Multi-Electrostatic FPGA Placement Considering SLICEL-SLICEM Heterogeneity and Clock Feasibility

Abstract

Modern field-programmable gate arrays (FPGAs) contain heterogeneous resources, including CLB, DSP, BRAM, IO, etc. A configurable logic block (CLB) slice is further categorized to SLICEL and SLICEM, which can be configured as specific combinations of instances in {LUT, FF, distributed RAM, SHIFT, CARRY}. Such kind of heterogeneity challenges the existing FPGA placement algorithms. Meanwhile, limited clock routing resources also lead to complicated clock constraints, causing difficulties in achieving clock feasible placement solutions. In this work, we propose a heterogeneous FPGA placement framework considering SLICEL- SLICEM heterogeneity and clock feasibility based on a multi-electrostatic formulation. We support a comprehensive set of the aforementioned instance types with a uniform algorithm for wirelength, routability, and clock optimization. Experimental results on both academic and industrial benchmarks demonstrate that we outperform the state-of-the-art placers in both quality and efficiency.