Joint logic restructuring and pin reordering against NBTI-induced performance degradation

Negative Bias Temperature Instability (NBTI), a PMOS aging phenomenon causing significant loss on circuit performance and lifetime, has become a critical challenge for temporal reliability concerns in nanoscale designs. Aggressive technology scaling trends, such as thinner gate oxide without proportional downscaling of supply voltage, necessitate a design optimization flow considering NBTI effects at the early stages. In this paper, we present a novel framework using joint logic restructuring and pin reordering to mitigate NBTI-induced performance degradation. Based on detecting functional symmetries and transistor stacking effects, the proposed methodology involves only wire perturbation and introduces no gate area overhead at all. Experimental results reveal that, by using this approach, on average 56% of performance loss due to NBTI can be recovered. Moreover, our methodology reduces the number of critical transistors remaining under severe NBTI and thus, transistor resizing can be applied to further mitigate NBTI effects with low area overhead.