Patents by Inventor Daniel W. Cervantes

Daniel W. Cervantes 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: 8214170
    Abstract: A method for test pattern compression generates a first test pattern comprising a plurality of bits. The method identifies bits comprising a don't-care bit value in the first test pattern and replaces the identified bit values with random bit values, to generate a second test pattern. The method determines a fault coverage level of the second test pattern. In the event the determined fault coverage level of the second test pattern exceeds a predetermined individual test pattern fault coverage level, for at least one bit position in the second test pattern corresponding to a replaced identified bit value and detecting at least one fault, the method exchanges the don't care value in the bit position in the first test pattern with the bit value in the corresponding bit position in the second test pattern. The method merges subsequent test patterns that increase fault coverage with the second test pattern.
    Type: Grant
    Filed: January 15, 2009
    Date of Patent: July 3, 2012
    Assignee: International Business Machines Corporation
    Inventors: Patrick R. Crosby, Daniel W. Cervantes, Johnny J. LeBlanc, Samuel I. Ward
  • Patent number: 7856582
    Abstract: A method, system and computer program product for performing real-time LBIST diagnostics of IC devices. During LBIST, stump data and identifiers of test cycles are saved in the IC device-under-test (DUT). If compressed stump data does not match a pre-defined coded value (i.e., “signature” of the test cycle), the saved stump data and an identifier of the failed test cycle are preserved, otherwise the determination is made the DUT passed the test cycle. Identifiers and stump of the failed test cycles are used to analyze errors, including virtually non-reproducible errors.
    Type: Grant
    Filed: April 3, 2008
    Date of Patent: December 21, 2010
    Assignee: International Business Machines Corporation
    Inventors: Daniel W. Cervantes, Robert B. Gass, Joshua P. Hernandez, Timothy M. Skergan
  • Publication number: 20100179784
    Abstract: A method for test pattern compression generates a first test pattern comprising a plurality of bits. The method identifies bits comprising a don't-care bit value in the first test pattern and replaces the identified bit values with random bit values, to generate a second test pattern. The method determines a fault coverage level of the second test pattern. In the event the determined fault coverage level of the second test pattern exceeds a predetermined individual test pattern fault coverage level, for at least one bit position in the second test pattern corresponding to a replaced identified bit value and detecting at least one fault, the method exchanges the don't care value in the bit position in the first test pattern with the bit value in the corresponding bit position in the second test pattern. The method merges subsequent test patterns that increase fault coverage with the second test pattern.
    Type: Application
    Filed: January 15, 2009
    Publication date: July 15, 2010
    Applicant: International Business Machines Corporation
    Inventors: Patrick R. Crosby, Daniel W. Cervantes, Johnny J. LeBlanc, Samuel I. Ward
  • Publication number: 20090254788
    Abstract: A method, system and computer program product for performing real-time LBIST diagnostics of IC devices. During LBIST, stump data and identifiers of test cycles are saved in the IC device-under-test (DUT). If compressed stump data does not match a pre-defined coded value (i.e., “signature” of the test cycle), the saved stump data and an identifier of the failed test cycle are preserved, otherwise the determination is made the DUT passed the test cycle. Identifiers and stump of the failed test cycles are used to analyze errors, including virtually non-reproducible errors.
    Type: Application
    Filed: April 3, 2008
    Publication date: October 8, 2009
    Inventors: Daniel W. Cervantes, Robert B. Gass, Joshua P. Hernandez, Timothy M. Skergan
  • Patent number: 7519889
    Abstract: A method to reduce logic built in self test manufacturing test time of integrated circuits, comprising: loading a plurality of test seeds in bulk into a locally accessible on-chip memory array locally disposed on an integrated circuit, each of the plurality of test seeds is associated with a set of LBIST control information; sending the plurality of test seeds from the locally accessible on-chip memory array repetitively into a pseudo-random pattern generator one at a time during an LBIST operation being under the control from the set of LBIST control information; generating random bit streams serially into a plurality of parallel shift registers of the integrated circuit through the use of the plurality of test seeds; and performing a logic built-in self test on a plurality of logic blocks in the integrated circuit to detect defects within the integrated circuit.
    Type: Grant
    Filed: April 1, 2008
    Date of Patent: April 14, 2009
    Assignee: International Business Machines Corporation
    Inventors: Daniel W. Cervantes, Joshua P. Hernandez, Tung N. Pham, Timothy M. Skergan