for example, an interval for measuring data (measurement data acquisition interval), a range for determining the measurement data to be normal (upper and lower limit values), or the number of measurement data in one block N Value, initial address, and the like. These initial values may be stored in the RAM 130. These initial values may be set according to the measurement object.

  Then, the address of the given storage area is designated by the write address designation unit 25, and the process of writing the measurement data to the designated address is repeated, thereby writing N data of one block in the given storage area ( Step S12).

  Then, the order specifying data generating unit 30 generates the order specifying data assigned to the one block, and writes the order specifying data to the address of the storage area specified by the write address specifying unit 25 (step S14).

  Then, the storage area to which data is written is changed (selected) (step S16), and the write start address (start address) of the new storage area is set (step S18).

  Then, the write address designating unit 25 designates an address from the write start address, and repeats the procedure of writing N measurement data of one block (step S12).

  FIG. 4 is a flowchart for explaining the operation of the data recording apparatus 1, particularly the procedure for determining the write start address of a new storage area (step S18). Here, a case where the first storage area 11 is selected as a new storage area will be described as an example. 5A to 5C are schematic diagrams showing how data is written to the nonvolatile memory 10 in the data recording device 1. FIG.

  First, among the blocks written in the first storage area 11, the N pieces of data of the last written block (hereinafter referred to as “first block data D1”) and the data D1 of the first block are stored. Next, it is determined whether or not all the N pieces of measurement data of the acquired block (hereinafter referred to as “second block data D2”) are data within a predetermined range (step S20). . The data D2 of the second block may be N pieces of data of the last written block among the measurement data written in the second storage area 12. However, the data D2 of the second block may be N pieces of data before being written in the storage unit 10 (second storage area 12).

  Here, the “predetermined range of values” is a threshold value that defines at least one of an upper limit value and a lower limit value for determining whether or not the measurement data indicates the occurrence of an event. That is, when the value of the measurement data is a value within a predetermined range, the measurement data indicates that the measurement target is normal. On the contrary, when the value of the measurement data is outside the predetermined range, the measurement data indicates that an abnormality has occurred in the measurement target. This “predetermined range of values” may be a value determined in advance based on the measurement target, for example. Alternatively, the “predetermined range of values” may be a value set based on measurement data. For example, a value in a predetermined range may be set in comparison with the data measured immediately before.

  The data D1 and D2 of the first and second blocks are the newest N pieces of data (N pieces of data written last) among the data written in the first and second storage areas 11 and 12. It may be. Further, the data D1 and D2 of the first and second blocks may be N pieces of measurement data obtained continuously.

  For example, as shown in FIG. 5A, the data D1 and D2 of the first and second blocks are N pieces of measurement data sequentially written from the addresses A11 and A21 of the first and second storage areas 11 and 12, respectively. It may be. Further, for example, the order specifying data ID1 and ID2 assigned to the data D1 and D2 of the first and second blocks, respectively, are the addresses next to the last address where the data D1 and D2 are written (FIG. 5 (A ) May be written at addresses A12 and A22), respectively.

  When the data D1 and D2 of the first and second blocks are all data within a predetermined range (Yes in step S20), the write control unit 20 determines that the data D1 of the first block and A write start address is set so that the order specifying data ID1 is overwritten (step S22), and new block data is written to the first storage area 11 (step S12). For example, the write address designating unit 25 may designate the head address (address A11 in FIG. 5B) where the data D1 of the first block is written as the write start address. In this case, as shown in FIG. 5B, the data D1 written to the addresses below the address A11 is overwritten and erased by the newly acquired data D3. Further, the order specifying data ID1 written in the address next to the last address in which the data D1 is written (address A12 in FIG. 5B) is overwritten by the order specifying data ID3 assigned to the data D3. Will be erased.

  Conversely, when at least one of the data D1 and D2 of the first and second blocks includes data having a value outside the predetermined range (No in step S20), the write control unit 20 determines that the data of the first block A write start address is set so that D1 and the order specifying data ID1 are not overwritten (step S24), and new block data is written to the first storage area 11 (step S12). For example, the write address designation unit may designate an address (address A13 in FIG. 5C) after the address where the data D1 and the order specifying data ID1 of the first block are written as the write start address. In this case, as shown in FIG. 5C, the new data D3 and the order specifying data ID3 are written avoiding the first block data D1 and the order tech data ID1, so the first block data D1 and the order The specific data ID1 is stored without being erased.

