Dual read mode non-volatile memory semiconductor device

Abstract

A method of operating a semiconductor device having a plurality of memory cells programmable to a plurality of program states, wherein each of the program states is associated with a range of read currents bounded by a pair of reference read currents, comprising storing data by programming a first memory cell of the plurality of memory cells to a first program state of the plurality of program states, and programming a second memory cell of the plurality of memory cells to a second program state of the plurality of program states; and reading the data by reading the first memory cell to determine a first read current through the first memory cell, reading the second memory cell to determine a second read current through the second memory cell, and comparing the first read current, the second read current and a first one of the reference read currents to each other.