Abstract: A method of testing PRAM devices is disclosed. The method simultaneously writes input data to a plurality of memory banks by writing set data to a first group of memory banks and writing reset data to a second group of memory banks, performs a write operation test by comparing data read from the plurality of memory banks with corresponding input data, and determines a fail cell in relation to the test results.

Abstract: A phase change random access memory is provided which includes a memory array including a plurality of phase change memory cells, and wordlines respectively connected to the phase change memory cells, where, in a read operation, a voltage of a wordline connected to a selected phase change memory cell is transitioned between at least two voltage stages having different voltage levels.

Abstract: A method of testing PRAM devices is disclosed. The method simultaneously writes input data to a plurality of memory banks by writing set data to a first group of memory banks and writing reset data to a second group of memory banks, performs a write operation test by comparing data read from the plurality of memory banks with corresponding input data, and determines a fail cell in relation to the test results.

Abstract: A nonvolatile memory device includes multiple first bit lines extending in a first direction, multiple word lines formed on the first bit lines and extending in a second direction different from the first direction, and multiple second bit lines, formed on the word lines and extending in the first direction. The nonvoliative memory device also includes multiple twin memory cells, each of which includes a first memory cell coupled between a first bit line and a word line and a second memory cell coupled between the word line and a second bit line. The first and second memory cells store different data.

Abstract: In a phase-change random access memory (PRAM) device, a write operation is performed by applying a set pulse to failed PRAM cells. The set pulse comprises a plurality of stages sequentially decreasing from a first current magnitude to a second current magnitude. The first current magnitude or the second current magnitude varies from one write loop to another.

Abstract: A method of biasing a memory cell array during a data writing operation and a semiconductor memory device, in which the semiconductor memory device includes: a memory cell array including a plurality of memory cells in which a first terminal of a memory cell is connected to a corresponding first line among a plurality of first lines and a second terminal of a memory cell is connected to a corresponding second line among a plurality of second lines; and a bias circuit for biasing a selected second line to a first voltage and non-selected second lines to a second voltage.

Abstract: A non-volatile memory device, in which data values are determined by polarities at cell terminals, includes a memory cell array. The memory cell array is divided into multiple sub cell arrays, each sub cell array including at least one input/output line and an X-decoder/driver. First input/output lines included in different sub cell arrays may be simultaneously activated and bias voltages may be applied to the activated first input/output lines in accordance with the data values. The non-volatile memory device may be a bi-directional resistive random access memory (RRAM).

Abstract: A method of programming a one-time programmable device is provided. A switching device disposed in a substrate is turned on and a program current is applied to a fuse electrically connected to the switching device, thereby cutting the fuse. The fuse includes a first electrode electrically connected to the switching device, a second electrode spaced apart from the first electrode, and a chalcogenide pattern disposed between the first and second electrodes. Related one-time programmable devices, phase change memory devices and electronic systems are also disclosed.

Abstract: An apparatus, a nonvolatile memory device and a nonvolatile memory system include an array of nonvolatile variable resistive memory (VRM) cells and a writing driver circuit having a pulse selection circuit, a current control circuit, and a current drive circuit. The current control circuit receives a bias voltage, outputs a control signal at a second level during an enable duration of the reset pulse when the data is at a first level, and outputs a control signal at a first level during an enable duration of the set pulse when the data is at a second level. The current drive circuit outputs writing current to the phase-change memory array during the enable duration of the reset pulse or the set pulse. The writing driver circuit can select the reset pulse or the set pulse according to the logic level of the data, and control the level of current applied to the phase-change memory array according to the reset pulse or the set pulse.

Abstract: In a phase-change random access memory (PRAM) device, a write operation is performed by applying a set pulse to failed PRAM cells. The set pulse comprises a plurality of stages sequentially decreasing from a first current magnitude to a second current magnitude. The first current magnitude or the second current magnitude varies from one write loop to another.

Abstract: A memory system includes a resistance variable memory device, and a memory controller for controlling the resistance variable memory device. The resistance variable memory device includes a memory cell connected to a bitline, a high voltage circuit adapted to generate a high voltage from an externally provided power source voltage, where the high voltage is higher than the power source voltage, a precharging circuit adapted to charge the bitline to the power source voltage and further charge the bitline to the high voltage, a bias circuit adapted to provide a read current to the bitline with using the high voltage, and a sense amplifier adapted to detect a voltage level of the bitline with using the high voltage.