  In the present invention, in the procedure for determining the write start address of the new storage area (step S18), the data is acquired not only in the first and second block data D1 and D2 but also before the first block data D1. The write start address may be determined based on the data D0 of the 0th block. The procedure for determining the write start address in this case will be described with reference to FIG.

  First, whether or not the data D1 and D2 of the first and second blocks are values within a predetermined range, and the data D0 of the 0th block acquired before the data D1 of the first block is within a predetermined range. It is determined whether the value is within the range (step S25).

  Write control when the data D1 and D2 of the first and second blocks are values within a predetermined range and the data D0 of the 0th block is a value within the predetermined range (Yes in step S25) The unit 20 designates the write start address so that the data D1 and the order specifying data ID1 of the first block are overwritten (step S22), and the measurement data of the new block and the new block are allocated to the first storage area 11. The sequence specifying data is written (steps S12 and S14).

  Conversely, when at least one of the data D1 and D2 of the first and second blocks includes data outside the predetermined range, or when the data D0 of the 0th block includes data outside the predetermined range (in step S25) In the case of No), the write control unit 20 designates a write start address so that the data D1 and the order specifying data ID1 of the first block are not overwritten (step S24), and the new block data and the relevant data are stored in the first storage area 11 The order specifying data assigned to the new block is written (steps S12 and S14).

  According to this, when the data D0 of the 0th block acquired immediately before the data D1 of the first block includes data indicating the occurrence of an event, the values of the data D1 and D2 of the first and second blocks are set. Regardless, the data D1 of the first block and the order specifying data ID1 are stored. Therefore, according to this data recording apparatus, it is possible to store data for a predetermined period after an event occurs.

  That is, according to the data recording device of the present invention, since at least N data acquired before the event occurrence and at least N data obtained after the event occurrence can be stored, before and after the event occurrence Data changes can be analyzed.

  Specifically, in the present invention, as described above, data is divided into N pieces (taken as blocks), and each is handled as one unit. Therefore, data at the time of event occurrence is also included in any block. That is, the data at the time of event occurrence is written at any position from the beginning to the end of one block. For example, when the data at the time of event occurrence is written as the head data of one block, if the data of the block before the relevant block is saved, N data before the time of event occurrence can be saved. . Conversely, if the data at the time of event occurrence is written as the end data of one block, if the data of the block after the block is saved, N data after the event occurrence time can be saved. it can. In other words, if N data (data of one block) including data at the time of event occurrence and data of blocks before and after the data are stored, where the data at the time of event occurrence is written in one block However, since data at the time of event occurrence, at least N data before and at least N data after that can be stored, it is possible to analyze data changes before and after the event occurrence.

  On the other hand, if an event does not occur, the N data and order specifying data of one block temporarily stored are sequentially overwritten by the newly acquired N data and order specifying data of one block. Since it is deleted, only the data before and after the event can be saved. Therefore, even before a memory having a small storage capacity, data before and after the occurrence of an event can be efficiently left. That is, the data recording apparatus according to the present invention can be used as an event recorder.

Further, in the present invention, in the procedure for determining the write start address of a new storage area (step S18), if the data D1 of the first block includes data that satisfies a predetermined condition (acquisition condition), this first One block of data D1 may be determined as data to be stored. For example, when the data D1 of the first block includes data acquired at a predetermined interval wider than the measurement data acquisition interval (measurement interval), the data D1 of the first block should be stored It may be determined as data. According to this, even when an event does not occur, measurement data is periodically saved, so that it can be confirmed that the data recording device is operating normally. Alternatively, the data D1 of the first block may be determined as data to be stored when the usage amount of the addresses in the first and second storage areas 11 and 12 becomes large. According to this, it is possible to adjust the difference in the memory usage area.
Note that when the measurement data for the first block after the start of measurement is not data to be saved, there will be no data to be overwritten even if the data is overwritten in the next cycle. is necessary. For example, data for one block may be left for the first time.

  On the other hand, the data recording apparatus according to the present invention may store at least one of the N pieces of data in one block in the dedicated storage area of the nonvolatile memory regardless of whether or not an event has occurred. Hereinafter, data saved in the dedicated storage area in this way is referred to as general data. For example, a procedure for storing at least one of N pieces of data as general data in the writing process of N pieces of data of one block shown in step S12 of FIG. 3 will be described with reference to FIG.

