APPARATUS AND METHODS FOR CARRYING OUT OPERATIONS IN A NON-VOLATILE MEMORY CELL HAVING MULTIPLE MEMORY STATES

摘要

Apparatus and methods for carrying out operations in a non-volatile memory cell having multiple memory states are disclosed. One of the methods is a method for programming N bits in a non-volatile memory cell configured to store up to N+1 bits, where N is an integer greater than zero. The method for programming includes programming N bits of data in the cell. The method for programming also includes programming an additional bit of data that is a logical function of the N bits of data in the cell. The cell is configured to provide 2N+1 threshold voltage ranges for bit storage and, in accordance with the logical function: i) a first set of 2N threshold voltage ranges of the 2N+1 threshold voltage ranges are used to store the N bits of data; and ii) a remaining second set of 2N threshold voltage ranges alternating with the first set are unused.