Patent ID: 7911835
Filing Date: 2011-03-22
Classification: G11C

Abstract:
1. A method of programming a non-volatile memory device comprising a first non-volatile memory cell and a second non-volatile memory cell, each of which can be programmed with first through sixth threshold voltage levels that sequentially increase, the method comprising: programming five bits of data in the first and second nonvolatile memory cells by programming an initial subset of two of the five bits of data into the first and second non-volatile memory cells, respectively, and then programming a remaining subset of three of the five bits of data into the first and second non-volatile memory cells according to threshold voltage levels at which the initial subset of the two of the five bits have been programmed into the first and second non-volatile memory cells, wherein programming the remaining subset of three of the five bits of data comprises determining whether to program the remaining subset into the first non-volatile memory cell or the second non-volatile memory cell and whether to program the remaining subset with which one of the third through sixth threshold voltages, according to threshold voltage levels at which the initial subset of two of the five bits have been programmed into the first and second non-volatile memory cells.