VLSI floorplanning with boundary constraints based on corner block list

Abstract

In floorplanning of a typical VLSI design, some modules are required to satisfy some placement constraints in the final packing. Boundary constraint is one kind of those placement constraints to pack some modules along one of the four sides: on the left, on the right, at the bottom or at the top of the final floorplan. We implement the boundary constraint algorithm for general floorplan by extending the corner block list (CBL)-a new efficient topology representation for nonslicing floorplan. Our contribution is to find the necessary and sufficient characterization of the modules along the boundary represented by corner block list. We can check the boundary constraints by scanning the intermediate solutions in linear time during the simulated annealing process and fix the corner block list in case the constraints are violated. The experiment results are demonstrated by several examples of MCNC benchmarks and the performance is remarkable.