Hierarchical Global Routing Integrated with Floorplanning and Placement

Physical design tasks are very complex and therefore, are usually decomposed into several simple subtasks. However, the interdependence between these subtasks and its effect on the quality of the design is increasingly becoming more obvious. On the other hand, the increasing complexity of systems prevents the integration of the physical design subtasks. This paper presents an integrated approach to the floorplanning, placement and routing of very large macrocell-based designs. The framework is given a hierarchical specification and performs the physical design subtasks while preserving the specification hierarchy. There are some challenging problems in this approach mainly due to the high degree of interdependence between levels in the specification hierarchy which makes pure 'divide and conquer' strategies useless. A hierarchical global routing algorithm is also introduced in this paper.