JPH02219101A - Output processor - Google Patents

Abstract

PURPOSE:To perform abnormality processing even when a microcomputer runs away by storing exactly the same contents of output data in a 1st and a 2nd storage device and comparing their data with each other. CONSTITUTION:The output data determined by an output determination device 1 is stored in the 1st and 2nd storage devices 2 and 3 as exactly the same contents and the stored data are compared with each other. When the data coincide with each other, it is judged that the output data is normal, the data is outputted by using the data in the 1st storage device, and the contents of the 1st storage data is cleared. If the data in one storage device varies owing to a noise, static electricity, etc., it is decided that they do not coincide with each other, and the abnormality processing is performed. Further, the data in the storage device can be cleared after the output operation, so even if the microcomputer runs away to disable the processing for output data determination to be performed, the data in the 1st and 2nd storage device become different from each other and the abnormality can be judged.

Description

[Detailed Description of the Invention] (Industrial Application Field) The present invention uses a microcomputer (hereinafter referred to as microcomputer) to control various loads, and in particular outputs during interrupt processing. The present invention relates to an output processing device for a device that performs processing.

(Prior Art) Conventionally, as shown in FIG. 3, this type of output processing device includes an output determining device t21 that performs calculations to determine output data, a storage device 22 that stores the output data, and a storage device 22 that performs output. The output device 23 is configured such that output is performed during interrupt processing. FIG. 4 shows a circuit diagram of a device that controls a heater using this output processing device, in which a power control element 25 is controlled by the output of a microcomputer 24 to control energization of a heater 26. 27 is a circuit that generates a zero cross pulse (hereinafter referred to as ZCP) of the AC power supply 28. The microcomputer 24 detects this ZCP by inputting an external interrupt signal and outputs it in synchronization with the ZCP.

For example, when outputting four pieces of data, instead of using four independent pieces of data,
Treated as one bit of data, assign each of the 4 bits to an individual output, and turn OFF when it is 0.
, 1, it is stored in the RAM as ON. Output can be done by writing 4-bit data as it is to the output register of the 4-bit configured output port, or outputting 4 at the same time.
This can be done individually by determining the data bit by bit.

(Problem to be Solved by the Invention) However, in the above method, since one output data is stored as a 1-bit Oll, the bits may be reversed due to noise, static electricity, etc., and 0 may change to 1. In some cases, it turns on even though it should be off. Also, output is performed using external interrupt processing,
Even though the output data cannot be rewritten due to a runaway of the microcomputer, if only external interrupt processing is performed in synchronization with the ZCP, the same output will always be performed and normal control will not be performed. Therefore, the controlled object is
If it is a heater, there is a problem that there is a risk of burns or fire due to heating.

The present invention provides an output processing device that solves the above problems.

(Means for Solving the Problems) In order to solve the above problems, the output processing device of the present invention includes:
an output determining device that determines output data based on the calculation result; first and second storage devices that store output data with exactly the same content; and comparing the data stored in the first and second storage devices; - It consists of an output device that outputs data using the data in the first storage device when it loses, clears the data in the first storage device, and performs abnormal processing if they do not match.

(Function) With the above configuration, it is possible to handle an abnormality when the stored output data is reversed due to noise, static electricity, etc., or when the output data cannot be rewritten due to runaway of the microcomputer.

(Example) Hereinafter, one example of the present invention will be described based on the accompanying drawings. FIG. 1 is a block diagram of the output processing device in this embodiment, in which 1 is an output determining device, 2 and 3 are first and second storage devices, respectively, and 4 is an output device.

FIG. 2 is a flowchart in this embodiment, showing the output procedure. First, output data is determined by calculation S5, and then the determined output data is stored in the first and second storage devices S6. S7L, wait for interrupt processing to end S8; actual output is interrupt processing S
In the 0 interrupt process S9 performed in step 9, the data in the first and second storage devices are first compared S10, and if they do not match, it is determined that there is an abnormality, and an abnormality process S14 is performed.

If so, it is determined that the output data is normal, the output Sll is performed using the data in the first storage device, and the data in the first storage device is cleared S12. Clearing here means writing data of output OFF, and when the value is 0 or more, the interrupt processing 9 is ended and the process returns to the output data determination processing S5 again at S13.

Therefore, if the data in the storage device has changed due to noise, static electricity, etc., when the data is compared, it will be determined that there is a mismatch, and abnormality processing can be performed. Of course, if the data in the first and second storage devices change in exactly the same way, no abnormality processing can be performed even if the data is abnormal.
In reality, this is a very rare case, and this method is extremely effective in practice. In addition, since the data in the first storage device is cleared after output, in the unlikely event that the microcomputer goes out of control and cannot perform the process of determining the output data, the data in the first and second storage devices will be cleared. The data will be different and can be determined to be abnormal. If the data in the second storage device is OFF data, it will match the data in the first storage device, but in this case the output will be OFF.
Since it is a FF, runaway of the microcomputer cannot be detected, but the operation can be made on the safe side. If such an output processing device is applied to the heater control shown in FIG. 4, a control circuit with higher safety can be provided.

(Effects of the Invention) As described above, according to the output processing device of the present invention, the following effects can be obtained.

(1) Discover data abnormalities due to noise, static electricity, etc.
Abnormality processing can be performed.

(2) Runaway of the microcomputer can be detected and abnormality processing can be performed.

(3) It is possible to prevent malfunctions such as burns and fires, which have been problems when applied to control circuits for heaters, etc., and to obtain a significant effect in terms of safety.

[Brief explanation of the drawing]

Fig. 1 is a block diagram of an output processing device showing an embodiment of the present invention, Fig. 2 is a flowchart of the same device, Fig. 3 is a block diagram of a conventional output processing device, and Fig. 4 is an application of the output processing device. FIG. 2 is a circuit diagram showing an example of a heater control circuit according to the present invention. 1...Output determining device, 2...First storage device, 3...Second storage device, 4...
・Output device.

Claims (2)

[Claims] (1) An output determining device that determines output data based on the calculation result, first and second storage devices that store the output data with exactly the same content, and a device that stores the output data in the first and second storage devices. An output process consisting of an output device that compares the data and, when they match, outputs using the data in the first storage device, clears the data in the first storage device, and performs abnormal processing if they do not match. Device. (2) an output determining device that determines output data based on calculation results; and a first storage device that stores the output data;
A second storage device that stores inverted data of the output data is compared with the contents of the first and second storage devices, and if normal, output is performed using the data of the first storage device. , an output device that clears data in a first storage device, and performs abnormal processing if it is abnormal.