Patents by Inventor Fred Leung

Fred Leung 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: 5764586
    Abstract: A semiconductor memory device that operates as a normal memory device as long as existing memory is being addressed, but appears to external hardware and software to have a larger size (or standard size) memory array than is actually present in the semiconductor memory device is disclosed. To external hardware and software, the semiconductor memory device operates as if it has more addressable memory cells than in fact actually exist in the memory array. When addressing missing memory cells, the semiconductor memory device emulates or mimics their presence for the benefit of the external hardware or software. Preferably, the semiconductor memory device is a non-volatile electrically alterable semiconductor memory device. A method for emulating missing memory cells is also disclosed.
    Type: Grant
    Filed: October 10, 1996
    Date of Patent: June 9, 1998
    Assignee: Catalyst Semiconductor, Inc.
    Inventors: Radu Vanco, Gelu Voicu, Dumitru Cioaca, Fred Leung
  • Patent number: 5748981
    Abstract: An architecture is described for a single chip microcontroller wherein the microcode stored in the microcontroller's program memory may be easily modified without refabrication or removal of the microcontroller from its target environment. This is made possible by the utilization of a RAM based architecture for program memory instead of the traditional ROM based architecture.
    Type: Grant
    Filed: November 13, 1996
    Date of Patent: May 5, 1998
    Assignee: National Semiconductor Corporation
    Inventors: Paul J. Patchen, Hon C. Fung, Fred Leung, Steven McGinness