Cadence Design Systems, Inc.

Martin Thomas Amodeo

Joseph Michael Swenton

Arvind Chokhani

An integrated circuit (IC) test engine generates N-cycle at-speed test patterns for testing for candidate faults and/or defects of a first set of transition faults and/or defects of an IC design. A diagnostics engine that receives test result data characterizing application of the N-cycle at-speed test patterns to a fabricated IC chip based on the IC design by an ATE, in which the test result data includes a set of miscompare values characterizing a difference between an expected result and a result measured by the ATE for a given N-cycle at-speed test pattern. The diagnostics engine employs a fault simulator to fault-simulate the N-cycle at-speed test patterns against a fault model that includes a first set of transition faults and/or defects and fault-simulate a subset of the N-cycle at-speed test patterns against a fault model that includes multicycle transition faults and/or defects utilizing sim-shifting.

Diagnosing multicycle transition faults and/or defects with AT-speed ATPG test patterns

An IC test engine generates a plurality of two-cycle delay test patterns that target a first set of multicycle faults and/or defects of a fabricated IC chip based on an IC design. Each two-cycle delay test pattern includes a scan-in shift window operating at a test clock frequency, and a capture window with a launch cycle and a capture cycle operating at a functional clock frequency. The IC test engine fault simulates the plurality of two-cycle delay test patterns against a second set of multicycle faults and/or defects in the IC design utilizing sim-shifting, such that a state of the IC design after at least a last two shift clock cycles of a scan-in shift in window of each two-cycle delay test pattern of the plurality of two-cycle delay test patterns are fault simulated to provide two fault initialization cycles for detection of a multicycle delay fault and/or defect.

Utilizing transition ATPG test patterns to detect multicycle faults and/or defects in an IC chip

An integrated circuit (IC) test engine generates single cycle test patterns for testing for candidate faults and/or defects of a first set of static faults and/or defects of an IC design. A diagnostics engine receives single cycle test result data characterizing application of the single cycle test patterns to a fabricated IC chip based on the IC design and fault-simulates a subset of the single cycle test patterns against a fault model that includes multicycle faults and/or defects utilizing sim-shifting to diagnose a second set of static faults and/or defects in the fabricated IC chip that are only detectable with multicycle test patterns. The diagnostics engine further scores candidate faults and/or defects in the first set of static faults and/or defects and the second set of static faults and/or defects for applicable test patterns to determine a most likely fault and/or defect present in the fabricated IC chip.

Diagnosing multicycle faults and/or defects with single cycle ATPG test patterns

An integrated circuit (IC) test engine can generate a plurality of single cycle test patterns that target a plurality of static single cycle defects of a fabricated IC chip based on an IC design. The IC test engine can also fault simulate the plurality of single cycle test patterns against a plurality of multicycle defects in the IC design, wherein a given single cycle test pattern of the plurality of single cycle test patterns is sim-shifted to enable detection of a given multicycle fault and/or defect of the plurality of multicycle faults and/or defects.

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Santa Clara, CA, United States of America

Martin Thomas Amodeo