Patents by Inventor James Douglas Warnock

James Douglas Warnock 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: 11074391
    Abstract: A method and system for improving the performance of a computer in identifying and mitigating electromigration violations of a semiconductor device. A set of library gates is obtained and parasitic layout extraction is performed for each gate in the set of library gates to generate an extracted netlist. One or more passes of an electromigration analysis of the extracted netlist are performed to characterize each gate over a set of input parameters and to generate a maximum slew rate (MAX_SLEW) table and a maximum capacitance (MAX_CAP) table.
    Type: Grant
    Filed: January 22, 2019
    Date of Patent: July 27, 2021
    Assignee: International Business Machines Corporation
    Inventors: Leon Sigal, David Kadzov, Nagashyamala R. Dhanwada, James Douglas Warnock
  • Publication number: 20200233933
    Abstract: A method and system for improving the performance of a computer in identifying and mitigating electromigration violations of a semiconductor device. A set of library gates is obtained and parasitic layout extraction is performed for each gate in the set of library gates to generate an extracted netlist. One or more passes of an electromigration analysis of the extracted netlist are performed to characterize each gate over a set of input parameters and to generate a maximum slew rate (MAX_SLEW) table and a maximum capacitance (MAX_CAP) table.
    Type: Application
    Filed: January 22, 2019
    Publication date: July 23, 2020
    Inventors: Leon Sigal, David Kadzov, Nagashyamala R. Dhanwada, James Douglas Warnock
  • Patent number: 10666415
    Abstract: Techniques for determining the quality of a clock signal are provided. In one example, a method can comprise comparing, by a sensory circuitry of a system, a first output of a first sensor and a second output of a second sensor. The first output and the second output can be based on a parameter of a clock signal. Further, in some embodiments, the first sensor and the second sensor can be local clock buffers. The method can also comprise determining, by a controller of the system, a quality of the clock signal based on the comparing of the first output and the second output.
    Type: Grant
    Filed: January 6, 2017
    Date of Patent: May 26, 2020
    Assignee: INTERNATIONAL BUSINESS MACHINES CORPORATION
    Inventors: Phillip John Restle, Christos Vezyrtzis, James Douglas Warnock
  • Patent number: 10652006
    Abstract: Techniques for determining the quality of a clock signal are provided. In one example, a method can comprise comparing, by a sensory circuitry of a system, a first output of a first sensor and a second output of a second sensor. The first output and the second output can be based on a parameter of a clock signal. Further, in some embodiments, the first sensor and the second sensor can be local clock buffers. The method can also comprise determining, by a controller of the system, a quality of the clock signal based on the comparing of the first output and the second output.
    Type: Grant
    Filed: December 14, 2017
    Date of Patent: May 12, 2020
    Assignee: INTERNATIONAL BUSINESS MACHINES CORPORATION
    Inventors: Phillip John Restle, Christos Vezyrtzis, James Douglas Warnock
  • Publication number: 20180198596
    Abstract: Techniques for determining the quality of a clock signal are provided. In one example, a method can comprise comparing, by a sensory circuitry of a system, a first output of a first sensor and a second output of a second sensor. The first output and the second output can be based on a parameter of a clock signal. Further, in some embodiments, the first sensor and the second sensor can be local clock buffers. The method can also comprise determining, by a controller of the system, a quality of the clock signal based on the comparing of the first output and the second output.
    Type: Application
    Filed: December 14, 2017
    Publication date: July 12, 2018
    Inventors: Phillip John Restle, Christos Vezyrtzis, James Douglas Warnock
  • Publication number: 20180198595
    Abstract: Techniques for determining the quality of a clock signal are provided. In one example, a method can comprise comparing, by a sensory circuitry of a system, a first output of a first sensor and a second output of a second sensor. The first output and the second output can be based on a parameter of a clock signal. Further, in some embodiments, the first sensor and the second sensor can be local clock buffers. The method can also comprise determining, by a controller of the system, a quality of the clock signal based on the comparing of the first output and the second output.
