JPH0784786A - Program execution control method - Google Patents

Abstract

(57) [Summary] [Purpose] To realize a program execution control method capable of preventing abnormal processing such as runaway due to noise or static electricity. [Constitution] The control device includes a CPU 11 for performing various data processing including control of the entire device and program execution processing.
And a program memory 12 composed of a main routine program, subroutine I, subroutine II and subroutine III, a work memory 13 for temporarily storing data during arithmetic processing, and all returns from subroutine I, subroutine II and subroutine III The sub-routine table 14 for storing addresses is provided, and all the return addresses from the sub-routine I, the sub-routine II and the sub-routine III are stored in the sub-routine table 14 in advance. It is checked whether the return address is stored in the table 14, and if the return address is not stored in the sub-routine table 14, processing such as reset is performed as a subroutine call due to an abnormal operation.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a program execution control method, and more particularly to a program execution control method capable of preventing abnormal processing of a program.

[0002]

2. Description of the Related Art An interrupt is a computer that responds to an asynchronous or exceptional event that occurs during program execution, forcibly suspending the program being executed and automatically executing a specified routine. To transfer control to. At that time, the CPU state is automatically saved so that the program being executed at the time of the interruption can be restarted later. The cause of the interrupt can be classified according to whether it is a hardware factor or a software factor. The notification of the end of the input / output operation and the notification of the failure of various devices are due to the hardware factor, and the overflow due to the calling of the control program and the calculation are due to the software factor. Also,
It can also be classified by whether or not the factor of the interrupt occurrence is related to the program being executed at the time of the interrupt occurrence.

[0003]

Similar to the case of the above-mentioned interrupt, when the main routine is executed, a subroutine capable of executing a specific process is called and executed, and after the completion of the subroutine process, the process returns to the main routine to execute the main routine process. continue. However, if a subroutine is called due to an abnormal operation due to noise or static electricity, an abnormal process due to a runaway may occur due to an unspecified return destination. That is, in the conventional subroutine processing, it is not possible to prevent the abnormal processing because it is not taken into consideration that the subroutine is called due to an abnormal operation due to noise, static electricity or the like.

Therefore, an object of the present invention is to provide a program execution control method capable of preventing abnormal processing such as runaway due to noise, static electricity or the like.

[0005]

In order to achieve the above-mentioned object, the present invention is a program execution control method for executing a series of programs according to a routine stored in advance, which is provided when returning from a subroutine to a main routine. , The return address in the main routine is checked, the checked address is compared with all the return addresses stored in the predetermined table memory corresponding to the above subroutine, and if there is no match, the subroutine The process is terminated as if it was abnormally executed.

[0006]

In the present invention, first, it is assumed that all return addresses from the subroutine are previously stored in the table memory.

When performing the subroutine processing, when returning from the subroutine to the main routine, the return address on the main routine is checked and compared with all the return addresses stored in the table memory. When the return address matches the return address stored in the table memory, the subroutine normally returns to the main routine, and if there is no match, it is regarded as abnormal execution of the subroutine and the processing ends (for example, reset). )
Let

Therefore, it is possible to prevent abnormal processing due to runaway caused by noise, static electricity or the like.

[0009]

EXAMPLES Examples will be described below with reference to FIGS.

1 to 3 are diagrams showing an embodiment of a program execution control method, and this embodiment is an example in which the program execution control method is applied to a control device.

First, the structure will be described. FIG. 1 is a block diagram of the control device. In this figure, reference numeral 11 denotes a CPU (Central Processing Unit) that controls the entire apparatus and performs various data processing including program execution processing described later, and the CPU 11 of the control apparatus follows a microprogram stored in a ROM (not shown) Controls various operations. The CPU 11 has a main routine program,
A program memory 12 composed of a subroutine I, a subroutine II and a subroutine III, a work memory 13 for temporarily storing data being processed, and a subroutine
A sub-routine table 14 for storing all return addresses from I, sub-routine II and sub-routine III is connected to each.

The sub-routine table 14 is a table in which all return addresses from the sub-routines I, II and III are stored in advance.

Next, the operation of this embodiment will be described.

First, the basic flow of the routine of the program execution control method of this embodiment will be described with reference to the flow chart shown in FIG.

If there is a subroutine call during the execution of the main routine (step S1), the process moves to the called subroutine and the subroutine is executed (step S2). When the subroutine processing ends, there is a subroutine call. To return to the main routine (step S3).

FIG. 3 is a flowchart of a subroutine check process when the above subroutine process is executed.

First, the current return address is checked in step S11, and the table information (return address) corresponding to the current subroutine number is read in step S12.
Next, it is checked whether the return address checked in step S13 matches the detected table information, and step S1
In step 4, it is determined whether or not there is a match between the return address and the detected table information. When there is a match between the return address and the detected table information, it is determined that the subroutine is executed normally, the subroutine process is executed in step S15, and after the subroutine process is completed, the process returns to the main routine.

On the other hand, when there is no match between the return address and the detected table information, it is determined that the subroutine is called due to an abnormal operation, reset processing is performed in step S16, and the process returns to the beginning of the main routine.

As described above, the control device of this embodiment comprises the CPU 11 for controlling the entire device and various data processing including program execution processing, the main routine program, the subroutine I, the subroutine II and the subroutine III. A program memory 12 and a work memory 13 for temporarily storing data being processed,
The sub-routine table 14 for storing all return addresses from the sub-routine I, the sub-routine II and the sub-routine III, and storing all return addresses from the sub-routine I, the sub-routine II and the sub-routine III in advance in the sub-routine table 14 , Before the subroutine processing, the return address is table 1 by subroutine
4 is checked, and when the return address is not stored in the subroutine-specific table 14, reset processing is performed as a subroutine call due to abnormal operation, so abnormal processing due to runaway due to noise, static electricity, etc. is performed. Can be prevented.

In the present embodiment, the above-mentioned check routine is performed before the subroutine processing, but the present invention is not limited to this, and it may be performed at the end of the subroutine processing, and may be performed before and after the subroutine processing. Good.

Further, in the present embodiment, the program execution control method is applied to the control device, but the present invention is not limited to this, and the program execution control when executing a series of programs according to a routine stored in advance. It goes without saying that any control method can be applied as long as it is a method.

Needless to say, the circuits and elements that make up the control device and the types thereof are not limited to those in the above-described embodiments.

[0023]

According to the present invention, when returning from the subroutine to the main routine, the return address on the main routine is checked and the checked address is stored in a predetermined table memory corresponding to the subroutine. Compared with all the return addresses that have been set, and if there is no match, it is considered as abnormal execution of the subroutine and the processing is terminated, so abnormal processing such as runaway due to noise or static electricity can be prevented. it can.

[Brief description of drawings]

FIG. 1 is a block configuration diagram of a control device of an embodiment of a program execution control method according to the present invention.

FIG. 2 is a flowchart showing a basic flow of a routine of the same embodiment.

FIG. 3 is a flowchart of a subroutine check process when the subroutine process of the embodiment is executed.

[Explanation of symbols]

 11 CPU 12 Program Memory 13 Work Memory 14 Subroutine Table

Claims (1)

[Claims] 1. A program execution control method for executing a series of programs according to a routine stored in advance, wherein the return address on the main routine is checked when returning from the subroutine to the main routine. The specified address is compared with all the return addresses stored in the specified table memory corresponding to the above subroutine, and if there is no match, it is considered as abnormal execution of the subroutine and the processing is terminated. And a program execution control method.