JP2000235524A - Data maintenance device/method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To sufficiently maintain data in a non-volatile storage part by inspecting data stored in a second data area in a prescribed cycle and rewriting and restoring only error data as an object with a precise logic value when error data are detected. SOLUTION: A first data area 6 and a second data area 7, which are comprised of one or more data areas, are set in a non-volatile storage part 5. A writing storage means 3 writes/stores data of the same contents into the respective areas 61, 62, 71 and 72 of the first and second data areas 6 and 7 at the time of writing initial data into the non-volatile storage part 5 and at the time of rewriting data. Data stored in the second data area 7 are inspected in a prescribed cycle by an inspection restoration means 4 and only error data as an object are rewritten/restored by a precise logic value by an error correction method.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a combustion control device used for combustion equipment such as an automatic water heater or a fan heater, and a control device for handling digital data. The present invention relates to a data security device and a data security method.

[0002]

2. Description of the Related Art The above-mentioned control device is constituted by a microcomputer and controls various digital data,
For example, the correction is performed based on set temperature data desired by the user, data obtained from various sensors, and correction data thereof. Also, even if it is not directly related to control,
As data handled by the control device, there is timekeeping data and the like in the case where the device has a clock display unit.

[0003] When using these digital data, some control devices determine whether the data is valid or invalid, and if invalid, control to discard the data. Some remote controllers for operation in devices perform the same control. Also, in order to retain the contents even if the power of the device is turned off, predetermined important data is stored in an external EEPROM
Some are stored in 0M (an electrically rewritable nonvolatile storage unit).

[0004]

However, in the case of such a control device that handles various data and controls various operations, when such various data is damaged by disturbance or power failure, if it is detected that the data cannot be communicated, the control device simply operates. In some cases, the control operation was simply stopped. The above-described combustion equipment and the like are used constantly every day, and this is of course inconvenient, so that measures have been taken to correct the damaged data. However, if the most common sum check method is used as the data correction principle, when multiple errors occur in the same digit, it may become the same as the original checksum and it may not be noticed, Not preferred for safety.

On the other hand, a so-called BCH (Bose-
In an error correction method called a "Chaudhuri-Hocquenghem" method, even if an error occurs in some bits in a plurality of bit strings constituting individual data, the error is corrected by a BCH code added to the data. It is possible, and a high effect can be obtained for a relatively simple principle. However, even in this case, there is a limit to the number of bits that can be repaired, and if the BCH code itself is damaged in the first place, error correction becomes completely impossible.

On the other hand, no matter which method is used for the error correction method, as another attempt, a plurality of mutually independent data areas are set in a rewritable nonvolatile storage unit, for example, EEPR0M, With the control operation,
When writing or rewriting data in EPR0M,
A method of preserving data by writing data of the same content to the plurality of data areas was also considered. However, even in this method, if damage occurs in all data areas, it is impossible to maintain data.

Further, EE used as a nonvolatile storage unit
The PR0M is generally configured to selectively store logic values “1” and “0” depending on whether electrons are selectively injected into the floating gate. However, the electrons stored in the floating gate are not stored. Is not permanent and the stored electrons may escape, and the general data retention period is about 10 years. In order to prevent the stored electrons from leaking and to maintain the data, a method of periodically refreshing the data is adopted. Note that refreshing refers to the work of intentionally rewriting data irrespective of the necessary data rewriting accompanying the control operation of the control device. Even if there is no change in data, the same logical value data is used. Say the work of rewriting.

On the other hand, rewriting of data is an operation of injecting or extracting electrons from the floating gate via a gate insulating film interposed between the floating gate and a channel region facing the floating gate. According to the generally used avalanche breakdown principle, the damage rate of the gate insulating film increases, and it is said that normal rewriting can be performed about 100,000 times.

Therefore, as described above, if the data is regularly refreshed frequently in order to maintain the data, the number of rewrites is limited, and the life of the nonvolatile storage section is substantially reduced. The result is that

As described above, since the number of rewritable times is limited in the nonvolatile storage unit, the number of data refreshes is naturally limited, and at present, data is not sufficiently maintained.

The present invention has been proposed in view of the above,
An object of the present invention is to provide a data security device and a data security method that can sufficiently secure data in a nonvolatile storage unit.

