Patent · US Expired

Multiprocessing system employing a coherency protocol including a reply count

US5897657A · kind A · utility

32Cited by
1References
22Claims
0Family size

Assignee

Inventors

Key dates

Filing dateJul 1, 1996
Grant dateApr 27, 1999
Priority date
Expiry dateJul 1, 2016

Classification

  • Technology area (CPC G)Physics
  • CPC primaryG06F2212/2542
  • WIPO fieldComputer technology
  • WIPO sectorElectrical engineering

Abstract

A multiprocessing computer system employing a three-hop communications protocol including a reply count communication. When a request is sent by a requesting node to a home node, the home node sends read and/or invalidate demands to any slave nodes holding cached copies of the requested data. The demands from the home node the slave nodes may each advantageously include a value indicative of the number of replies the requesting agent should expect to receive. The slaves reply back to the requesting node with either data or an acknowledge. Each reply may further include the number of replies the requester should expect. Upon receiving all expected replies, the requesting node may send a completion message back to the home and may treat the transaction as completed and proceed with subsequent processing.

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