JPH07295894A - Data preservation device - Google Patents

Abstract

PURPOSE:To improve the life of a device by using storage blocks in a data preserving in an averaging manner part. CONSTITUTION:In this data preserving device, on the basis of the last time block information of a used block storage means 10 a last time contents comparing means 3 reads out by the position information of a position information storage means 8 in response to the input of a write command, the contents of every storage block of a RAM 1 and the contents written in each storage block of the data preserving part at the last time are compared, and only when this comparison results in noncoincidence, an unused block writing means 4 writes the contents of the storage block of the RAM 1 in the unused storage block of the data preserving part, and only when write-in is executed, an information generating means 5 generates newly the last time block information and the position information, and a preserved data reading means 6 reads the contents out of each storage block of the data preserving part, and writes them in each storage block of the RAM 1 on the basis of the latest position information and the last time block information and their arrangement in response to the input of a read command.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a data storage device capable of storing data stored in a storage block of a RAM in a storage block of a data storage unit, and particularly uses the storage block in the data storage unit on average. Thus, the present invention relates to a data storage device that can improve the life of the device.

[0002]

2. Description of the Related Art Generally, in order to store operating parameters of equipment, a data storage device having a data storage unit having a writable count (hereinafter referred to as a life) for each storage block, such as an EEPROM, is widely used. Has been.

This type of data storage device normally operates as shown in any of the following (a) to (c). (B) As shown in FIG. 9, at the time of writing, the data in the parameter area (storage block) arranged on the RAM is written as it is in the storage block of the EEPROM. EE when reading
The data in the PROM is read as it is into the parameter area on the RAM. (B) As shown in FIG. 10, at the time of writing, the parameter area arranged on the RAM is compressed by the compression algorithm to E
Write to storage block of EPROM. When reading, EEPR
The data in the OM is expanded by the expansion algorithm and read in the parameter area on the RAM. As a result, the amount of data written is reduced and the writing time is reduced. (C) As shown in FIG. 11, at the time of writing, the parameter area arranged in the RAM is compared with the data in the EEPROM, and only when the data is different, the data is written in the storage block of the EEPROM. When reading, the data in the EEPROM is directly RA
Read to the parameter area on M. As a result, the amount of data written is reduced and the writing time is reduced.

[0004]

However, in the data storage device as described above, since the same memory block in the EEPROM is frequently rewritten in any of (a) to (c), the life cannot be improved. There's a problem. In addition,
The EEPROM has a property that the failure occurrence rate becomes high when writing is executed in excess of a specified guaranteed write count for each storage block.

The present invention has been made in consideration of the above situation, and an object of the present invention is to provide a data storage device which can improve the life of the device by using the storage blocks in the data storage unit evenly.

[0006]

The present invention includes a RAM having a plurality of storage blocks and a data storage unit,
The contents stored in the respective storage blocks of the RAM are stored in the respective storage blocks of the data storage unit on the basis of the input of the write command, and the contents are stored in the respective storage blocks of the data storage unit on the basis of the input of the read command. In a data storage device for extracting the stored contents into each storage block of the RAM, the data storage device has previous block information indicating a storage block provided in the storage block of the data storage unit and having a previous storage content in the data storage unit. Further, the previous block information is provided in the used block storage means arranged corresponding to each storage block of the RAM and the storage block of the data storage unit, and the position information indicating the position of the used block storage means is stored. Position information storage means and the use according to the position information in the position information storage means when the write command is input. The last block information in the lock storage means with reading, on the basis of the previous block information,
Only when the previous content comparison means for comparing the content of each storage block of the RAM with the content previously written in each storage block of the data storage unit and the comparison result by the previous content comparison means do not match, An unused block writing unit that writes the contents of the storage block of the RAM to an unused storage block in the data storage unit based on the previous block information in the used block storage unit, and the unused block writing unit. Only when the writing is executed, the information creating means for newly creating the previous block information and the position information, and when the read command is input, the creating is performed according to the position information created by the information creating means. The previously stored block information is read out, and each storage block of the data storage unit is read based on the previous block information and its arrangement. It reads the contents written by the unused block writing means from a data storage device that includes a stored data reading means for writing the contents of each storage block in the RAM.

