Patents by Inventor Richard E. Calcagni

Richard E. Calcagni 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).

  • Digital processor with bit mask for counting registers for fast register saves
    Patent number: 5321823
    Abstract: A high-performance, pipelined CPU in which an improved method is used for saving registers in memory upon the occurrence of a procedure CALL or RETURN. The registers which need to be saved are defined by a bit-mask, and the number of bits is counted by a hardwired circuit, in each machine cycle, producing an output in the form of an offset from a stack pointer which represents the highest memory location needed to save the registers being used. Then a memory probe can be done to see if this location is writable. Thus, in one microinstruction cycle, the count is made and the memory probe can begin.
    Type: Grant
    Filed: June 21, 1990
    Date of Patent: June 14, 1994
    Assignee: Digital Equipment Corporation
    Inventors: William J. Grundmann, George M. Uhler, Richard E. Calcagni