K-Way Partitioning Based Packing for FPGA Logic Blocks without Input Bandwidth Constraint

Cluster-based logic blocks from most commercial FPGA products do not have an input bandwidth constraint, i.e., limiting the number of signals going from routing channels into the block. We show that high quality packing for such logic blocks can be easily achieved based on k-way partitioning. We implemented 2 such packing tools: PPack (routability-only) and its timing driven version TPPack. Experimental results show that they have superior quality. Compared to T-VPack, PPack reduces total wire-length and minimal channel width by 22.6% and 22.6% with a 1.9% performance gain; TPPack reduces total wire-length and minimal channel width by 20.0% and 20.2% with a 9.0% performance gain. These results are achieved at no loss of utilization.