JPH11259370A - Data writing device and method therefor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To effectively utilize a physical block for storing invalid data, to suppress the number of times of writing in a physical block for storing valid data and to average the number of times of the data writing in each physical block by writing data in a block whose number of times of writing is the smallest among blocks for storing invalid data. SOLUTION: When a receiving part 21 receives a write-request for data existing in a file system, a dividing part 22 divides write-data into the data size of each block. When the part 22 transfers data for one block to the buffer of a RAM 14, a write-block retrieving part 23 refers to the number of times of data writing and flag of each block stored in a management table of the RAM 14 and retrieves a block whose number of times of data writing is the smallest among blocks for storing invalid data. When the part 23 retrieves such a block among blocks of storing invalid data, a writing part 24 outputs a data write-command to a device driver.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a flash EE
The present invention relates to a data writing device and a data writing method for writing data to a PROM.

[0002]

2. Description of the Related Art FIG. 21 is a block diagram showing the processing contents of a conventional data writing device disclosed in, for example, JP-A-8-16482. In FIG. Is a logical block having a large number of times of writing, 3 is a group of physical blocks of a flash EEPROM having a small number of times of writing, 3a is a physical block allocated to the logical block 1, 3b is a free physical block from which data has been erased, and 4 is a writing block. A group of physical blocks of the flash EEPROM having a large number of times of writing, 4a is a physical block allocated to the logical block 2, and 4b is a free physical block from which data has been erased.

Next, the operation will be described. First, in a flash EEPROM which is a nonvolatile semiconductor memory, the reliability of data decreases as the number of times of data writing increases, so that the number of times of data writing is limited (the data erasing process is the same as the writing process). Treat it as something). Even when the number of times of writing of the entire flash EEPROM is small, if the number of times of writing of a specific block increases,
There is a property that the entire ROM cannot be used. Therefore,
Avoiding the concentration of write processing for a specific block and averaging the number of times of writing for each block is called flash EE.
This is important in securing the number of times of writing of the entire PROM.

Therefore, conventionally, when a data write request for a logical block 2 (a logical block having a large number of write operations) is received from a higher-level device (not shown), the physical block 4a (write When a physical block with a large number of times is allocated, first, data stored in the physical block 3a (a physical block with a small number of writes) is stored in the physical block 4b in order to suppress an increase in the number of times of data writing in the physical block 4a. (Free physical block belonging to the physical block group 4 with a large number of write operations).

When the data copying is completed, the physical blocks are assigned to the logical block 2 from the physical block 4a (the physical block with a large number of write operations) to the physical block 3b (the physical block group 3 with a small number of write operations). (Free physical block). Thus, when there is a data write request to the logical block 2 thereafter, the data of the physical block 3b is updated.

[0006]

Since the conventional data writing device is configured as described above, the number of times of writing data in each physical block is averaged. Is invalid data (data that no longer needs to be stored), the data is copied to the physical block 4b, so that the number of times of writing data in the physical block 4b increases. In addition, since the averaging process is performed in consideration of only the data write count of each physical block, the physical block storing invalid data cannot be effectively utilized, and the write count of the physical block storing valid data cannot be effectively used. There was also a problem that it increased.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problem, and effectively utilizes physical blocks for storing invalid data to suppress the number of times of writing of physical blocks for storing valid data. An object of the present invention is to provide a data writing device and a data writing method capable of averaging the number of times of writing data in a physical block.

[0008]

A data writing apparatus according to the present invention refers to the number of times of data writing and a flag of each block to minimize the number of times of data writing among blocks storing invalid data. A block is searched and data is written to the block.

In the data writing device according to the present invention, when the data size of the data to be written to the flash EEPROM is larger than the data size of each block, the data to be written to the flash EEPROM is divided into the data size of each block. Things.

[0010] In the data writing device according to the present invention, of the blocks searched by the search means, data stored in the block having the smallest data write count is copied to the block having the largest data write count. Things.

In the data writing device according to the present invention, when searching for a block having the minimum number of times of data writing, a block in which a predetermined time has elapsed from the data writing time is searched.

