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:
Feb. 16, 1999
Filed:
Aug. 18, 1995
Saba Rahman, Austin, TX (US);
Victor F Andrade, Austin, TX (US);
Advanced Micro Devices, Inc., Sunnyvale, CA (US);
Abstract
An integrated processor is provided with a memory control unit having refresh queue logic for refreshing dynamic random access memory (DRAM) banks during idle memory cycles. The refresh queue logic includes a queue counter and allows the refresh requests to be given a lower priority than other memory transactions until the required refresh rate is in danger of being violated. At this lower priority the refresh requests are honored and retired from a refresh queue only in the absence of other memory transactions. In the event that the refresh queue becomes full, top priority is given to the execution of a refresh request. In this case, a refresh request is honored and retired from the queue immediately after the conclusion of the current memory transaction. This queuing mechanism allows the refresh requests to be buffered until idle memory cycles are available or until absolutely necessary to prevent the violation of refresh timing constraints.