NTUplace4dr: A Detailed-Routing-Driven Placer for Mixed-Size Circuit Designs With Technology and Region Constraints

A placer without considering modern technology and region constraints could generate solutions with irresolvable detailed-routing (DR) violations or even illegal solutions. This paper presents a high-quality placement algorithm to satisfy technology and region constraints and optimize DR routability with five major techniques: 1) a clustering algorithm followed by two-round quadratic placement to obtain an initial placement satisfying region constraints; 2) a novel density control technique to handle prefixed architectures and minimize global routing congestions; 3) an analytical placement algorithm with new wirelength and density models to consider region constraints; 4) a dynamic penalty increment strategy that reduces wirelength increments during global placement; and 5) a legalization algorithm that preserves the solution quality of global placement while satisfying technology and region constraints. Compared with the winning teams of the ISPD 2015 Blockage-Aware Detailed Routing-Driven Placement Contest and recent works, our placer achieves the best overall score and DR results.