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:
Jan. 29, 2019
Filed:
Sep. 22, 2016
Qualcomm Incorporated, San Diego, CA (US);
Liyong Wang, Cary, NC (US);
QUALCOMM Incorporated, San Diego, CA (US);
Abstract
According to various aspects, a memory controller may schedule ZQ commands to periodically calibrate individual memory ranks in a multi-rank memory. The memory controller may schedule a ZQ short command at each ZQ interval and record that the ZQ short command was missed with respect to a memory rank in a self-refresh mode at the ZQ interval. After the missed ZQ short commands reaches a first threshold, a ZQ long command may be scheduled at the next ZQ interval and normal ZQ behavior may resume in the event that the memory rank exits the self-refresh mode and the ZQ long command is executed. However, if the memory rank stays in the self-refresh mode until missed ZQ long commands reaches a second threshold, the memory controller may trigger a ZQ long command once the memory rank exits the self-refresh mode and skip a next ZQ calibration before resuming normal ZQ behavior.