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, 2004
Filed:
Mar. 29, 2000
Junya Matsushima, Kawasaki, JP;
Takumi Takeno, Kawasaki, JP;
Kenichi Nabeya, Campbell, CA (US);
Daisuke Ban, Kawasaki, JP;
Fujitsu Limited, Kawasaki, JP;
Abstract
The present invention prevents, at high speed, a malfunction from occurring at the time of changing a mode in a processor, in which information to be decoded varies with modes. The processor is provided with a circuit for referring to a result of decoding information or issuing an instruction when a write operation is performed on a register for storing data containing a bit that indicates a current mode, and for outputting a purge signal if the result of decoding information or issuing an instruction is information represented by a mode switching signal. Thus, when a mode switching signal is written to the register, a purge signal is outputted to a cache memory. Consequently, the valid bit of prefetched cache data is turned off. This prevents prefetched data from being decoded in a different mode. As a result, operations are normally performed after the switching of the mode. Alternatively, the purge signal is outputted by detecting a change in the value of the bit indicating the current mode.