Patent · US Expired

Cache coherent computer system that minimizes invalidation and copyback operations

US5706463A · kind A · utility

35Cited by
8References
19Claims
0Family size

Assignee

Inventors

Key dates

Filing dateMay 12, 1997
Grant dateJan 6, 1998
Priority date
Expiry dateMay 12, 2017

Classification

  • Technology area (CPC G)Physics
  • CPC primaryG06F12/0815
  • WIPO fieldComputer technology
  • WIPO sectorElectrical engineering

Abstract

A multi-processor computer system is disclosed that reduces the occurrences of invalidate and copyback operations through a memory interconnect by disabling a first write optimization of a cache coherency protocol for data that is not likely to be written by a requesting processor. Such data include read-only code segments. The code segments, including instructions and data, are shared among the multiple processors. The requesting processor generates a Read to Share Always request upon a cache miss of a read-only datablock, and generates a Read to Share request otherwise. The Read to Share Always request results in the datablock stored in cache memory being labeled as in a "shared" state, while the Read to Share request results in the datablock being labeled as in an "exclusive" state.

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