[0007]

Therefore, the present invention has the previous block information indicating the storage block provided in the storage block of the data storage unit and having the previous storage contents in the data storage unit by taking the above means, Further, the used block storage means in which the previous block information is arranged corresponding to each storage block of the RAM, and the position information which is provided in the storage block of the data storage unit and stores the position information indicating the position of the used block storage means When the write command is input, the previous content comparison unit reads the previous block information in the used block storage unit according to the position information in the position information storage unit, and based on the previous block information, Then, the content of each storage block of the RAM is compared with the content previously written in each storage block of the data storage unit,
The unused block writing means writes the contents of the storage block of the RAM to the unused storage block in the data storage unit based on the previous block information in the used block storage means only when the comparison result by the previous content comparison means does not match. And the information creating means newly creates the block information and the position information last time only when the writing is executed by the unused block writing means, and the save data reading means inputs the read command. Reading the previous block information created in accordance with the position information created by the information creating means, and using unused block writing means from each storage block of the data storage unit based on the previous block information and its arrangement. Since the written contents are read and the contents are written in each storage block of the RAM, the storage block in the data storage unit By averagely used, it is possible to improve the device life.

[0008]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a functional block diagram showing a configuration of a data storage device according to an embodiment of the present invention, and FIGS. 2 and 3 are diagrams showing a configuration of an EEPROM applied to the data storage device. The data storage device includes a RAM 1, an EEPROM 2 as a data storage unit, a previous content comparison unit 3, an unused block writing unit 4, an information creating unit 5, and a stored data reading unit 6.

Here, the RAM 1 has, for example, eight storage blocks in the parameter area, and data is stored in each of these storage blocks. EEPROM2
2 has 32 storage blocks, for example, as shown in FIGS. 2 and 3, and these storage blocks can be used as data blocks or control blocks.

The control block (CB) 7 has a latest position information area 8 as position information storage means, a used block information area 9 and a block information arrangement area 10 as used block storage means. The latest position information area 8 is an area in which the latest control block flag (latest CB flag) indicating the latest control block or the next control block pointer (next CB pointer) indicating the next control block is set.

The used block information area 9 is an EEPROM.
2 is an area in which a used block flag (previous block information) indicating a memory block having a previous saved content among the 32 memory blocks in 2 is set, and 32 memory blocks are used block flag areas of 4 rows and 8 columns. It corresponds to and is shown. For example, in FIG. 3, the first row and first column is EEPR.
The 0th storage block in the OM, the 1st row and 2nd column sequentially correspond to the 1st storage block, and the 4th row and 8th column show the 31st storage block. It should be noted that in FIG. 3, the used block flags are set in the 1st row, 2nd column, 1st row, 6th column, 2nd row, 1st column, and 2nd row, 2nd column, and the storage block having the previously saved contents is No. 1,
It indicates that the blocks are the fifth, eighth, and ninth storage blocks.

The block information arrangement area 10 is EEPRO.
This is an area in which a data block pointer (previous block information) indicating a storage block having a previous saved content among the 32 storage blocks in M2 is written, and the previous block information is arranged corresponding to each storage block in RAM. Has been done. For example, the first line in FIG. 3 is 0 in RAM1.
No. 7 storage block, and the 8th row corresponds to No. 7 storage block. In FIG. 3, in the data block pointer, the data corresponding to the 0th storage block of RAM 1 is in the 1st storage block of EEPROM 2, and RA
The data corresponding to the second storage block of M1 is EEPR
It indicates that the data in the fifth storage block of OM2 and the data corresponding to the third storage block of RAM1 are in the ninth storage block of EEPROM2. In the second line,
"0" s in the 4th to 8th lines are the 1st and 4th of the RAM1.
This indicates that the 7th storage block has no data.

On the other hand, when the write command is input, the last time content comparison unit 3 follows the next CB pointer in the latest position information area 8 and the latest CB flag (position information), and the data block pointer in the block information arrangement area 10 And RAM1 based on this data block pointer.
It has a function of comparing the contents of each storage block of 1 with the contents previously written in each storage block of the EEPROM 2.

The unused block writing unit 4 determines, based on the data block pointer in the block information arrangement area 10, only when the result of comparison by the previous content comparing unit 3 does not match.
The contents corresponding to the comparison result in the RAM1 are EEPRO
The data is written in an unused storage block in M2.

The information creating section 5 newly creates a data block pointer, a next CB pointer, and the latest CB flag only when writing is executed by the unused block writing section 4.

