Disclosed herein is a memory cell including a memory element and a selector device. Data may be stored in both the memory element and selector device. The memory cell may be programmed by applying write pulses having different polarities and magnitudes. Different polarities of the write pulses may program different logic states into the selector device. Different magnitudes of the write pulses may program different logic states into the memory element. The memory cell may be read by read pulses all having the same polarity. The logic state of the memory cell may be detected by observing different threshold voltages when the read pulses are applied. The different threshold voltages may be responsive to the different polarities and magnitudes of the write pulses.

An embodiment of the present invention provides a method for implementing Boolean functionality to create AND, OR, NAND, NOR, or NOT logic gates using a single memristor. In an embodiment, a first voltage is applied to the memristor within a predetermined range of one of the prescribed Boolean functions to be performed by the memristor. A second voltage is then applied within the predetermined range of the prescribed Boolean function. The memristor then provides an output based on the Boolean function that has been prescribed. In an embodiment, the resistance value of the memristor is then reset by a reset pulse, wherein the reset pulse is another applied voltage.

Disclosed is a nonvolatile memory device including a plurality of memory cells operable to store data, each memory cell structured to include a resistance change layer exhibiting different resistance states with different resistance values for representing data, a write circuit suitable for generating a write pulse in a write mode to write data in a memory cell of the plurality of memory cells, and a read circuit suitable for generating a read pulse in a read mode to read data from a memory cell of the plurality of memory cells, wherein the memory cells are each structured to be operable in writing or reading data when a range of a voltage level change of the read pulse corresponding to a pulse width change of the read pulse is within a range of a voltage level change of the write pulse corresponding to a pulse width change of the write pulse.

According to one embodiment, a memory device includes a memory cell including a resistance change memory portion and a switching portion, and a voltage applying circuit carrying out, at a time of writing data to the memory cell, an operation of applying a voltage of a first polarity to the memory cell and applying a first voltage to the memory cell, an operation of applying a voltage of a second polarity to the memory cell and applying a second voltage to the memory cell, an operation of applying a voltage of the first polarity to the memory cell and applying a third voltage to the memory cell, or an operation of applying a voltage of the second polarity to the memory cell and applying a fourth voltage to the memory cell.

A variable resistance memory device includes: a memory cell including a first and second sub memory cell; and a first, second and third conductor. The first sub memory cell is above the first conductor, and includes a first variable resistance element and a first bidirectional switching element. The second sub memory cell is above the second conductor, and includes a second variable resistance element and a second bidirectional switching element. The second conductor is above the first sub memory cell. The third conductor is above the second sub memory cell. The variable resistance memory device is configured to receive first data and to write the first data to the memory cell when the first data does not match second data read from the memory cell.

Embodiments disclosed include memory cell operating methods, memory cell programming methods, memory cell reading methods, memory cells, and memory devices. In one embodiment, a memory cell includes a wordline, a first bitline, a second bitline, and a memory element. The memory element is electrically connected to the wordline and selectively electrically connected to the first bitline and the second bitline. The memory element stores information via a resistive state of the memory element. The memory cell is configured to convey the resistive state of the memory element via either a first current flowing from the first bitline through the memory element to the wordline or a second current flowing from the wordline through the memory element to the second bitline.

Embodiments disclosed include memory cell operating methods, memory cell programming methods, memory cell reading methods, memory cells, and memory devices. In one embodiment, a memory cell includes a wordline, a first bitline, a second bitline, and a memory element. The memory element is electrically connected to the wordline and selectively electrically connected to the first bitline and the second bitline. The memory element stores information via a resistive state of the memory element. The memory cell is configured to convey the resistive state of the memory element via either a first current flowing from the first bitline through the memory element to the wordline or a second current flowing from the wordline through the memory element to the second bitline.

Two-terminal memory can be set to a first state (e.g., conductive state) in response to a program pulse, or set a second state (e.g., resistive state) in response to an erase pulse. These pulses generally provide a voltage difference between the two terminals of the memory cell. Certain electrical characteristics associated with the pulses can be manipulated in order to enhance the efficacy of the pulse. For example, the pulse can be enhanced or improved to reduce power-consumption associated with the pulse, reduce a number of pulses used to successfully set the state of the memory cell, reduce wear or damage to the memory cell, or to improve Ion or Ioff distribution associated with changing the state of the memory cell.

Circuits, systems, and methods for double-polarity reading of double-polarity stored data information are described. In one embodiment, a method involves applying a first voltage with a first polarity to a plurality of the memory cells. The method involves applying a second voltage with a second polarity to one or more of the plurality of memory cells. The method involves detecting electrical responses of the one or more memory cells to the first voltage and the second voltage. The method also involves determining a logic state of the one or more memory cells based on the electrical responses of the one or more memory cells to the first voltage and the second voltage.

A memory architecture comprises a first memory macro comprising a first plurality of memory cells, a second memory macro comprising a second plurality of memory cells, and a control logic coupled to the first and second memory macros. The control logic is configured to write a logical state to each of the first and second pluralities of memory cells by using first and second signal levels, respectively, thereby causing the first and second memory macros to be used in first and second applications, respectively, the first and second signal levels being different and the first and second applications being different. The first and second memory macros are formed on a single chip, and wherein the first and second pluralities of the memory cells comprise a variable resistance dielectric layer formed using a single process recipe.