Design and synthesis of self-checking VLSI circuits

Self-checking circuits can detect the presence of both transient and permanent faults. A self-checking circuit consists of a functional circuit, which produces encoded output vectors, and a checker, which checks the output vectors. The checker has the ability to expose its own faults as well. The functional circuit can be either combinational or sequential. A self-checking system consists of an interconnection of selfchecking circuits. The advantage of such a system is that errors can be caught as soon as they occur; thus, data contamination is prevented. Although much effort has been concentrated on the design of self-checking checkers by previous researchers, very few results have been presented for the design of self-checking functional circuits. In this paper, we explore methods for the costeffective design of combinational and sequential self-checking functional circuits and checkers. The area overhead for all proposed design alternatives is studied in detail.