Buffer planning as an Integral part of floorplanning with consideration of routing congestion

The dominating contribution of interconnect to system performance has made it critical to plan the resources of the buffers and routes in the early stage of the layout. In this paper, we integrate floorplanning with buffer insertion for performance-driven design processes. We devise a two-step method to evaluate the feasible buffer insertion sites, which can improve the efficiency of the buffer-planning algorithm. By partitioning all empty spaces into blocks in the packing process, the buffer allocation is handled as an integral part of the floorplanning. Our buffer-planning algorithm maps the buffers into tiles with consideration of routing congestion. In this approach, we construct a distribution graph to model the possible routes. The buffer allocation method is performed on the updated distribution graph to find the buffer locations with their respective congestion costs. The method is based on a simulated annealing approach, which is composed of multiple phases to speed up the optimization. Since there is more freedom with floorplan optimization, the empirical results demonstrate better performance.