JPH0784894A - Method for writing nonvolatile memory - Google Patents

Abstract

PURPOSE:To eliminate the possibility of a defect in writing data, etc., even if a power source function is disabled during the rewriting of the nonvolatile memory. CONSTITUTION:The nonvolatile memory is provided with an in-operation memory area 5 and a backup memory area 4, which are written successively with time. In the memory area which is written precedently, a flag 4e is written after the writing and in the memory area which is written latter, the flag 4e is preferably reset after the data writing is completed; and at least write data 4a, the mark 4b of the write data, and check data 4d are preferably written in the backup memory area 4. Further, data are written in the backup memory area 4 preferably precedently to the in-operation memory 5.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of writing to a non-volatile memory provided in a data processing device or the like by a computer, and in particular, it is erroneous even when a power failure occurs when writing to the non-volatile memory. The present invention relates to a safe non-volatile memory writing method in which data is not written to the memory.

[0002]

2. Description of the Related Art A control constant for a machine or a data processor utilizing various computers inputs a control constant for operating the machine from a data setting device such as a numeric keypad. It may be written in the non-volatile memory attached to the computer. In addition, such a system may be provided with a means for automatically writing the operating data to a non-volatile memory at a necessary time such as for saving during a power failure. In order to write and modify predetermined data in such a non-volatile memory, for example, the configuration shown in FIG. 3 is used. In FIG. 3, 11 is, for example, EEP
ROM (electrical erasable pr
grammable read only memory
y) is a non-volatile memory configured by a non-volatile storage element such as y). Data processing function of computer body 1
Created in 2 or setter or sensor such as numeric keypad
Data input for writing from the input device 12a such as a computer is written in a specified address of the memory 11 via a buffer storage unit 13 such as a register provided in the computer main body. The data written in the non-volatile memory as described above is the data for operating the system using this computer.
Used for data etc.

[0003]

By the way, according to the above-described method for writing the non-volatile memory, when the power supply function is down due to a power failure or the like during the data writing operation, the data being written is destroyed. ， The correct data may be lost from this system. That is, for example, when new data is set by the setter, since it takes time to set, even if the power failure protection function is provided in this system, the non-volatile memory 11 cannot be processed in time. There is a problem such as erroneous data being stored in
If incorrect data is recorded, it will cause confusion in system operation after a power failure is restored. The present invention is a method of writing to a non-volatile memory, which is less likely to cause a write failure of data even if the power supply function is down during writing to the non-volatile memory, except for the above-mentioned conventional problems. The purpose (issue) is to provide.

[0004]

In order to solve the above-mentioned problems, in a method for writing a nonvolatile memory according to the present invention, an operating memory area and a backup memory area are provided in the nonvolatile memory, and The backup memory area and the backup memory area are written continuously in time. When writing data to the above-mentioned operational memory area and backup memory area, a flag is set in the memory area to be written in advance after the predetermined data is written, and a predetermined data is written in the memory area to be subsequently written. It is desirable to reset the flag after the writing is completed, and at least the write data, the write data indicator, and the check data are written in the backup memory area. Is desirable. Furthermore, it is desirable to write data in the backup memory area before the operational memory area.

[0005]

