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. 04, 2014
Filed:
Jul. 08, 2011
Apparatus and method for determining a read level of a flash memory after an inactive period of time
Aldo G. Cometti, San Diego, CA (US);
Lun Bin Huang, San Diego, CA (US);
Ashot Melik-martirosian, San Diego, CA (US);
Aldo G. Cometti, San Diego, CA (US);
Lun Bin Huang, San Diego, CA (US);
Ashot Melik-Martirosian, San Diego, CA (US);
STEC, Inc., Santa Ana, CA (US);
Abstract
Disclosed is an apparatus and method for determining a dwell time in a non-volatile memory circuit after a shutdown of the memory circuit. A voltage shift is calculated by comparing a first read level voltage required to read a test block stored before the shutdown and a second read level voltage required to read a second test block stored after the shutdown. A shutdown time is determined from a look up table indexed by the voltage shift and a number of program/erase cycles. The dwell time is calculated as a function of the drive temperature, a clock, and a block time stamp. Once the dwell time is calculated, a controller calculates a new read level voltage based, in part, on the dwell time and provides one or more programming commands representative of the new read level voltage to the memory circuit to read the memory circuit.