Analytical Global Placement for Heterogenous FPGAs Based on the eDensity Model

Abstract

Recent years have seen increased research attention given towards the global placement problem due to the growing capability and heterogeneity of FPGAs. Designed specially for heterogeneous FPGAs, a novel analytical algorithm for global placement problem is proposed and introduced in this paper. On the basis of the eDensity model , our well-proven algorithm aims to get a high-quality solution without efficiency loss. Besides, a fence region processing strategy is implemented to satisfy the heterogeneity constraints. To make the placement solution more compact and thus optimize the total wirelength, we inject appropriate doses of redundant eDensity charges onto instances to be placed. Furthermore, a repulsive force generation technology is adopted to prevent cells from entering the unplaceable regions. We use the nonlinear optimizer to solve our heterogenous objective function. Experimental results on modern industry benchmarks show that our proposed algorithm achieves 8.16% wirelength reduction and 38.89% runtime acceleration on average compared with the commercial tool Procise™.