JPH1125001A - Non-volatile memory overwrite processor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a highly reliable device for overwriting up-dated data in a non-volatile memory including data areas A and B in which one requires overwrite and the other does not. SOLUTION: A data area C is newly prepared in a non-volatile memory 11, the contents of data areas A, B are duplicated in the data area C and an external medium, and while referring to a management table in which the area sizes of the data areas A, B are set up, updated data are stored in the addition areas of the data areas A, B when the sizes allow storage. When the stored up-dated data are normal, a storing area for the updated data and a remaining area are reset in the management table as the area sizes of new data areas A, B. When the stored updated data are abnormal, a flag for instructing operation using the contents of the data area C is set up in an area specification means. If the size does not allow storage of the updated data in the addition areas, overwriting operation is interrupted without storing the updated data.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a first data area which requires overwriting when storing update data, and a second data area which does not require overwriting when storing data. The present invention relates to a non-volatile memory overwrite processing device that includes a non-volatile memory provided and performs an overwrite process of the update data on a first data area.

[0002]

2. Description of the Related Art For updating and writing data in a nonvolatile memory, see, for example, Japanese Patent Application Laid-Open Nos. 7-168770, 7-248978, and 7-6.
No. 4867.

Conventionally, in a nonvolatile memory, a first data area for storing data such as a program that requires overwriting and a second data area for storing error information when a failure occurs without requiring overwriting. Data area.

When overwriting update data in a first data area requiring overwriting, if overwriting is stopped due to a power failure or the like while the update data is being overwritten, the update data is completely written to the first data area. 1
After that, the normal operation cannot be performed, and the original data has disappeared, so that even the original data cannot be restored.

Further, when the data to be updated is a program and there is a defect in the program, if the defective update data is overwritten in the first data area, then the normal data is restored. The operation cannot be performed, and the original normally operating programs and data have already disappeared and cannot be restored.

Usually, the amount of data to be overwritten is often different from the previous amount of data. For example, if the amount of data to be overwritten exceeds a certain amount, the overwrite operation itself cannot be performed. When the amount of data to be overwritten is reduced, the empty area of the first data area after overwriting is simply wasted.

[0007]

As described above, the first problem of the prior art is that a power failure or the like occurs while update data is being overwritten in the first data area requiring overwriting. When overwriting is stopped, the original programs and data that normally operate have disappeared, and the original programs and data cannot be restored.

A second problem of the prior art is that the data to be updated is a program, and when there is a defect in the program, the defective update data is overwritten in the first data area. Then, the normal operation cannot be performed thereafter, and the original normally operating programs and data have already disappeared and cannot be restored.

A third problem of the above prior art is that the amount of data to be overwritten in the first data area is usually changed every time overwriting is performed. However, even if the amount of data to be overwritten is reduced, the free area of the first data area after overwriting is increased and the area cannot be used effectively.

The reason is that the first data area for storing data to be overwritten is usually fixed.

[0011] An object of the present invention is to provide a method for updating when overwriting is stopped due to a power failure or the like while updating data is being overwritten, or when the data to be overwritten is a program and the program has a defect. An object of the present invention is to make it possible to restore data that was originally operating normally even when data has been overwritten.

Another problem of the present invention is that even when the amount of data to be overwritten increases from the previous amount of data,
By using a second data area that does not require overwriting as a first data area, overwriting can be performed depending on the amount of increase.

Still another object of the present invention is to use a surplus portion of the first data area as a second data area that does not require overwriting even when the amount of data to be overwritten is smaller than the previous data amount. And to enable the non-volatile memory to be used effectively.

[0014]

According to a first aspect of the present invention, a first data area (A) that requires overwriting when storing update data and an overwrite when storing data are stored. A non-volatile memory (11) having a second data area (B) that does not require writing; and a non-volatile memory overwrite processing device for performing an overwriting process of the update data on the first data area. In the above, the nonvolatile memory further includes a third data area (C) used for backup of the first data area, and the nonvolatile memory overwrite processing device includes the first data area and the third data area. An area size management table (14) in which each data area size of the second data area is set, and the contents of the first data area are stored in the third data area. First means for copying the rear (1
0, I), second means (10, 13, II) for saving the contents of the second data area on an external medium, and acquiring the update data and referring to the area size management table. , The second data area in the first data area.
Is determined as a temporary first data area, and it is determined whether or not there is an area in which the size of the update data can be stored in the temporary first data area. Means (10, 13, III, II
I ') and when the third means determines that there is an area in which the size of the update data can be stored in the temporary first data area, the update data is stored in the temporary first data area. Fourth means (10, V) for storing, and fifth means (step VI) for determining whether the update data stored in the temporary first data area is normal,
When the fifth means determines that the update data stored in the temporary first data area is normal,
Of the temporary first data area, an area in which the update data is stored is determined as a new first data area, and the remaining area of the temporary first data area is determined as a new first data area. A sixth means (10, IX) for determining as the second data area and resetting each data area size of the new first data area and the new second data area in the area size management table
And a non-volatile memory overwrite processing device characterized by comprising:

According to a second aspect of the present invention, the above-mentioned first aspect is provided.
In the nonvolatile memory overwrite processing device according to the aspect, when the third means determines that there is no area in which the size of the update data can be stored in the temporary first data area, the temporary data of the update data is A non-volatile memory overwrite processing device further comprising means (10, XI) for canceling without overwriting the first data area.

