Patent ID: 6496418
Filing Date: 2002-12-17
Classification: G11C

Abstract:
A non-volatile memory system comprising:a non-volatile memory device; and a control circuit, wherein said non-volatile memory device comprises a plurality of non-volatile memory cells and is capable of receiving a first programming command and a second programming command, wherein each of said plurality of non-volatile memory cells has a threshold voltage within one of a plurality of threshold voltage distributions determined according to data, wherein said non-volatile memory device controls a first programming operation when receiving said first programming command so that, during said first programming operation, said threshold voltage of non-volatile memory cell is set in a first width of threshold voltage distribution according to first data, wherein said non-volatile memory device controls a second programming operation when receiving said second programming command so that, during said second programming operation, said threshold voltage of non-volatile memory cell is set in a second width of threshold voltage distribution according to said first data, and wherein said control circuit issues said first programming command corresponding to occurrence of a first event and issues said second programming command corresponding to occurrence of a second event.