A structured test re-use methodology for core-based system chips

This paper describes a structured test re-use methodology and infrastructure for core-based system chips. The methodology is based on the use of a structured test bus framework that provides access to virtual components in a system chip allowing the test methodologies and test vectors for these components to be re-used. It addresses the test access, isolation, interconnect and shadow logic test problems without requiring modifications to the components, even for cores with more ports than chip pins. The test area overhead required, including test bus routing, to implement this methodology can be less than 1%