  First, the address of a given storage area is designated by the write address designation unit 25, and new measurement data is written to the designated address (step S30).

  Then, the write address designating unit 25 updates the write address for writing the next measurement data (step S32). The updated write address is designated as a write address by the write address designation unit 25 when new measurement data is written in step S30.

  Then, it is determined whether or not the condition for saving the measurement data written in the given storage area in step S30 as general data is satisfied (step S34). If the condition is not satisfied (No in step S34), the general data writing process (steps S36 and S38) is not performed and the process proceeds to the next procedure (step S40). If the condition is satisfied (Yes in step S34), the measurement data is written to the address of the dedicated storage area designated by the write address designation unit 25 and stored as general data (step S36). For example, the measurement data at the head of one block may always be stored as general data.

  Then, the write address designating unit 25 updates the write address for writing the next general data (step S38). The updated write address is designated as a write address by the write address designation unit 25 when new general data is written in step S36.

  Then, it is determined whether or not the writing of N pieces of measurement data has been completed (step S40). If the measurement data has not been completed (No in step S40), the processes of steps S30 to S38 are repeated. When the writing of the N pieces of measurement data is completed (Yes in step S40), the writing process for the given storage area is ended.

  Next, an algorithm for realizing this data recording apparatus will be described with reference to FIG.

  First, an initial value is input (steps S50 and S52). In step S50, the value of N that is the number of measurement data for one block, the measurement data interval Tint, the start addresses XX and YY in the first and second storage areas, and the start address ZZ in the dedicated storage area Are specified respectively. In step S52, an initial value of the flag is set.

  Then, the storage area for writing data is selected (step S54). In the present embodiment, for example, the first storage area 11 may be selected when FLG1 = 0, and the second storage area 12 may be selected when FLG1 ≠ 0.

  The procedure of the process when the first storage area 11 is selected (when FLG1 = 0) and the process when the second storage area 12 is selected (when FLG1 ≠ 0) are the same. The processing procedure when the first storage area 11 is selected (when FLG1 = 0) will be described as an example.

  When FLG1 = 0 in step S54 (when the first storage area 11 is selected), the order specifying data N2 is first updated (step S56). Note that the order specifying data N2 may be data that can be assigned to each block and specify the order in which each block is acquired. In the present embodiment, every time the acquired block is updated (N The order specifying data N2 is incremented by 1 (N2 = N2 + 1) and updated every time one piece of measurement data is acquired.

  Then, the write start address of the selected storage area is determined (step S58, step S60). In this example, when FLG3 = 0 and FLG5 = 0 (in the case of Yes in step S58), a process of incrementing the address by N + 1 is performed in order to overwrite N measurement data and order specifying data of one block (step S58). S60 (corresponding to step S22)). If at least one of FLG3 and FLG5 is not 0 (No in step S58), the process of incrementing the address is not performed and the process proceeds to the next procedure (corresponding to step S24).

  Then, a flag delivery process is performed (step S62), and a data writing (recording) process is performed (steps S64 to S84).

  In the data write process, first, a write address and a counter value are set (step S64). Then, data is measured (step S66), and it is determined whether or not the value of the measurement data is within a predetermined range (step S68).

  When the measured data value is outside the predetermined range (Yes in step S68), the flag value is set (step S70), and the data writing process is performed (step S72). In the present embodiment, the write addresses of the first and second storage areas are set by the flag set in step S70, and overwriting of data is restricted (see steps S58 to S62).

  If the value of the measurement data is within a predetermined range (No in step S68), the data writing process is performed without changing the flag value (step S72).

  Then, it is determined whether or not the current measurement data is the first measurement data of one block (n = 2) (step S74). If the measurement data is the first measurement data (Yes in step S74), the measurement data is stored as general data (steps S76 and S78). If the measurement data is not the first measurement data (No in step S74). The process proceeds to the next procedure (step S80).

  The first measurement data is written at the address ZZ in the dedicated storage area 13 and stored as general data (step S76). Further, the order specifying data assigned to the current block is written and stored at the next address (ZZ + 1) in the dedicated storage area 13 (step S78). Here, the order specifying data is saved when the saved data is read and analyzed, the block including the general data saved in the dedicated storage area 13, and the first storage area 11 or the second storage area. This is because it is easy to specify the order in which the blocks including the data stored in 12 are acquired.

