JP2001209567A - Journal writing system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a journal writing system which can extend a service life when journal data are recorded into an external storage device managed by file allocation table(FAT) system employing flash ATA-PC card, such as a nonvolatile memory. SOLUTION: The system comprises a fixed size journal data file 32 which can store plurality of journal data on the flash ATA-PC card 3. The file is opened when the system starts, and is not closed till the end of operation, thereby the frequency of writing into FAT area 31 can be reduced. Additionally, when the journal data are buffered in a temporary storage area 21 of journal data and then become larger than a sector size, the frequency of writing can be reduced by writing them into the journal data file 32 in one unit of sector.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to a journal writing system, and more particularly to a journal writing system for recording journal data (transaction recording) using a flash ATA-PC card capable of greatly extending a usable period.

[0002]

2. Description of the Related Art A conventional writing method for a nonvolatile memory is disclosed in, for example, Japanese Patent Application Laid-Open No. 4-276391. This conventional nonvolatile memory writing method has an area for holding the number of times of writing in units of records. Then, the number of times of writing corresponding to the record writing is incremented (increased sequentially), and it is determined from the number of times of writing whether or not the record can be continuously used. If it is determined that it cannot be used continuously, the next record is used. As a result, the number of times of writing to the nonvolatile memory can be used up to the limit of the number of times of writing for each record, and the utilization rate of the nonvolatile memory is improved.

[0003] Japanese Patent Application Laid-Open No. 11-249968 discloses a file recording method and a file system, which is a related technique for extending the life of a recording medium having a limited number of times of writing. That is, a boot sector, a FAT (file allocation table) area and a data area are provided in the flash memory, and the FAT area is further divided into a plurality of FATs (FATs 1, 2, and 3). The CPU of the file system starts FAT
When any one of FATs 1, 2, and 3 is selected and a file is written, the cluster information is written to the selected FAT. By selecting a different FAT every time the system is started, the number of times of writing in the FAT area is leveled and the life is extended.

[0004]

However, the above-mentioned prior art has the following problems. That is, flash AT
FAT using non-volatile memory such as A-PC card
When an external storage device managed by the method is used, the expected effect cannot always be realized. The reason is that a flash ATA-PC card managed by the FAT has a FAT area corresponding to each file. However, if each record is in the same file, no matter which record is written, writing occurs in the same FAT area when the file is closed.

When a file exists for each record, the number of files that can be simultaneously opened is usually limited. Therefore, when a large number of records are required, there is also a problem that all files cannot be left open. Further, in the case of a flash ATA-PC card, the number of times of writing is limited on a sector basis. Therefore, when a record smaller than the sector size is set, it cannot be used up to the number of times that the number of times of writing in the nonvolatile memory is limited in units of record.

[0006]

Accordingly, an object of the present invention is to provide a flash A
In journal recording using TA-PC card,
An object of the present invention is to provide a journal writing method capable of greatly extending the usable period.

[0007]

A journal writing system according to the present invention has a processing unit to which journal data is input, a flash ATA-PC card and a buffer memory, and stores journal data in a flash ATA-P.
Writes the journal data file of the C card, keeps the journal data file open from the system start to the end, temporarily stores the journal data in the buffer memory, and stores the journal data in the sector in the journal data file. It is characterized by writing in units.

According to a preferred embodiment of the present invention,
The flash ATA-PC card has a file allocation table (FAT) area, and is managed by the FAT method. Further, the processing unit checks whether the system is terminated after the system is started, and closes the journal data file only when the system is terminated. Further, the buffer memory may be a RAM or an SRA
M. Further, the journal data file is characterized by comprising a plurality of fixed-size records each capable of storing one journal data.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The configuration and operation of a preferred embodiment of a journal writing system according to the present invention will be described below in detail with reference to the accompanying drawings.

FIG. 1 is a block diagram showing the configuration of a first embodiment of a journal writing system according to the present invention. This journal writing method includes a processing unit 1 to which journal data is input, a RAM (random access memory) 2, and a flash ATA-PC card 3. The processing unit 1 includes a computer (CPU, processor, or data processing device) that operates under program control.

