Patent · US Expired

Methods and apparatus for transferring cache block ownership

US6775748B2 · kind B2 · utility

9Cited by
5References
31Claims
0Family size

Assignee

Inventors

Key dates

Filing dateJan 24, 2002
Grant dateAug 10, 2004
Priority date
Expiry dateOct 14, 2022

Classification

  • Technology area (CPC Y)Emerging Cross-Sectional Technologies
  • CPC primaryY02D10/00
  • WIPO fieldComputer technology
  • WIPO sectorElectrical engineering

Abstract

Methods and apparatus for transferring cache block ownership from a first cache to a second cache without performing a writeback to a main memory are disclosed. Prior to the ownership transfer, the first cache holds the memory block in an “owned” state, and the second cache holds the same memory block in a “shared” state. Main memory does not yet reflect modifications made to the memory block. When the processor associated with the first cache attempts to write-back the modified memory block to main memory, the second cache asserts a signal to the first cache which cancels the write-back. In addition, the memory block in the second cache changes to an “owned” state. If additional caches also hold the memory block, an arbitration mechanism selects one cache to be the new owner. In this manner, communications with main memory and power consumption are reduced.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.