JPH01196636A - Runout detecting device for processor - Google Patents

Abstract

PURPOSE:To easily execute the integration of a circuit by providing a counter circuit to obtain the clock output signal of a reference clock circuit as an input and to obtain a pulse output signal by the program of a processor as a reset input. CONSTITUTION:A reference clock circuit 14 and a counter circuit 15 are used as a timer 13 and a time to count-up by the counter circuit 15 is obtained longer than the period of a pulse output signal (b) which is outputted from a processor 11. Then, when abnormality is generated in the processor 11, the pulse output signal (b) is not outputted and the abnormality of the processor can be detected by counting-up the timer 13. Since a runout detecting device is composed of the reference clock circuit 14 and counter circuit 15, circuit constitution can be executed only by digital circuit parts. Thus, the integration of the circuit can be easily executed.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a processor runaway detection device in a circuit controlled by a processor.

2. Description of the Related Art A conventional processor runaway detection device of this type will be described with reference to the schematic circuit diagram of FIG.

In FIG. 3, l is an R-S flip-flop circuit, to which an output X from a processor (not shown) is input as a reset input, and an output X obtained by inverting the output X is input as a set input. R-S flip-flop circuit 1
The output Q and the output Q of are respectively input to an integrating circuit 2゜3 consisting of a capacitor and a resistor, and the outputs of the integrating circuits 2 and 3 are outputs of O
The signal is input to the R circuit 4, and the output of the OR circuit 4 is further input to a level detection circuit (not shown). It is assumed that during normal operation, the processor inverts and outputs the outputs x and x at regular intervals, and that the integrating circuits 2 and 3 are reset when their inputs become zero.

The operation of the processor runaway detection device having the above configuration will be described below. Since the outputs x, It is reset every time, the output of the OR circuit is suppressed below the detection level of the level detection circuit, the level detection circuit does not operate, and it is detected that the processor is normal. However, if an abnormality occurs in the processor, the processor outputs The number continues to increase until it reaches the detection level of the level detection circuit, and the level detection circuit operates, and an abnormality in the processor is detected. The abnormality detection time is determined by the time constants of the integrating circuits 2 and 3.

Problems to be Solved by the Invention However, in the configuration of the conventional processor abnormality detection device described above, when the integration of circuits is promoted, the integration circuit 2
, 3 uses capacitors, making it difficult to integrate.

The present invention solves the above problems, and aims to provide a processor abnormality detection device whose circuits can be easily integrated.

Means for Solving the Problems In order to solve the above problems, the present invention provides a processor with a program that outputs pulses at regular intervals as one output during normal operation, and includes a reference clock circuit and a clock output of the reference clock circuit. A counter circuit is provided which receives a signal as an input and receives a pulse output signal according to a program of the processor as a reset input.

Effect With the above configuration, the reference clock circuit and the counter circuit are used as a timer, and the time during which the counter circuit counts up is set longer than the period of the pulse output signal of the reset input output from the processor, and the pulse output signal is prevented from occurring due to an abnormality in the processor. When the processor stops and this timer counts up, it is detected that the processor has stopped or gone out of control.

Example Hereinafter, one embodiment of the present invention will be described based on the drawings.

FIG. 1 is a block diagram of a control device equipped with a processor abnormality detection device according to the present invention. In FIG. 1, 11 is a processor that controls the controlled circuit ν, and as shown in FIG. The program has a program in which the pulse output is outputted as a -output at regular intervals by inverting the output at each time. Reference numeral 13 designates a timer, which includes a reference clock circuit 14 and a counter circuit 15 which receives the clock output signal a of the reference clock circuit 14 as an input and receives the pulse output signal S according to the program of the processor 11 as a reset input. is the reference clock output signal a
When the processor B is in normal operation, it is reset by the pulse output signal output from the processor 11 at regular intervals.

The set time for the timer is obtained from the frequency of the reference clock circuit 14 and the set value of the counter circuit section, and this set time is set to be longer than twice the longest time required for processing the program of the processor 11.

If an abnormality occurs in the processor 11, the pulse output signal will not be output from the processor 11, so the timer B will not be reset at regular intervals, and the timer 13 will operate, that is, the counter circuit will count up, and the processor H will be abnormal. is detected. When an abnormality in the processor 11 is detected at the timer port, the error processing circuit 16 at the subsequent stage operates the signal cutoff circuit 17.
At this point, the output of the processor 11 to the controlled circuit is cut off.

In this way, the abnormality detection device for the processor 11 can detect an abnormality in the processor 11, and since it is configured with a timer port that receives the pulse signal output from the processor 11 at regular intervals as a reset input, it is possible to detect abnormalities in the processor 11. The circuit can be easily integrated.

Effects of the Invention As described above, according to the present invention, the reference clock circuit and the counter circuit are used as a timer, and if the time for the counter circuit to count up is longer than the cycle of the pulse output signal output from the processor, the processor may be abnormal. When this occurs, the pulse output signal is not output and the timer counts up, making it possible to detect an abnormality in the processor. Furthermore, since it is composed of a reference clock circuit and a counter circuit, the circuit can be constructed using only digital circuit components, and the circuit can be easily integrated.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of a control device equipped with a processor abnormality detection device according to an embodiment of the present invention, FIG. 2 is a program flowchart of the processor shown in FIG. 1, and FIG. 3 is a conventional processor abnormality detection system. FIG. 3 is a circuit diagram of the device. 11... Processor, B... Timer 1114...
Reference clock circuit, 15... Counter circuit, a...
Clock output signal, b...pulse output signal.

Claims (1)

[Claims] 1. Provide a processor with a program that outputs pulses at regular intervals as an output during normal operation, input a reference clock circuit and the clock output signal of the reference clock circuit, and reset the pulse output signal according to the program of the processor. A processor runaway detection device equipped with a counter circuit as an input.