Three-dimensional integrated circuits (3D IC) Floorplan and Power/Ground Network Co-synthesis

Abstract

Three Dimensional Integrated Circuits (3D ICs) are currently being developed to improve existing 2D designs by providing smaller chip areas and higher performance and lower power consumption. However, before 3D ICs become a viable technology, the 3D design space needs to be fully explored and 3D EDA tools need to be developed. To help explore the 3D design space and help fill the need for 3D EDA tools, the 3D Floorplan and Power/Ground (P/G) Co-synthesis tool is developed in this work, which develops the floorplan and the P/G network concurrently. Most current 3D IC floorplanners neglect the effects of the 3D P/G network on the design, which may lead to large IR drops in the circuit. To create feasible floorplans with efficient P/G networks, the 3D Floorplan and P/G Co-synthesis tool optimizes the floorplan in terms of wirelength, area and P/G routing area and IR drops. The tool integrates a 3D B*-tree floorplan representation, a resistive P/G mesh, and a Simulated Annealing (SA) engine to explore the 3D floorplan and P/G network. The results of experiments using the 3D Floorplan and P/G Co-synthesis tool show that 3D ICs tend to increase the P/G routing area while decreasing the IR drops in the circuit. By considering the IR drop while floorplanning, exploring the 3D P/G design space, and evaluating 3D IC's effect on 3D P/G networks, the 3D Floorplan and P/G Co-synthesis tool can develop a more efficient 3D IC.