CPU ABNORMALITY DETECTION DEVICE

摘要

PURPOSE: To provide a CPU abnormality detection device which can effectively reduce the power consumption of the CPU that is connected to a battery power supply. CONSTITUTION: A W/W circuit 107 consists of a 1st reset circuit 107a, a 2nd reset circuit 107b and a pulse output circuit 107c. The circuit 107a outputs the reset signals to the port RESET of a CPU 100 by the signal outputted from a port PO. The cycle when the reset signals are outputted from the circuit 107a is set by a resistor R3 and a capacitor C3. The circuit 107b outputs the reset signals to the port RESET of the CPU 100 like the circuit 107a. The reset signal output cycle of the circuit 107b is set by a resistor R4 and a capacitor C4. The reset cycle of the circuit 107b is set longer than the pulse signal output cycle of the circuit 107c.