Incorporating physical design-for-test into routing

In addition to automatically generating correct wiring, routers are used to meet additional design goals. Examples include reducing capacitive coupling and improving yield. Using routers to improve testability has been mentioned in the literature, but concrete rules or methods have not been explained or implemented. In this paper, we show how a modified router improves bridge fault testability for two different test metrics, static-voltage testing and pseudo-exhaustive segmentation testing, with no significant increase in area or time. This method is flexible in that further testability improvements are possible by trading off routing area or routing time.