When a read command is input, the saved data reading section 6 reads the next CB pointer created by the information creating section 5 and the data block pointer created by the information creating section 5 in accordance with the latest CB flag, and Based on these data block pointers and their placement, E
The contents written by the unused block writing unit 4 are read from each storage block of the EPROM 2, and the contents are stored in the RAM.
1 is written in each storage block.

Next, the operation of the data storage device configured as described above will be described. FIG. 4 is a data flow diagram for explaining the operation of the data storage device. The device of this embodiment is, for example, an EEPROM 2 having data d1 and d3.
Data space d1 to d4 and memory space without data All 0
When writing the contents of the RAM1 having the data, the data d2 and d4 which are not in the EEPROM2 are written in the unused storage blocks in the EEPROM2, and the number of the written storage block and the numbers of the storage blocks of the already existing data d1 and d3 are written. By writing the arrangement of the memory space and the memory space All 0 in the latest control block CB3, the EEPROM2
The storage blocks are used on average and the writing speed is improved.

At the time of reading, the data can be read by referring to the block information arrangement area 10 in the latest control block. next,
The write operation will be described in detail with reference to FIG. 5, and then the read operation will be described with reference to FIG.

The previous content comparing section 3 reads the control block written in the 0th storage block indicated by the head address of the EEPROM 2, and at the same time, reads the next CB pointer from the latest position information area 8 in the control block 7. Then, the control block 7 written in the memory block indicated by the CB pointer is read. Similarly, when the latest position information area 8 is referred to, the last written control block 7 having the latest CB flag is searched in the latest position information area 8 (ST
1).

Further, the last time content comparison unit 3 performs step ST
At the same time as the search by 1, the storage block used for the control block 7 is checked from the block information arrangement area 10 of the control block being referred to, and the used block flag indicating this storage block is set in the used block information area 9 (ST2).

When the last time content comparing section 3 reads the control block 7 written last time as a result of steps ST1 and ST2, the block information arrangement area 10 of this control block 7 is referred to and the memory used last time is read. A storage block having a number next to the storage block having the largest number is reserved as an unused block for use as the control block 7 for current writing (ST3).

Next, the previous content comparison unit 3 sequentially determines for each storage block of the RAM 1 (ST4) and determines the presence / absence of write data (ST5). When the determination result indicates that there is no data, the current control is performed. A flag of "0" is arranged in the corresponding line of the block information arrangement area 10 in the block 7 (S
T6) When the result of the determination shows that there is data, the contents of the storage block of the RAM 1 are compared with the contents written last time (ST7), and the comparison result is given to the unused block writing unit 4.

The unused block writing section 4 executes the step ST.
As a result of the judgment in 7, when both contents match, writing is omitted and the process proceeds to step ST12. When both contents do not match, it is judged whether or not there is an unused storage block (ST8).
When there is an unused block, the process proceeds to step ST10 for writing, and when there is no unused block, EEP
The latest CB flag “0” is set in the latest position information area 8 of the first storage block of the ROM 2, and the control block 7 other than the used block flag in the control block 7 currently written and previously written is left. Clear the used block flag in (ST9), EEPROM2
Reserve an unused storage block in it.

After that, the unused block writing unit 4 makes R
The contents of the storage block of AM1 are written to an unused storage block in the EEPROM 2 (ST10), and it is judged whether this writing has succeeded or failed (ST11). The process returns to step ST8 in order to write in the used memory block, and when the writing is successful, the information creating unit 5 is notified of the writing completion.

Upon receiving this notification, the information creating section 5 sets the data block pointer indicating the storage block in which the writing has been executed or the storage block having the same content as the writing target in the control block 7 for writing this time. It is written in the block information arrangement area 10 (ST12).

Thereafter, similarly, the processes of steps ST4 to ST12 are executed for each storage block of the RAM 1 (ST13). The information creating section 5 carries out step ST13.
After completion of the above, the control block 7 for writing this time is compared with the control block 7 for which writing was done last time (ST1
4) When the two match, the process is terminated without writing the control block 7, and when the two do not match, the control block 7 for current writing is written and the control for this writing is performed. The next CB pointer indicating the block 7 is written in the latest position information area 8 in the previously written control block 7 (ST15). The information creating unit 5 writes the control block 7 for current writing to another unused storage block when the writing of the control block 7 for current writing fails during execution of step ST15. In addition, the information creating unit 5 writes the next C to the previously written control block 7 during execution of step ST15.
When the writing of the B pointer fails, the CB pointer indicating the control block 7 for writing this time is written in the control block 7 that has been written previously.