In the data writing apparatus according to the present invention, when searching for a block having the minimum number of data writings, a block having a data writing number equal to or less than the reference number is searched.

In the data writing apparatus according to the present invention, the reference number of times is set in consideration of the number of times of data writing of each block.

In the data writing apparatus according to the present invention, the copy processing of the copy means is performed asynchronously with the write processing of the write means.

In the data writing device according to the present invention, of the data divided by the dividing means, only data for which the data is not recognized to be identical by the comparing means is written in the block.

According to the data writing device of the present invention, even when the data stored in each block is invalid data,
The file name of the data is stored.

The data writing device according to the present invention stores information indicating the type of data stored in the block and the data writing time in each block, and stores the storage contents of the information storage means based on the information. The block is specified.

The data writing device according to the present invention stores information indicating the number of times of data writing of the block, a flag, a data writing time, a file name, and a data storage order in each block, and stores information based on the information. The contents stored in the storage means are reproduced.

In the data writing method according to the present invention, the number of times of data writing among blocks storing invalid data is minimized by referring to the number of times of data writing of each block and a flag for determining validity of data. A search process for searching for the block is executed, and a write process for writing data to the block is executed.

[0020] The data writing method according to the present invention includes a copy process of copying data stored in a block having the smallest data write count among blocks searched by the search process to a block having the largest data write count. It is intended to be executed.

[0021]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below. Embodiment 1 FIG. FIG. 1 is a configuration diagram showing a schematic configuration of a data writing device according to a first embodiment of the present invention. In FIG. 1, reference numeral 11 denotes a file system for storing data to be written in a flash EEPROM 18, reference numeral 12 denotes a bus, and reference numeral 13 denotes a file system 11. Receives data to be written to the flash EEPROM 18 from the device, refers to the information stored in the management table 15, selects a block in which to write the data, and outputs a data write command to the block to the device driver 17. The device 14 is an RA comprising a management table 15 and a buffer 16.
M (information storage means), 15 is a flash EEPROM 1
8, a management table for storing the number of times of data writing of each block, a flag for determining the validity of data stored in each block, and a data writing time of each block, 16 a buffer, 17 a data writing device 13 When a write command is received from the device driver, the device driver writes data to the flash EEPROM 18, and the device driver 18 is a flash EEPROM.

FIG. 2 is a block diagram showing a detailed configuration of the data writing device according to the first embodiment of the present invention. In FIG. 2, reference numeral 21 denotes a data write request from the file system 11 and write data (file data). ) Receiving unit, 2
Reference numeral 2 denotes a dividing unit (dividing means) for dividing the data to be written to the flash EEPROM 18 into the data size of each block when the data size of the data to be written to the flash EEPROM 18 is larger than the data size of each block. When a write request is received, referring to the data write count and the flag stored in the management table 15 of the RAM 14,
A write block search unit (search means) for searching for a block having the minimum number of data write operations among blocks storing invalid data, and a command 24 for writing data to the block searched by the write block search unit 23 (Writing means) which outputs the data to the device driver 17, increments the data write count of the block searched by the write block search unit 23, and inverts the contents of the flag related to the block. Update unit (information update means)
It is. FIG. 3 is a flowchart showing a data writing method according to the first embodiment of the present invention.

Next, the operation will be described. First, the flash EEPROM 18, which is a nonvolatile semiconductor memory,
When the number of times of data writing increases, the reliability of data decreases, so the number of times of data writing is limited (the data erasing process is treated as the same as the writing process). Further, even when the number of times of writing of the entire flash EEPROM 18 is small, if the number of times of writing of a specific block increases, the entirety of the flash EEPROM 18 becomes unusable. Therefore, it is important to avoid the concentration of the writing process for a specific block and to average the number of times of writing of each block in order to secure the number of times of writing of the entire flash EEPROM 18.

Therefore, in the first embodiment, the receiving unit 2
1 receives a write request for data (file) in the file system 11, the dividing unit 22 writes the write data in blocks.
However, if the data size of the write data is larger than the data size of each block, the write data is divided into the data sizes of the blocks (step ST1), and the data for one block is stored in the buffer 16 of the RAM 14. Transfer (step ST2).