[0012]

To achieve the above object, a data security device according to the present invention is a data security device for storing and securing digital data in a rewritable nonvolatile storage part. Set in the first data area and the second data area each consisting of one or more data areas, at the time of initial data writing and data rewriting to the nonvolatile storage unit, each of the first and second data area Write storage means for writing and storing data of the same content in each area, refresh means for refreshing the data stored in the first data area at a predetermined cycle, and data stored in the second data area at a predetermined cycle And if error data is found, only the error data is It is characterized by comprising a inspection repair means for rewriting repair the correct logic value target, the.

According to another aspect of the present invention, there is provided a data security method for storing and securing digital data in a rewritable nonvolatile memory unit. A first data area and a second data area comprising the above data area are set, and the same contents are respectively set in the first and second data areas when initial data is written and data is rewritten in the nonvolatile storage unit. When the data stored in the first data area is refreshed at a predetermined cycle, the data stored in the second data area is checked at a predetermined cycle, and error data is found. And rewrite and repair only the error data with the correct logical value using the error correction method. It is.

[0014]

Embodiments of the present invention will be described below in detail with reference to the drawings.

FIG. 1 is a block diagram showing the overall configuration of the data security device of the present invention. In the figure, a data security device 1 of the present invention is a device for storing and maintaining digital data in a rewritable nonvolatile storage unit 5, from one or more data areas set in the nonvolatile storage unit 5. The first data area 6 and the second data area 7 and the respective areas 61, 62,... , 72,... And the first data area 6 (61, 62,.
..) And a second data area 7 (71, 7).
The data stored in (2,...) Is inspected at predetermined intervals,
And checking and restoring means for rewriting and restoring only the error data with a correct logical value by using an error correction method when error data is found.

Since the refresh means 2 periodically refreshes the data stored in the first data area 6 (61, 62,...) Belonging to the first group, the logical value in the data bit may be lost naturally. However, there is a risk that the number of data rewrites will be exceeded over the years. On the other hand, the inspection / restoration means 4 is configured to provide the second data area 7 (71, 72,
…), The data bits that are found to be damaged by periodic inspection among the multiple bits that make up the data are rewritten to the correct logical value at that time, but if no damage is found, Leave as before. Therefore, the number of rewritable times expected in the non-volatile storage unit 5 is unlikely to be restricted even after a lapse of years, but the risk of losing the storage logical value is increased for data bits that have not been damaged. However, by providing the data areas 6 and 7 having different risks from each other, such as the first data area 6 which is resistant to natural loss of data and the second data area 7 which is hardly limited by the number of times of data rewriting as described above,
It is more likely that the data in at least some of the data areas will remain correct, eventually increasing the life of the non-volatile storage unit 5 or achieving an effect equivalent to increasing the data holding capacity. it can.

An inspection is also performed when all data bits of the data stored in the first data area 6 are refreshed at a predetermined cycle. If an error is found in the data, the error is corrected by an error correction method. Alternatively, all data bits may be refreshed, including the logical values of the data bits that have not been damaged, while rewriting the logical values of the damaged data bits with the restored logical values.

The cycle related to the refresh of the first data area 6 and the cycle related to the inspection of the second data area 7 may be the same cycle, and may be set arbitrarily, for example, every five days or one week. Can be. However, if it is too short, it is not desirable because the upper limit of the number of rewritable times in the nonvolatile storage unit is easily exceeded. Therefore, from the same viewpoint, when data is rewritten due to a control operation or the like, the time at which the rewriting is performed may be set as the start time of a new cycle.

On the other hand, since this data rewriting is also a good refresh for the second data area 7, this idea is promoted, and the inspection of the data in the second data area 7 every predetermined cycle is performed more than a predetermined number of times. When it reaches,
At this point, it is also desirable to refresh all data bits in the second data area 7 as well.

It has been described that if the refresh interval is too short, the upper limit of the number of rewrites in the nonvolatile storage unit 5 is likely to be exceeded. (Writing data "1" to each data bit and injecting electrons), and then writing new data (extracting electrons from the data bits to make the data "0"). This is because only the “0” portion is stressed by the number of times. Therefore, instead of writing with the same data content in the refresh method, the life of the number of rewritable times can be approximately doubled by inverting the data “0” and “1” every time a refresh is requested.

