公开(公告)号：US11892501B1

公开(公告)日：2024-02-06

申请号：US17865104

申请日：2022-07-14

Applicant: Cadence Design Systems, Inc.

Inventor： Arvind Chokhani ,  Joseph M. Swenton ,  Martin Amodeo

IPC: G01R31/28

CPC classification number: G01R31/287 ,  G01R31/2879 ,  G01R31/2882

Abstract: 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.

公开(公告)号：US11435401B1

公开(公告)日：2022-09-06

申请号：US17181486

申请日：2021-02-22

Applicant: Cadence Design Systems, Inc.

Inventor： Arvind Chokhani ,  Joseph Michael Swenton ,  Santosh Subhaschandra Malagi

IPC: G01R31/3183 ,  G01R31/3181 ,  G06F30/31 ,  G06F30/33

Abstract: A fault rules engine generates a plurality of fault rules files, each of the fault rules files is associated with a respective cell type of a plurality of cell types in an integrated circuit (IC) design. Each fault rules file includes data quantifying a nominal delay for a given two-cycle test pattern and data quantifying a delta delay for the given two-cycle test pattern corresponding to a given candidate defect of a plurality of candidate defects of a given cell type of the plurality of cell types in the IC design. An IC test engine extracts an input to output propagation delay for each cell instance from a standard delay format (SDF) file for the IC design and generates cell-aware test patterns for each cell instance of each cell type in the IC design based on the plurality of fault rules files and the extracted input to output propagation delays.

公开(公告)号：US11893336B1

公开(公告)日：2024-02-06

申请号：US17499414

申请日：2021-10-12

Applicant: CADENCE DESIGN SYSTEMS, INC.

Inventor： Arvind Chokhani ,  Joseph Michael Swenton ,  Martin Thomas Amodeo

IPC: G06F30/398 ,  G06F119/18 ,  G06F119/12

CPC classification number: G06F30/398 ,  G06F2119/12 ,  G06F2119/18

Abstract: 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.

公开(公告)号：US11579194B1

公开(公告)日：2023-02-14

申请号：US17342764

申请日：2021-06-09

Applicant: Cadence Design Systems, Inc.

Inventor： Arvind Chokhani ,  Joseph Michael Swenton ,  Martin Thomas Amodeo

IPC: G01R31/28 ,  G06F11/00 ,  G01R31/3183 ,  G01R31/3185

Abstract: 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.

公开(公告)号：US11740284B1

公开(公告)日：2023-08-29

申请号：US17366227

申请日：2021-07-02

Applicant: Cadence Design Systems, Inc.

Inventor： Arvind Chokhani ,  Joseph Michael Swenton ,  Martin Thomas Amodeo

IPC: G01R31/3177 ,  G06F30/392 ,  G06F30/31

CPC classification number: G01R31/3177 ,  G06F30/392 ,  G06F30/31

Abstract: 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.

公开(公告)号：US11461520B1

公开(公告)日：2022-10-04

申请号：US17180239

申请日：2021-02-19

Applicant: Cadence Design Systems, Inc.

Inventor： Arvind Chokhani ,  Joseph Micahel Swenton ,  Santosh Subhaschandra Malagi

IPC: G06F30/31 ,  G01R31/3183 ,  G06F30/343 ,  G06F30/323 ,  G06F30/333 ,  G06F30/367 ,  G06F30/398 ,  G06F30/3323

Abstract: An integrated circuit (IC) test engine extracts an input to output propagation delay for each cell instance of each of a plurality of cell types in an IC design from an SDF file for the IC design. The IC test engine extracts a node slack of each cell instance of each of the plurality of cell types of the IC design from a node slack report. The IC test engine also generates cell-aware test patterns for each cell instance of each cell type in the IC design to test a fabricated IC chip that is based on the IC design for defects corresponding to a subset of a plurality of candidate defects characterized in the plurality of fault rules files. Each cell-aware test pattern is configured to sensitize and propagate a transition along the longest possible path to test small delay defects in cell instances of the fabricated IC chip.

公开(公告)号：US11429776B1

公开(公告)日：2022-08-30

申请号：US17181470

申请日：2021-02-22

Applicant: Cadence Design Systems, Inc.

Inventor： Arvind Chokhani ,  Joseph Michael Swenton ,  Santosh Subhaschandra Malagi

IPC: G06F30/398

Abstract: A fault rules engine generates a plurality of fault rules files. Each of the fault rules files is associated with a respective cell type of a plurality of cell types in an integrated circuit (IC) design, and each fault rules file of the plurality of fault rules files can include data quantifying a nominal delay for a given two-cycle test pattern of a set of two-cycle test patterns and data quantifying a delta delay for the given two-cycle test pattern corresponding to a given candidate defect of a plurality of candidate defects for a given cell type in the IC design. An IC test engine generates cell-aware test patterns based on the plurality of fault rules files to test a fabricated IC chip that is based on the IC design for defects corresponding to a subset of the plurality of candidate defects characterized in the plurality of fault rules files.