According to a third aspect of the present invention, the above-mentioned first aspect is provided.
In the nonvolatile memory overwrite processing device according to the aspect, when the fifth means determines that the update data stored in the temporary first data area is not normal, the fifth data is stored in the first data area. Area designating means (12) for setting a flag for instructing operation using the third data area storing the original data,
A non-volatile memory overwrite processing device is further provided.

According to a fourth aspect of the present invention, the above-mentioned third aspect is provided.
In the nonvolatile memory overwrite processing device according to the aspect, when the third means determines that there is no area in which the size of the update data can be stored in the temporary first data area, the temporary data of the update data is A non-volatile memory overwrite processing device further comprising means (10, XI) for canceling without overwriting the first data area.

[0018]

According to the present invention, when the update data is to be overwritten in the first data area, the original data of the first data area is always stored and held in the third data area for backup.

Even if the amount of overwritten update data increases or decreases from the previous data amount, that amount is managed,
When the data amount increases, the second data area that does not require overwriting is used as the first data area by the increased amount, so that the second data area is reduced, and overwriting is performed as much as possible. The required first data area increases. On the other hand, when the amount of update data decreases, the remaining portion of the first data area remaining after overwriting the update data in the first data area is replaced with the second data that does not require overwriting. By setting as an area, the second data area that does not require overwriting is increased.

[0020]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, embodiments of the present invention will be described with reference to the drawings.

Referring to FIG. 1, a nonvolatile memory overwrite processing device (information processing device) 1 according to an embodiment of the present invention includes a first data area (overwrite) that requires overwriting when storing update data. A non-volatile memory 11 having a second data area (not shown later) that does not require overwriting when storing data, and a third data area (not shown later). The overwrite process of data to the first data area is performed.

The nonvolatile memory overwrite processing device (information processing device) 1 includes a bus 10. The processor 10 is connected to the bus 10. The nonvolatile memory 11 is also connected to the bus 10. The area designating means 12 is also connected to the bus 10 and uses the first data area in the nonvolatile memory 11 or determines whether to use the third data area.
A flag (to be described later) that specifies whether to use the data area is set. The external medium access means 13 is also connected to the bus 10 and various external media (not shown). Area size management table 1
4 is also connected to the bus 10, and the sizes of the first data area and the second data area in the nonvolatile memory 11 are set.

Referring to FIG. 2, the nonvolatile memory 11
Is a first data area A that stores updated data as the latest data in a state where the updated data is overwritten on the original data.
A second data area B that normally stores data without overwriting the original data, a third data area C that is used as a backup of the first data area A, and a first data area. Copy the data in area A to third data area C, save the data in second data area B to some external medium (which is typically an external storage medium), or And a program area in which a program for loading update data into the first data area A is stored. That is, this program area stores a program for an operation of an overwrite process of the processor 10 of the nonvolatile memory overwrite processing device (information processing device) 1 of FIG.

Referring to FIG. 3, there is shown a flowchart of an overwrite process of the nonvolatile memory overwrite processing device (information processing device) 1 of FIG.

Hereinafter, the overwriting process of the non-volatile memory overwriting processing device (information processing device) 1 of FIG. 1 will be described with reference to the processing flow of FIG.

When updating data in the first data area A (FIG. 2) of the nonvolatile memory 11 in the nonvolatile memory overwrite processing device (information processing device) 1, the processor 10 The following operation is performed according to the program stored in the program area 11 (FIG. 2).

First, the processor 10 stores the contents (original data before being updated) of the first data area A (FIG. 2) in the nonvolatile memory 11 in the third data area C in the nonvolatile memory 11. (Fig. 2) (Step I).
Further, the processor 10 includes an external medium access unit 13.
Then, the contents of the second data area B (FIG. 2) in the nonvolatile memory 11 are copied to a certain external medium (external storage medium) (step II).

Next, the processor 10 starts the operation of loading the update data from the external medium access means 13 (step III). At this time, the processor 10 causes the external medium access means 13 to acquire update data for loading into the first data area A from another external medium described above.

Subsequently, referring to the area size management table 14, the processor 10 determines a data area obtained by adding the second data area B to the first data area A as a temporary first data area A. Then, it is determined whether or not the temporary first data area A has an area in which the size of the update data can be stored (step III ′). When determining that the update data can be stored in the temporary first data area A, the processor 10 stores the update data in the temporary first data area A (step V).