As described above, the present invention basically relates to data security in the non-volatile storage unit 5, so that any error correction method used for data inspection may be used.
However, it is desirable to use a BCH error correction method for repairing damaged data by adding a BCH error correction code to real data. In this case, the following contrivance can be further applied.

First, it is possible to propose a method of adding an additional BCH code for restoring the actual data of each data area 61 and the like to the original BCH code added for restoration thereof by a BCH error correction technique. .

As a further advanced technique, the data stored in each data area 61 and the like is composed of two or more consecutive data frame strings, and each subsequent data frame except for the first data frame contains actual data. And a BCH code. Each of the BCH codes is a BCH code for restoring the entire data in the immediately preceding data frame as one new real data by the BCH error correction method, After the last data frame, the BCH code and the real data contained in the last data frame are regarded as one new real data, and
A BCH code for restoration by a CH error correction method is provided, and the last BCH code is added to the last BCH code.
It is also possible to propose a method in which an additional BCH code is added to repair the damage of the CH code itself by a BCH error correction method. Here, all of the data stored in the above-described first data frame may be real data used for control, or may be real data.
A BCH code for restoring the actual data may be stored.

Next, a more specific description will be given with reference to FIGS.

FIG. 2 is a diagram schematically showing the overall configuration of a combustion apparatus in which data security according to the present invention is performed. The illustrated device is a combustion device such as an automatic water heater or a fan heater, and its control device 50 is constituted by a microcomputer having a CPU 51 as a center, and has a RAM 52 and a ROM 53. An electrically rewritable (electrically erasable and programmable) EEPROM 30 is provided externally.

Then, the CPU 51 of the control device 50
The data security control according to the present invention is executed according to the program according to the present invention stored in the OM 53 in advance. That is, the above-described data security device 1 is configured as a part of the control executed by the control device 50, and includes the above-described write storage unit 3, refresh unit 2, and inspection restoration unit 4.
Are configured as functions of software executed by the CPU 51 according to the program according to the present invention.

Controlled part 4 controlled by control device 50
0 includes a combustion mechanism section 41, a fan motor section 42, and various sensors 43. Such a relationship between the controlled unit 40 and the control device 50 may be similar to that of an existing combustion apparatus of this type. A remote controller (hereinafter, referred to as “remote controller”) 60 is further coupled to the control device 50. The remote controller 60 has an operation unit 61, and various setting data such as setting temperature data (water heater Is provided to the controller 50 for inputting hot water supply temperature data and desired room temperature data for a fan heater. The configuration of this portion also does not need to be modified by the present invention from the existing configuration. Depending on the model, the control device 50 may also execute a clock function and display the current time on a clock display unit 62 composed of a liquid crystal display or the like. In such a case, the operation unit 61 displays the current time. An operation member for setting an initial value of time is also provided.

The rewritable EEPR0M30 includes general data including various setting data that can be set by a user, as well as set temperature data relating to room temperature and hot water supply temperature, and data directly related to the safety of combustion equipment, for example, Control unit 4
0, including various sensors 4
Correction data for analog output finally obtained from 3 and correction data for fan motor control, and in the case of gas-fired equipment, data on restrictions on gas proportional valve current, etc. Various data to be stored are stored.

In any case, such as when the power switch is turned on or when the power is restored after a power failure, the control device 50 first supplies the EEPR0M30
From the EEPR0M30
And reads them out from the RAM 52 and stores them in the RAM 52. Then, it is determined whether each data stored in the RAM 52 is normal or abnormal, that is, whether the data is valid data or invalid data. Although the BCH code is desirably used for this discrimination, since this is related to the data restoration according to the present invention, the details will be described later.

In this embodiment to which the present invention is applied, E
In the EPR0M30, at least two or more data areas capable of storing at least one or more types of data to be stored therein are set in an isolated manner.
Is secured. In the present invention, the plurality of data areas are divided into a first data area A belonging to the first group and a second data area B belonging to the second group, and the number of data rewrites in the used EEPR0M30 is exceeded. Disperse the risk and the risk of spontaneous data loss. In the first data area A, two more data areas A1 and A2 are set, and in the second data area B, two more data areas B1 and B2 are set independently of each other.

