Compatible class encoding in Roth-Karp decomposition for two-output LUT architecture

Roth-Karp decomposition is one of the most popular techniques for LUT-based FPGA technology mapping because it can decompose a node into a set of nodes with fewer numbers of fanins. In this paper, we show how to formulate the compatible class encoding problem in Roth-Karp decomposition as a symbolic-output encoding problem in order to exploit the feature of the two-output LUT architecture. Based on this formulation, we also develop an encoding algorithm to minimize the number of LUT´s required to implement the logic circuit. Experimental results show that our encoding algorithm can produce promising results in the logic synthesis environment for the two-output LUT architecture.