Tolerating hard faults in microprocessor array structures

In this paper, we present a hardware technique, called self-repairing array structures (SRAS), for masking hard faults in microprocessor array structures, such as the reorder buffer and branch history table. SRAS masks errors that could otherwise lead to slow system recoveries. To detect row errors, every write to a row is mirrored to a dedicated "check row". We then read out both the written row and check row and compare their results. To correct errors, SRAS maps out faulty array rows with a level of indirection.