JPS6010669B2 - Storage device control method - Google Patents

Description

[Detailed description of the invention] This invention relates to a storage device control method.

This invention relates to a storage device control system, and particularly relates to an improvement in a processing method for confidential information left on a storage device. In information processing systems such as electronic computers, many people's programs may be processed simultaneously (multiprogramming).

In this case, the program to be processed may contain confidential information that cannot be known by others, and it is necessary to either prohibit access from others or delete it yourself. A main memory device generally used in an information processing system has the property that once information is stored, it retains the information until it is written next. Therefore, in order to protect confidentiality, each program must ensure that the information in the main memory is erased after completing its processing. If this is done by a program, the processing capacity of the information processing system will be reduced. The purpose of this invention is to eliminate the above-mentioned conventional problems, and it is possible to erase all the information that you have used in the main memory with one command without having to carefully erase all the information that you have used in the main memory. An object of the present invention is to provide a storage device control method that has the effect of erasing an address immediately above a main storage device that has been used by a user.

A feature of the present invention is that the main memory is generally divided into many blocks, and each block is determined and processed by which program it will be used.

Therefore, a circuit is provided to erase stored information in block units (turning off the power or applying a special voltage to erase the information), and all blocks used at the end of the program are simultaneously erased using the above circuit. Next, embodiments of the present invention will be described in detail with reference to the drawings.

The figure is a block diagram of one embodiment of the present invention. Storage device 1
01 is divided into a plurality of blocks 102. Block 102 is the minimum unit structure that can be used by individual programs. Therefore, multiple blocks 102 are used to process one program. A set register 103 is provided corresponding to the block 102. This register is made up of a number of bits that can distinguish the number of programs that the information processing system processes simultaneously, and is a register that stores a program number. In a system that can process 15 programs at the same time, it becomes a 4-bit register.

When the system operates, writing to the storage device occurs. When writing, a write address is given to the block 102 to be written by obscuring the data set line 107, and writing is performed, but at the same time, the program number specified for writing is set in the set register 103 corresponding to that block 102. . In this way, whenever writing is performed to an address in each block, the program number is set in the set register 103, thereby making it possible to determine which program is in use in any block 102. However, since multiple programs are of course being processed at the same time, the system program manages the blocks to prevent the same block from being used twice. When the processing of a certain program is finished and a command is issued to erase all the information used at the end of that program,
In the system program, the program number is set in the reset register 104 through the set line 108.
As a result, the reset register 104 and all set registers 03 are compared in the match circuit 105, and the reset line 1
A pulse is applied to only those circuits that match 06, erasing all information on the addresses in the corresponding block 102, and also resetting the contents of the set register 103. Various methods of erasing contents are known, and any method can be used. For example, a circuit may be provided for each block to turn off the power to that block, and a matching output from the matching circuit 105 may cause the circuit to turn off the fin source to erase the stored information of that block. Another method is to provide a circuit that applies a special voltage to each block, and
It is also possible to use the match output from 5 and erase it. This makes it possible to erase all the information used in the 0 program at once by providing only one reset command in the program. With the configuration as described above, the following effects can be obtained in the present invention.

It is possible to erase all the information used for convenience by using only one instruction in the program, and the performance of the entire information processing system is not degraded.

In addition, information related to a program can be deleted at any time and kept confidential.

[Brief explanation of drawings]

0 is a block diagram showing an embodiment of the present invention. 101... Storage device, 102... Flock, 103... Set register, 104... Reset register, 105... Coincidence circuit. evening

Claims (1)

[Claims] 1 The storage device is divided into a plurality of blocks, and a reset register is set in which a number identifying the program to be deleted is set by an instruction specifying that all information used by a certain program be deleted, and a reset register is set for each block corresponding to the above block. A set register is provided in which a number identifying the program to be used is set, and when the above instruction is issued,
A storage device control method characterized in that the contents of a reset register and each set register are matched, and the contents of a block corresponding to a set register having a matching number are erased.