  In the present embodiment, the order specifying data N2 is numerical data obtained by counting up in step S56 and may be indistinguishable from measurement data. Therefore, the order specifying data N2 may be distinguished from measurement data. It is converted into a possible separation flag (F (N2)) and stored. The delimiter flag (F (N2)) may be considered as order specifying data.

  Then, predetermined data (tail delimiter data) for specifying the address at which the measurement data was written last is written to the address next to the address at which the measurement data was written in step S72 (step S80). For example, even during the recording of measurement data in steps S64 to S84 (for example, during a waiting time Tint in step S82 described later), the data recording device reaches the end of its life and ends the measurement data writing process. Since the end delimiter data remains, the last written measurement data can be specified. In the present embodiment, the end delimiter data is overwritten and erased by writing the measurement data in step S72 of the next cycle until the number of measurement data reaches N. Further, after the number of measurement data reaches N, the end delimiter data is overwritten and erased by writing the last delimiter data in step S90 described later. Therefore, the necessary storage capacity of the first storage area 11 is not increased by the tail delimiter data.

  Then, after the waiting time Tint has elapsed (step S82), it is determined whether or not N data of one block has been written in the first storage area 11 (step S58), and until N data has been written. The data writing process (steps S64 to S84) is repeated. The reason for waiting for the elapse of the waiting time Tint is to control the time interval until the next measurement.

  When N pieces of data are written in the first storage area 11, the write address of the first storage area 11 is counted up, an input address of the order specifying data (separation flag) is set, and the write address of the dedicated storage area 13 is set. Count up to set the write address of the next general data (step S86). Here, by setting ZZ = ZZ + 2, not only each general data but also each order specifying data (separation flag) assigned to each block including each general data is left in the dedicated storage area 13. Yes. In this way, the time relationship between the general data remaining in the dedicated storage area 13 and the data stored in block units in the first storage area 11 or the second storage area 12 can be easily organized.

  Then, the order specifying data assigned to the current block is written and stored in the address XX after increment (XX = XX + 1) in step S86 (step S88). Here, the order specifying data is saved when the stored data is read and analyzed, and the order in which each block including each N pieces of data saved in the first storage area 11 is acquired and saved. This is because the number of blocks acquired between each block is specified.

  Then, in step S88, predetermined data for specifying the address at which N measurement data of one block was written last is added to the address next to the address where the order specifying data (separation flag) is written. ) Is written (step S90). In the present embodiment, the tail end delimiter data is overwritten and erased in step S72 by the first measurement data of new N measurement data to be written next. Therefore, the necessary storage capacity of the first storage area 11 does not increase due to the last segment data.

  Then, the value of FLG1 is set to 1 (step S92), the second storage area 12 is selected (step S54), and the same processing is repeated.

  In the present embodiment, when data is written in all of the storage areas of the first storage area 11 or the second storage area 12, subsequent data storage may not be performed. In this case, the data at the time of the first event occurrence after the start of data recording can be prevented from being overwritten. Further, both the first storage area 11 and the second storage area 12 are configured as ring buffers, and when data is written in all of the storage areas, new data is started in order from the oldest data (in order from the data stored at the head address). May be overwritten and erased. In this case, the data at the time of the last event occurring immediately before the end of data recording can be prevented from being overwritten.

  On the other hand, since the dedicated storage area 13 for storing general data is periodically written, it is preferably configured as a ring buffer and used while being overwritten and erased in order from the old data.

  In the present embodiment, as described above, the write address may be set by setting a flag. According to this, since it becomes possible to set the write address by exchanging data with a small size, it is possible to provide a data recording apparatus with a small data processing load and a small circuit scale.

(3) Effect The data recording apparatus according to the present embodiment is configured as described above. According to this data recording apparatus, it is possible to provide a data recording apparatus that can efficiently use the storage area. Hereinafter, the effect will be described.

  As described above, in the data recording apparatus 1, N pieces of measurement data (first block data D1) written in the first storage area 11 and N pieces of measurement data (second data) acquired thereafter are stored. The necessity of the data D1 of the first block is determined based on the block data D2). That is, in this data recording apparatus, it is determined using the measurement data (second block data D2) acquired thereafter whether or not N pieces of measurement data (first block data D1) are to be stored. . That is, according to this data recording apparatus, whether or not N pieces of measurement data need to be stored is determined after a predetermined time has elapsed after the N pieces of measurement data have been acquired (written to the storage unit). The N pieces of measurement data are held until it is determined whether or not storage is necessary. Therefore, when measurement data indicating the occurrence of an event is acquired, data before the occurrence of the event can be automatically saved.

