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:
May. 08, 2007
Filed:
Jan. 04, 2005
Christer Karlsson, Linköping, SE;
Göran Gustafsson, Linköping, SE;
Mats Johansson, Linköping, SE;
Per Sandström, Linköping, SE;
Per-erik Nordal, Asker, NO;
Hans Gude Gudesen, Brussels, BE;
Johan Carlsson, Linköping, SE;
Christer Karlsson, Linköping, SE;
Göran Gustafsson, Linköping, SE;
Mats Johansson, Linköping, SE;
Per Sandström, Linköping, SE;
Per-Erik Nordal, Asker, NO;
Hans Gude Gudesen, Brussels, BE;
Johan Carlsson, Linköping, SE;
Thin Film Electronics ASA, Oslo, NO;
Abstract
In a method for operating a passive matrix-addressable ferroelectric or electret memory device, a voltage pulse protocol based on a 1/3 voltage selection rule is used in order to keep disturb voltages at minimum, the voltage pulse protocol comprising cycles for read and write/erase bases on time sequence of voltage pulses with defined parameters. The method comprises a refresh procedure wherein cells for refresh are selected and refresh requests processed by a memory device controller, the refresh requests are monitored and processed in regard of ongoing or scheduled memory operations, and refresh voltage pulses with defined parameters are applied to the memory cells selected for refresh, while simultaneously ensuring that non-selected memory cells are subjected to zero voltage or voltages which do not affect the polarization state of these cells.