When the division unit 22 transfers the data of one block to the buffer 16 of the RAM 14, the write block search unit 23 refers to the data write count and the flag of each block stored in the management table 15 of the RAM 14. (See FIG. 4) to store invalid data (data that no longer needs to be stored) (hereinafter, block).
A block with the minimum number of times of data writing is searched for in "empty block") (step ST3).

When the write block search unit 23 searches for a block having the minimum number of times of data writing, the writing unit 24 outputs a data write command to the device driver 17.
As a result, the device driver 17 executes a process of reading the data stored in the buffer 16 of the RAM 14 and writing the data into the found empty block (step ST4). When the device driver 17 completes the data writing process, the information updating unit 25 updates the information stored in the management table 15 to match the current situation.
The number of times of data writing of the block in which the data writing process has been performed is incremented, and the content of the flag related to the block is inverted (step ST5). That is, the content of the flag related to the block is changed from the content indicating that the block stores invalid data to the content indicating that the block stores valid data.

When the writing process of the data of one block is completed (including the updating process of the management table 15), the process of writing the remaining data in the other blocks is executed in the same manner (step S1). ST6), end the series of processing.

As is apparent from the above, the first embodiment
According to the configuration, the block in which the number of times of data writing is the smallest among the blocks storing invalid data is searched by referring to the number of times of data writing and the flag of each block, and data is written to the block. Therefore, the number of times of writing of blocks storing valid data is suppressed, and the number of times of writing data of each block can be averaged.

Embodiment 2 FIG. 5 is a configuration diagram showing a detailed configuration of a data writing device according to a second embodiment of the present invention. In the figure, the same reference numerals as those in FIG. 26, when the receiving unit 21 receives the data write request, the management table 1 of the RAM 14
With reference to the data write count, flag and data write time stored in 5, a block having the minimum data write count among the blocks storing valid data is searched,
A rewrite block search unit (search means) for searching for a block having the largest number of data writes among blocks storing invalid data, and a block 27 having a data write count of 27 A copy unit (copy means) 28 for copying data stored in the smallest block to a block having the largest number of data writings has the same processing function as the information update unit 25 in FIG. The information updating unit (information updating means) which increments the data writing frequency of the block having the largest data writing frequency searched by the above and inverts the content of the flag relating to each block searched by the rewrite block searching unit 26 is there. FIG. 6 is a flowchart showing a data writing method according to the second embodiment of the present invention.

Next, the operation will be described. Flash E
The process of writing data to the EPROM 18 is the same as that in the first embodiment, and a description thereof will be omitted.
Receives a data write request from the file system 11, before performing the data write process, it performs an averaging process on the number of data writes in each block.

That is, when the reception unit 21 receives a data write request, the rewrite block search unit 26 sets the management table 1
With reference to the flag and the data write time stored in 5, a block in which valid data is stored, for example, one month or more after the data write time is searched for (step ST <b> 11). Then, the rewrite block search unit 2
When a plurality of blocks are searched, the block 6 searches for a block having the minimum number of times of data writing among the blocks. Then, the rewrite block search unit 26 compares the number of times of data writing of the block with the number of times of data writing of each block constituting the flash EEPROM 18, and finds that the upper 10% of the block having the smaller number of times of data writing.
It is determined whether it is within the range (step ST12).

When the block is within the upper 10%, the rewrite block search unit 26 refers to the number of times of data writing and the flag stored in the management table 15 to check the block storing invalid data. The block having the largest number of data write operations is searched for (step ST1).
3).

Thus, the rewrite block search section 26
When searching for a block with the smallest number of data writes and a block with the largest number of data writes, the copying unit 27
As shown in (1), after the data stored in the block having the smallest number of times of data writing is transferred to the buffer 16 of the RAM 14 (step ST14), a command to write the data is output to the device driver 17. As a result, the device driver 17 reads the data stored in the buffer 16 of the RAM 14 and executes a process of writing the data in the block having the largest number of data writes (step ST15).

