Abstract: A nonvolatile latch circuit according to the present invention includes: a latch operating unit in which outputs of cross-coupled connected inverter circuit and inverter circuit are connected via a series circuit which includes a transistor, a variable resistance element, and a transistor in this order, and store and restore in a latch state are controlled by control terminals of the transistors; and a comparator circuit which compares a signal obtained by amplifying the value of the sum of potentials at both ends of the variable resistance element with the logic state of the latch operating unit, wherein writing to and reading from the variable resistance element are repeated until an output of the comparator circuit indicates that normal write operation has been performed.

Abstract: A variable resistance nonvolatile memory device includes a plurality of memory cells in each of which a variable resistance element and a current steering element having two terminals are connected in series. Additionally, a current limit circuit limits a first current flowing in a direction for changing the memory cells to a low resistance state, and a boost circuit increases, when one of the memory cells changes to the low resistance state, the first current in a first period before the memory cell changes to the low resistance state.

Abstract: The nonvolatile storage device includes a variable resistance element and a write circuit which writes data into the variable resistance element, wherein the variable resistance element has a property of changing from a first resistance state to a second resistance state when a pulse of a first voltage is applied to the variable resistance element, and changing from the second resistance state to the first resistance state when a pulse of a second voltage is applied to the variable resistance element, and the write circuit applies, to the variable resistance element, at least the pulse of the first voltage, a pulse of a third voltage, and the pulse of the first voltage in this order, when the variable resistance element is caused to change from the first resistance state to the second resistance state.

Abstract: A nonvolatile latch circuit according to the present invention wherein the outputs of an inverter circuit and other inverter circuit which are cross-coupled are connected to each other via a series circuit in which a transistor, a variable resistance element, and other transistor are connected in this order; a store operation and a restore operation for a latch state are controlled by application of a voltage to control terminals of the transistor and the other transistor; and both end potentials of the variable resistance element are summed, an amount of the sum is amplified and inverted, and the inverted amount is returned to an input of the inverter circuit or the other inverter circuit, thereby restoring a logic state in which a forming process of the variable resistance element can be performed.

Abstract: The nonvolatile storage device includes a variable resistance element (106) and a write circuit (101) which writes data into the variable resistance element, wherein the variable resistance element has a property of changing from a first resistance state (LR state or HR state) to a second resistance state (HR state or LR state) when a pulse of a first voltage (Vh or Vl) is applied to the variable resistance element, and changing from the second resistance state to the first resistance state when a pulse of a second voltage (Vl or Vh) is applied to the variable resistance element, and the write circuit applies, to the variable resistance element, at least the pulse of the first voltage, a pulse of a third voltage (VlLow or VhLow), and the pulse of the first voltage in this order, when the variable resistance element is caused to change from the first resistance state to the second resistance state.

Abstract: A resistance variable layer changes: to a second resistance state in such a manner that its resistance value stops decreasing when an interelectrode voltage reaches a negative first voltage; to a first resistance state in such a manner that its resistance value starts increasing when the interelectrode voltage reaches a positive second voltage which is equal in absolute value to the first voltage; to the first resistance state in such a manner that the resistance variable layer flows an interelectrode current such that the interelectrode voltage is maintained at a third voltage higher than the second voltage, when the interelectrode voltage reaches the third voltage; and to the first resistance state in such a manner that its resistance value stops increasing when the interelectrode current reaches a first current in a state where the interelectrode voltage is not lower than the second voltage and lower than the third voltage.

Abstract: A cross point variable nonvolatile memory device includes a memory cell array including: first memory cells (e.g., part of a memory cell array) having a common word line; and second memory cells (e.g., another part of the memory cell array or a compensation cell unit). When a predetermined memory cell among the first memory cells is written to by changing the predetermined memory cell to a first resistance state, a word line write circuit supplies a first voltage or a first current to a selected word line, a first bit line write circuit supplies a third voltage or a third current to one bit line of the first memory cells, and a second bit line write circuit supplies the third voltage or the third current to A bit line or lines of the second memory cells.

