Patents by Inventor Simon J. Levy

Simon J. Levy 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).

  • Apparatus and method for detecting and handling memory-mapped I/O by a pipelined microprocessor
    Patent number: 4802085
    Abstract: A method for detecting and handling memory-mapped I/O in a pipelined data processing system is provided. The method uses two signals on the system interface: when the system generates a read bus cycle, it activates an output signal if certain I/O requirements are not satisfied; an input signal is activated when the reference is to a peripheral device that exhibits certain characteristics; when the system detects that both the input signal and the output signal are active, it discards the data read during the bus cycle, serializes instruction execution and regenerates the read bus cycle, this time satisfying the requirements for I/O such that the output signal is driven inactive.
    Type: Grant
    Filed: January 22, 1987
    Date of Patent: January 31, 1989
    Assignee: National Semiconductor Corporation
    Inventors: Simon J. Levy, Donald B. Alpert