On Increasing the Observability of Modern Microprocessors

Microprocessors are becoming increasingly complex and difficult to debug. Researchers are constantly looking for new methods to increase the observability and control-lability of microprocessors. This paper introduces a new method to improve the observability of modern microprocessors and thus simplifying the task of debugging them. The method revolves around an observation circuit that provides access to important internal signals without interrupting the microprocessor execution. The output of the observation circuit is ported to the output of the microprocessor in order to easily detect various physical faults and design errors. Experimental results show that physical faults and design errors are detected faster using our method. Moreover, several errors are detected by the observation circuit without being detected by the microprocessor outputs.