A Logic Programming Framework for Combinational Circuit Synthesis

Abstract. Logic Programming languages and combinational circuit synthesis tools share a common "combinatorial search over logic formulae" background. This paper attempts to reconnect the two fields with a fresh look at Prolog encodings for the combinatorial objects involved in circuit synthesis. While benefiting from Prolog's fast unification algorithm and built-in backtracking mechanism, efficiency of our search algorithm is ensured by using parallel bitstring operations together with logic variable equality propagation, as a mapping mechanism from primary inputs to the leaves of candidate Leaf-DAGs implementing a combinational circuit specification. After an exhaustive expressiveness comparison of various minimal libraries, a surprising first-runner, Strict Boolean Inequality "<" together with constant function "1" also turns out to have small transistor-count implementations, competitive to NAND-only or NORonly libraries. As a practical outcome,...

• Type: Journal
• Year: 2008
• Where: CORR
• Authors: Paul Tarau, Brenda Luderman
• Keywords: Circuit Synthesis, Combinational Circuit, Combinational Circuit Synthesis, CORR 2008, Education