Patent ID: 8392868
Filing Date: 2013-03-05
Classification: G01R

Abstract:
1. A method to evaluate whether one or more test patterns is power safe for use during manufacturing testing of an integrated circuit that includes a nonuniform power grid and that includes a scan chain with first scan elements associated with a first region of the power grid having a first physical characteristics and with second scan elements associated with a second region of the power grid having a second physical characteristics, the method comprising: obtaining a first threshold that includes a first threshold number of toggles per scan shift cycle for the first scan elements associated with the first power grid region; determining whether a number of toggles by the first scan elements meets the first threshold number of toggles during at least one scan-shift cycle in the course of scan-in of a test pattern within the scan chain; obtaining a second threshold that includes a threshold number of toggles per scan shift cycle for the second scan elements associated with the second power grid region; determining whether a number of toggles by the second scan elements meets the second threshold number of toggles during at least one scan-shift cycle in the course of scan-in of the test pattern within the scan chain; storing in a non-transitory computer readable storage medium, parameter information indicative of physical characteristics of one or more power grid regions of the circuit; and determining the first threshold based at least in part upon application of stored parameter information to physical characteristics of the first grid region.