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:
Jul. 06, 1999
Filed:
Feb. 12, 1997
Tsukasa Shirotori, Tokyo, JP;
Shigeyuki Hayakawa, Tokyo, JP;
Kabushiki Kaisha Toshiba, Kawasaki-shi, JP;
Abstract
A cache memory automatically sets a low-, semi-, or high-speed mode operation according to a result of comparison between a half-period of a reference clock signal and a pulse width of a reference pulse signal provided by a reference pulse signal generator. Namely, a start signal generator generates a start signal used to access data memories, according to the frequency of the reference clock signal and a difference between the reference clock and pulse signals. According to the start signal and information indicating a hit tag memory, the cache memory dynamically switches the modes from one to another, without external instructions to the cache memory. In one embodiment, the cache memory is an n-way set associative cache memory having a plurality of data memories, and an enable signal is supplied only to a data memory associated with the hit tag memory when receiving hit information before a low speed mode start signal, or to all of the data memories when receiving the hit information after the high-speed mode start signal.