T-Trees: A Tree-Based Representation for Temporal and Three-Dimensional Floorplanning

Improving logic capacity by time-sharing, dynamically reconfigurable FPGAs are employed to handle designs of high complexity and functionality. In this article, we model each task as a 3D-box and deal with the temporal floorplanning/placement problem for dynamically reconfigurable FPGA architectures. We present a tree-based data structure, called T-trees, to represent the spatial and temporal relations among tasks. Each node in a T-tree has at most three children which represent the dimensional relationship among tasks. For the T-tree, we develop an efficient packing method and derive the condition to ensure the satisfaction of precedence constraints which model the temporal ordering among tasks induced by the execution of dynamically reconfigurable FPGAs. Experimental results show that our tree-based formulation can obtain significantly better solution quality with less execution time than the most recent state-of-the-art work.