Patent ID: 8982603
Filing Date: 2015-03-17
Classification: G11C

Abstract:
1. A cross point variable resistance nonvolatile memory device comprising: a cross point memory cell array having a plurality of memory cells each of which includes a variable resistance element and a bidirectional current steering element and is placed at a different one of cross points of a plurality of bit lines extending in an X direction and a plurality of word lines extending in a Y direction, the variable resistance element reversibly changing between at least two states including a low resistance state and a high resistance state when voltages of different polarities are applied to the variable resistance element, and the bidirectional current steering element being connected in series with the variable resistance element and having nonlinear current-voltage characteristics; a decoder circuit that selects at least one of the memory cells from the memory cell array by selecting at least one of the bit lines and at least one of the word lines; a read circuit that reads data from the selected memory cell; a first current source that supplies a first constant current; and a control circuit that controls the reading of the data from the selected memory cell, wherein the control circuit controls the decoder circuit, the read circuit, and the first current source so that when the read circuit reads data, a first voltage for reading outputted from the read circuit is applied to a selected bit line that is one of the bit lines which is selected by the decoder circuit, a second voltage is applied to a selected word line that is one of the word lines which is selected by the decoder circuit, and the first constant current is supplied to an unselected word line that is, among the word lines, a word line not selected by the decoder circuit.