DescriptionWe introduce Mixed row flow to get more performance and area gain on specific range by combining two libraries together. The contribution of mixed row flow is to improve PPA without development of new library for specific application. The technical challenges of mixed row flow such as aligning with rules between two different libraries and decision on row ratio are addressed for better PPA sweet-spot of mixed row flow. To deal with these challenges, we modified several design rules and used hybrid power rail to solve the broken rules. We enable a new design method to resolve the placement constraints through cell swapping over rows. It is also shown that a proper row ratio can improve area & performance Combination of cells varies depending on target frequency. In this works, we demonstrate 4.1% area gain and 9.1% performance gain in high performance design and 6.1% area gain over library for high performance and 2% area overhead over library for high density in high density design.