A scalable quantitative measure of IR-drop effects for scan pattern generation

Analysis of power grid IR-drop during scan test application has drawn growing attention because excessive IR-drop may cause a functionally correct device to fail at-speed testing. The analysis is challenging since the power grid IR-drop profile depends on not only the switching cells locations but also the power grid structure. This paper presents a scalable implementation methodology for quantifying the IR-drop effects of a set of switching cells. An example of its application to guide power-safe scan pattern generation is illustrated. The scalability and effectiveness of the proposed quantitative measure is evaluated with a 130 nm industrial design with 800 K cells.