Patents by Inventor James E. Burnette, II

James E. Burnette, II 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: 9389635
    Abstract: Embodiments of a jitter detection circuit are disclosed that may allow for detecting both cycle and phase jitter in a clock distribution network. The jitter detection circuit may include a phase selector, a data generator, a delay chain, a logic circuit, and clocked storage elements. The phase selector may be operable to select a clock phase to be used for the launch clock, and the data generator may be operable to generate a data signal responsive to the launch clock. The delay chain may generate a plurality of outputs dependent upon the data signal, and the clocked storage elements may be operable to capture the plurality of outputs from the delay chain, which may be compared to expected data by the logic circuit.
    Type: Grant
    Filed: November 9, 2015
    Date of Patent: July 12, 2016
    Assignee: Apple Inc.
    Inventors: Greg M. Hess, James E. Burnette, II
  • Publication number: 20160062388
    Abstract: Embodiments of a jitter detection circuit are disclosed that may allow for detecting both cycle and phase jitter in a clock distribution network. The jitter detection circuit may include a phase selector, a data generator, a delay chain, a logic circuit, and clocked storage elements. The phase selector may be operable to select a clock phase to be used for the launch clock, and the data generator may be operable to generate a data signal responsive to the launch clock. The delay chain may generate a plurality of outputs dependent upon the data signal, and the clocked storage elements may be operable to capture the plurality of outputs from the delay chain, which may be compared to expected data by the logic circuit.
    Type: Application
    Filed: November 9, 2015
    Publication date: March 3, 2016
    Inventors: Greg M. Hess, James E. Burnette, II
  • Patent number: 9230690
    Abstract: Embodiments of a register file test circuit are disclosed that may allow for determining write performance at low power supply voltages. The register file test circuit may include a decoder, a multiplexer, a frequency divider, and a control circuit. The decoder may be operable to select a register cell within a register file, and the control circuit may be operable to controllably activate the read and write paths through the selected register cell, allowing data read to be inverted and re-written back into the selected register cell.
    Type: Grant
    Filed: November 7, 2012
    Date of Patent: January 5, 2016
    Assignee: Apple Inc.
    Inventors: Greg M Hess, James E Burnette, II
  • Patent number: 9207705
    Abstract: Embodiments of a jitter detection circuit are disclosed that may allow for detecting both cycle and phase jitter in a clock distribution network. The jitter detection circuit may include a phase selector, a data generator, a delay chain, a logic circuit, and clocked storage elements. The phase selector may be operable to select a clock phase to be used for the launch clock, and the data generator may be operable to generate a data signal responsive to the launch clock. The delay chain may generate a plurality of outputs dependent upon the data signal, and the clocked storage elements may be operable to capture the plurality of outputs from the delay chain, which may be compared to expected data by the logic circuit.
    Type: Grant
    Filed: November 7, 2012
    Date of Patent: December 8, 2015
    Assignee: Apple Inc.
    Inventors: Greg M Hess, James E Burnette, II
  • Patent number: 8988957
    Abstract: A sense amplifier test circuit that may allow for detecting soft failures may include a voltage generator circuit, a sense amplifier, and a detection circuit. The voltage generator may be operable to controllably supply different differential voltages to the sense amplifier, and the detection circuit may be operable to detect an analog voltage on the output of the sense amplifier.
    Type: Grant
    Filed: November 7, 2012
    Date of Patent: March 24, 2015
    Assignee: Apple Inc.
    Inventors: Greg M Hess, James E Burnette, II
  • Publication number: 20140129884
    Abstract: Embodiments of a register file test circuit are disclosed that may allow for determining write performance at low power supply voltages. The register file test circuit may include a decoder, a multiplexer, a frequency divider, and a control circuit. The decoder may be operable to select a register cell within a register file, and the control circuit may be operable to controllably activate the read and write paths through the selected register cell, allowing data read to be inverted and re-written back into the selected register cell.
    Type: Application
    Filed: November 7, 2012
    Publication date: May 8, 2014
    Applicant: APPLE INC.
    Inventors: Greg M. Hess, James E. Burnette, II
  • Publication number: 20140129868
    Abstract: Embodiments of a jitter detection circuit are disclosed that may allow for detecting both cycle and phase jitter in a clock distribution network. The jitter detection circuit may include a phase selector, a data generator, a delay chain, a logic circuit, and clocked storage elements. The phase selector may be operable to select a clock phase to be used for the launch clock, and the data generator may be operable to generate a data signal responsive to the launch clock. The delay chain may generate a plurality of outputs dependent upon the data signal, and the clocked storage elements may be operable to capture the plurality of outputs from the delay chain, which may be compared to expected data by the logic circuit.
