JPS6345648A - Automatic runaway processor for microcomputer - Google Patents

Abstract

PURPOSE:To ensure automatic runaway detection of a program with high accuracy by providing a detection means which detects the runaway of the program from the holding value of an executing frequency holding means obtained when a prescribed time is lapsed and a runaway processing means. CONSTITUTION:An automatic runaway deciding means 10, an interrupting means 20 and an abnormality processing means 30 consist of a memory 1, an arithmetic part 2 and a control part 3. The means 10 includes a processing repetitive executing part 11, a main processing frequency memory 12 serving as an executing frequency holding means which holds the executing frequency of a main program, an interruption frequency memory 13 and a checking part 14. The memory 13 stores the interruption frequency NI received from the means 20 and the part 14 checks the main action executing frequency for each main processing, i.e., at every time the interruption frequency received from the means 20 exceeds the prescribed frequency NIC. The means 30 performs the processing against the program runaway of a microcomputer MC when the main processing has an abnormal action, i.e., when the program runaway is occurred.

Description

[Detailed Description of the Invention] "Industrial Application Field" The present invention detects and processes the abnormality when the operation of a microprocessor deviates from the normal program execution state and performs abnormal execution. This invention relates to a self-runaway processing device for a microcomputer.

[Prior Art] Conventionally, as a self-runaway processing device for a microcomputer, one in which a retrigger type monostable multi-octabulator is provided outside the microcomputer is known.

That is, a trigger signal is sent from a predetermined port of the microcomputer to a monostable multivibrator within a predetermined period according to a program instruction, and the output terminal of the monostable multivibrator is connected to the reset terminal or interrupt terminal of the microcomputer. be.

The monostable multivibrator is driven by setting the width of the output pulse of the monostable multivibrator to be longer than the predetermined period of the trigger signal from the microcomputer. Therefore, as long as the microcomputer is operating normally, the monostable multivibrator is always retriggered and its output is always on. If the program goes out of control for some reason and the monostable multivibrator is not retriggered, its output changes from the on state to the off state. Therefore, self-runaway of the microcomputer can be detected by detecting the output state of this monostable multi-octibrator.

[Problems to be Solved by the Invention] Therefore, in conventional devices, special hardware is required to detect self-runaway, and the configuration becomes complicated and if a detection configuration is not incorporated at the time of design, It was not possible to add functionality.

[Means for Solving the Problem] As a means for solving this problem, for example, an execution number holding means for holding the number of executions of a predetermined program in a microcomputer, and an execution number holding means for each execution of a predetermined program are provided. A count up means for counting up the number of times, a detection means for detecting program runaway based on the value held in the execution count holding means when a predetermined time has elapsed, and a runaway processing means for processing the program runaway detected by the detection means are increased by 4 inches.

[Operation] By incorporating such a configuration into a microcomputer, program runaway detection and program runaway processing can be performed with almost no other configuration required.

〔Example〕

FIG. 1 is a block diagram showing one embodiment of the present invention, and FIG. 2 is a block diagram showing the embodiment shown in FIG. 1 in more detail.

In FIG. 1, a microcomputer MC has a memory 1, an arithmetic section 2, and a control section 3.

The memory 1 stores predetermined programs and predetermined data, the calculation unit 2 performs predetermined calculations, and the control unit 3 stores data in the memory 1 while controlling the memory 1 and the calculation unit 2, etc. The program is executed sequentially.

The self-runaway determination means 10, the interrupt means 20, and the abnormality processing means 30 shown in FIG. US2 are connected to the memory 1 and v! shown in FIG. ′
It is composed of the JX section 2 and the control 883.

Here, the self-runaway determination means 10 monitors the program execution operating state (hereinafter referred to as main processing) in the microcomputer MC, and the processing repeat execution unit 11 has an execution count holding unit that holds the number of executions of the main program. It has a main processing number memory 121, an interrupt number memory 13, and an inspection section 14, which are means.

The main processing number memory 12 is for storing main processing execution information, specifically the number of main operations, and the interrupt number memory 13 is for storing the number of interrupts NI from the interrupt means 20. Furthermore, the inspection unit 14 inspects the number of executions of the main operation for each main process (every time the number of interruptions from the interrupting means 20 has elapsed by a predetermined number of NICs).

Note that the main processing here refers to a certain set of processing.

The interrupt means 20 periodically interrupts using an internal timer of the microcomputer MC (7), and may be executed using an external timer instead of the internal timer of the microcomputer MC.

The abnormality processing means 30 is a means for processing a runaway program of the microcomputer MC when the main processing malfunctions (when a program runaway occurs), and displays an abnormality on the display means 40, or displays a predetermined program. This is for restarting, etc.

Next, the operation of this embodiment with the above configuration will be explained in FIG. 3 (A
), CB) will be explained with reference to the flowcharts.

First, the main processing in the calculation section 2 and the control section 3 will be explained with reference to the main processing flowchart in FIG. 3(A).

First, in step S1, an initial value is set in the memory 1 of the microcomputer MC, one interrupt is allowed, and the main processing number memory 12 is reset.

Here, both the main processing number memory 12, which stores the number M of main processing, and the interrupt number memory 13, which holds the number NI of interrupts from the interrupt means, are set to "O".

