A High-speed Watchdog Processor for Multitasking Systems

A new watchdog processor scheme for concurrent checking of program control flow is presented. This method is intended to check state of the art processor architectures with on-chip caches as building blocks of multiprocessor systems. The signatures are assigned, so that the processor instruction bus needs not be monitored. The run-time and reference signatures are embedded into the checked program, making obsolete the reference database and the time-consuming search and compare engine in the watchdog processor.The scheme is extended to check multitasking and multiprocessor systems. 1. Introduction Since computing intensive applications require extremely long execution times, fault tolerance in microprocessor systems becomes a key design factor. As it was shown by both previous practical experience and by fault injection experiments, the majority of computer failures originates in transient faults. A high portion of these faults is manifested as disturbances in the program cont..