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:
Oct. 13, 1992
Filed:
Dec. 17, 1991
Ross V La Fetra, Cupertino, CA (US);
John F Shelton, Aptos, CA (US);
Hewlett-Packard Company, Palo Alto, CA (US);
Abstract
A computing system includes a processor, a system memory containing data utilized by the processor and two cache memories. Each cache memory is connected directly to the processor. A first cache memory is connected to the processor and to the system memory. The first cache memory contains a subset of data in the system memory. A second cache memory is also connected to the processor. The second cache memory contains a subset of data in the first cache memory. Data integrity in the system memory is maintained using the first cache memory only. Whenever the processor writes data, the processor writes data both to the first cache memory and to the second cache memory. Whenever the processor reads data, the processor attempts to read data from the second cache memory. If there is a miss at the second cache memory, the processor attempts to read data from the first cache memory. If there is a miss at the first cache memory, the data is retrieved from the system memory and placed in the first cache memory. The processor then reads the data from the first cache memory. Generally, when the processor reads data from the first cache memory, the read data is written into the second cache memory.