Nonvolatile memory device having resistive memory cells including at least one resistive memory cell initial state

Abstract

A nonvolatile memory device includes: resistive memory cells each of which takes either a variable state or an initial state, the resistive memory cells including at least one resistive memory cell in the initial state; and a read circuit that includes a resistance detection circuit that obtains resistance value information of the at least one resistive memory cell, and a data generation circuit that generates digital data corresponding to the resistance value information. The resistance detection circuit applies a second read voltage to the at least one resistive memory cell to obtain the resistance value information. The second read voltage is larger than a first read voltage and smaller than a voltage of a forming pulse that is an electrical stress for changing from the initial state to the variable state. The first read voltage is for reading a resistive memory cell in the variable state.