TDD: a technology dependent decomposition algorithm for LUT-based FPGAs

A major drawback of the previous algorithms that perform decomposition and covering for LUT-based FPGA technology mapping is the lack of a fast, and reasonably accurate evaluation scheme for the decomposition phase. In this paper, we will show how a fast covering algorithm can be used as an evaluation engine for the decomposition phase. We show that decomposition has a significant impact on the quality of the final mapping result. More specifically, we show that starting from the same circuit topology, a blind decomposition leads to mapping results that use an average of 70 to 150% more LUTs compared to the results obtained using a technology driven decomposition algorithm. A technology driven decomposition algorithm is developed based on the proposed idea. Experiments on a number of MCNC benchmark circuits show an average of 12% to 72% improvement on the number of LUTs compared to the previously reported results.