JPH0455927A - Data area protection system - Google Patents

Abstract

PURPOSE:To protect the data at discontinuation of a CPU operation by updating and recovering the data for a storage area containing a back-up function which supplies the power via a battery and a processing procedure program of the CPU with use of a data updating means and a data recovery means. CONSTITUTION:A storage device includes a back-up storage area which receives the power of a battery and can hold the storage contents despite the cut-off of a power supply. The storage device also stores other information 32 including an under data updating flag 31, a data updating address, etc., and a data updating work area 33. A data storage area 34 is added to the storage device to temporarily store the data. In such a constitution, the flag is kept ON as long as the data are actually being written into the storage area and the contents of a buffer are already updated when the operation of a CPU is stopped during the updating of the data. Thus the data can be recovered when the data are transferred again to an actual storage area from the buffer.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a data area protection system, and in particular, the present invention relates to a data area protection system, and in particular, in a central processing unit, when data on a storage device is updated, the central processing unit is stopped due to a power cut, etc. The present invention relates to a data area protection method that can prevent data destruction in cases where data is destroyed.

[Conventional technology]

In conventional computer systems, when the central processing unit is stopped due to a power outage while updating the data on the storage device, there is a system that prevents the data to be held on the storage device from being destroyed. The common method was to duplicate the data to be updated and take backup data before updating the data.

[Problem to be solved by the invention]

In the conventional data area protection method described above, it is necessary to duplicate the entire data, so when there is a large amount of data to be protected, there is a drawback that the capacity of the data storage device increases and costs increase. Furthermore, since data duplication processing must be performed every time an update is made, there is a drawback that processing time increases.

[Means to solve the problem]

The data area protection method of the present invention is a data area protection method when the central processing unit is stopped due to a power outage of the computer, etc. In the data area protection method, information such as data update flag information, data update address, etc., and data update work storage area information are used. a backup storage unit protected by a battery power source storing the information, and means for starting up the central processing unit;
and data update processing means to protect data contents even if the central processing unit is temporarily stopped.

〔Example〕

Next, the present invention will be explained with reference to the drawings.

FIG. 1 is a block diagram of a storage device according to an embodiment of the present invention.

That is, the storage device has a backup storage area powered by a battery that can retain the stored contents even when the power is cut off, and includes a data update flag 31, other information 32 that stores data update addresses, etc. A data update work storage area 33 is stored therein. In addition to this backup storage area, it also includes a data storage area 34 for normal temporary storage.

Next, the procedure for starting up the central processing unit of this embodiment using this storage device will be explained with reference to the flowchart of FIG. First, power on the central processing unit (step 20).
), the central processing unit is started up (step 21). Next, raise the data update flag (step 22), and if the flag is on, write the data on the buffer to the data storage area (step 23).Next, turn off the flag (step 24) and proceed to the next process. Move (step 25)
. If the flag is off in step 22, the process similarly moves to the next step.

Next, the processing at the time of data update in this embodiment will be explained with reference to the flowchart of FIG. In this method, data update processing step 1
0, the data to be updated in that process is realized by first rewriting the backup area buffer 33 instead of directly rewriting the actual storage area 34. The procedure for this update process is performed in steps 11, 12, and 13. When the update on the buffer is completed, step 14 is performed to turn on the flag 31, and then an actual write step 15 is performed to transfer the updated data from the buffer to the actual storage area. , after completing step 15, step 16 is performed to turn off the flag, and the data update process is completed. Here, if we consider the case where the central processing unit stops during data update, if step 15 is being executed while writing to the actual storage area, the flag is on and the buffer contents are Since the update has been completed, the data can be recovered by retransferring the data from the buffer to the actual storage area. Therefore, when a central processing unit startup factor occurs such as power-on, the central processing unit startup step 21
In the process, a flag check (step 22) is performed, and if the flag is on, step 23 of retransferring from the buffer to the actual storage area is executed, and step 24 of turning off the flag is performed.
Execute.

〔Effect of the invention〕

As explained above, the present invention provides data update processing by performing data update means and data recovery means on a storage area having a backup function that supplies power with a battery and a processing procedure program of a central processing unit. One of the benefits is that data can be protected even if the central processing unit is stopped due to a power outage or the like.

[Brief explanation of drawings]

FIG. 1 is a configuration diagram of a storage device according to an embodiment of the present invention, FIG. 2 is a flowchart of startup processing of a central processing unit according to this embodiment, and FIG.
The figure is a flowchart when updating data in this embodiment. 31... Data updating flag, 32... Other information, 33... Data update working storage area, 34... Data storage area.

Claims (1)

[Claims] In the data area protection method when the central processing unit stops due to a computer power cut, etc., it is protected by a battery power source that stores information such as data update flag information, data update address, and data update work storage area information. A data area comprising a backup storage unit, a means for starting up the central processing unit, and a data update processing means, the data area being characterized in that the data contents are protected even if the central processing unit is temporarily stopped. Protection method.