Method and apparatus to use physical design information to detect IR drop prone test patterns
AssigneeCadence Design Systems, Inc.
InventorsSenthil Arasu Thirunavukarasu, Shaleen Bhabu, Vivek Chickermane
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Abstract
A method is provided 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, the method comprising: assigning respective toggle count thresholds for respective power grid regions of the non-uniform power grid; and determining whether respective numbers of toggles by scan elements of the scan chain within one or more respective power grid regions meet respective toggle count thresholds for the one or more respective regions during at least one scan-shift cycle in the course of scan-in of a test pattern to the scan chain.
Claims4
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 non-uniform power grid and that includes a scan chain, the method comprising:
- obtaining, using a computer, respective toggle count thresholds for respective power grid regions of the non-uniform power grid based at least upon power grid density;
- and
- determining whether respective numbers of toggles during at least one scan shift cycle in the course of at least one of a scan-in of a test pattern within the scan chain by scan elements of the scan chain within one or more respective power grid regions meet respective toggle count thresholds for the one or more respective regions during at least one scan-shift cycle in the course of scan-in of a test pattern to the scan chain.
A system to evaluate whether one or more test patterns is power safe for use during manufacturing testing of an integrated circuit that includes a non-uniform power grid and that includes a scan chain, wherein the system includes a processor, a communication bus and a non-transitory machine readable storage device encoded with program code to configure the processor to perform a process comprising:
- obtaining respective toggle count thresholds for respective power grid regions of the non-uniform power grid based at least upon power grid density;
- and
- determining whether respective numbers of toggles during at least one scan shift cycle in the course of at least one of a scan-in of a test pattern within the scan chain by scan elements of the scan chain within one or more respective power grid regions meet respective toggle count thresholds for the one or more respective regions during at least one scan-shift cycle in the course of scan-in of a test pattern to the scan chain.
Dependencies are inferred from the claim text.