The method of improving the test possibility of the circuit and the circuit which improve test possibility

摘要

The testability of a near-acyclic circuit (14) can be enhanced by the addition of one or more control points and observation points to allow for increased observability and controllability of selected nodes (28). The control points and/or test points are added by first computing the controllability and observability and fault detection probability at each node. A fault is then selected. If either the controllability or observability for such fault is not inside a prescribed value range, and the fault detection probability is below a prescribed value and then either a control point and/or an observation point may be added. IMAGE