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:
Oct. 27, 2009
Filed:
Jan. 17, 2007
Charles C. Lee, Cupertino, CA (US);
I-kang Yu, Palo Alto, CA (US);
Edward W. Lee, Mountain View, CA (US);
Ming-shiang Shen, Taipei Hsien, TW;
Charles C. Lee, Cupertino, CA (US);
I-Kang Yu, Palo Alto, CA (US);
Edward W. Lee, Mountain View, CA (US);
Ming-Shiang Shen, Taipei Hsien, TW;
Super Talent Electronics, Inc., San Jose, CA (US);
Abstract
A flash-memory cache card caches data that a host writes to a hard disk drive. A flash-memory array has physical blocks of flash memory arranged into first and second data areas having M blocks each, and a wear-leveling-counter pool. An incoming logical sector address (LSA) from a host is mapped to one of M entries in a RAM lookup table using a hash of modulo M. The RAM entry stores a mapping to a physical block in a foreground area that is either the first or the second data area. Pages in the physical block are read for a matching LSA that indicates a cache hit. Full pages are written back to the hard disk and erased in the background while the other data area becomes the foreground area. A new physical block with a low wear-level count is selected from blocks in the new foreground area.