    Type: Application
    Filed: January 6, 2017
    Publication date: July 12, 2018
    Inventors: Phillip John Restle, Christos Vezyrtzis, James Douglas Warnock
  • Patent number: 8117579
    Abstract: A method, system and program are provided for generating level sensitive scan design (LSSD) clock signals from a general scan design (GSD) clock buffer using an intermediate clock signal and one or more first mode control signals to generate a plurality of LSSD clock signals from an output section of the GSD clock buffer that receives the intermediate clock signal and the first mode control signal(s), where the GSD clock buffer is also configured to generate a plurality of GSD clock signals in response to receiving a GSD mode, generating an intermediate clock signal from the input section of the GSD clock buffer in response receiving a GSD mode signal.
    Type: Grant
    Filed: January 31, 2008
    Date of Patent: February 14, 2012
    Assignee: International Business Machines Corporation
    Inventors: James Douglas Warnock, Wendel Dieter, David E. Lackey, William Vincent Huott, Leon Jacob Sigal, Louis Bernard Bushard, Sang Hoo Dhong
  • Patent number: 7962811
    Abstract: An apparatus, a method and a computer program product are provided for conserving energy during functional mode of a processor by disabling the scan chain. By inserting logic gating into the scan chain it is possible to disable the scan chain during the processor's functional mode. During functional mode the scan out port of the latch bit in a scan chain toggles, which leads to unnecessary energy consumption. By gating scan control signals and the scan out port of a latch bit, the scan chain segment between latch bits can be disconnected. Therefore, the scan control signals can disable the scan chain during functional mode.
    Type: Grant
    Filed: October 25, 2006
    Date of Patent: June 14, 2011
    Assignee: International Business Machines Corporation
    Inventors: Sang Hoo Dhong, Joel Abraham Silberman, Osamu Takahashi, James Douglas Warnock, Dieter Wendel
  • Publication number: 20090160515
    Abstract: A system and method for generating a clock signal is disclosed. In various embodiments of the invention disclosed herein, a global clock signal is generated and provided as an input to local clock circuitry operable to generate a local clock signal therefrom. The local clock circuitry comprises logic components that are susceptible to negative bias thermal instability (NBTI) effects resulting in degradation of the local clock signal. Clock propagation adjustment circuitry is used to modify the duty cycle of the global clock signal to compensate for the degradation resulting from NBTI effects thereby providing an optimized local clock signal.
    Type: Application
    Filed: December 19, 2007
    Publication date: June 25, 2009
    Inventor: James Douglas Warnock
  • Publication number: 20090121747
    Abstract: A system and method for maintaining circuit delay characteristics during power management mode. The method for maintaining circuit delay characteristics during power management mode continually toggles the clock distribution circuits at a frequency sufficiently low that it does not significantly impact chip power dissipation. The clock frequency used to toggle the clock distribution circuits is high enough to minimize the asymmetrical stress on the clock buffer transistors so that both P and N device characteristics equally change over time.
    Type: Application
    Filed: November 12, 2007
    Publication date: May 14, 2009
    Inventors: Sang Hoo Dhong, Peter Harm Hofstee, Mack Wayne Riley, James Douglas Warnock, Stephen Douglas Weitzel
  • Patent number: 7191419
    Abstract: The present invention provides for determining arrival times in a circuit. An arrival time for a main signal is assigned. An arrival time for a secondary signal is assigned. It is determined whether a test is for an early arrival or for a later arrival. If the test type is for a late arrival, it is determined whether the arrival time for the secondary signal is later than for the first signal. If the test type is for an early arrival, it is determined whether the arrival time for the secondary signal is earlier than for the first signal. If the test type is for the late arrival and the arrival time for the secondary signal is later than for the first signal, assume maximum interference between the signals. If the test type is for the late arrival and the arrival time for the secondary signal is not later than for the first signal, calculate the actual interference between the signals.
