Method and system for optimizing reliability and performance of programming data in non-volatile memory devices

Abstract

Methods of managing memory devices, and devices so managed. A value of a parameter, that is used to program one or more memory cells, is adapted to a monitored condition of the cell(s). Either the number of bits per cell is held fixed or the monitored condition is an intrinsic condition of the cell(s). The initial value of the parameter is optimized for those specific cells, relative to a pre-selected criterion, by programming the cell(s) in accordance with candidate values of the parameter.

1 . A method of managing a memory, comprising the steps of: for at least one cell of the memory that is free of accumulated stress:
 (a) selecting a criterion for optimizing at least one programming parameter of the at least one cell; and   (b) optimizing said at least one programming parameter relative to said criterion, thereby obtaining an optimum value of each said at least one programming parameter that is specific to the at least one cell, said optimizing including programming said at least one cell.   
     
     
         2 . The method of  claim 1 , wherein said criterion is that a number of programming iterations needed to program said at least one cell is minimized. 
     
     
         3 . The method of  claim 1 , wherein said at least one programming parameter includes a programming base voltage. 
     
     
         4 . The method of  claim 1 , wherein said at least one programming parameter includes a programming iteration stepping voltage. 
     
     
         5 . The method of  claim 1 , wherein at least two said programming parameters are optimized jointly. 
     
     
         6 . A data storage device, comprising:
 (a) a plurality of cells for storing the data;   (b) a programming unit for programming the data into said plurality of cells in accordance with at least one parameter; and   (c) a mechanism for optimizing said at least one parameter, for at least a portion of said plurality of cells that is free of accumulated stress, said optimizing being relative to a pre-selected criterion, thereby obtaining an optimum value, of each said at least one parameter, that is specific to said at least portion of said plurality of cells, wherein said optimizing includes programming said at least portion of said plurality of cells using said programming unit.