When the device driver 17 completes the data write processing, the information updating unit 28 updates the information stored in the management table 15 to match the current situation.
The number of times of data writing of the block in which the data writing process has been performed (the block with the largest number of times of data writing) is incremented, and the data writing time is updated. Further, the content of the flag relating to each block searched by the rewrite block search unit 26 is inverted (step ST16). That is,
The content of the flag relating to the block with the smallest number of data write operations is changed from the content indicating that it is a block storing valid data to the content indicating that it is a block storing invalid data (hereinafter, the data for this block will be described. (See Embodiment 1), the contents of the flag relating to the block with the largest number of data write operations are stored as valid data from the contents indicating that the block stores invalid data. Change the content to indicate that it is a block.

When the copying of the data stored in the block with the smallest number of data writings is completed (including the updating of the management table 15), the same processing is performed again, excluding the smallest block. Is repeated, and the above conditions (data write time, data write count and flag contents) are repeated.
(Step ST17).

As is clear from the above, this embodiment 2
According to the configuration, among the blocks searched by the rewrite block search unit 26, the data stored in the block with the smallest data write count is copied to the block with the largest data write count. This makes it possible to effectively use the blocks to be stored. As a result, the number of times of writing the blocks for storing the effective data is suppressed, and the number of times of writing the data of each block can be averaged.

In the second embodiment, the searched block is the top one of the blocks having the smaller number of data write operations.
Although the case of determining whether or not the number is within 0% has been described, the reference number is simply set to, for example, 100,000, and whether or not the number of times of data writing of the searched block is within 100,000 is determined. Needless to say, this may be done.

Embodiment 3 In the second embodiment, when the receiving unit 21 receives a data write request from the file system 11, before performing the data write process,
Although the processing for averaging the number of times of data writing in each block has been described, as shown in FIGS. 8 and 9, when the receiving unit 21 receives a request for averaging the number of times of writing from the file system 11, The averaging process of the number of times of data writing in the block may be performed.

As described above, if the process of averaging the number of times of writing data is performed asynchronously with the process of writing data,
When writing data to the flash EEPROM 18, it is not necessary to average the number of times of data writing, and the data writing process can be speeded up.

It should be noted that the receiving unit 21 is the file system 11
It is needless to say that the averaging process may be automatically executed at regular time intervals, not limited to the case where the request for averaging the number of writings is received from.

Embodiment 4 FIG. FIG. 10 is a configuration diagram showing a detailed configuration of a data writing device according to a fourth embodiment of the present invention. In the figure, the same reference numerals as in FIG. 8 denote the same or corresponding parts, and a description thereof will not be repeated. 29 is the RAM 14 of FIG.
RAM (information storage means, file name storage means) for storing a management table for storing a file name of data stored in each block, in addition to storing the same management table as
Numeral 30 has the same processing function as the write block search unit 23 in FIG.
When a request to write data to the data file 8 is received, a determination process is performed to determine whether the same file name as the file name of the data is stored in the management table of the RAM 29, and the determination result of the determination process indicates that the same file name is used. In the case of indicating the existence, a write process having a comparison process of searching for blocks storing data relating to the file name, and comparing the data stored in each block with the data of one block divided by the dividing unit 22. Block search section (search means,
The discriminating means and the comparing means) and 31 have the same processing function as the writing unit 24 in FIG.
Is a writing unit (writing means) for writing only the data indicating the data difference into the block. Note that FIG.
FIG. 12 is a flowchart showing a data writing method according to the fourth embodiment of the present invention.

Next, the operation will be described. First, when the receiving unit 21 receives a data write request, write data, and a file name from the file system 11, the write data can be written in block units as in the first embodiment. Therefore, when the data size of the write data is larger than the data size of each block, the dividing unit 22 divides the write data into the data size of each block (step ST1) and divides the data for one block. The data is transferred to the buffer 16 of the RAM 14 (step ST2).

When the dividing unit 22 transfers one block of data to the buffer 16 of the RAM 14, the write block search unit 30 determines that the file name of the write data is
Then, it is determined whether or not the information is stored in the management table 15 (step ST21). If the same file name is not stored in the management table 15 of the RAM 29, the data received by the receiving unit 21 is determined to be new data, and the writing process is performed in the same manner as in the first embodiment. To start.

