6T&6TPPNN Cell Legalization Considering Complex Minimum width Constraint

Due to the progress of manufacturing process, the minimum width (MW) constraint of 6TPPNN cells incurs a new challenge in modern circuit designs. This paper presents the first work to address general 6T&6TPPNN cell legalization with minimum width constraint and fragmentation effect. We first propose a MW-aware clustering algorithm to fix MW constraint, and then find an optimal region for each cluster with minimizing wirelength. Furthermore, we apply a fragmentation-effect aware cell moving technique to mitigate the fragmentation effect. After 6TPPNN cluster transforming, the 6TPPNN cells/clusters can be treated as triple-row-height cells. Finally, we formulate our general 6T&6TPPNN cell legalization problem as a quadratic programming problem, which is efficiently solved by a modulus-based matrix splitting iteration method. Experimental results show that our algorithm can achieve high-quality results for this problem and is very robust for resolving all MW constraint and effectively mitigating the fragmentation effect in a reasonable runtime.