Multiple-Valued Logic—its Status and its Future

Multiple-valued logic, in which the number of discrete logic levels is not confined to two, has been the subject of much research over many years. The practical objective of this work has been to increase the information content of the digital signals in a system to a higher value than that provided by binary operation. In this tutorial/survey paper we will review the historical developments in this field, both in circuit realizations and in methods of handling multiple-valued design data, and consider the present state-of-the-art and future expectations.