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:
Apr. 06, 1999
Filed:
Nov. 14, 1996
William C Moyer, Dripping Springs, TX (US);
John Arends, Austin, TX (US);
Lea Hwang Lee, Austin, TX (US);
Motorola Inc., Austin, TX (US);
Abstract
A data processing system (20) has a cache (26) that does not use a TAG array for storing a TAG address as in a conventional cache. The cache (26), according to one embodiment, uses a state machine (30) for transitioning the cache (26) to an active state in response to a change of flow instruction which is a short backward branch instruction of a predetermined displacement. The predetermined displacement is less than the number of entries in the cache (26), so the cache can remain active as long as the program is in a loop which can be contained entirely within the cache. A look ahead feature for the valid bit array is provided that associates the valid bit for a current instruction with a previous instruction, such that during a read of the cache, the valid bit for a next instruction is checked with the same index used to read the current instruction.