Concurrent Checking and Unidirectional Errors in Multiple-Valued Circuits

This paper examines the concept of unateness for multiple-valued logic circuits, and its usefulness for concurrent checking through the use of unidirectional error-detecting codes. Three such codes are adapted for multiple-valued logic, and the set of operators which provide an internally unate circuit are described. For each code, modiications are also provided to incorporate testing for primary input faults. Some area overhead evaluations are performed using benchmarks implemented on binary and quaternary programmable logic arrays.