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:
Jun. 25, 2002
Filed:
Feb. 08, 1999
Masashi Sasahara, Kawasaki, JP;
Rakesh Agarwal, Palo Alto, CA (US);
Kamran Malik, San Jose, CA (US);
Michael Raam, Cupertino, CA (US);
Kabushiki Kaisha Toshiba, Kawasaki, JP;
Abstract
A microprocessor includes an MMU which converts from a virtual address to a physical address, and an LSU which controls an execution of a load/store instruction. The LSU includes a DCACHE which temporarily stores data to read out from and to write into an external memory, an SPRAM used for a specific purpose besides caching, and an address generator which generates the virtual address to access the DCACHE and the SPRAM. The MMU generates a conversion table which performs a conversion from the virtual address to the physical address. A flag information showing whether or not the access to the SPRAM is performed is included in this conversion table. The LSU absolutely accesses the SPRAM if the flag is being set. Accordingly, it is unnecessary to allocate the SPRAM to a memory map of the main memory, and the allocation of the memory map simplifies.