These four data areas A1, A2,
B1 and B2 are stored at the time of initial writing or the control unit 5
The same contents are written at the time of rewriting accompanying the control operation of 0. The controller 50 reads out the data in the data areas A1, A2, B1, and B2 by turning on the power as described above,
When the data is stored in the RAM 52 and all the data are determined to be valid, any of these four identical data may be used.
A predetermined control operation is performed using the data. If the read data is, for example, set temperature data as general data, the combustion mechanism section 41 and the fan motor section 42 are set so that the actual temperature satisfies the set temperature indicated thereby.
Control. Further, as more important data regarding combustion, for example, data for correcting the output of the flame detection sensor included in the various sensors 43, correction data for the fan motor, or restriction data for the gas proportional valve current, etc. The control is performed according to a predetermined control function by using the data. However, the control device 50 does not enter the control operation when the operation of the combustion equipment starts immediately, but enters the operation standby state, and then enters the control device 50 according to a user's instruction.
Is configured to start the combustion control.

As described above, when the plurality of data areas A1, A2, B1, and B2 are set in the EEPR0M30, particularly,
The ability to maintain data in the event of a power outage while rewriting data is increased. If only a single area is set, there is no way to recover data if a power failure occurs while data is currently being written to that area. On the other hand, if there are a plurality of data areas A1, A2, B1, and B2, the data in the area being written is damaged at the moment of the power failure, but the data has already been written in the remaining areas. , The latest data remains, and if not, at least the data before the update remains, so that there is little risk of serious trouble.

By the way, even though a plurality of data areas are provided, all of the plurality of data areas are under the same environmental condition. Therefore, if the number of times of data rewriting increases, there is a risk that they will exceed the maximum number of times of rewriting which can be expected in the EEPR0M30 used at the same time. On the other hand, under the condition that data rewriting is not performed for a considerably long time, on the contrary, there is a possibility that all the data areas A1, A2, B1, B2 almost simultaneously exceed the limit of the data holding capacity. As a result, there is a high possibility that data in all data areas will be damaged or lost, and if this happens, there is no way to recover anymore. As will be described later, even if an error correction method that is strong in recovery is adopted, recovery may still be impossible.
If the number of physical rewrites exceeds 30, the recovery by any means becomes impossible.

In this embodiment, a plurality of data areas A1, A2, B1, and B2 in the EEPR0M30 shown in FIG. 2 are stored in accordance with the gist of the present invention, as shown in FIG. , The first data area A (A1, A2) belonging to the first group and the second data area B (B1, B2) belonging to the second group. At the time of initial data writing or at the time of data rewriting accompanying the control operation of the control device 50, all of these data areas A
1, A2, B1, and B2 are written with the same data.

Thereafter, irrespective of the control operation of the control device 50, the first data areas A1 and A2 are switched at predetermined intervals, for example, every five days or one week. Refresh all of the constituent data bits. Prior to this refresh, all data bits are checked, and if an error is found in the data, an appropriate error correction method (preferably, B
In the case where this is repaired by the CH error correction method, the logical value of the damaged data bit is rewritten with the repaired logical value after the repair, and the logical value of the data bit that has not been damaged is restored. Refresh everything, including Therefore, the first data areas A1 and A2 are data areas that are resistant to spontaneous loss of data.

If the refresh interval is too short, the EEPR
Since the upper limit of the number of rewritable times of the OM 30 is easily exceeded, as described above, instead of writing the refresh method with the same data contents, the data “0” and “1” are inverted every time a refresh is requested. Let me write. By doing so, the life of the rewritable times can be approximately doubled.

In this case, in order to determine whether the normal data is written or the inverted data is written, recognition data for determining whether the data is the normal data or the inverted data is written in the uppermost part of the actual data (FIG. 3). (B)). For example, the normal recognition data is “0101”, and the reverse recognition data is “1”.
010 ". By looking at the recognized data, it can be determined whether the data to be written subsequently is normal data or inverted data.

