Patent ID: 8495433

Claim:
A microcomputer mutual monitoring system in which mutual monitoring is performed between a first microcomputer and a second microcomputer, wherein if a reset of the second microcomputer is performed due to an occurrence of an abnormal event in the second microcomputer, the monitoring of the first microcomputer is performed by an alternative monitoring function incorporated in the first microcomputer instead of the monitoring of the first microcomputer by a monitoring function of the second microcomputer during the reset, a computing equation calculated by the first microcomputer for the purpose of the monitoring of the first microcomputer by the second microcomputer before the reset of the second microcomputer and a calculation result thereof are stored as stored data in the first microcomputer, and the alternative monitoring function implements the monitoring of the first microcomputer during the reset of the second microcomputer by comparing a calculation result obtained when the first microcomputer recalculates the computing equation in the stored data with the corresponding calculation result in the stored data during the reset of the second microcomputer.