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:
Dec. 13, 1988
Filed:
Jul. 31, 1985
David J Angel, Hudson, NH (US);
Gary A Cardone, Groton, MA (US);
Mark D Holbrook, Pepperell, MA (US);
James P Moskun, Nashua, NH (US);
Bruce Patterson, Andover, MA (US);
Wang Laboratories, Inc., Lowell, MA (US);
Abstract
An information processing system includes a processor responsive to instructions for performing operations. The processor includes instruction queue for fetching and storing instructions in advance of execution and the system is responsive to certain of the instructions for causing execution of a corresponding sequence of instructions. A prefetch monitor includes circuitry for detecting instructions which may result in the execution of a corresponding sequence of instructions. The prefetch monitor further includes an instruction substitution circuit which is responsive to the detecting circuitry for inhibiting the reading of following instructions from a memory to the processor and is responsive to instruction fetching operation of the processor for reading null instructions to the processor. The prefetch monitor also includes a synchronization which is responsive to a fetching operation of the processor circuit for detecting transfer of execution to a next valid instruction, wherein the substitution circuit is responsive to the synchronization circuit for resuming reading of instructions from the memory to the processor with the next valid instruction. The synchronization includes circuitry for maintaining synchronization between the operations of substituting null instructions and the execution of the instructions. In a specific implementation, the instructions which may result in the execution of a corresponding sequence of instructions are foreign to the system, a corresponding non-maskable interrupt results in the execution of a routine which emulates the execution of the foreign instruction and the null instructions are jump-to-self instructions.