JPH0934802A - Error display method in check program - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide the error display method in which error indication at RAM access is ensured. SOLUTION: The method employs a ROM 4 storing an error check program for a RAM 3 and an error display program for the RAM 3, a CPU 1 allows the RAM 3 to read the error display program of the RAM 3 and uses the error display program for the RAM 3 to conduct read/write of the RAM 3, and when the read/write of the RAM 3 is not normally operated, the error display program is moved to other area than the area having stored the error display program and a display means 5 conducts error display of access of the RAM 3.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of displaying an error in a check program such as a diagnosis.

[0002]

2. Description of the Related Art A conventional error display method in a check program is such that when an error display occurs in a work area used by the program for displaying an error,
There is a problem that an error cannot be displayed because the CPU registers cannot be saved and restored normally.

FIG. 4 shows an explanatory view of a conventional RAM check.

Reference numeral 11 is a CPU, and 12 is a RAM. CP
It is assumed that there are 16 registers in U11. When the next display is performed, the information of the register is once saved and saved in the area of the RAM 12 in order to use 16 or more registers. However, if the RAM 12 is damaged, the information in the register cannot be restored in the CPU 11 and the display routine cannot be started.

[0005]

Therefore, the conventional method cannot display to the user or service person that the error has occurred in the RAM. Therefore, it took a long time to deal with repairs and the like. It also means that you do not know the cause of the error and the program that made the error. Furthermore, if the error is an error in which the displayed program is broken, everyone has no clue, and a great deal of labor and time are spent to deal with the repair.

[0006]

SUMMARY OF THE INVENTION It is an object of the present invention to provide an error display method for surely displaying an error when a RAM is accessed, with the object of solving these problems of the prior art. .

In order to solve the above problems, the present invention provides
A ROM that stores a RAM error check program and a RAM error display program is used. The RAM reads the RAM error display program by the CPU, and the RAM read / write is performed by the RAM error display program. When the read / write does not operate normally, the error display program is moved and stored in an area different from the area in which the error display program is stored, and the RAM access error display is performed by the display means.

[0008]

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

FIG. 1 is a block diagram of the present invention.
Is a flowchart.

Reference numeral 1 is a CPU, and 2 is a display program for coding data and reading it by the CPU 1. 3
Is a RAM, and 4 is an R storing an error display program of the RAM3 and a check program of the RAM3.
Reference numeral 5 is a display means for displaying an error message and the like, and 6 is an input / output device for the peripheral device 7.
FIG. 3 is a diagram showing a memory area of the RAM 3. Areas include an error display program work area 3a and an error display program work area 3b after movement.
This is provided to avoid a place where a read / write error occurs. The operation of the present invention will be described with reference to the flowchart of FIG.

First, the CPU 1 checks by reading / writing a specific pattern in the RAM 3 (step 1). It is checked whether or not the RAM 3 can be normally read / written (step 2). If the RAM 3 is operating normally, the display means 5 displays "Ready" indicating that the RAM 3 is operating normally. (Step 3). If the RAM 3 is not operating normally in step 2, it is determined whether or not a read / write error of the RAM 3 has occurred in the work area 4a used by the error display program 2 (step 4). If a read / write error has occurred, the error display program 2 sets an offset in the work area 3a to be used and automatically searches the area 3b in which no read / write error has occurred. Move (step 5). Then, in order to notify the user or service person that an error has occurred in the RAM 3, an error message is displayed on the display means 5 such as an LCD and the operation is stopped (step 6).

[0012]

As described above, according to the configuration and method of the present invention, the user or service person can be immediately notified of the RAM access error. Therefore, quick repairs can be taken.

[Brief description of drawings]

FIG. 1 is a block diagram of the present invention.

FIG. 2 is a flowchart showing the operation of the present invention.

FIG. 3 is a diagram showing a memory area of a RAM3.

FIG. 4 is an operation explanatory diagram of a conventional RAM check.

[Explanation of symbols]

 1 CPU 2 display program 3 RAM 3a area 3b area 4 ROM 5 display means 6 input / output device 7 peripheral device 11 CPU 12 RAM

Claims (1)

[Claims] 1. An error check program for RAM and R
Using the ROM storing the AM error display program, the RAM reads the RAM error display program by the CPU, and the RAM read / write is performed by the RAM error display program, and the RAM read / write operates normally. If not, the error display program is moved to and stored in an area different from the area in which the error display program is stored, and the error display of the RAM access is performed by the display means. Display method.