On polynomial-time testable classes of combinational circuits

The problem of test generation for detecting stuck-at faults in combinational circuits is computationally intractable. Consequently, the identification of classes of circuits that support polynomial-time test generation algorithms is very important from testing and design viewpoints. The authors discuss several classes of polynomially-time testable circuits. First, they consider the existing polynomial classes obtained by using decompositions of the circuits. Another type of decomposition is proposed, based on fanout-reconvergent pairs, which also lead to classes of polynomial-time testable circuits. Then, the authors present the classes of polynomial-time testable circuits that are formed by the Boolean formulae belonging to the classes of weakly positive, weakly negative, bijunctive and affine.<>