    Type: Grant
    Filed: July 22, 2004
    Date of Patent: March 13, 2007
    Assignee: International Business Machines Corporation
    Inventors: Jeffrey Paul Soreff, James Douglas Warnock
  • Patent number: 7165006
    Abstract: An apparatus, a method and a computer program product are provided for conserving energy during functional mode of a processor by disabling the scan chain. By inserting logic gating into the scan chain it is possible to disable the scan chain during the processor's functional mode. During functional mode the scan out port of the latch bit in a scan chain toggles, which leads to unnecessary energy consumption. By gating scan control signals and the scan out port of a latch bit, the scan chain segment between latch bits can be disconnected. Therefore, the scan control signals can disable the scan chain during functional mode.
    Type: Grant
    Filed: October 28, 2004
    Date of Patent: January 16, 2007
    Assignee: International Business Machines Corporation
    Inventors: Sang Hoo Dhong, Joel Abraham Silberman, Osamu Takahashi, James Douglas Warnock, Dieter Wendel
  • Patent number: 6927615
    Abstract: A local clock signal generation system is disclosed including multiple local clock buffers each receiving a global clock signal and producing a version of one or more local clock signals derived from the global clock signal. Each local clock buffer includes an input section and an output section. The input sections are substantially identical such that timing differences between the versions of the one or more local clock signals are reduced. An electronic circuit is described including the local clock signal generation system and a latch (e.g., a master latch of a flip-flop). A local clock buffer produces a gating signal and a local clock signal received by the latch. When the gating signal is a certain logic value, the local clock signal is a steady logic value, and the latch produces an input data signal as an output signal. An integrated circuit including the electronic circuit is disclosed.
    Type: Grant
    Filed: June 5, 2003
    Date of Patent: August 9, 2005
    Assignee: International Business Machines Corporation
    Inventors: Sang Hoo Dhong, Joel Abraham Silberman, Osamu Takahashi, James Douglas Warnock, Dieter Wendel
  • Patent number: 6922818
    Abstract: A method and apparatus for reducing power consumption of a clocked circuit containing a plurality of latches is provided. A first latch, within the plurality of latches, is located which has more than a predetermined slack. The possibility of substituting an available second latch, that requires less power to operate, is then determined, subject to the constraint that the slack after substitution should still be positive, although it may be less than the predetermined number mentioned above. Where such a possibility is determined to exist, the first latch is then replaced with the available second latch.
    Type: Grant
    Filed: April 12, 2001
    Date of Patent: July 26, 2005
    Assignee: International Business Machines Corporation
    Inventors: Sam Gat-Shang Chu, Joachim Gerhard Clabes, Michael Normand Goulet, Thomas Edward Rosser, James Douglas Warnock
  • Patent number: 6901546
    Abstract: A device for fault testing in a microprocessor chip provides a LBIST circuit which has a first reference signature. A loading unit is further provided for receiving and outputting a set of masking data. A file unit connected to the loading unit is yet further provided for receiving the masking data. A masking unit connected to the file unit is yet further provided for generating a second reference signature based on the masking data from the file unit and a scanning data from a scan string in the chip. And, a signature logic connected to the output of the masking unit is yet further provided for compressing the second reference signature and inputting the compressed second reference signature to the LBIST circuit, wherein the compressed second reference signature replaces the first reference signature.
    Type: Grant
    Filed: June 7, 2001
    Date of Patent: May 31, 2005
    Assignee: International Business Machines Corporation
    Inventors: Sam Gat-Shang Chu, Joachim Gerhard Clabes, Michael Normand Goulet, Johnny J. Leblanc, James Douglas Warnock
  • Publication number: 20040246037
    Abstract: A local clock signal generation system is disclosed including multiple local clock buffers each receiving a global clock signal and producing a version of one or more local clock signals derived from the global clock signal. Each local clock buffer includes an input section and an output section. The input sections are substantially identical such that timing differences between the versions of the one or more local clock signals are reduced. An electronic circuit is described including the local clock signal generation system and a latch (e.g., a master latch of a flip-flop). A local clock buffer produces a gating signal and a local clock signal received by the latch. When the gating signal is a certain logic value, the local clock signal is a steady logic value, and the latch produces an input data signal as an output signal. An integrated circuit including the electronic circuit is disclosed.
