Proactive NBTI mitigation for busy functional units in out-of-order microprocessors

Due to fast technology scaling, negative bias temperature instability (NBTI) has become a major reliability concern in designing modern integrated circuits. In this paper, we present a simple and proactive NBTI recovery scheme targeting at critical and busy functional units with storage cells in modern microprocessors. Existing schemes have limitations when recovering these functional units. By exploiting the idle time of busy functional units at per-buffer-entry level, our scheme achieves on average 5.57x MTTF (Mean Time To Failure) improvement at the cost of <1% IPC degradation and <1% area overhead.