    Type: Application
    Filed: November 7, 2012
    Publication date: May 8, 2014
    Applicant: APPLE INC.
    Inventors: Greg M Hess, James E Burnette, II
  • Publication number: 20140126312
    Abstract: Embodiments of a sense amplifier test circuit are disclosed that may allow for detecting soft failures. The sense amplifier test circuit may include a voltage generator circuit, a sense amplifier, and a detection circuit. The voltage generator may be operable to controllably supply different differential voltages to the sense amplifier, and the detection circuit may be operable to detect an analog voltage on the output of the sense amplifier.
    Type: Application
    Filed: November 7, 2012
    Publication date: May 8, 2014
    Applicant: APPLE INC.
    Inventors: Greg M. Hess, James E. Burnette, II
  • Patent number: 8558603
    Abstract: A level shifting multiplexer is disclosed. In one embodiment, a multiplexer is coupled to receive a first input signal from circuitry in a first power domain and a second input signal from circuitry in a second power domain. The multiplexer is configured to output a selected one of the first and second input signals to circuitry in the second power domain. The multiplexer also includes a level shifter circuit. When the first input signal is selected, the level shifter circuit may be enabled. When enabled, the level shifter circuit may level shift the first signal such that its voltage swing corresponds to that of the second voltage domain. The multiplexer may also include isolation circuitry configured to inhibit the level shifter.
    Type: Grant
    Filed: December 15, 2011
    Date of Patent: October 15, 2013
    Assignee: Apple Inc.
    Inventors: Greg M. Hess, Naveen Javarappa, James E. Burnette, II
  • Publication number: 20130154712
    Abstract: A level shifting multiplexer is disclosed. In one embodiment, a multiplexer is coupled to receive a first input signal from circuitry in a first power domain and a second input signal from circuitry in a second power domain. The multiplexer is configured to output a selected one of the first and second input signals to circuitry in the second power domain. The multiplexer also includes a level shifter circuit. When the first input signal is selected, the level shifter circuit may be enabled. When enabled, the level shifter circuit may level shift the first signal such that its voltage swing corresponds to that of the second voltage domain. The multiplexer may also include isolation circuitry configured to inhibit the level shifter.
    Type: Application
    Filed: December 15, 2011
    Publication date: June 20, 2013
    Inventors: Greg M. Hess, Naveen Javarappa, James E. Burnette, II
  • Patent number: 8397199
    Abstract: In an embodiment, an aging analysis tool may be configured to identify transistors that are expected to experience aging effects according to worst case stress vectors and/or designer identified worst case conditions. The aging analysis tool may modify a representation of the circuit (e.g. a netlist), replacing the identified transistors with aged transistors (e.g. by modifying parameters of the transistors in the netlist). The aging analysis tool may process the modified netlist over a range of conditions at which the circuit is expected to operate, to ensure that the design meets specifications after aging. The process may be repeated until the aged design meets specifications (with circuit modifications made by the designer to improve the design).
    Type: Grant
    Filed: April 19, 2010
    Date of Patent: March 12, 2013
    Assignee: Apple Inc.
    Inventors: Apurva H. Soni, Antonietta Oliva, Edgardo F. Klass, Matthew J. T. Page, James E. Burnette, II
  • Publication number: 20110257954
    Abstract: In an embodiment, an aging analysis tool may be configured to identify transistors that are expected to experience aging effects according to worst case stress vectors and/or designer identified worst case conditions. The aging analysis tool may modify a representation of the circuit (e.g. a netlist), replacing the identified transistors with aged transistors (e.g. by modifying parameters of the transistors in the netlist). The aging analysis tool may process the modified netlist over a range of conditions at which the circuit is expected to operate, to ensure that the design meets specifications after aging. The process may be repeated until the aged design meets specifications (with circuit modifications made by the designer to improve the design).
    Type: Application
    Filed: April 19, 2010
    Publication date: October 20, 2011
    Inventors: Apurva H. Soni, Anonietta Oliva, Edgardo F. Klass, Matthew J.T. Page, James E. Burnette, II