Watch dog timer system

Abstract

A watch dog timer system which has an abnormality checking function of a high degree of reliability. In the watch dog timer system, abnormality of a computer system is detected as a variation of a value allocated in accordance with an execution condition of a program. To this end, a register receives execution state data defined in accordance with an execution condition of the program from a processor or CPU of the computer system and stores the execution state data before a counter of the watch dog timer system overflows. A comparator compares the execution condition data stored in the register and state sequence data indicative of a state sequence of the program stored in a ROM in advance with each other and generates a reset signal for resetting the computer system when the comparison reveals incoincidence.

Dependencies are inferred from the claim text.