Synthesis of pseudo-random pattern testable designs

A method of synthesizing scan designs that are testable with pseudorandom patterns is presented. The logic is first simplified by various transformations in a logic synthesis system. A fault simulator is then used to guide the placement of control points and observation points. In order to reduce the overhead, control points are shared when possible and a condensation network is used with the observation points. Experimental results which indicate that pseudorandom testability can be achieved with small area overheads using simple techniques are presented.