The data stored in the first data area A and the data stored in the second data area B may be the same as or different from the refresh cycle of the first data area. If an error is found as a result of the inspection at each cycle, the error is corrected using an error correction method, and then only the logical value of the damaged data bit is replaced with the restored logical value. The data in the bit is not refreshed,
Leave as before. Of course, if no data bits have been corrupted, the logical value of each data bit is maintained as before. As can be understood from the above, the second data areas B1 and B2 are hardly subject to restrictions on the number of rewritable times.

As described above, according to the present invention, one EEPR
In the 0M30, data areas with different environmental conditions can be intentionally created, and the risk of exceeding the number of rewritable times and the risk of exceeding the data retention capacity are reduced by the first and second different data areas A and B. , The possibility that correct data remains in any of the data areas increases.

In principle, the refresh of the first data areas A1 and A2 and the refresh of the second data area B
Inspections 1 and B2 are performed, but when data is rewritten due to the control operation of the control device 50, it is preferable that the time at which the rewriting is performed be set as the start time of a new cycle. When the data is updated by the control device 50,
Since the correct data is written to the EEPROM 30,
This point in time may be considered as a refresh, and it is sufficient to perform the data refresh or data check according to the present invention after a predetermined period from that point, thereby avoiding increasing the number of rewrites. In addition, in this case, if there is no data corruption in the second data area B, the same data is kept for a long time, and there is anxiety that the data will be lost naturally. Is a refresh operation for the data in the second data area, which is preferable.

Therefore, if this idea is developed, when the data in the second data area B has been inspected at a predetermined number of times or more at a predetermined cycle, all data in the second data area B are also stored at that time. It is desirable to refresh the bits. Even in such a case, as compared with the first data area A in which all data bits are always refreshed every predetermined period, the disadvantage of the second data area B on the number of rewrites is reduced.

Next, an error correction method more desirably used in combination with the basic configuration of the present invention will be described. As mentioned above, there is a technique using a BCH code as a desirable error correction technique. However, if the BCH code itself is damaged in addition to the damage of the actual data,
It cannot be corrected by the CH error correction method. Therefore, in the present invention, a method shown in FIGS. 3B and 3C is proposed. FIGS. 3B and 3C show the first data area A
(A1, A2) and a data frame configuration example in the second data area B (B1, B2).

First, as shown in FIG. 3B, a BCH code 12 for restoring the real data 11 used for control by the control device 50 in accordance with a known BCH error correction method. Is provided. Then, the original BCH code 12 for correcting the actual data 11 is further added.
An additional BCH code 21 for repairing itself is provided. In this way, if the actual data 11 is damaged, the original B
If the CH code 12 is not damaged, the actual data 11 can be restored using the original BCH code 12 according to a normal BCH error correction method. On the other hand, if the original BCH code 12 is damaged, the recovery of the actual data 11 is no longer possible conventionally, but according to this aspect of the present invention, the additional BCH code for correcting the original BCH code 12 itself is used. Since the data 21 is used, the original BCH code 12 is first corrected according to the BCH error correction method, so that the actual data 11 can be restored with the restored original BCH code.

In practice, this effect is remarkable, and the reliability of even the devices requiring a high degree of safety, such as the above-described combustion devices, can be enhanced by the function of restoring the actual data. Further, as shown in the illustrated device, the control device 50 and the remote
In particular, when wired communication is performed between them, the communication is strongly affected by disturbance. However, by using the present invention, highly reliable communication can be performed.

In the present invention, as shown in FIG. 3C, a method effective for handling long data is also proposed. For data with a long data length (a long bit string),
In general, each of them is often divided into a plurality of data frames fixed to a predetermined bit length. in this case,
According to the method shown in FIG. 3B, the actual data 11 and the original BCH code 12 for correcting it are provided for each data frame having a long bit string, and the additional BC according to the present invention.
The H code 21 may be stored, but more rationally, FIG.
A method as shown in (C) can be proposed.