That is, the write block search unit 30
With reference to the data write count and the flag of each block stored in the 29 management table 15 (see FIG. 13), a block having the minimum data write count is searched for among the free blocks storing invalid data (see FIG. 13). Step ST3).

When the write block search unit 30 searches for a block having the minimum number of times of data writing, the writing unit 31 outputs a data write command to the device driver 17.
Thus, the device driver 17 executes a process of reading the data stored in the buffer 16 of the RAM 29 and writing the data into the searched block (step S).
T4). When the device driver 17 completes the data writing process, the information updating unit 28 updates the data writing of the block in which the data writing process was performed in order to adjust the information stored in the management table 15 to the current situation. In addition to incrementing the number of times of loading, the file name of the data is registered in the management table 15, and the contents of the flag relating to the block are inverted (step ST5). That is, the content of the flag related to the block is changed from the content indicating that the block stores invalid data to the content indicating that the block stores valid data.

On the other hand, if the same file name is stored in the management table 15 of the RAM 29, it is determined that the data is to be rewritten, and the write block search unit 30 determines whether or not a valid data is stored in the block. In each of them, a block for storing data relating to the file name is searched (FIG. 1).
Step ST22 of FIG. 1 and Step ST31 of FIG. 12).
Specifically, when the file name of the data received by the receiving unit 21 is, for example, “aaa”, as shown in FIG. 13, two blocks storing the data having the file name “aaa” are provided. Since it exists, two blocks are searched.

When the two blocks are searched in this way, the write block search unit 30 firstly stores the data stored in the block whose storage block order is “1” among the two blocks, 1 which is first output from the dividing unit 22
The data for the blocks are compared (step ST32).
If the two data match, the process ends without executing the data write process for the block whose storage block order is “1”.

Next, the write block search unit 30 compares the data stored in the block whose storage block order is "2" with the data of one block output next from the division unit 22 (step ST32). . If the two data do not match, it is the same as the case where the same file name does not exist. Therefore, the detailed description is omitted. Perform writing processing (steps ST3 to ST3).
5).

As is apparent from the above, the fourth embodiment
According to the data of the data divided by the dividing unit 22,
As a result of the comparison process performed by the write block search unit 30, only the data whose identity is not recognized is written to the block, so that the data writing to the block storing the data whose identity is recognized is performed. As a result, it is possible to suppress an increase in the number of times of writing data to the block and to increase the speed of the data writing process.

Embodiment 5 In the fourth embodiment, the search for the block storing the data having the same file name among the blocks storing the valid data is described. However, as shown in FIG.
Then, a file name of invalid data may be registered, and a block storing data relating to the same file name may be searched for among blocks storing invalid data. As a result, even if the data stored in the block is invalid data, if the data matches the write data, it is not necessary to execute the write processing of the write data, and as a result, the number of times of data writing increases Can be suppressed,
This has the effect of speeding up the data writing process. 14 and 15 show a fifth embodiment of the present invention.
Is a flowchart showing a data writing method according to the first embodiment.

Embodiment 6 FIG. In the first to fifth embodiments, the management table 15 is stored in the RAM 1 from the beginning.
Although the description has been made on the premise that the management table 15 is stored in the flash EEPROM 18, the management table 15 may be stored in any block of the flash EEPROM 18, read from the block, and copied to the RAM 14 or 29. However, if the block storing the management table 15 is fixed to the same block, it is necessary to update the contents of the management table 15 every time data writing processing is performed on the block. Causes a problem that the number of times of writing data increases.

Therefore, in the sixth embodiment, as shown in FIG. 18, information indicating the type of data stored in the block and the data write time is stored in each block. When the file writing device receives a command to read the management table, a table management unit (not shown) activates the device driver 17 and first transfers information indicating the type of data from an arbitrary block to the buffer 16. The processing is performed (step ST61 in FIG. 17).