The processing section 1 processes the input journal data in accordance with the following operation method. RAM2
Is a volatile memory and holds data only when power is supplied. The flash ATA-PC card 3 is an external storage device composed of a flash read only memory (FROM) which is a non-volatile memory and managed by the FAT method.

Next, referring to FIGS. 2, 3 and 4,
First of the journal writing method according to the present invention shown in FIG.
The overall operation of the embodiment will be described in detail. FIG. 2 shows FIG.
1 shows an overall data configuration of the first embodiment of the journal writing method according to the present invention shown in FIG. FIG. 3 is a detailed diagram of the data configuration of FIG. FIG. 4 is a flowchart showing the operation of the first embodiment according to the present invention. First, as shown in FIG. 2, the RAM 2 has a journal data temporary storage area 21. Also, the flash ATA-PC card 3
Indicates the FAT area 31 and the journal data file 3
2 Further, as shown in FIG. 3, the journal data temporary storage area 21 of the RAM 2 includes a plurality of pieces of journal data each having a size (size) S2 and a size S1.
Constitutes a sector. The journal data file 32 of the flash ATA-PC card 3 has the size S2
Have a plurality of records 1 to n.

Next, a description will be given with reference to the flowchart of FIG. In step A1, the flash ATA-P
A fixed-size journal data file 32 capable of storing n pieces of journal data on the C card 3 is opened (opened). As a result, as shown in FIG.
The journal data file 32 in the TA-PC card 3
And the FAT area 31 are secured. Next step A2
In, it is determined whether or not the system is terminated. If the system is not terminated (No), the process proceeds to step A3. In step A3, journal data is input. Here, the input journal data is stored in the journal data temporary storage area 21 of the RAM 2 shown in FIG. Next, in step A5,
It is determined whether the journal data stored in the temporary journal data storage area 21 of the RAM 2 is equal to or larger than the sector size of the flash ATA-PC card 3. If it is smaller than the sector size (No), the process returns to step A2 described above. If the size is equal to or larger than the sector size (Yes), the process proceeds to step A6. Step A6
In step 2, the journal data of the sector size stored in the journal data temporary storage area 21 on the RAM 2 is extracted and recorded (written) on the flash ATA-PC card 3.

As described above, FIG.
Structure of journal data file 32 in PC card 3 and journal data temporary storage area 21 in RAM 2
The structure of is shown. The journal data file 32 has n sizes S each capable of storing one piece of journal data.
This is a ring buffer composed of two records 1 to n. In the journal data temporary storage area 21, there is an area where a plurality of journal data of size S2 corresponding to the sector size S1 can be stored.

In the flowchart shown in FIG. 4, when the end of the system is detected in step A2 (Yes), the process proceeds to step A7. This step A
At 7, the journal data file 32 on the flash ATA-PC card 3 is closed (closed).
Shut down the system. Also, in this particular embodiment,
Since the journal data file 32 has a fixed size, the FAT area 31 cannot be changed except for the file update date and time. As a result, even if the processing is terminated without a file close due to an unexpected power-off or the like, it is possible to prevent the journal data file 32 from being destroyed.

In the first embodiment of the present invention described with reference to FIGS.
By keeping the file open from the start to the end of the system with 2 as a fixed size, the number of times of writing in the FAT area 31 is greatly reduced. Furthermore, since writing of journal data is performed in a sector size which is a writing restriction unit of the flash ATA-PC card 3, it is possible to greatly reduce the number of times of writing as compared with the case of writing one by one described later.

Next, the operation of the journal writing system according to the first embodiment of the present invention will be described with reference to a specific example.
The sector size is 512 bytes, the journal data size is 128 bytes, and the average number of journals per day is 10,000.
0, the number of records in the journal data file 32 is 1
Assume a system in which the number of write operations for the flash ATA-PC card 3 is 300,000 and the number of write operations is 0000. The input journal data is stored in the journal data temporary storage area 21 on the RAM 2. Thereafter, the journal data stored in the journal data temporary storage area 21 is
At the time when the number of records corresponding to the sector size reaches four, the condition equal to or more than the sector size is met, and the data is moved (written) to the journal data file 32 on the flash ATA-PC card 3.

