Patents by Inventor Gopinath Ranganathan

Gopinath Ranganathan has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Patent number: 11143700
    Abstract: An optic probe is used to measure signals from a device under test. The optic probe is positioned at a target probe location within a cell of the device under test, the cell including a target net to be measured and a plurality of non-target nets. A test pattern is applied to the cell with the optic probe a laser probe (LP) waveform is obtained in response. A target net waveform is extracted from the LP waveform by: (i) simulating a combinational logic analysis (CLA) cross-talk waveform to model cross-talk from selected non-target nets by simulating an optical response of the cell to the test pattern with the target net masked; (ii) estimating a cross-talk weight; and (iii) determining a target net waveform by weighting the CLA cross-talk waveform according to the cross-talk weight and subtracting the weighted CLA cross-talk waveform from the LP waveform.
    Type: Grant
    Filed: September 25, 2019
    Date of Patent: October 12, 2021
    Assignee: Advanced Micro Devices, Inc.
    Inventors: Venkat Krishnan Ravikumar, Nathan Linarto, Wen Tsann Lua, Abel Tan Yew Hong, Shei Lay Phoa, Gopinath Ranganathan, Jiann Minn Chin
  • Publication number: 20210088582
    Abstract: An optic probe is used to measure signals from a device under test. The optic probe is positioned at a target probe location within a cell of the device under test, the cell including a target net to be measured and a plurality of non-target nets. A test pattern is applied to the cell with the optic probe a laser probe (LP) waveform is obtained in response. A target net waveform is extracted from the LP waveform by: (i) simulating a combinational logic analysis (CLA) cross-talk waveform to model cross-talk from selected non-target nets by simulating an optical response of the cell to the test pattern with the target net masked; (ii) estimating a cross-talk weight; and (iii) determining a target net waveform by weighting the CLA cross-talk waveform according to the cross-talk weight and subtracting the weighted CLA cross-talk waveform from the LP waveform.
    Type: Application
    Filed: September 25, 2019
    Publication date: March 25, 2021
    Applicant: Advanced Micro Devices, Inc.
    Inventors: Venkat Krishnan Ravikumar, Nathan Linarto, Wen Tsann Lua, Abel Tan Yew Hong, Shei Lay Phoa, Gopinath Ranganathan, Jiann Minn Chin
  • Publication number: 20200284837
    Abstract: A control system for placing an optic probe includes a receiver circuit that receives reflected light produced from the optic probe and provides a laser probe (LP) waveform of the reflected light in response to an activation of a trigger signal. A combinational logic analysis (CLA) processor provides a CLA waveform in response to simulating an optical response at a target location on a surface of a cell of a device under test to a test pattern. A test controller receives the CLA waveform and the LP waveform, and has a first output for providing the trigger signal, a second output for providing the test pattern, and a third output for providing a position signal. The test controller updates the position signal to move the optic probe closer to the target location according to a degree of fit between the LP waveform and the CLA waveform.
    Type: Application
    Filed: March 8, 2019
    Publication date: September 10, 2020
    Applicant: Advanced Micro Devices, Inc.
    Inventors: Venkat Krishnan Ravikumar, Wen Tsann Lua, Gopinath Ranganathan, Yi Xuan Seah, Shei Lay Phoa, Nathan Linarto, Jiann Min Chin
  • Patent number: 10768225
    Abstract: A control system for placing an optic probe includes a receiver circuit that receives reflected light produced from the optic probe and provides a laser probe (LP) waveform of the reflected light in response to an activation of a trigger signal. A combinational logic analysis (CLA) processor provides a CLA waveform in response to simulating an optical response at a target location on a surface of a cell of a device under test to a test pattern. A test controller receives the CLA waveform and the LP waveform, and has a first output for providing the trigger signal, a second output for providing the test pattern, and a third output for providing a position signal. The test controller updates the position signal to move the optic probe closer to the target location according to a degree of fit between the LP waveform and the CLA waveform.
    Type: Grant
    Filed: March 8, 2019
    Date of Patent: September 8, 2020
    Assignee: Advanced Micro Devices, Inc.
    Inventors: Venkat Krishnan Ravikumar, Wen Tsann Lua, Gopinath Ranganathan, Yi Xuan Seah, Shei Lay Phoa, Nathan Linarto, Jiann Min Chin