FAILURE DETECTING METHOD, SEMICONDUCTOR DEVICE, AND MICROCOMPUTER APPLICATION SYSTEM

The present invention is directed to improve the precision of failure detection by performing the failure detection by changing an analog amount of a circuit to be subjected to the failure detection. An analog amount of the circuit to be subjected to failure detection is changed under a predetermined condition by a tuning circuit, and a state change in the circuit to be subjected to failure detection based on the change in the analog amount in the circuit to be subjected to failure detection is determined by a failure detection circuit, thereby detecting a failure in the circuit to be subjected to failure detection. In such a manner, without monitoring an output of the failure detection circuit on the outside of a semiconductor device, a failure in the circuit to be subjected to failure detection can be detected. Moreover, an actual state change in the circuit to be subjected to failure detection based on a change in the analog amount in the circuit to be subjected to failure detection is determined by the failure detection circuit, so that precision of failure detection is improved.