When the present invention is not adopted (in the case of the conventional system), writing to the FAT area 31 occurs for each case (see FIG. 5A). Therefore, FA will take about 30 days
The T area 31 exceeds the write limit, and writing of journal data becomes impossible. However, when the present invention is employed (see FIG. 5B), writing to the FAT area 31 is performed only at the end of the system. Even if the power supply is cut off once a day, it can theoretically be used for 300,000 days (about 820 years). Also,
In the journal data file 32, the number of times of writing per sector is once when 10,000 journals are stored, so that it can theoretically be used for 300,000 days. Therefore, when the present invention is adopted, theoretically 3
It can be used for an extremely long time of 10,000 days.

Next, a second embodiment of the journal writing system according to the present invention will be described with reference to FIGS. FIG. 6 shows the configuration of a second embodiment of the journal writing system according to the present invention. In FIG. 6, a processing unit 1 to which journal data is input, a static random access memory (SRAM) 6, and a flash AT
It is composed of an A-PC card 3. That is, the second embodiment shown in FIG. 6 is characterized in that the SRAM 6 is used instead of the RAM 2 as compared with the first embodiment shown in FIG. The SRAM 6 is a semiconductor memory backed up by a backup battery. FIG. 7 shows a detailed configuration of the SRAM 6 and the flash ATA-PC card 3. As in FIG. 2, the flash ATA-PC
The card 3 includes a FAT area 31 and a journal data file 32, and the SRAM 6 includes a journal data temporary storage area 61. In the second embodiment, since the SRAM 6 is used in place of the RAM 2, even if an unexpected power failure or the like occurs, loss of journal data can be reliably prevented.

The configuration and operation of the preferred embodiment of the journal writing system according to the present invention have been described above in detail. However, such embodiments are merely examples of the present invention and do not limit the present invention in any way. It will be readily apparent to those skilled in the art that various modifications can be made without departing from the spirit of the invention.

[0021]

As will be understood from the above description, the journal writing method of the present invention has the following remarkable effects. First, when recording a journal on a flash ATA-PC card 3 with write restrictions,
The service life can be extended. The reason is that the journal data file 32 is kept open, so that the number of times of writing in the FAT area 31 and the number of times of writing can be greatly reduced by writing journal data in sector units.

Second, data loss due to unexpected power cutoff due to a power failure or erroneous operation, etc. is to be reliably prevented. The reason is that the SR is temporarily stored in the journal data temporary storage area.
Due to the adoption of AM. This is because the SRAM is backed up by a battery, so that even if the power is turned off, the data is reliably retained.

[Brief description of the drawings]

FIG. 1 is a block diagram showing an overall configuration of a first embodiment of a journal writing system according to the present invention.

FIG. 2 is a diagram showing the entire data configuration in FIG. 1;

FIG. 3 is a diagram showing details of a data configuration in FIG. 2;

FIG. 4 is a flowchart showing an operation of the first embodiment of the journal writing system of FIG. 1;

FIG. 5 is a diagram for explaining the effect of the journal writing method of FIG. 1;

FIG. 6 is a block diagram showing an overall configuration of a journal writing system according to a second embodiment of the present invention;

FIG. 7 is a data configuration diagram of the journal writing method of FIG. 6;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Processing part 2, 6 Buffer memory (RAM, SRAM) 3 Flash ATA-PC card 21, 61 Journal data temporary storage area 31 FAT area 32 Journal data file

Claims (6)

[Claims] A flash ATA-PC card and a buffer memory, wherein the journal data is input to the flash ATA-P;
In a journal writing method for writing to a journal data file of a C card, the journal data file is maintained in an open state from a system start to an end, and the journal data is temporarily stored in the buffer memory. A journal writing method characterized by writing to a journal data file in sector units. 2. The flash ATA-PC card has a file allocation table (FAT) area,
2. The journal writing method according to claim 1, wherein the journal writing method is managed by a FAT method. 3. The journal writing method according to claim 1, wherein the processing unit checks whether or not the system is terminated after the system is started, and closes the journal data file only when the system is terminated. 4. The buffer memory according to claim 1, wherein said buffer memory is a random access memory (RAM).
Or the journal writing method according to 3. 5. The journal writing method according to claim 1, wherein said buffer memory is a static random access memory (SRAM). 6. The journal writing method according to claim 1, wherein said journal data file is composed of a plurality of fixed-size records each capable of storing one piece of said journal data. .