Abnormality monitoring method and control system

Abstract

To suppress the load of abnormality monitoring processing when a microcomputer is normal, and appropriately secure specified data when an abnormality occurs in the microcomputer.SOLUTION: This is an abnormality monitoring method for monitoring abnormalities in a microcomputer 100 that constitutes a control system 1. The microcomputer 100 includes a CPU 110, a memory 120, and a timer circuit 141. The control system further includes an external monitoring device 200 and a nonvolatile memory 300. The external monitoring device 200 detects an abnormality in the microcomputer 100 based on an output interval of a pulse signal S1 becoming equal to or greater than a second abnormality detection line T1, and outputs an HW reset signal S2. The microcomputer 100 detects an abnormality in the microcomputer 100 based on the output interval of the pulse signal S1 becoming equal to or greater than a first abnormality detection line T3, and stores saved data held in the microcomputer 100 in the nonvolatile memory 300.SELECTED DRAWING: Figure 4

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