Macro-Aware Row-Style Power Delivery Network Design for Better Routability

Reliability of a P/G network is one of the most important concerns in a chip design, which makes powerplanning the most critical step in the physical design. Traditional P/G network design mainly focuses on reducing usage of routing resource to satisfy voltage drop and electromigration constraints according to a regular mesh. As the number of macros in a modern design increases, this style may waste more routing resource and make routing congestion more severe in local regions. In order to save routing resource and increase routability, this paper proposes a delicate powerplanning method. First, we propose a row-style power mesh to facilitate connection of pre-placed macros and increase routability of signal nets in the later stage. Besides, an effective power stripe width which can reduce wastage of routing resource and provide stronger supply voltage is found. Moreover, we propose the first work to use the linear programming algorithm to minimize P/G routing area and consider routability at the same time. The experimental results show that routability of a design with many macros can be significantly improved by our row-style power networks.