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. 25, 1989
Filed:
Apr. 01, 1988
David J Sager, Acton, MA (US);
Raj K Ramanujan, Leominster, MA (US);
Jeffrey L Bell, Maynard, MA (US);
Digital Equipment Corporation, Maynard, MA (US);
Abstract
A cache memory system in a data processor that has a main memory and a processing unit, the cache memory system including a virtually addressed storage cache. This virtually addressed storage cache is connected to the main memory for storing in storage cache locations preselected portions of data from the main memory. Each cache location includes a valid indicator to indicate the data in the cache location is current. A translation buffers is coupled to the storage cache, and translates a virtual address to a physical address. The backmap is coupled to the storage cache and the translation buffer, and invalidates data in the storage cache by generating an invalidate index to the cache location at which a valid indicator is to be cleared only when data in the storage cache is to be invalidated. The cache memory system includes at least one lockout register for storing addresses for data which may exist in more than one storage location. The backmap invalidates all copies of the data in the storage cache after every reference to data in the storage cache using an address in the lockout register.