Therefore, for example, the EEPROM 2 before writing
However, it is assumed that the 0th storage block is used as the control block 7 as shown in FIG. It should be noted that this EEPROM 2 has the contents of R shown in FIG.
Data is written from AM1.

Subsequently, when the RAM 1 has the contents shown in FIG. 7C, for example, when the writing process is executed as described above, the data D not existing in the EEPROM 2 before the writing is written.
3 is written in the storage block of the EEPROM 2 as shown in FIG. 7 (d).

Next, the read operation of this data storage device will be described. The saved data reading unit 6 is operated by the operator to
When the read command is input, similarly to the above, the control block 7 previously written is searched according to the next CB pointer (ST21).

When the previously written control block 7 is read, the saved data reading unit 6 sequentially determines from the first row of the block information arrangement area 10 in this control block 7 (ST22) whether there is data to be read. Shi (ST
23), when the line indicating that there is no read data by the flag of “0”, clears the corresponding memory block of the RAM 1 (ST24), and when the line indicates that there is read data by the data block pointer, this data The storage block of the EEPROM 2 indicated by the block pointer is read and written in the corresponding storage block of the RAM 1 (S
T25).

Thereafter, similarly, the processes of steps ST22 to ST25 are executed for each row of the block information arrangement area 10 (ST26). As described above, according to the present embodiment, the block information arrangement having the data block pointer indicating the storage block having the previously stored contents in the EEPROM 2 and the data block pointer arranged corresponding to each storage block of the RAM 1 The EEPROM 2 is provided with the latest position information area 8 in which the latest CB flag indicating the position of the area 10 and the control block 7 having this block information arrangement area 10 and the next CB pointer are stored. When entered,
The latest control block 7 is read in accordance with the next CB pointer and the latest CB flag in the latest position information area 8, and the block information arrangement area 10 of this latest control block 7 is referred to, and the contents of each storage block of the RAM 1 are read. The contents previously written in the respective memory blocks of the EEPROM 2 are compared with each other, and the unused block writing unit 4 sets the data block pointer in the block information arrangement area 10 only when the comparison result by the previous contents comparing unit 3 is not matched. Based on the contents of the storage block of RAM1, EEPROM2
Write to unused storage blocks of.

Thereafter, the information creating unit 5 newly creates the block information arrangement area 10, the latest CB flag, and the next CB pointer only when the unused block writing unit 4 writes, and saves data. When the read command is input, the reading unit 6 reads the latest control block 7 according to the newly created latest CB flag and the next CB pointer, and reads the data block pointer from the block information arrangement area 10 of this control block 7. At the same time, the contents written by the unused block writing unit 4 are read from each storage block of the EEPROM 2 based on these data block pointers and their arrangement, and the contents are written into each storage block of the RAM 1.

As described above, the data in the RAM 1 is stored in the EEPR.
Since the written data can be read in the unused storage block of OM2, EEPRO
The storage blocks in M2 can be used on average to improve device life.

For example, FIGS. 8 (e) to 8 (f) show the number of times of writing of the storage block of the EEPROM 2 by the device of this embodiment and the number of times of writing of the memory block by the device as in the conventional devices (a) to (c). It is a figure for comparing and explaining for every memory block. As shown in the figure, in the conventional cases (a) to (c), since only the fourth to the first storage blocks are intensively used, the actual number of times of writing becomes equal to the guaranteed number of times of writing. Since the device of the present embodiment uses each storage block evenly, the actual number of times of writing can be made larger than the guaranteed number of times of writing, and thus the life of the device can be improved.

Further, according to the present embodiment, since the data to be written is only the data which does not exist in the EEPROM 2, it is possible to reduce the number of times of writing and improve the writing speed.
Since the EEPROM 2 has a high read speed and a slow write speed, the write speed can be further improved.

Further, according to this embodiment, step ST
If writing fails in step 8 or step ST15, writing to another storage block is executed, so reliability can be improved.