In the following step S2, the process repeat execution unit 11 executes one main process, and when this process is finished, the process repeats in step S3.
Increment the main processing number memory 12 by 1 with
[M]=[M]+1 and returns to step S2 again.

In the main process, steps S2 and S3 are repeatedly executed each time the process is executed.

Next, the runaway detection process in the self-runaway determination means o is carried out in the third step.
This will be explained with reference to the interrupt processing flowchart shown in FIG.

When an interrupt is generated from the interrupt means 20 or another external device in step SIO, the calculation section 2 and the control section 3 execute predetermined interrupt processing. When the interrupt processing is completed, the interrupt count memory 13 is incremented by one in step Sll to set [NI]=[NI]+1, and the subsequent step S
In step 12, it is checked whether the number of interrupts (NI) held in the interrupt number memory 13 is smaller than the value of the predetermined number [NIC]. Here, if (NI)<(Nxc), nothing is done, the process is skipped, and the process returns to the main process. If (NI)<(NIC), the process advances to step S13, and the main processing number memory 12
Check whether the value of satisfies [a<M<bl,
If not satisfied, the process advances to step 515 and abnormality processing is performed.

If satisfied, the process proceeds from step S13 to restep S14, where the main processing number memory 12 and the interrupt number memory 13 are stored.
are cleared to "O°", exit the process, and return to the main routine.

Here, the above-mentioned number of interrupt executions [NIC] can be determined arbitrarily, and is preferably selected at an appropriate time depending on the number of interrupts from the interrupt means 20 that occur when the main process is executed once.

Furthermore, each of “a”′ and b″° is a value determined according to the number of times the main process is expected to be executed while [N I Cl interrupt processes are executed; A value slightly smaller than the minimum number of times the main processing is executed is set as "a", and a value slightly larger than the maximum number is set as "b".

If an abnormal jump occurs from one program to another due to self-runaway during execution of the main process, or if no interrupt occurs, step S13
In this case, the value M of the main processing number memory 12 does not fall within the predetermined range (that is, a to b). In this case, the process proceeds from step S13 to step S15, and the display means 40 displays a program runaway message. Perform processing such as displaying.

In addition, as an abnormality process, instead of displaying on the display means 40, depending on the case, the device may be started to initial reset and restarted from step S1. In this case, the reset terminal of the microcomputer MC may be All you have to do is input a reset signal.

Note that a counter may be provided outside the microcomputer MC, and this counter may be configured to count the number of the above-mentioned interrupts, and to determine whether or not self-runaway has occurred.

Furthermore, in the above description, the abnormality is detected after the main processing is executed a plurality of times, which is suitable for relatively long programs. In other words, if the program is relatively long, the number of main processings that occur during one interrupt processing is small, so it is difficult to discover the number of main processings in one interrupt processing, but if the interrupt is executed multiple times. By doing so, the number of main processing times can be reliably detected, self-runaway programs can be detected reliably, and the processing can be carried out appropriately.

As described above, according to this embodiment, self-runaway of a microcomputer can be detected and dealt with without the need for any other special hardware circuit. Furthermore, by checking whether the above counter value falls within a certain range, it is possible to detect not only cases where there are no specified interrupts within a specified period of time, but also cases where there are too many interrupts. .

Self-runaway detection can be performed with extremely high accuracy.

[Effects of the Invention] As explained above, according to the present invention, self-runaway detection of a program can be performed with extremely high accuracy, and a microprocessor that does not require the addition of a special hardware configuration for this self-runaway detection can be performed. A computer self-runaway processing device can be provided.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing an embodiment according to the present invention, FIG. 2 is a detailed block diagram of the embodiment, and FIG. 3 (A) and CB) are flowcharts showing the operation of the embodiment. In the figure, ■...Memory, 2...Arithmetic unit, 3...Control unit. lO... Self-runaway determination means, 11... Processing repetition execution unit, 12... Main processing number memory, 13...
Interruption number memory, 14... Inspection unit, 20... Interruption means, 30... Abnormality processing means, 40... Display means, M
C... It is a microcomputer. Patent applicant Yasunori Otsuka, patent attorney, Canon Co., Ltd., V-. ;・-ll↑□ ,-.・ ・ , −÷. (!□-! MC. Figure 1 < MC Figure 2 Figure 3 (A) Mainter/1 Logic

Claims (5)

[Claims] (1) Execution count holding means for holding the number of executions of a predetermined program in a microcomputer; count-up means for counting up the execution count holding means every time the predetermined program is executed; and the number of executions after a predetermined time elapses. A self-runaway processing device for a microcomputer, comprising a detection means for detecting a program runaway based on a value held by the holding means, and a runaway processing means for processing the program runaway detected by the detection means. (2) Self-runaway processing of a microcomputer according to claim 1, wherein the detection means determines that the program has runaway when the count-up value of the execution number holding means after a predetermined time has elapsed is not within a predetermined range. Device. (3) A self-runaway process of a microcomputer as set forth in claim 1 or 2, wherein the detection means determines the elapse of a predetermined time based on a measured value of a timer clocking means provided in the microcomputer. Device. (4) A self-runaway processing device for a microcomputer according to claim 1, wherein the runaway processing means operates a display means for displaying a runaway state. (5) A self-runaway processing device for a microcomputer according to claim 1, wherein the runaway processing means restarts a predetermined program.