On-chip diagnosis for early-life and wear-out failures

One approach for achieving integrated-system robustness centers on performing test during runtime, identifying the location of any faults (or potential faults), and repairing or avoiding the affected portion of the system. Fault dictionaries can be used to locate faults but conventional approaches require significant memory storage and are therefore limited to simplistic fault types. To overcome these limitations, three contributions are made that include: (i) enhancement of an unspecified transition fault model (called here the transition-X fault model, or TRAX for short) for capturing the misbehaviors expected from scaled technologies, (ii) development of a new type of hierarchical dictionary that only localizes to the level of repair or fault avoidance, and (iii) the design of a scalable architecture for retrieving and using the hierarchical dictionary for performing on-chip diagnosis. Experiments involving various circuits, including the OpenSPARC T2 processor, demonstrate that early-life and wear-out failures can be accurately diagnosed with minimum overhead using TRAX dictionaries that are up to 2600x smaller than full-response dictionaries.