Abstract:
A method of operating a resistive memory device including a plurality of memory cells comprises determining whether to perform a refresh operation on memory cells in a memory cell array; determining a resistance state of each of at least some of the memory cells; and performing a re-writing operation on a first memory cell having a resistance state from among a plurality of resistance states that is equal to or less than a critical resistance level.
Abstract:
A method of writing data in a resistive memory device having a memory cell array divided into first and second tiles includes; performing a first simultaneous write operation by performing a set write operation performed on resistive memory cells of the first tile while simultaneously performing a reset write operation on resistive memory cells of the second tile in response to the write command, and performing a second simultaneous write operation by performing a reset write operation on resistive memory cells of the first tile while simultaneously performing a set write operation on resistive memory cells of the second tile in response to the write command.
Abstract:
A method of operating a memory device, which includes of memory cells respectively arranged in regions where first signal lines and second lines cross each other, includes determining a plurality of pulses so that each of the plurality of pulses that are sequentially applied to a selected memory cell among the plurality of memory cells is changed according to a number of times of executing programming loops. In response to the change of the plurality of pulses, at least one of a first inhibit voltage and a second inhibit voltage is determined so that a voltage level of at least one of the first and second inhibit voltages that are respectively applied to unselected first and second signal lines connected to unselected memory cells among the plurality of memory cells is changed according to the number of times of executing the programming loops.
Abstract:
A resistive memory device including multiple resistive memory cells arranged in regions where first signal lines and second signal lines cross each other, and a method of operating the resistive memory device, are provided. The method includes applying a first voltage to a first line, from among unselected first signal lines connected to unselected memory cells, that is not adjacent to a selected first signal line connected to a selected memory cell from among the multiple memory cells; applying a second voltage that is lower than the first voltage to a second line, from among the unselected first signal lines, that is adjacent to the selected first signal line; floating the unselected first signal lines; and applying a third voltage that is higher than the first voltage to the selected first signal line.
Abstract:
An operating method for a resistive memory device includes; applying a bias control voltage to a memory cell array of the resistive memory device, measuring leakage current that occurs in the memory cell array in response to the applied bias control voltage to generate a measuring result, generating a control signal based on the measuring result, and adjusting a level of the bias control voltage in response to the control signal.
Abstract:
A method of operating a memory device includes; applying a pre-write voltage to a selected memory cell by applying a first voltage to a first signal line connected to the selected memory cell and a second voltage to a second signal line connected to the selected memory cell during a first set writing interval, wherein a level of the first voltage is higher than a level of the second voltage, and thereafter, applying a write voltage to the selected memory cell by applying a third voltage having a level lower than the level of the first voltage and higher than the level of the second voltage to the first signal line during a second set writing interval.
Abstract:
A sensing circuit includes a plurality of cell read current generators, a reference current generator and a plurality of sense amplifiers. Each of the cell read current generators generates a cell read current from each of a plurality of memory cells. The reference current generator sums the cell read currents to generate a sum current. Each of the sense amplifiers determines data state stored in each of the memory cells based on each of the cell read currents and an average current. The average current is obtained based on the sum current.
Abstract:
A method of reading a memory device that includes a memory cell that stores data of at least two bits includes determining whether a cell resistance level is no greater than a threshold resistance level. If the cell resistance level is smaller than or equal to the threshold resistance level, then the data is read based on a first factor that is inversely proportional to the cell resistance level. If the cell resistance level is greater than the threshold resistance level, then the data is read based on a second factor that is proportional to the cell resistance level.
Abstract:
A method of operating a resistive memory device having a plurality of word lines and a plurality of bit lines includes selecting one or more first memory cells connected to a first bit line, selecting one or more second memory cells connected to a second bit line, and simultaneously performing a reset write operation on the first and second memory cells using a first write driver.
Abstract:
In operating a resistive memory device including a number of memory cells, a write pulse is applied to each of the plurality of memory cells such that each of the memory cells has a target resistance state between a first reference resistance and a second reference resistance higher than the first reference resistance. The resistance of each of the memory cells is read by applying a verify pulse to each of the plurality of memory cells. A verify write current pulse is applied to each of the memory cells that has resistance higher than the second reference resistance, and a verify write voltage pulse is applied to each of the memory cells that has resistance lower than the first reference resistance.