    Type: Application
    Filed: June 5, 2003
    Publication date: December 9, 2004
    Applicant: International Business Machines Corporation
    Inventors: Sang Hoo Dhong, Joel Abraham Silberman, Osamu Takahashi, James Douglas Warnock, Dieter Wendel
  • Publication number: 20040246027
    Abstract: Several local clock buffers are disclosed, each including an input section and an output section. The input sections are substantially identical, and include control logic and gating logic. The control logic produces a gating signal dependent upon multiple control signals and a time-delayed global clock signal. The gating logic produces an intermediate clock signal dependent upon the global clock signal and the gating signal. The output section produces at least one local clock signal dependent upon the intermediate clock signal. In one embodiment, the output section produces a first local clock signal dependent upon the intermediate clock signal and a second local clock signal dependent upon the first local clock signal. In another embodiment, the gating logic produces the intermediate clock signal dependent upon the global clock and gating signals and a feedback signal. The output section produces the feedback signal and one or more local clock signals.
    Type: Application
    Filed: June 5, 2003
    Publication date: December 9, 2004
    Applicant: IBM Corporation
    Inventors: Sang Hoo Dhong, Joel Abraham Silberman, Osamu Takahashi, James Douglas Warnock, Dieter Wendel
  • Patent number: 6825695
    Abstract: Several local clock buffers are disclosed, each including an input section and an output section. The input sections are substantially identical, and include control logic and gating logic. The control logic produces a gating signal dependent upon multiple control signals and a time-delayed global clock signal. The gating logic produces an intermediate clock signal dependent upon the global clock signal and the gating signal. The output section produces at least one local clock signal dependent upon the intermediate clock signal. In one embodiment, the output section produces a first local clock signal dependent upon the intermediate clock signal and a second local clock signal dependent upon the first local clock signal. In another embodiment, the gating logic produces the intermediate clock signal dependent upon the global clock and gating signals and a feedback signal. The output section produces the feedback signal and one or more local clock signals.
    Type: Grant
    Filed: June 5, 2003
    Date of Patent: November 30, 2004
    Assignee: International Business Machines Corporation
    Inventors: Sang Hoo Dhong, Joel Abraham Silberman, Osamu Takahashi, James Douglas Warnock, Dieter Wendel
  • Patent number: 6744282
    Abstract: A latching dynamic logic structure is disclosed including a static logic interface, a dynamic logic gate, and a static latch. The static logic interface receives a data signal, a select signal, and a clock signal, and produces a first intermediate signal such that when the select signal is active, the first intermediate signal is dependent upon the data signal for a period of time following a clock signal transition. The dynamic logic gate discharges a dynamic node following the clock signal transition dependent upon the first intermediate signal. The static latch produces an output signal assuming one of two logic levels following the clock signal transition, and assuming the other logic level in the event the dynamic node is discharged. A scan-testing-enabled version of the latching dynamic logic structure is described, as is an integrated circuit including the latching dynamic logic structure.
    Type: Grant
    Filed: March 27, 2003
    Date of Patent: June 1, 2004
    Assignee: International Business Machines Corporation
    Inventors: Sang Hoo Dhong, Joel Abraham Silberman, Osamu Takahashi, James Douglas Warnock, Dieter Wendel
  • Publication number: 20020188903
    Abstract: A device for fault testing in a microprocessor chip provides a LBIST circuit which has a first reference signature. A loading unit is further provided for receiving and outputting a set of masking data. A file unit connected to the loading unit is yet further provided for receiving the masking data. A masking unit connected to the file unit is yet further provided for generating a second reference signature based on the masking data from the file unit and a scanning data from a scan string in the chip. And, a signature logic connected to the output of the masking unit is yet further provided for compressing the second reference signature and inputting the compressed second reference signature to the LBIST circuit, wherein the compressed second reference signature replaces the first reference signature.
    Type: Application
    Filed: June 7, 2001
    Publication date: December 12, 2002
    Applicant: International Business Machines Corporation, Armonk, New York
    Inventors: Sam Gat-Shang Chu, Joachim Gerhard Clabes, Michael Normand Goulet, Johnny J. Leblanc, James Douglas Warnock