Abstract: A variable resistance nonvolatile memory element writing method of, by applying a voltage pulse to a memory cell including a variable resistance element, reversibly changing the variable resistance element between a first resistance state and a second resistance state according to a polarity of the applied voltage pulse is provided. The variable resistance nonvolatile memory element writing method includes applying a first preliminary voltage pulse and subsequently applying the first voltage pulse to the variable resistance element to change the variable resistance element from the second resistance state to the first resistance state, the first preliminary voltage pulse being smaller in voltage absolute value than the second threshold voltage and different in polarity from the first voltage pulse.

Abstract: A method of programming a variable resistance nonvolatile memory element that removes a defect in a resistance change, ensures an operation widow, and stably sustains a resistance change operation, the method including: applying, when the detect in the resistance change occurs in the variable resistance nonvolatile memory element, a recovery voltage pulse at least once to the variable resistance nonvolatile memory element, the recovery voltage pulse including: a first recovery voltage pulse that has an amplitude greater than amplitudes of a normal high resistance writing voltage pulse and a low resistance writing voltage pulse; and a second recovery voltage pulse that is the low resistance writing voltage pulse following the first recovery voltage pulse.

Abstract: A nonvolatile latch circuit of the invention includes a variable resistance element which is formed by interposing an oxide layer between electrodes, and changes to a low resistance state by applying a voltage to cause current flow in the direction from the first to the second electrode, and changes to a high resistance state by applying a voltage to cause current flow in the reverse direction, wherein a first terminal of a transistor, a first terminal of other transistor, an output terminal of an inverter circuit, and an output terminal of other inverter circuit are respectively connected to one electrode, the other electrode, a second terminal of the transistor, and a second terminal of the other transistor, and a current flowing through the variable resistance element when changed to a low resistance state is smaller in absolute value than a current therethrough when changed to a high resistance state.

Abstract: A nonvolatile latch circuit according to the present invention wherein the outputs of an inverter circuit and other inverter circuit which are cross-coupled are connected to each other via a series circuit in which a transistor, a variable resistance element, and other transistor are connected in this order; a store operation and a restore operation for a latch state are controlled by application of a voltage to control terminals of the transistor and the other transistor; and both end potentials of the variable resistance element are summed, an amount of the sum is amplified and inverted, and the inverted amount is returned to an input of the inverter circuit or the other inverter circuit, thereby restoring a logic state in which a forming process of the variable resistance element can be performed.

Abstract: A cross point variable resistance nonvolatile memory device including: a cross point memory cell array having memory cells each of which is placed at a different one of cross points of bit lines and word lines; a word line decoder circuit that selects at least one of the memory cells from the memory cell array; a read circuit that reads data from the selected memory cell; an unselected word line 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 word line decoder circuit, the read circuit, and the unselected word line current source so that when the read circuit reads data, the first constant current is supplied to an unselected word line.

Abstract: A resistance variable layer has a characteristic in which the resistance variable layer changes to a second resistance state (RL) in such a manner that its resistance value stops decreasing when an interelectrode voltage reaches a first voltage (V1) which is a negative voltage, the resistance variable layer changes to a first resistance state (RH) in such a manner that its resistance value starts increasing when the interelectrode voltage reaches a second voltage (V2) which is a positive voltage which is equal in absolute value to the first voltage, the resistance variable layer changes to the first resistance state in such a manner that the resistance variable layer flows an interelectrode current such that the interelectrode voltage is maintained at a third voltage (V3) higher than the second voltage, when the interelectrode voltage reaches the third voltage, and the resistance variable layer changes to the first resistance state in such a manner that its resistance value stops increasing when the interelec

Abstract: A method of inspecting a variable resistance nonvolatile memory device detecting a faulty memory cell of a memory cell array employing a current steering element, and a variable resistance nonvolatile memory device are provided. The method of inspecting a variable resistance nonvolatile memory device having a memory cell array, a memory cell selection circuit, and a read circuit includes: determining that a current steering element has a short-circuit fault when a variable resistance element is in a low resistance state and a current higher than or equal to a predetermined current passes through the current steering element, when the resistance state of the memory cell is read using a second voltage; and determining whether the variable resistance element is in the low or high resistance state, when the resistance state of the memory cell is read using a first voltage.

