Patents by Inventor Chwen-Cher Chang

Chwen-Cher Chang 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: 6651225
    Abstract: In a verification system, a dynamic logic evaluation system and method dynamically calculates the minimum evaluation time for each input. Thus, this system and method will remove the performance burden that a fixed and statically calculated evaluation time would introduce. By dynamically calculating different evaluation times based on the input, 99% of the inputs will not be delayed for the sake of 1% of the inputs that actually need the worst possible evaluation time. The dynamic logic evaluation system and method comprises a global control unit coupled to a propagation detector, where the propagation detector is placed in each FPGA chip. The propagation detector in the FPGA chip alerts the global control unit of any input data that is currently propagating within the FPGA chips. A master clock controls the operation of this dynamic evaluation system and method. As long as any input data is propagating, the global control unit will prevent the next input from being provided to the FPGA chips for evaluation.
    Type: Grant
    Filed: April 10, 2000
    Date of Patent: November 18, 2003
    Assignee: Axis Systems, Inc.
    Inventors: Sharon Sheau-Pyng Lin, Ping-Sheng Tseng, Chwen-Cher Chang, Su-Jen Hwang
  • Patent number: 5461576
    Abstract: An electronic design automation tool embodiment uses a single slack graph structure throughout a process to provide communication between a placer (performing placement) and a timing constraint generator (performing slack distribution). The tool includes a slack graph generator, a timing calculator, a timing analyzer, a timing constraint generator and a net bounding box generator. A list of net constraints and a list of complete path constraints are fed to the slack graph generator during operation. Timing calculations from the delay calculator and zero net RC delays from a clustering process in a placer also provide input to the slack graph generator. The list of net constraints, a list of pin-to-pin constraints and a set of specifications for system clocking are input to the timing analyzer. The timing constraint generator receives a composite slack graph from the timing calculator, slack graph generator and timing analyzer.
    Type: Grant
    Filed: September 1, 1993
    Date of Patent: October 24, 1995
    Assignee: Arcsys, Inc.
    Inventors: Ren-Song Tsay, Chwen-Cher Chang