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:
Mar. 01, 1994
Filed:
Feb. 28, 1992
David N Cutler, Bellevue, WA (US);
David A Orbits, Redmond, WA (US);
Dileep Bhandarkar, Shrewsbury, MA (US);
Wayne Cardoza, Merrimack, NH (US);
Richard T Witek, Littleton, MA (US);
Digital Equipment Corporation, Maynard, MA (US);
Abstract
In a multiprocessor data processing unit, a data element in the main memory unit, that has system wide significance, can have a requirement that this data element be altered in a controlled manner. Because other data processing units can have access to this data element, the alteration of the data element must be synchronized so the other data processing units are not in the process of altering the same data element simultaneously. The present invention includes an instruction that acquires access to an interlock signal in the main memory unit and initiates an interlock in the main memory unit, thereby excluding other data processing units from gaining access to the interlock signal simultaneously. The instruction causes the data element related to the interlock signal to be transferred to the data processing unit where the data element is saved, can be entered in mask apparatus and then have a quantity added thereto. The altered data element is returned to the main memory unit location and the main memory interlock signal is released, thereby completing the instruction.