  For example, when the data D2 of the second block includes data indicating the occurrence of an event (data having a value outside a predetermined range), the data D2 of the second block and N measurements acquired immediately before the data D2 By storing the data (measurement data D1 of the first block), even if data indicating event occurrence is arranged at any position from the beginning to the end of the data D2 of the second block, At least N data can be automatically saved.

  In the data recording apparatus 1, after N pieces of measurement data are written in the first storage area 11, N pieces of measurement data are written in the second storage area 12. Then, after determining whether it is necessary to save the N pieces of measurement data (first block data D1) written in the first storage area 11, the write address of the first storage area 11 is designated. That is, according to the data recording apparatus 1, before writing new data to the first storage area 11, the data D1 of the first block (N pieces of data acquired the most recently among the data written to the first storage area 11). Data) can be determined.

  Then, based on whether or not the N pieces of measurement data are necessary, it is determined whether the data D1 of the first block is to be overwritten (overwritten and erased) or stored without being overwritten. Specifically, if the address after the address where the first block data D1 is written is designated as the new data write address, the first block data D1 can be stored. On the contrary, if the first address where the data D1 of the first block is written is designated as the write address of the new data, the data D1 of the first block is overwritten and erased. Therefore, it is possible to provide a data recording apparatus that can use the address of the first storage area 11 from the upper level without any gap while determining whether or not the data D1 of the first block is necessary.

  Further, in this data recording apparatus, when the N pieces of data (first block data D1 or second block data D2) written in the first storage area or the second storage area are data that do not need to be saved The write address designating unit may store the head data of the first block data D1 and the head data of the second block data D2 in the dedicated storage area. According to this, regardless of the occurrence of an event, the top data (data acquired at a predetermined interval longer than the measurement data acquisition interval) is stored in the dedicated storage area, so long-term data fluctuations are prevented. It becomes possible to confirm. Here, the head data is data acquired at a time interval (N × Tint interval) wider than the measurement data acquisition interval, and even if the data is stored, the capacity of the stored data does not increase greatly. . Therefore, measurement data can be recorded for a long time without using a memory with a large capacity. Note that the head data referred to here may be one piece of data or a plurality of pieces of data. Furthermore, the data stored in the dedicated storage area 13 is not limited to the top data, and may be any one or a plurality of data respectively included in the first block data D1 and the second block data D2.

  Here, in order to save the measurement data immediately before the event occurrence, it is essential to temporarily save the measurement data of the block before the event occurs. Due to the occurrence of an event, for example, the power supply to the data recording device 1 may stop, so it is important to save the measurement data in a nonvolatile memory. Furthermore, in order not to increase the storage capacity of the non-volatile memory, it is desirable to temporarily store the measurement data immediately before the occurrence of the event, and overwrite and delete the measurement data when the event does not occur. That is, it is important that the nonvolatile memory can be frequently rewritten and has no limit on the number of rewrites (the upper limit of the number of rewrites is so large that it is substantially unnecessary to consider the limit on the number of rewrites). For example, an EEPROM or flash memory which is a nonvolatile memory has a limited number of rewrites, and is not necessarily an optimal memory when the data recording apparatus 1 is used for an application in which data rewrite occurs frequently. In such a case, it is preferable to configure the non-volatile memory with FeRAM that does not need to substantially consider the limit of the number of rewrites.

  In addition, when the data recording device 1 is used, for example, in an active RF tag having a battery for memory retention or transmission, it is important that the nonvolatile memory consumes less power when data is rewritten. FeRAM consumes very little power when data is rewritten. In such a case, it is preferable to form a nonvolatile memory using FeRAM.

  That is, by configuring the nonvolatile memory of the data recording apparatus 1 with FeRAM, a data recording apparatus having high performance and a long product life can be provided.

  In addition, the conventional data recording apparatus stores and transmits a large amount of measurement data, selects necessary data from the measurement data received on the host side, and performs data analysis. However, the data recording apparatus 1 performs measurement internally. Data can be selected and only necessary data can be automatically saved and transmitted. Therefore, the data recording device 1 can greatly reduce the memory capacity for storing the measurement data. Further, since the data recording apparatus 1 can reduce the amount of data to be transmitted, the power consumption during data transmission can be greatly reduced. Therefore, if the data recording apparatus 1 is used, for example, an active type RF tag that satisfies the demands for miniaturization and low power consumption can be realized.