According to the present invention, since the backup memory area is provided as described above, the data recorded in the backup memory area is read and written in the regular address even if the writing in the operation memory area fails. be able to. If at least the write data and the flag are written in the memory area to be written in advance and the flag is reset after the writing to the memory area to be subsequently written is completed, the write completion status of the data can be seen by looking at the flag. It can be easily determined. Furthermore, if a write data indicator is written in the backup memory area in addition to the write data, even if the number of types of write data is large,
It is possible to easily determine which kind of data is recorded in this backup memory or at which address the data should be written, based on the contents of the written marker. Further, by writing and recording the check data, it can be easily determined that the data recorded in the backup memory has no error. Furthermore, if the data is written in the backup memory area prior to the operation memory area, there is a high probability that the contents of the operation memory can be preserved even if the writing in the backup memory area fails.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A writing method of a nonvolatile memory applied to a data processing device such as a computer or a control device according to the present invention will be described in detail with reference to FIGS. Figure 1
FIG. 1A shows a schematic configuration example of the main functional elements for realizing the present invention, and the configuration as a computer, the control line of the memory, etc. are omitted. FIG. 1B shows an example of types of data recorded in the backup non-volatile memory to which the present invention is applied. In FIG. 1 (A),
1 is, for example, an EEPROM (electrical scale)
rasable programmable read
A non-volatile memory (hereinafter referred to as a memory) configured by a non-volatile storage element such as an online memory). Created by the data processing function 2 of the computer body,
Alternatively, data (hereinafter referred to as data) to be input and written from a setting device such as a numeric keypad or an input device 2a such as a sensor.
Data) is written to a specified address of the memory 1 via a buffer storage unit 3 such as a register provided in the computer main body. That is, the memory 1 is directly operated during the operation of the backup memory area 4 to which the present invention is applied and the host system equipped with this nonvolatile memory, which is provided in the conventional device used for the operation of this system. It is composed of an operational memory area (hereinafter abbreviated as a memory area) 5 that operates. The data processing function 2 also has a data writing operation command function for implementing the present invention described later.

An example of the kind of data stored in the backup memory area 4 is shown in FIG. The memory area 4 is provided with respective data storage areas for storing each data.
In FIG. 1B, 4a is data to be transferred to and stored in the memory area 5, 4b is an indicator of the data 4a, for example, this data 4a required when transferring to the memory area 5 is stored. The address in the memory area 5 (which will be described as an address below), 4c is the number of bytes forming the data 4a, and 4d is a parity for checking whether the contents of the above-mentioned data 4a to 4c have an error. -Check data created and stored for checking, etc. 4e is the above-mentioned data 4
This is a flag that is set after storing a to 4d.

Next, a method of using the above-described structure will be described in detail with reference to the outline flow chart shown in FIG. The outline flow shown in FIG. 2 describes an example of writing in the backup memory area prior to the memory area. When a data writing operation occurs while the system equipped with this non-volatile memory is operating, the data 4a to be written and the marker of this data 4a are written according to a command preset in the data processing function 2. An address 4b to be written to the memory area 5 of the data 4a and a byte number 4c of the data 4a are written to predetermined addresses of the backup memory area 4 (step A1). Next, with respect to the data written and stored in step A1, the check data 4d created according to the preset condition is written in a predetermined address of the backup memory area 4 (step A2). When the above writing is completed, the flag 4e is set (step A3). Next, the same data as the data 4a is written in a predetermined address of the memory area 5 used when operating this system (step A4), and whether or not it is normally stored is determined according to a preset condition. If it is checked, the flag 4e set in step A3 is reset if normal (step A5). When the above write operation is completed, the system executes the operation of normal operation until the next data write request is generated. That is, when the data recorded in the non-volatile memory becomes necessary, the data processing function 2 reads out predetermined data from the memory area 5 to a work memory (not shown). Used. The data mentioned above
The data write operation requires time to execute, and if there are other items to be executed, the data write operation is executed by dividing it into idle time.

When the system is in operation, such as during the above-mentioned writing operation, and the power is turned off and then restored again (step B).
1) In accordance with the command from the data processing function 2, first, the check data 4d stored in the backup memory area 4 checks the stored data 4a to 4c (step B2). If the check result is abnormal, the processing according to the processing function set in advance in this system is executed. For example, the data in the memory area 5 to which this data 4a is to be written is used as it is. Or, an alarm is issued and the operator is requested to write correct data. If the check result of the check data 4d is normal, the flag 4e is checked (step B3).
If the flag 4e is not set, it means that the data 4a is normally stored in the memory area 5, and the operation of this system is restarted as it is (step B5). If the flag 4e is set, this data 4a is not normally stored in the memory area 5 and the backup memory area 4 stores correct data. The data 4a of the backup memory is transferred to and written in the address of the memory area 5 described in 4b (step B4). When the above-mentioned writing is completed, the operation of this system is restarted (step B5).

