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:
Dec. 17, 2013
Filed:
Jun. 28, 2010
Mei-man L. Syu, Fremont, CA (US);
Matthew Call, Ladera Ranch, CA (US);
Ho-fan Kang, Aliso Viejo, CA (US);
Lan D. Phan, Laguna Hills, CA (US);
Mei-Man L. Syu, Fremont, CA (US);
Matthew Call, Ladera Ranch, CA (US);
Ho-Fan Kang, Aliso Viejo, CA (US);
Lan D. Phan, Laguna Hills, CA (US);
Western Digital Technologies, Inc., Irvine, CA (US);
Abstract
Systems and methods for retaining data in non-volatile solid-state are disclosed in which refresh copy operations are performed on data stored in non-volatile solid-state memory. A controller can comprise a data retention module configured to issue copy commands within different periods of time, and to maintain usage data on a storage subsystem. A refresh copy operation helps ensure that data written to memory retain integrity by causing data to be programmed again onto the memory, which minimizes the risk of data error caused by electron leak in the non-volatile solid-state memory. One or more data structures may be used to determine memory blocks that require refresh copy operations. In one embodiment, a validity bit array is used to track blocks that contain valid data. In another embodiment, a least recently used list is used to track blocks that have been least recently written.