Faults in processor control subsystems: testing correctness and performance faults in the data prefetching unit

The processor control subsystems have for a long time been recognized as a bottleneck in the process of achieving complete fault coverage through various functional test propagation approaches. The difficult-to-test corner cases are further accentuated in fault-resilient control subsystems as no functional effect is incurred as a result of the fault, even though performance suffers. We investigate the construction of software programs, capable of providing full fault coverage at minimal hardware cost, for one such fault resilient subsystem in processor architecture: the data prefetching unit. Experimental results confirm the efficacy of the proposed method.