  In addition, since only the data before and after the event occurrence acquired at a relatively short time interval is stored in the plurality of storage areas of the nonvolatile memory, the data recording apparatus 1 can be used as an event recorder. In other words, by analyzing the data stored in the plurality of storage areas, it is possible to determine the presence / absence of an event and the detailed situation when the event occurs.

  In addition, since data acquired periodically at a relatively long time interval is stored in the dedicated storage area of the non-volatile memory, the data recording apparatus 1 uses data for analyzing the long-term data fluctuation situation. It can be used as a recording device.

  Further, when the data recording device 1 has a plurality of storage areas and dedicated storage areas, the data acquired before and after the occurrence of the event stored in the plurality of storage areas and the periodic acquisition stored in the dedicated storage area It is possible to perform a more detailed analysis in combination with the obtained data. In the data recording apparatus 1, since the order specifying data is recorded in these storage areas in association with the respective blocks, the order in which the stored data is acquired can be easily specified.

  In addition, this invention is not limited to the above-mentioned embodiment, A various deformation | transformation is possible.

  For example, according to the flowchart of FIG. 8, the measurement data at the head of the block stored in the first storage area 11 or the second storage area 12 is also stored in the dedicated storage area as general data. It may not be saved. For example, in step S72, when n = 2, the first storage area 11 may not be saved.

  Further, in the flowchart of FIG. 8, the order specifying data (separation flag) assigned to the block including the last written general data is left in the dedicated storage area 13. However, the present invention is not limited to this. For example, by changing ZZ = ZZ + 2 in step S86 to ZZ = ZZ + 1, the write address of the next general data is set to the address where the order specifying data (separation flag) is written in step S78. It may be. That is, the order specifying data (separation flag) written in the dedicated storage area 13 by the next general data write is overwritten and erased. Therefore, the necessary storage capacity of the dedicated storage area 13 is not increased by the order specifying data (separation flag). As a result of such processing, only the order specifying data (separation flag) assigned to the block including the last written general data remains in the dedicated storage area 13. However, since one data is regularly stored as general data for each block, if only the last order specifying data (separation flag) remains, each general data stored in the dedicated storage area 13 is stored. It is possible to specify the order in which each block included and each block including each N pieces of data stored in the first storage area 11 or the second storage area 12 are acquired.

  In the flowchart of FIG. 8, only the block in which the event has occurred and the blocks before and after the event are stored. However, the number of data in one block is reduced, the block in which the event has occurred, Alternatively, a plurality of blocks after the event occurrence may be stored. If the number of data in one block is reduced and multiple blocks before and after the event occur are saved, this is unnecessary compared to the case where the number of data in one block is increased and each block before and after the event occurs is saved. There is no need to store data, and the memory can be used efficiently. For example, in order to securely store N measurement data before and after the occurrence of an event, if one block is composed of N measurement data, the block includes the block where the event has occurred and one block before and after the occurrence of the event, that is, three blocks. 3N pieces of data must be stored. On the other hand, if one block is composed of N / 2 pieces of measurement data, 2.5N data over a block where an event has occurred and two blocks before and after the event, that is, five blocks may be stored.

  The present invention includes configurations that are substantially the same as the configurations described in the embodiments (for example, configurations that have the same functions, methods, and results, or configurations that have the same objects and effects). In addition, the invention includes a configuration in which a non-essential part of the configuration described in the embodiment is replaced. In addition, the present invention includes a configuration that exhibits the same operational effects as the configuration described in the embodiment or a configuration that can achieve the same object. Further, the invention includes a configuration in which a known technique is added to the configuration described in the embodiment.

The figure for demonstrating the structure of a data recording device. 1 is a block diagram of a data recording device. The flowchart for demonstrating operation | movement of a data recording device. The flowchart for demonstrating operation | movement of a data recording device. The schematic diagram which shows a mode that data are written in a non-volatile memory. The flowchart for demonstrating operation | movement of a data recording device. The flowchart for demonstrating operation | movement of a data recording device. The flowchart for demonstrating operation | movement of a data recording device.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Data recording device, 10 ... Non-volatile memory, 11 ... 1st storage area, 12 ... 2nd storage area, 20 ... Write control part, 25 ... Write address designation part, 30 ... Order specification data generation part, 35 ... Write Stop processing unit, 100 ... CPU, 110 ... FeRAM, 120 ... ROM, 130 ... RAM, D0 ... 0th block data, D1 ... 1st block data, D2 ... 2nd block data, D3 ... 3rd block data