When the information indicating the type of data is stored in the buffer 16, the table management unit determines whether the data stored in the block is a management table based on the information (step ST62). ). Then, this process is executed for all the blocks, and when there are a plurality of blocks that are considered to store the management table, the data write time of each block is compared, and the data write time is It is determined that the management table is stored in the new block (steps ST63 to ST63)
T65). This is because the management table is updated every time data writing processing is performed, and thus the data writing time of the block storing the management table is always the latest time.

When the block that stores the management table is specified in this way, the table management unit starts the device driver 17 and executes processing for transferring the management table from that block to the RAMs 14 and 29.

As is apparent from the above, the sixth embodiment
According to the configuration, the information indicating the type of data stored in the block and the data write time is stored in each block, and the block storing the management table 15 is specified based on the information. Even if 15 is stored in the flash EEPROM 18, an effect that the problem that only the number of times of writing data of a specific block increases can be solved.

Embodiment 7 FIG. In the sixth embodiment, the block for storing the management table 15 is specified based on the information indicating the type of data and the data write time. However, as shown in FIG. Information indicating the number of times, the flag, the data writing time, the file name, and the storage block order may be stored in each block, and the management table 15 may be reproduced based on the information.

That is, when the file writing device receives a command to read the management table, a table management unit (not shown) activates the device driver 17 to buffer information indicating the number of times data has been written from an arbitrary block. 16 (steps ST71 and ST72 in FIG. 19). Then, the table management unit reproduces the management table 15 based on the information.

As a result, it is possible to solve the problem that only the number of times of writing data in a specific block is increased, and even if a failure occurs in the flash EEPROM 18, the influence of the failure can be limited to one block. As a result, there is an effect that data loss can be suppressed to a minimum.

[0059]

As described above, according to the present invention, by referring to the data write count and the flag of each block, a block having the minimum data write count among the blocks storing invalid data is searched. However, since the data is written in the block, the number of times of writing in the block storing the valid data is suppressed, and the number of times of writing data in each block can be averaged.

According to the present invention, flash EEPROM
If the data size of the data to be written to M is larger than the data size of each block, the flash EEPROM
Is configured to divide the data to be written into the data size of each block, so that even if the data size of the data to be written is large, there is an effect that the writing process can be performed in block units.

According to the present invention, of the blocks searched by the search means, the data stored in the block with the smallest number of data writes is copied to the block with the largest number of data writes. As a result, it is possible to effectively utilize the blocks for storing data. As a result, the number of times of writing of the blocks for storing valid data is suppressed, and the number of times of writing data for each block can be averaged. is there.

According to the present invention, when searching for a block having the minimum number of data write operations, a block which has passed a predetermined time from the data write time is searched.
Blocks that store data that is not updated frequently can be effectively used. As a result, the number of times of writing of blocks that store valid data is suppressed, and the number of times of data writing of each block is averaged. There is an effect that can be.

According to the present invention, when searching for a block having the minimum number of data writings, a block having a number of data writings equal to or smaller than the reference number is searched, so that a block for storing data that is not updated frequently is stored. Can be effectively utilized, and as a result, the number of times of writing of blocks storing valid data can be suppressed, and the number of times of writing data of each block can be averaged.

According to the present invention, since the reference number is set in consideration of the number of times of writing data in each block, the averaging process can be efficiently performed.

According to the present invention, since the copying process of the copying device is performed asynchronously with the writing process of the writing device, the data writing to the flash EEPROM is performed when the data is written to the flash EEPROM. It is not necessary to perform the averaging process of the number of times, and as a result, there is an effect that the speed of the data writing process can be increased.

According to the present invention, of the data divided by the dividing means, only the data of which the data identity is not recognized by the comparing means is written in the corresponding block. Data is not written to the block storing the data, and as a result, an increase in the number of times of writing data to the block can be suppressed, and the speed of the data writing process can be increased. There is.

According to the present invention, even when the data stored in each block is invalid data, the file name of the data is stored, so that the data stored in the block is invalid data. However, if the write data coincides with the write data, it is not necessary to execute the write processing of the write data. As a result, it is possible to suppress an increase in the number of data write operations and to increase the speed of the data write processing. There is an effect that can be achieved.

