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:
Jun. 11, 2002
Filed:
Aug. 02, 2000
Subir Ghosh, San Jose, CA (US);
Hsu-Tien Tung, San Jose, CA (US);
OPTi Inc., Mountain View, CA (US);
Abstract
When a PCI-bus controller receives a request from a PCI-bus master to transfer data with an address in secondary memory, the controller performs an initial inquire cycle and withholds TRDY# to the PCI-bus master until any write-back cycle completes. The controller then allows the burst access to take place between secondary memory and the PCI-bus master, and simultaneously and predictively, performs an inquire cycle of the L1 cache for the next cache line. In this manner, if the PCI burst continues past the cache line boundary, the new inquire cycle will already have taken place, or will already be in progress, thereby allowing the burst to proceed with, at most, a short delay. Predictive snoop cycles are not performed if the first transfer of a PCI-bus master access would be the last transfer before a cache line boundary is reached.