Design of robustly testable combinational logic circuits

An integrated approach to the design of combinational logic circuits in which all path delay faults and multiple line stuck-at, transistor stuck-open faults are detectable by robust tests is proposed. Robustly testable static CMOS primitive logic circuit designs are presented for any arbitrary combinational logic function. They require no special gates, and fan-in and fan-out constraints do not affect the designs. Extra controllable inputs or additional hardware to achieve testability was not used. It is demonstrated that the method guarantees the design of CMOS logic circuits in which all path delay faults are locatable