Partial scan with preselected scan signals

This paper deals with partial scan approaches that select scan signals oblivious to the availability of flip-flops (FFs). Such approaches can greatly reduce the number of scan signals since maximum freedom is presented when selecting signals. However, to actually scan the selected signals, one must make them drive FFs. We study the problem of replicating and retiming a circuit to make a set of scan signals drive FFs while preserving the set of cycles broken by the signals. We present a framework for solving the problem. Based on the framework, we present an efficient algorithm which also minimizes the amount of logic replication