Abstract: A method of programming a one-time programmable device is provided. A switching device disposed in a substrate is turned on and a program current is applied to a fuse electrically connected to the switching device, thereby cutting the fuse. The fuse includes a first electrode electrically connected to the switching device, a second electrode spaced apart from the first electrode, and a chalcogenide pattern disposed between the first and second electrodes. Related one-time programmable devices, phase change memory devices and electronic systems are also disclosed.

Abstract: A line layout structure and method in a semiconductor memory device having a hierarchical structure are provided. In a semiconductor memory device having a global word line and a local word line, and a global bit line and a local bit line, and individually disposing all of the global word line, the local word line, the global bit line and the local bit line at conductive layers among at least three layers; at least two of the global word line, the local word line, the global bit line and the local bit line are together disposed in parallel on one conductive layer. Signal lines constituting a semiconductor memory device are disposed in a hierarchical structure, whereby a semiconductor memory device advantageously having high integration, high speed and high performance may be obtained.

Abstract: A line layout structure and method in a semiconductor memory device having a hierarchical structure are provided. In a semiconductor memory device having a global word line and a local word line, and a global bit line and a local bit line, and individually disposing all of the global word line, the local word line, the global bit line and the local bit line at conductive layers among at least three layers; at least two of the global word line, the local word line, the global bit line and the local bit line are together disposed in parallel on one conductive layer. Signal lines constituting a semiconductor memory device are disposed in a hierarchical structure, whereby a semiconductor memory device advantageously having high integration, high speed and high performance may be obtained.

Abstract: Provided is a phase change random access (PRAM) memory. The PRAM may include a memory cell array having a plurality of phase change memory cells, and a data read circuit including a compensation unit and a sense amplifier, the compensation unit configured to provide a sensing node with a compensation current to compensate for a decrease in a level of the sensing node caused by a current flowing through one of the plurality of phase change memory cells, and the sense amplifier configured to compare a level of the sensing node with a reference level and output a result of the comparison.

Abstract: There is provided a resistive memory device, the device including: a plurality of word lines and a plurality of bit lines arranged such that the word lines intersect the bit lines; a plurality of resistive memory cells each having a variable resistive material coupled between the corresponding word line and the corresponding bit line and an access element; selecting circuits selecting one of the plurality of resistive memory cells; and a filament-forming circuit supplying a filament-forming voltage to the selected resistive memory cell through the bit line coupled to the selected resistive memory cell while increasing the filament-forming voltage from a predetermined voltage level until filaments having a predetermined thickness are formed in the variable resistive material of the selected resistive memory cell.

Abstract: A semiconductor memory device includes a plurality of wordline driving circuits adapted to control the voltage level of a sub-wordline in response to a logic state of a global wordline and an address signal. The wordline driving circuit comprises first and second transistors configured to maintain the sub-wordline at a first voltage level when the global wordline and the address signal have a first logic state and at a second voltage level when the global wordline or the address signal have a second logic state.

Abstract: Provided is a phase change random access (PRAM) memory. The PRAM may include a memory cell array having a plurality of phase change memory cells, and a data read circuit including a compensation unit and a sense amplifier, the compensation unit configured to provide a sensing node with a compensation current to compensate for a decrease in a level of the sensing node caused by a current flowing through one of the plurality of phase change memory cells, and the sense amplifier configured to compare a level of the sensing node with a reference level and output a result of the comparison.

Abstract: Embodiments of the invention provide devices or methods that include a status bit representing an inversion of stored data. New data is written to selected cells, the new data is selectively inverted, and the status bit is selectively toggled, based on a comparison between pre-existing data and new data associated with a write command. A benefit of embodiments of the invention is that fewer memory cells must be activated in many instances (when compared to conventional art approaches). Moreover, embodiments of the invention may also reduce the average amount of activation current required to write to variable resistive memory devices and other memory device types.

Abstract: An apparatus, a nonvolatile memory device and a nonvolatile memory system include an array of nonvolatile variable resistive memory (VRM) cells and a writing driver circuit having a pulse selection circuit, a current control circuit, and a current drive circuit. The current control circuit receives a bias voltage, outputs a control signal at a second level during an enable duration of the reset pulse when the data is at a first level, and outputs a control signal at a first level during an enable duration of the set pulse when the data is at a second level. The current drive circuit outputs writing current to the phase-change memory array during the enable duration of the reset pulse or the set pulse. The writing driver circuit can select the reset pulse or the set pulse according to the logic level of the data, and control the level of current applied to the phase-change memory array according to the reset pulse or the set pulse.