According to the present invention, information indicating the type of data stored in the block and the data writing time is stored in each block, and the block storing the storage contents of the information storage means is specified based on the information. The information stored in the information storage means is stored in a flash EEPROM.
The effect of eliminating the problem that only the number of times of writing data in a specific block increases can be eliminated. Further, even if information that is considered to be the storage content of the information storage means is stored in a plurality of blocks, there is an effect that the block storing the storage content of the information storage means can be specified from the information indicating the data writing time. .

According to the present invention, information indicating the number of times of data writing of the block, the flag, the data writing time, the file name, and the data storage order are stored in each block, and the information storage means stores the information based on the information. Since the contents are reproduced, it is possible to solve the problem that only the number of times of writing data in a specific block increases, and to limit the influence of the failure to one block even if a failure occurs in the flash EEPROM. As a result, there is an effect that data loss can be minimized.

According to the present invention, a block having the minimum number of times of data writing among blocks storing invalid data is searched for by referring to the number of times of data writing of each block and a flag for determining the validity of data. In addition to executing a search process for writing data to the block and executing a write process for writing data to the block, the block for storing invalid data can be effectively used, and as a result, The number of times of writing of blocks to be stored is suppressed, and the number of times of writing data of each block can be averaged.

According to the present invention, of the blocks searched by the search processing, the copy processing of copying the data stored in the block with the smallest data write count to the block with the largest data write count is executed. Because we configured
Blocks for storing invalid data can be effectively used. As a result, the number of times of writing of blocks for storing valid data can be suppressed, and the number of times of data writing of each block can be averaged. There is.

[Brief description of the drawings]

FIG. 1 is a configuration diagram illustrating a schematic configuration of a data writing device according to a first embodiment of the present invention;

FIG. 2 is a configuration diagram showing a detailed configuration of the data writing device according to the first embodiment of the present invention;

FIG. 3 is a flowchart showing a data writing method according to the first embodiment of the present invention.

FIG. 4 is an explanatory diagram illustrating the contents stored in a management table.

FIG. 5 is a configuration diagram showing a detailed configuration of a data writing device according to a second embodiment of the present invention.

FIG. 6 is a flowchart showing a data writing method according to a second embodiment of the present invention.

FIG. 7 is an explanatory diagram illustrating processing contents of a data writing device according to a second embodiment of the present invention;

FIG. 8 is a configuration diagram showing a detailed configuration of a data writing device according to a third embodiment of the present invention.

FIG. 9 is an explanatory diagram illustrating processing contents of a data writing device according to a third embodiment of the present invention.

FIG. 10 is a configuration diagram showing a detailed configuration of a data writing device according to a fourth embodiment of the present invention.

FIG. 11 is a flowchart showing a data writing method according to a fourth embodiment of the present invention.

FIG. 12 is a flowchart showing a data writing method according to a fourth embodiment of the present invention.

FIG. 13 is an explanatory diagram illustrating processing contents of a data writing device according to a fourth embodiment of the present invention.

FIG. 14 is a flowchart showing a data writing method according to a fifth embodiment of the present invention.

FIG. 15 is a flowchart showing a data writing method according to a fifth embodiment of the present invention.

FIG. 16 is an explanatory diagram illustrating processing contents of a data writing device according to a fifth embodiment of the present invention.

FIG. 17 is a flowchart showing a data writing method according to a sixth embodiment of the present invention.

FIG. 18 is an explanatory diagram illustrating processing contents of a data writing device according to a sixth embodiment of the present invention.

FIG. 19 is a flowchart showing a data writing method according to a seventh embodiment of the present invention.

FIG. 20 is an explanatory diagram illustrating processing contents of a data writing device according to a seventh embodiment of the present invention.

FIG. 21 is a configuration diagram showing a conventional data writing device.

[Explanation of symbols]

14 RAM (information storage unit), 22 division unit (division unit), 23 write block search unit (search unit), 24,
31 writing unit (writing unit), 25, 28 information updating unit (information updating unit), 26 rewriting block searching unit (searching unit), 27 copying unit (copying unit), 29 RAM
(Information storage means, file name storage means), 30 write block search section (search means, determination means, comparison means).

