Architecture-Adaptive Routability-Driven Placement for FPGAs

Abstract. Current FPGA placement algorithms estimate the routability of a placement using architecture-specific metrics. The shortcoming of using architecture-specific routability estimates is limited adaptability. A placement algorithm that is targeted to a class of architecturally similar FPGAs may not be easily adapted to other architectures. The subject of this paper is the development of a routability-driven architecture adaptive FPGA placement algorithm called Independence. The core of the Independence algorithm is a simultaneous placeand-route approach that tightly couples a simulated annealing placement algorithm with an architecture adaptive FPGA router (Pathfinder). The results of our experiments demonstrate Independence’s adaptability to island-style FPGAs, a hierarchical FPGA architecture (HSRA), and a coarse-grained reconfigurable architecture (RaPiD). The quality of the placements produced by Independence is within 1.2 % of the quality of VPR’s placements, 17 % better than the placements produced by HSRA’s placer, and within 0.7 % of RaPiD's placer. Further, our results show that Independence produces clearly superior placements on routing-poor island-style FPGA architectures.