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. 09, 2001
Filed:
Aug. 09, 2000
Lawrence D. Engh, Redwood City, CA (US);
Albert V. Kordesch, San Jose, CA (US);
Ping Guo, Campbell, CA (US);
Chun-Mai Liu, San Jose, CA (US);
Information Storage Devices, Inc., San Jose, CA (US);
Abstract
Adaptive programming method and apparatus for flash memory analog storage. The present invention method is to adjust the voltage of the programming pulse each time based on the result of the previous pulse. The expected change in the programmed value is compared to the measured change, and the difference used to improve the model of that cell after each programming pulse. The algorithm is “adaptive” because the voltage of each pulse is adapted to whatever the cell needs. If the cell is programming too slowly, the voltage is increased dramatically to make it faster. Conversely if the results show that a particular cell is programming too fast, the next voltage pulse is increased by only a small amount (or even decreased if necessary). Because the response of the cell is non-linear, a special analog circuit is used to calculate the optimum voltage for each pulse. As one alternative, a digital calculation may also be used to program the cells. Because of the programming speed of the exemplary method, a voice signal may be sampled and stored in flash memory one cell at a time. Variable programming parameters other than voltage may be used if desired.