Reliability of Operation of Single Chip Microprocessor with Watchdog in Thermal Stress Conditions

The temperature influence (especially their irregular distribution in the digital chip structure) on proper operation of the microprocessor system has been presented in the paper. As the results of non-uniform heating of silicon structure the incorrect operation of selected functional blocks of single chip microprocessor can be observed. Especially, the circuits which operation is independent on global clock of the whole logic structure are endangered on such phenomena. The good example can be block which controls the correctness of program running - its operation is dependent on correct working of independent internal generator. In reality (especially where temperature changes are sudden - e.g. turn on of microprocessor system) the systems of temperature correction does not operate properly and watching time is changed. As result the incorrect clearing signal can be generated.