Subsequently, the processor 10 determines whether or not the update data in the temporary first data area A is normal (step VI), and determines whether the update data in the temporary first data area A is normal. When the operation can be performed, the area storing the updated data in the temporary first data area A is determined as a new first data area A, and the remaining area in the temporary first data area A is determined. The area is determined as a new second data area B, and the sizes of the new first data area A and the new second data area B are reset in the area size management table 14 (step IX),
A flag instructing the operation using the first data area A is set in the area specifying means 12, and the operation is started using the new first data area A (step X).

In step VI described above, if the updated data in the temporary first data area A cannot operate normally, the operation using the third data area C is instructed to the area specifying means 12. Set the flag (step
VII), the operation is started using the third data area C storing the original data of the first data area A (step VIII).

As described above, at the time of subsequent startup, it is determined whether to use the first data area A or the third data area C according to the flag of the area designating means 12,
Start operation.

If the processor 10 determines in the above step III 'that the update data cannot be stored in the temporary first data area A, the processor 10 stores the temporary data area A in the update data. Aborts without overwriting to (step XI).

[0034]

As described above, according to the present invention, when overwriting is stopped due to a power failure or the like while updating data is being overwritten, data to be overwritten is a program, Even if you overwrite the update data that has a problem,
The original normally operating data is stored in the third non-volatile memory.
Since the data area remains in the data area, it is possible to restore the original normally operating data, thereby increasing the reliability.

Further, according to the present invention, even when the amount of data to be overwritten is larger than the previous data amount, the second data area which does not require overwriting can be used as the first data area. Depending on the amount of increase, overwriting can be performed, and the non-volatile memory can be used effectively.

Further, according to the present invention, the surplus portion of the first data area can be used as the second data area which does not need to be overwritten even when the data amount to be overwritten is smaller than the previous data amount. Because it was
There is an effect that the nonvolatile memory can be used effectively.

[Brief description of the drawings]

FIG. 1 is a block diagram of a nonvolatile memory overwrite processing device (information processing device) according to an embodiment of the present invention.

FIG. 2 is a block diagram of a nonvolatile memory of the nonvolatile memory overwrite processing device (information processing device) of FIG. 1;

FIG. 3 is a flowchart for explaining an operation of the nonvolatile memory overwrite processing device (information processing device) of FIG. 1;

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Non-volatile memory overwrite processing apparatus (information processing apparatus) 10 Processor 11 Non-volatile memory 12 Area specifying means 13 External medium access means 14 Area size management table

Claims (4)

[Claims] 1. A first data area (A) that requires overwriting when storing update data, and a second data area (B) that does not require overwriting when storing data. A non-volatile memory (11), comprising: a non-volatile memory (11) for performing an overwrite process of the update data to the first data area, wherein the non-volatile memory further comprises: A third data area (C) used for area backup; the non-volatile memory overwrite processing device comprising: an area size in which each data area size of the first and second data areas is set; Management table (14)
First means (10, I) for copying the contents of the first data area to the third data area; and second means (save the contents of the second data area to an external medium ( 10, 13, II), while obtaining the update data and referring to the area size management table, the data area obtained by adding the second data area to the first data area is a temporary first data area. And a third means (10, 13, II) for determining whether or not the temporary first data area has an area capable of storing the size of the update data.
I, III '), when the third means determines that there is an area in which the size of the update data can be stored in the temporary first data area, the update data is stored in the temporary first data area. Fourth means (10, V) for storing in the area, and fifth means (step V) for determining whether the update data stored in the temporary first data area is normal.
I) and when the fifth means determines that the update data stored in the temporary first data area is normal,
Of the temporary first data area, an area in which the update data is stored is determined as a new first data area, and the remaining area of the temporary first data area is determined as a new first data area. A sixth means (10, IX) for determining as the second data area and resetting each data area size of the new first data area and the new second data area in the area size management table
And a non-volatile memory overwrite processing device. 2. When the third means determines that there is no area capable of storing the size of the update data in the temporary first data area, the temporary first data area of the update data is determined.
2. The non-volatile memory overwrite processing device according to claim 1, further comprising means (10, XI) for stopping without overwriting the data area. 3. When the fifth means determines that the update data stored in the provisional first data area is not normal, the fifth means stores the original data of the first data area. Area designating means (1) in which a flag instructing operation using the third data area is set.
2. The non-volatile memory overwrite processing device according to claim 1, further comprising: (2). 4. When the third means determines that there is no area in which the size of the update data can be stored in the temporary first data area, the temporary first data area is updated.
4. The non-volatile memory overwrite processing device according to claim 3, further comprising means (10, XI) for stopping without overwriting the data area.