The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Apr. 11, 1989
Filed:
Dec. 04, 1986
Jon F Hauris, Manassas, VA (US);
International Business Machines Corporation, Armonk, NY (US);
Abstract
A microsequencer includes at least two program counters which access microinstructions stored in a memory system. A first program counter is cyclicly incremented to sequentially access microinstructions of a principal microprogram. When a particular microinstruction is accessed which indicates that a subroutine will be the next program to be executed, a branched-from address, representing the microinstruction calling the subroutine, is retained in the first program counter. An address representing the first instruction of the subroutine is loaded into a second program counter. The second program counter is then cyclicly incremented to sequentially access microinstructions associated with the subroutine. After the subroutine has been executed, the first program counter is re-enabled and cyclicly incremented so that the execution of the principal program is resumed in an orderly manner.