Patents by Inventor Paul A. Swartz

Paul A. Swartz 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: 7373560
    Abstract: A system measures propagation delays in any number of test circuits, each having two asynchronous inputs and an output, without using their clock inputs to re-initialize the test circuits during measurement operations. The delay between one of the test circuit's asynchronous inputs and its output is measured by propagating a test signal from the one asynchronous input to the output, and the test circuit is re-initialized using the test circuit's other asynchronous input.
    Type: Grant
    Filed: December 8, 2004
    Date of Patent: May 13, 2008
    Assignee: Xilinx, Inc.
    Inventors: Christopher H. Kingsley, Kusuma Bathala, Richard D. J. Duce, Paul A. Swartz
  • Patent number: 7370245
    Abstract: Cross-correlation of delay line characteristics is described. An integrated circuit for cross-correlation testing includes: a first ring oscillator and a second ring oscillator. The first ring oscillator includes a first test circuit, and the second ring oscillator includes a second test circuit. The first test circuit is coupled via first programmable interconnects to first ring oscillator circuitry, and the second test circuit is coupled via second programmable interconnects to second ring oscillator circuitry. The first test circuit includes a first programmable delay line, and the second test circuit includes a second programmable delay line. The first test circuit and the second test circuit are configured to provide separately controllable outputs for cross-correlation as between the first programmable delay line and the second programmable delay line.
    Type: Grant
    Filed: February 25, 2005
    Date of Patent: May 6, 2008
    Assignee: XILINX, Inc.
    Inventors: Himanshu J. Verma, Ajay Dalvi, Paul A. Swartz
  • Patent number: 7308632
    Abstract: A method and apparatus for the utilization of on-chip, programmable resources to implement a signal distortion characterization circuit. Programmable logic resources, such as programmable delay lines and phase shifting circuits, are utilized to sample the logic value of a test signal after the test signal has traversed a path under test (PUT). A counter is used to determine the number of logic high valued samples and the number of logic low valued samples during a test period. A ratio is then taken to determine the resulting duty cycle for the test period.
    Type: Grant
    Filed: August 11, 2005
    Date of Patent: December 11, 2007
    Assignee: Xilinx, Inc.
    Inventors: Himanshu J. Verma, Paul T. Nguyen, Paul A. Swartz
  • Patent number: 7305604
    Abstract: First and second clock signals are provided to first and second sequential circuits, where the first and second clock signals are inversely coupled to logic high and low levels for clocking of the first and second sequential circuits. A third sequential circuit is clocked responsive to a first output from the first sequential circuit and receives first signature data. A fourth sequential circuit is clocked responsive to a second output from the second sequential circuit and receives second signature data. A third output from the third sequential circuit is monitored responsive to the first signature data and the first output. A fourth output from the fourth sequential circuit is monitored responsive to the second signature data and the second output. Whether the first clock signal and the second clock signal are phase aligned may be determined responsive to the third output and the fourth output.
    Type: Grant
    Filed: March 4, 2005
    Date of Patent: December 4, 2007
    Assignee: Xilinx, Inc.
    Inventors: Himanshu J. Verma, Ajay Dalvi, Paul A. Swartz