In the configuration example shown in FIG. 3C, the data frame is from the first data frame 10-1 to the n-th data frame.
There are n data frames 10-n. n is an integer of 2 or more. Of these data frames, only the actual data 11-1 used for control may be stored in the first data frame 10-1 at the head. On the other hand, the second to n-th data frames 10-2 to 10-1
0-n stores actual data 11-2 to 11-n and BCH codes 12-1 to 12- (n-1), and each of the BCH codes 12-1 to 12- (n-1) is A BCH for restoring all data (BCH code and real data) in the immediately preceding data frame as one new real data
Sign.

That is, when the relationship between the BCH code and the data restored by the BCH code is schematically shown by an arrow, the BCH code 12-1 in the second data frame 10-2 is the same as that in the first data frame 10-1. This is a BCH code for restoring all data, in this case, the actual data 11-1. The BCH code 12-2 in the third data frame 10-3 is the actual data 11 in the immediately preceding second data frame 10-2.
-2 as well as the recovery BCH of the actual data 11-2 and the actual data 11-1 in the first data frame 10-1.
It is regarded as one new real data including the code 12-1,
This is a BCH code for restoring this.

After continuing such a linking relationship after the fourth data frame, all data (BCH code 12- (n-11) and real data 11) of the last n-th data frame 10-n are obtained.
-N), the last BCH to repair this
After the code 12-n is provided, an additional BCH code 21 for restoring the last BCH code 12-n is further provided after the code 12-n. In this way, even the data 11 having a long bit length composed of a plurality of data frame strings is more likely to be repaired, and eventually the reliability and safety of the control device can be improved. Conversely, even data having a length that does not require division can be intentionally divided to enjoy the effects of the present invention.

Even in the first data frame 10-1, real data and a BCH code for restoring the real data are provided, and the whole of the second data frame 10-2 is regarded as one real data. BCH to repair this
A code may be provided. However, as is apparent from the above configuration, the first data frame 10-1 includes the real data 1
There is no problem if only 1-1 is provided, so that the occupation ratio of the actual data in the entire communication data length can be increased, which is reasonable.

Although the preferred embodiment of the present invention has been described above, any modifications according to the gist of the present invention are free. For example, in addition to the first and second data areas A and B, one or more other data areas are further provided, and the environment of those areas is defined by the first and second data areas A and B defined by the present invention.
The environment of B may be further different.

[0051]

Since the present invention has the above-described configuration,
The following effects can be obtained.

According to the present invention, the data stored in the first data area is refreshed at a predetermined cycle while the data stored in the second data area is inspected at a predetermined cycle. When erroneous data is found, non-volatile storage has a limit on the number of rewritable times and a limited data retention period because the error correction method rewrites and repairs only the error data with the correct logical value. Even in the non-volatile storage section, data security in the nonvolatile storage section can be sufficiently performed. In addition, the increase in data security capability means that even if the non-volatile storage unit itself does not have a long life by taking a structural measure, the life of the non-volatile storage unit can be substantially extended, and as a result, The life of the equipment using this can also be extended.

According to the second aspect of the present invention, at the time of refreshing, instead of writing with the same data content, data "0" is written every time a refresh is requested.
Since "1" is inverted and written, the life of the rewritable number can be approximately doubled.

According to the eighth, ninth and tenth aspects of the present invention, the BCH error correction code and the additional BCH error correction code are added to the data, so that the actual data provided for control is damaged. Even if the original BCH code for restoration is damaged, it is possible to exhibit a high ability in restoring the damaged actual data. Therefore, the possibility of erroneous operation without noticing a data error can be greatly reduced. This is extremely effective for controlling control devices requiring high safety, such as combustion devices. In addition, even in an environment where disturbance occurs, when various operations related to control can be performed by instructions from the remote controller, the safety can be improved. Can communicate even data that has been stepped on, and can create a more convenient environment for the user.

[Brief description of the drawings]

FIG. 1 is a block diagram showing the overall configuration of a data security device according to the present invention.

FIG. 2 is a diagram schematically showing an overall configuration of a combustion apparatus in which data security according to the present invention is performed.