The above description shows a basic method for realizing the technical idea of the present invention and a configuration example for its implementation, and can be variously modified. For example, in the above-mentioned embodiment, the data stored in the backup memory area 4 is transferred to the memory area and stored therein.
a, when the data 4a is transferred to the memory area 5, this data
Address 4b in memory area 5 for storing data 4a, number of bytes 4c constituting data 4a, data 4a to 4c
Check data 4d created and stored for parity check, etc. for checking whether or not there is an error, and
Although the flag 4e has been described, an appropriate indicator for displaying the data 4a corresponding to the data processing condition of this system may be stored instead of the address 4b. However, data 4
If the data 4a can be clearly determined by other means, such as when the address in the memory area 5 in which a is to be stored is predetermined, it is not necessary to store the indicator such as the address. Further, if it is not necessary to confirm the number of bytes for data processing or checking, it is not necessary to store the number of bytes 4c. As the check method for the check data 4d, the check method adopted by this system such as various parity check methods may be used. In addition to the above, auxiliary data suitable for operation may be recorded in the operation memory area and the backup memory area. If a write error occurs during the storage operation for the backup memory area, appropriate measures such as rewriting may be taken according to a command preset corresponding to the system condition. Further, the check data may be used as check data for checking whether or not transfer writing is normally performed after the transfer from the backup memory area to the memory area 5. Checked
It is natural that the data may be recorded and used not only in the backup memory area but also in the operation memory area. In the above-described embodiment, an example in which the backup memory area is written prior to the operation memory area has been described. However, even if the writing order of the backup memory area and the operation memory area is reversed, the memory area to be flagged is changed. Of course, the same can be done by The backup memory area is
It goes without saying that the system to which the present invention is applied may be appropriately used in accordance with the conditions of its control function and data processing function. In addition, it goes without saying that the same memory element may be used in common for the backup memory area and the original operation memory area or may be provided separately. Further, the present invention is
It is possible to deal with the type of non-volatile memory that is appropriately selected and set according to the conditions of the system to which the present invention is applied.

[0011]

Since the present invention is configured as described above,
It has excellent effects as described below. Even if the power is turned off while writing data, there is no risk that wrong data will be used after the power is restored. If at least the write data and the flag are written in the memory area to be written in advance and the flag is reset after the writing to the memory area to be subsequently written is completed, the flag is checked to see the write completion status of the data. Can be easily determined. By writing the write data indicator in the backup memory area in addition to the write data, even if the number of types of write data is large, the backup indicator will be written according to the contents of the written indicator. It is possible to easily determine what kind of data is recorded in the memory or at which address the data should be written. When the check data is written and recorded, it can be easily determined that the data recorded in the backup memory has no error. If data is written to the backup memory area before the operation memory area, the contents of the operation memory will be written even if writing to the backup memory area fails due to the effect of power failure occurring early. There is a high probability that the

[Brief description of drawings]

FIG. 1 is an explanatory diagram for explaining the present invention.
FIG. 1A is a block diagram showing a schematic configuration example of functional elements for realizing a writing method of a nonvolatile memory according to the present invention, and FIG. 1B is a block diagram showing recording in a backup nonvolatile memory to which the present invention is applied. It is an outline map figure in which the type name of data to be written is described.

FIG. 2 is a schematic flow chart illustrating the present invention.

FIG. 3 is a block diagram showing a schematic configuration example of functional elements for describing a conventional nonvolatile memory writing method.

[Explanation of symbols]

 1: Non-volatile memory 2: Data processing function 4: Backup memory area 4a: (Memory) data 4b: (Memory) address 4c: (Memory) number of bytes 4d: (Memory) check data 4e: Flag 5: Operation memory area

Claims (4)

[Claims] 1. A non-volatile memory writing method, wherein a non-volatile memory is provided with an operation memory area and a backup memory area, and when data is written, the operation memory area and the backup memory area are continuous in time. A method for writing to a non-volatile memory, which is characterized in that the writing is performed by writing. 2. When data is written to the operation memory area and the backup memory area according to claim 1, a flag is set and recorded in the memory area to be written in advance after the predetermined data is written, The writing method of the non-volatile memory, wherein the flag is reset after the completion of writing of predetermined data in the memory area to be written. 3. A non-volatile memory for writing at least the write data, an indicator of the write data, and check data in the backup memory area according to claim 1 or 2. How to write memory. 4. The non-volatile memory writing method according to claim 1, wherein data is written in the backup memory area prior to the operation memory area.