In the above embodiment, the case where the EEPROM 2 is used as the data storage unit has been described. However, the present invention is not limited to this, and a floppy disk (FD), a hard disk (HD), a magneto-optical disk (MO) and the like can be used. Even if a random access memory device having a writable number for each memory block is used as the data storage unit, the same effects can be obtained by implementing the present invention in the same manner.

Further, in the above embodiment, the case where the unused storage block is secured based on the data block pointer of the block information arrangement area 10 has been described, but the present invention is not limited to this, and the used block flag of the used block information area 9 is described. Even if the unused storage block is secured based on the above, the same effect as the present invention can be obtained. In addition, the present invention can be modified in various ways without departing from the scope of the invention.

[0039]

As described above, according to the present invention, the previous block information indicating the storage block provided in the storage block of the data storage unit and having the previous storage contents in the data storage unit, and Block information is RAM
And a position information storage unit that is provided in the storage block of the data storage unit and that stores position information indicating the position of the used block storage unit. When the write command is input, the content comparison means reads the previous block information in the used block storage means according to the position information in the position information storage means, and based on the previous block information, RA
The content of each storage block of M is compared with the content previously written in each storage block of the data storage unit, and the unused block writing means is used only when the comparison result by the previous content comparison means does not match. Based on the previous block information in the block storage means, the contents of the storage block of the RAM are written in the unused storage block in the data storage unit, and the information creating means executes the writing by the unused block writing means. Only when the previous block information and position information are newly created, when the read command is input by the saved data reading means, the created previous block information is read according to the position information created by the information creating means. With
Based on the previous block information and its arrangement, the contents written by the unused block writing means are read from each storage block of the data storage unit and the contents are written to each storage block of the RAM. It is possible to provide a data storage device that can improve the life of the device by averaging the storage blocks.

[Brief description of drawings]

FIG. 1 is a functional block diagram showing a configuration of a data storage device according to an embodiment of the present invention.

FIG. 2 is a diagram showing a configuration of an EEPROM in the embodiment.

FIG. 3 is a diagram showing a configuration of an EEPROM in the embodiment.

FIG. 4 is a data flow chart for explaining the operation in the embodiment.

FIG. 5 is a flowchart for explaining a write operation in the same embodiment.

FIG. 6 is a flowchart for explaining a read operation in the embodiment.

FIG. 7 is a diagram for explaining a write operation in the embodiment.

FIG. 8 is a comparison diagram of the same embodiment and a conventional one.

FIG. 9 is a diagram showing a data storage method by a conventional data storage device.

FIG. 10 is a diagram showing a data storage method by a conventional data storage device.

FIG. 11 is a diagram showing a data storage method by a conventional data storage device.

[Explanation of symbols]

1 ... RAM, 2 ... EEPROM, 3 ... previous content comparison section,
4 ... Unused block writing unit, 5 ... Information creating unit, 6 ... Saved data reading unit, 7 ... Control block, 8 ... Latest position information area, 9 ... Used block information area, 10 ... Block information arrangement area.

Claims (1)

[Claims] 1. RA having a plurality of storage blocks each other
M and a data storage unit are provided, and the contents stored in the respective storage blocks of the RAM are stored in the respective storage blocks of the data storage unit on the basis of the input of the write command, and the contents are stored on the basis of the input of the read command. A data storage device for extracting the content stored in each storage block of the data storage unit to each storage block of the RAM, wherein the storage block is provided in the storage block of the data storage unit and has the previous storage content in the data storage unit. Used block storage means having the previous block information indicating that the previous block information is arranged corresponding to each storage block of the RAM, and the used block storage means provided in the storage block of the data storage unit. Position information storage means for storing position information indicating the position of the position information storage means, and the position information storage means when the write command is input. The previous block information in the used block storage means is read according to the position information of the above, and based on the previous block information, the contents of each storage block of the RAM and the previous writing in each storage block of the data storage unit are previously written. The content of the storage block of the RAM is based on the previous block information in the used block storage means only when the comparison result by the previous content comparison means and the previous content comparison means for comparing Unused block writing means for writing to an unused storage block in the storage section, and information for newly creating the previous block information and the position information only when writing is executed by the unused block writing means Creating means, when the read command is input, the creating means according to the position information created by the information creating means The previously written block information is read, and the contents written by the unused block writing means are read from each storage block of the data storage unit on the basis of the last block information and the arrangement thereof, and the contents are read as described above. A data storage device comprising a storage data reading means for writing data in each storage block of a RAM.