JPH0441375B2 - - Google Patents

Description

[Detailed Description of the Invention] (a) Technical Field of the Invention The present invention relates to a written data check method, and more specifically, to a new check method that can detect with high accuracy whether or not numerical data written on a storage medium has been written successfully. It is related to the method.

(b) Conventional technology and problems In product inventory management systems using computers,
A block of numerical data such as a product code is frequently written to and read from a storage medium such as a magnetic disk. by the way,
Numerical data written to a storage medium must be subject to error control, and the following methods are known for checking this data. In other words, one is to read data written to a storage medium immediately after writing it,
This is a method in which this is stored in a memory and then compared with the written data, and if they do not match, it is output as a data write failure. The other type of detection is to read out the data written in the storage medium and its check code, calculate a check value from the data using a predetermined check code calculation method, and compare this with the read check code. It's a method. Although the former method has the advantage of being able to determine whether or not data has been correctly written to the storage medium, it has the disadvantage of requiring a long processing time. In addition, the latter method can process in a relatively short time, but even if no data has been written, the previously written data is read and checked, so it is judged as if the data writing at this time was performed normally. It had the disadvantage of being

(c) Purpose of the Invention The purpose of the present invention is to provide a new check method for the latter written data check method, which is also capable of checking whether or not written data has been correctly written to a storage medium. It is something to do.

(d) Structure of the Invention Briefly stated, the present invention provides a data processing device that writes multi-digit numerical data together with its check code into a block of a storage medium, in which a version number display area is attached to the block. death,
In this version number display area, the version number that is added each time new numerical data is input is written.
In addition, the total value of this version value and the related value of the input numerical data is written in the check area of the same block, and the block is The device is characterized in that it detects the quality of numerical data written in it.

(e) Embodiment of the invention Hereinafter, an embodiment of the invention will be described in detail with reference to the drawings.

FIG. 1 shows a unit block configuration of a storage medium according to this embodiment, and this block includes an area A1 for storing numerical data such as an input product code;
It consists of an area A2 for storing the writing version number and an area A3 for storing the check code. The version number data stored in the version number display area A2 is numerical data that is incremented by an integer "1" each time new numerical data is written to the data area A1 of the block. It is subject to a check code along with the written input numerical data. That is, the check code stored in the check area A3 is formed of a numerical value related to the total value of the numerical value of the input numerical data and the numerical value of the version number data. For example, if the input numerical data is a 4-digit number "1234" and the version data is a number "5", the check code will be the lower digit number "5" in these addition contents (1+2+3+4+5=15). ” is used.

Next, an example of the error checking operation of the input numerical data written in this manner will be explained according to the flowchart of FIG.

First, when writing of input numerical data is requested, the input data is temporarily stored in a register, etc., and the version number in the block selected for writing is read out and the numerical value "1" is added to it. . This added version number data is temporarily stored in a register or the like. Next, a check code is created from this input data and version number data in the manner described above, and this check code is written into the selection block along with the input numerical data and version number data. Next, after reading out all of the written contents, first, the numerical value of the read version number data is compared with the numerical value of the version number data in the temporary storage. If the comparison results match, it is assumed that the writing of the input data at this time was normal and the process moves on to the next process, but if they do not match, an abnormality notification signal is output as a writing error. This write error handling is different from the conventional check method described above. Assuming that this writing error does not occur, a check code is calculated based on the read input data value and the version number data value,
A numerical comparison is made between the calculated check code and the read check code. If the comparison result is a match, it is determined that the input data written at this time is correct, and if they are not a match, an abnormality notification signal is output as a write error. This write error handling is basically the same as the conventional method, and examples include cases where a certain digit value is written to data area A1 as a different value, or when no data is written to the same area. It is.

Note that writing quality determination processing based on version number data and writing quality determination processing based on check code are as follows.
In addition to performing in series as described above, it may also be performed simultaneously in parallel, and this parallel processing has the advantage of shortening the determination time. Also, regarding the handling of numerical data written to storage media, if you create a check code that recognizes the numerical value "0" as "10",
Even if a mistake is made in reading this "0" data, it is possible to prevent it from being detected as a write error using the conventional method.

(f) Effects of the Invention As is clear from the above description, according to the present invention, when writing numerical data to a storage medium, it is possible to prevent the data from being written at all, missing any digits, or writing errors. Since write errors can be detected in case of a write error, highly reliable data processing becomes possible.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing an example of the structure of a unit block in a storage medium to which the present invention is applied, and FIG. 2 is a flowchart for explaining one embodiment of the present invention. A1: Data area, A2: Version number display area, A
3: Check area.

Claims (1)

[Claims] 1. In a data processing device that writes multi-digit numerical data together with its check code to a block of a storage medium, a version number display area is attached to the block, and new numerical data is written in this version number display area. The edition value that is added each time the block is input is written, and the total value of this edition value and the related value of the input numerical data is written in the check area of the same block, and the total value is stored in this edition number display area. 1. A written data check method, characterized in that the quality of the numerical data written in the block is detected based on the written numerical value and the storage contents of the check area.