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:
Jul. 22, 1997
Filed:
Jun. 05, 1996
Gilman Chesley, Santa Cruz, CA (US);
Sun Microsystems, Inc., Mountain View, CA (US);
Abstract
A data processing system which utilizes dynamic memory that requires periodic refreshment includes a processor coupled to a memory controller which is in turn coupled to the dynamic memory. The memory controller includes a memory operation command queue for sequentially receiving memory operation commands from the processor and a refresh module for initiating refresh operations. The refresh module includes circuitry for initiating either a mandatory refresh operation or an optional refresh operation. Mandatory refresh operations are initiated at the conclusion of periodic intervals, unless an optional refresh operation has been initiated within the particular interval. An optional refresh operation is initiated within a particular interval if the memory operation command queue is empty. Optional refresh operations thereby serve to substitute for mandatory refresh operations, minimizing the system time lost to refresh operations.