Abstract: A nonvolatile latch circuit of the invention includes a variable resistance element which is formed by interposing an oxide layer between electrodes, and changes to a low resistance state by applying a voltage to cause current flow in the direction from the first to the second electrode, and changes to a high resistance state by applying a voltage to cause current flow in the reverse direction, wherein a first terminal of a transistor, a first terminal of other transistor, an output terminal of an inverter circuit, and an output terminal of other inverter circuit are respectively connected to one electrode, the other electrode, a second terminal of the transistor, and a second terminal of the other transistor, and a current flowing through the variable resistance element when changed to a low resistance state is smaller in absolute value than a current therethrough when changed to a high resistance state.

Abstract: The nonvolatile storage device includes a variable resistance element (106) and a write circuit (101) which writes data into the variable resistance element, wherein the variable resistance element has a property of changing from a first resistance state (LR state or HR state) to a second resistance state (HR state or LR state) when a pulse of a first voltage (Vh or Vl) is applied to the variable resistance element, and changing from the second resistance state to the first resistance state when a pulse of a second voltage (Vl or Vh) is applied to the variable resistance element, and the write circuit applies, to the variable resistance element, at least the pulse of the first voltage, a pulse of a third voltage (VlLow or VhLow), and the pulse of the first voltage in this order, when the variable resistance element is caused to change from the first resistance state to the second resistance state.

Abstract: A nonvolatile memory device (300) is provided, including a memory cell array having plural resistance variable elements which are switchable between plural resistance states in response to electric pulses with the same polarity. A series resistance setting unit (310) is provided between the memory cell array (70) and an electric pulse application unit (50). The series resistance setting unit is controlled to change a resistance value of a series current path with a predetermined range with time in at least one of a case where the selected resistance variable element is switched from a low-resistance state to a high-resistance state and a case where the selected resistance variable element is switched from the high-resistance state to the low-resistance state.

Abstract: A resistance variable memory apparatus (10) of the present invention comprises a resistance variable element (1) which is switched to a high-resistance state when a voltage exceeds a first voltage and is switched to a low-resistance state when the voltage exceeds a second voltage, a controller (4), a voltage restricting active element (2) which is connected in series with the resistance variable element (1); and a current restricting active element which is connected in series with the resistance variable element (1) via the voltage restricting active element (2), and the controller (4) is configured to control the current restricting active element (3) so that a product of a current and a first resistance value becomes a first voltage or larger and to control the voltage restricting active element (2) so that the voltage between electrodes becomes smaller than a second voltage when the element is switched to the high-resistance state, while the controller (4) is configured to control the current restricting

Abstract: A variable resistance nonvolatile memory device (100) according to an aspect of the present invention includes: a plurality of memory cells (M11, M12, M21, M22) in each of which a variable resistance element (R11, R12, R21, R22) and a current steering element (D11, D12, D21, D22) having two terminals are connected in series; a current limit circuit (105b) which limits a first current flowing in a direction for changing the memory cells (M11, M12, M21, M22) to a low resistance state; and a boost circuit (105d) which increases, when one of the memory cells (M11, M12, M21, M22) changes to the low resistance state, the first current in a first period before the memory cell changes to the low resistance state.

Abstract: A resistance variable layer has a characteristic in which the resistance variable layer changes to a second resistance state (RL) in such a manner that its resistance value stops decreasing when an interelectrode voltage reaches a first voltage (V1) which is a negative voltage, the resistance variable layer changes to a first resistance state (RH) in such a manner that its resistance value starts increasing when the interelectrode voltage reaches a second voltage (V2) which is a positive voltage which is equal in absolute value to the first voltage, the resistance variable layer changes to the first resistance state in such a manner that the resistance variable layer flows an interelectrode current such that the interelectrode voltage is maintained at a third voltage (V3) higher than the second voltage, when the interelectrode voltage reaches the third voltage, and the resistance variable layer changes to the first resistance state in such a manner that its resistance value stops increasing when the interelec