FIG. 3 is an explanatory diagram of a data area.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Data security device 2 Refresh means 3 Storage means 4 Inspection restoration means 5 Non-volatile storage part 6 First data area 7 Second data area 10-1 First data frame 10-2 Second data frame 10-3 Third data frame 10-n nth data frame 11 real data 11-1 real data 11-2 real data 11-n real data 12 BCH code (BCH error correction code) 12-1 BCH code (BCH error correction code) 12-2 BCH code (BCH error correction code) 12-n BCH code (BCH error correction code) 21 Additional BCH code (Additional BCH error correction code) 30 EEPR0M 40 Controlled part 41 Combustion mechanism part 42 Fan motor part 43 Various sensors 50 Control device 51 CPU 52 RAM 53 ROM 61, 62 Data area 71, 72 data Data area 80 remote controller (remote control) 81 operation section 82 clock display section A first data area A1, A2 data area B second data area B1, B2 data area

Claims (11)

[Claims] 1. A data security device for storing and maintaining digital data in a rewritable nonvolatile storage unit, comprising: a first data area and a second data area each having at least one data area set in the nonvolatile storage unit. A data area; and write storage means for writing and storing the same data in each area of the first and second data areas when initial data is written and data is rewritten to the nonvolatile storage unit; Refresh means for refreshing the data stored in the area at a predetermined cycle; and inspecting the data stored in the second data area at a predetermined cycle. If error data is found, only the error data is detected by an error correction method. Inspection and repair means for rewriting and repairing the target with correct logical values. Data integrity apparatus according to claim. 2. The data security apparatus according to claim 1, wherein the refresh means writes the data to be written at the time of data refresh by inverting “0” and “1”. 3. The data security device according to claim 1, wherein each of the first and second data areas includes two or more data areas. 4. The refresh means checks all data at the time of data refresh, and when error data is found, rewrites and repairs only the error data with a correct logical value using an error correction method, and thereafter, recovers all data. The data security device according to claim 1, wherein the data is refreshed. 5. The data security device according to claim 1, wherein the refresh unit and the inspection and repair unit execute at the same cycle. 6. When data is rewritten due to a control operation of the control device, the refreshing unit and the inspection and repairing unit set a point in time when the rewriting is performed as a new starting point of a cycle. The data security device according to claim 1, wherein: 7. The inspection and repairing means according to claim 1, wherein when inspections in a predetermined cycle have been performed a predetermined number of times or more, all data in the second data area is refreshed at that time. A data security device according to item 1. 8. In each of the first and second data areas, a BCH error correction code for the real data is added to the real data, and an additional BCH error correction code for the real data and the BCH error correction code is added. The data security device according to claim 1, wherein a correction code is added. 9. In each of the first and second data areas, data is composed of two or more consecutive data frame strings, actual data is stored in a first data frame, and data is stored in a second data frame. Stores the BCH error correction code for the real data of the first data frame with the real data added thereto, and stores the BCH error correction code of the immediately preceding data frame and the real data in the third and subsequent data frames. The real data is added to the BCH error correction code for the one real data when it is regarded as one real data, and the BCH error correction code of the last data frame and the real data are added after the last data frame. BC for one actual data when it is regarded as one actual data
H error correcting code, and furthermore, in this last BCH error correcting code,
The data security device according to claim 1, wherein a CH error correction code is additionally stored. 10. In each of the first and second data areas, data is composed of a sequence of two or more consecutive data frames, and the first data frame has real data and a BCH error correction code for the real data. When the real data of the immediately preceding data frame and the BCH error correction code are regarded as one real data, the second and subsequent data frames have the B data corresponding to the real data.
The actual data is added to the CH error correction code and stored, and the BC of the last data frame is added after the last data frame.
When the H error correction code and the real data are regarded as one real data, a BCH error correction code for the one real data is stored. Further, in the last BCH error correction code,
2. The data security device according to claim 1, wherein a BCH error correction code for the last BCH error correction code is additionally stored. 11. A data preservation method for storing and preserving digital data in a rewritable non-volatile storage unit, wherein a first data area and a second data area each comprising one or more data areas are stored in the non-volatile storage unit. Setting, at the time of initial data writing and data rewriting to the non-volatile storage unit, the same data is written and stored in each of the first and second data areas, and the data stored in the first data area is stored. Is refreshed at a predetermined cycle, while the data stored in the second data area is inspected at a predetermined cycle, and if error data is found, an error correction method is used to correct only the error data with a correct logical value. A data preservation method characterized by rewriting and restoring.