Claims (13)

[Claims] 1. An information storage means for storing the number of times of data writing of each block constituting a flash EEPROM, a flag for determining validity of data stored in each block, and writing data to the flash EEPROM. When the request is received, a search unit for searching for a block having the minimum number of data writes among blocks storing invalid data with reference to the number of data writes and a flag stored in the information storage unit; Writing means for writing data to the block searched by the means, and information updating means for incrementing the number of times of data writing of the block searched by the searching means and inverting the contents of a flag relating to the block. Data writer. 2. The data processing apparatus according to claim 1, further comprising a dividing unit configured to divide the data to be written into the flash EEPROM into the data size of each block when the data size of the data to be written into the flash EEPROM is larger than the data size of each block. Item 2. The data writing device according to Item 1. 3. A block which has the minimum number of times of data writing among blocks storing valid data with reference to the number of times of data writing and a flag stored in the information storage means, and stores invalid data. Searching means for searching for a block having the largest number of data writing times among blocks to be written, and, among blocks searched by the searching means, data stored in a block having the smallest number of data writing times is assigned a maximum number of data writing times. And a copy unit for copying to a block of the same type, and incrementing the data write count of the block having the largest data write count searched by the search means, and inverting the content of a flag relating to each block searched by the search means. 3. The data writing device according to claim 1, further comprising an information updating unit that performs the operation. 4. A search unit according to claim 3, wherein, when searching for a block having the minimum number of times of writing data, searching for a block after a predetermined time has elapsed from the data writing time.
The data writing device according to the above. 5. The data writing apparatus according to claim 3, wherein the search means searches for a block having a data write count equal to or less than a reference count when searching for a block having the minimum data write count. 6. The data writing device according to claim 5, wherein the search means sets the reference number of times in consideration of the number of times of data writing of each block. 7. The data writing device according to claim 3, wherein the copy processing of the copy means is performed asynchronously with the write processing of the write means. 8. File name storage means for storing a file name of data stored in each block, and a flash EEP
Upon receiving a request to write data to the ROM, determining means for determining whether or not the same file name as the file name of the data is stored in the file name storing means;
If the result of the determination by the determination means indicates the existence of the same file name, the respective blocks that store the data associated with the file name are searched, and the data stored in each block is compared with the data divided by the division means. 3. A comparison means, wherein the writing means writes only data, of the data divided by the division means, whose data is not recognized to be identical by the comparison means, to the block. Item 8. The data writing device according to any one of items 7. 9. The data writing device according to claim 8, wherein the file name storage means stores the file name of the data even when the data stored in each block is invalid data. 10. Information indicating the type of data stored in the block and the data write time is stored in each block.
The data writing device according to any one of claims 1 to 9, wherein a block for storing contents stored in the information storage means is specified based on the information. 11. Information indicating the number of times of data writing, a flag, a data writing time, a file name, and a data storage order of the block is stored in each block, and the storage content of the information storage means is reproduced based on the information. The data writing device according to any one of claims 1 to 9, wherein: 12. When a data write request to a flash EEPROM is received, a data write request is written in a block storing invalid data by referring to a data write count of each block and a flag for determining validity of data. A search process for searching for a block having the smallest number of write operations is performed, and a write process for writing data to the block is performed. When the write process is completed, the number of data write operations for the block is incremented, and A data writing method for inverting the contents of a flag relating to a block. 13. A block which has the minimum number of times of data writing among blocks storing valid data with reference to the number of times of data writing and a flag of each block, and
While performing a search process of searching for a block having the largest number of data writes among blocks storing invalid data,
Among the blocks searched by the search process, a copy process of copying data stored in the block with the smallest data write count to a block with the largest data write count is executed, and when the copy process is completed, the above search is performed. 13. The method according to claim 12, wherein the number of times of data writing of a block having the largest number of times of data writing searched by the processing is incremented, and the content of a flag relating to each block searched by the searching is inverted. Data writing method.