Temporal floorplanning using the three-dimensional transitive closure subGraph

Abstract

Improving logic capacity by time-sharing, dynamically reconfigurable Field Gate Programmable Arrays (FPGAs) are employed to handle designs of high complexity and functionality. In this paper, we use a novel graph-based topological floorplan representation, named 3D-subTCG (3-Dimensional Transitive Closure subGraph), to deal with the 3-dimensional (temporal) floorplanning/placement problem, arising from dynamically reconfigurable FPGAs. The 3D-subTCG uses three transitive closure graphs to model the temporal and spatial relations between modules. We derive the feasibility conditions for the precedence constraints induced by the execution of the dynamically reconfigurable FPGAs. Because the geometric relationship is transparent to the 3D-subTCG and its induced operations (i.e., we can directly detect the relationship between any two tasks from the representation), we can easily detect any violation of the temporal precedence constraints on 3D-subTCG. We also derive important properties of the 3D-subTCG to reduce the solution space and shorten the running time for 3D (temporal) foorplanning/placement. Experimental results show that our 3D-subTCG-based algorithm is very effective and efficient.