Claims (11)

A data recording device that performs processing of writing a plurality of measurement data received in time series into a memory,
A nonvolatile memory including a plurality of storage areas in which the measurement data is written;
A predetermined number of measurement data as one block, each measurement data for one block is sequentially written in a given storage area of the nonvolatile memory, and then each measurement data for the next one block is stored in another storage area. A write control unit that repeatedly performs a sequential writing process,
The write control unit
In the storage area of the nonvolatile memory in which the measurement data of each block is written, the order specifying data for specifying the order in which each block is allocated and acquired is written in association with each block,
Whether one block last written in a given storage area of the non-volatile memory and the next one block acquired after the one block include measurement data having a value outside a predetermined range. If at least one of them contains, the measurement data for one block last written in the given storage area and the order specifying data assigned to the one block are not overwritten. , Writing each measurement data for one new block and the order specifying data assigned to the one block to the given storage area, and if none of them includes the measurement data and the order specifying data, In order to be overwritten, each measurement data for one new block and the sequence specifying data assigned to the one block are written in the given storage area. Data recording apparatus characterized by writing. In claim 1,
The write control unit
It is determined whether or not one block acquired before the last block written in the given storage area includes measurement data having a value outside the predetermined range. Each measurement data of one block newly written in the given storage area and each of the measurement data of one block written in the storage area and the order specifying data assigned to the block are not overwritten. A data recording apparatus, wherein the order specifying data allocated to one block is written. In claim 2,
The nonvolatile memory is
3n (n is an integer of 1 or more) or more of the storage area,
The write control unit
Each block of measurement data is sequentially written in the k-th (k is an integer between 1 and 3n-1) storage area of the non-volatile memory, and then the next block is measured in the k + 1 storage area. After sequentially writing data and sequentially writing each measurement data for one block in the 3n storage area, the process of sequentially writing each measurement data for the next block in the first storage area is repeatedly performed. A data recording device. In any one of Claims 1 thru | or 3,
The write control unit
A data recording apparatus, wherein the predetermined range is set to a predetermined value in advance. In any one of Claims 1 thru | or 3,
The write control unit
A data recording apparatus characterized in that the predetermined range is set based on measurement data. In any one of Claims 1 thru | or 5,
The write control unit
A write stop process for determining whether or not the measurement data satisfies a predetermined write stop condition and performing control to stop writing data to the nonvolatile memory when the predetermined write stop condition is satisfied A data recording apparatus comprising a section. In any one of Claims 1 thru | or 6.
The data recording apparatus according to claim 1, further comprising a detection unit that detects that the storage capacity of the unused area for each storage area has fallen below a predetermined value. In any one of Claims 1 thru | or 7,
The write control unit
It is determined whether or not each measurement data for one block last written in the given storage area satisfies a predetermined acquisition condition, and when it is satisfied, 1 last written in the given storage area Each measurement data for one block and the order specification assigned to the one block are stored in the given storage area so that each measurement data for the block and the order specification data assigned to the one block are not overwritten. A data recording apparatus for writing data. In any one of Claims 1 thru | or 8.
The write control unit
When the write destination is switched from the other storage area to the given storage area, and each measurement data for one new block and the order specifying data assigned to the one block are written to the given storage area, By designating the highest address of the area corresponding to each measurement data for one block last written in the given storage area and the order specifying data assigned to the one block, the given data Control to overwrite each measurement data for one block last written in the storage area and the order specifying data assigned to the one block,
By designating a lower address than the lowest address of the area corresponding to each measurement data for one block last written in the given storage area and the order specifying data assigned to the one block A data recording apparatus, wherein control is performed so as not to overwrite each measurement data for one block and the order specifying data assigned to the one block. In any one of Claims 1 thru | or 9,
The nonvolatile memory is
A predetermined dedicated storage area not included in the plurality of storage areas;
The write control unit
A data recording apparatus, wherein at least one measurement data of each block sequentially written in a given storage area of the nonvolatile memory is sequentially written in the dedicated storage area of the nonvolatile memory. In any one of Claims 1 thru | or 10.
The data recording apparatus according to claim 1, wherein the nonvolatile memory is a ferroelectric memory.

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