Synthesis of Toffoli Networks: Status and Challenges

This paper gives a brief overview of the current trends in reversible logic synthesis. The basic building block for reversible circuits considered here is the multiple-control Toffoli gate. Some approaches to synthesis are reviewed and challenges are explained. Since many practical functions are not reversible, they must be embedded into reversible ones, if they are to be implemented using reversible logic. The complexity of such embeddings is expounded. A two phase synthesis is described were particular attention is devoted to the optimization phase via template matching.