A New Congestion-Driven Placement Algorithm Based on Cell Inflation

A new congestion driven placement Algorithm is described based on the cell inflation. In this approach, the methods of probability estimation and star model are used to evaluate the routing of nets. Global placement can be done by using the algorithm of global optimization and slicing partitioning. The denotation of virtual area of cell is given to indicate not only the area of cell but also the routing demand.The virtual area of a cell is got by using the strategy of cell inflation, with which in the slicing partitioning, the routing congestion is eliminated. Further reduction in congestion is achieved by cell moving. The algorithm has been tested on a set of sample circuits from American companies, with great improvement in routablity having been obtained.