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:
Feb. 24, 1998
Filed:
Jan. 18, 1996
Yooichi Shintani, Machida, JP;
Yoshikazu Tanaka, Tokorozawa, JP;
Naohiko Irie, Kokubunji, JP;
William S Worley, Jr, Denver, CO (US);
B Ramakrishna Rau, Los Altos, CA (US);
Rajiv Gupta, Los Altos, CA (US);
Frederic C Amerson, Los Altos, CA (US);
Hitachi, Ltd., Tokyo, JP;
Hewlett-Packard Company, Palo Alto, CA (US);
Abstract
To improve the function of a circuit for prefetching data accessed by a processor, a prefetch unit incorporates therein a circuit for issuing a request to read out one group of data to be prefetched and registers for holding the group of data read in response to the read request therein. The group of data are read out from a cache memory or a main memory under the control of a cache request unit. A plurality of groups of data can be prefetched. When data designation is made, the processor requests the cache memory to read a block to which the data to be prefetched belongs. A circuit is also included in the prefetch unit, wherein when prefetched data is subsequently updated by the processor, its updated data is made invalid. Elements of a vector complex in structure, such as an indexed vector or the like can be also read out. It is also possible to cope with an interrupt generated within the processor.