Abstract: The test circuit for measuring a resistance distribution of memory cells includes a sensing circuit and a digital value generation circuit. The sensing circuit compares a reference voltage with a voltage of a sensing node receiving a voltage of a bit line connected with a resistive element and generates a sensing signal. The digital value generation circuit generates a digital value corresponding to a resistance-capacitance (RC) delay of the bit line in response to the sensing signal from the sensing circuit.

Abstract: A method of writing multi-bit data to a semiconductor memory device with memory cells storing data defined by a threshold value, the method comprising, for each memory cell, writing a least significant bit, verifying completion of writing the least significant bit, verifying including comparing a written value to one of a low least significant bit verification value and a high least significant bit verification value, and writing a next significant bit upon completion of writing the least significant bit.

Abstract: Memory devices that include a semiconductor substrate defining a data storage area and a peripheral circuit area. A first magnetic memory device is provided in the peripheral area of the semiconductor substrate and is configured to exchange data signals externally. A second magnetic memory device is provided in the data storage area of the semiconductor substrate and is configured to exchange the data signals with the first magnetic memory device. Each portion of the first magnetic memory device and a portion of the second magnetic memory device include a magnetic tunnel junction structure having at least one magnetic layer. Related data storage devices and systems are also provided.

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: A nonvolatile memory device comprises a first voltage generation unit, a second voltage generation unit, a first circuit block, and a discharge unit. The first voltage generation unit generates a first voltage with a first magnitude. The second voltage generation unit generates a second voltage with a second magnitude greater than the first magnitude. The first circuit block selectively receives the first voltage or the second voltage through an input node. The discharge unit discharges the input node between a time point where the input node has been charged with the second voltage and a time point where the input node receives the first voltage.

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 cell array layers including a plurality of word lines extending in a first direction, a plurality of bit lines extending in a second direction that intersects the first direction, and a plurality of memory cells disposed at intersections of the word lines and the bit lines. Each of the word lines has a word line position, each of the bit lines has a bit line position, and each of the memory cells includes a variable resistance device in series with a diode. The cell array layers are arranged in layers in a third direction that is perpendicular to the first and second directions. The bit lines of each of the cell array layers having a same bit line position are connected to a common column selector transistor, or the word lines of the cell array layers having a same word line position are connected to a common word line driver.

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: In various methods of performing program operations in phase change memory devices, selected memory cells are repeatedly programmed to obtain resistance distributions having desired characteristics such as adequate sensing margins.

Abstract: A method of programming a memory array including a plurality of memory cells is provided. The memory cells may include phase-change memory elements. In one aspect, the method includes applying in succession first through nth current pulses to each of the memory cells to be programmed to a first state (e.g., a crystalline state), where a current amplitude of the first through nth current pulses decreases with each successive pulse, and where a pulse duration of the first through nth current pulses increases with each successive pulse.

Abstract: Provided are a phase-change memory device and method that maintains a resistance of a phase-change material in a set state within a constant resistance range. In the method, data is provided to a first phase-change memory cell and then it is first determined whether data stored in the first phase-change memory cell and the data provided to the first phase-change memory cell are identical. If the data stored in the first phase-change memory cell and the data provided to the first phase-change memory cell are not identical, a complementary write current is provided to the first phase-change memory cell and it is second determined whether the data stored in the first phase-change memory cell and the data provided to the first phase-change memory cell are identical. If the data stored in the first phase-change memory cell and the data provided to the first phase-change memory cell are identical, data is provided to a second phase-change memory cell.

Abstract: A phase change memory device includes a memory cell having a phase change material, a write driver adapted to supply a program current to the memory cell during a programming interval, and a pump circuit adapted to enhance a current supply capacity of the write driver during the programming interval. The pump circuit is activated prior to the programming interval in response to an external control signal.

Abstract: A phase change memory device includes a memory cell having a phase change material, a write driver adapted to supply a program current to the memory cell during a programming interval, and a pump circuit adapted to enhance a current supply capacity of the write driver during the programming interval. The pump circuit is activated prior to the programming interval in response to an external control signal.

Abstract: Phase change memory devices having cell diodes and related methods are provided, where the phase change memory devices include a semiconductor substrate of a first conductivity type and a plurality of parallel word lines disposed on the semiconductor substrate, the word lines have a second conductivity type different from the first conductivity type and have substantially flat top surfaces, a plurality of first semiconductor patterns are one-dimensionally arrayed on each word line along a length direction of the word line, the first semiconductor patterns have the first conductivity type or the second conductivity type, second semiconductor patterns having the first conductivity type are stacked on the first semiconductor patterns, an insulating layer is provided on the substrate having the second semiconductor patterns, the insulating layer fills gap regions between the word lines, gap regions between the first semiconductor patterns and gap regions between the second semiconductor patterns, a plurality of p

Abstract: A phase change memory device of one aspect includes a memory array including a plurality of phase change memory cells, a write boosting circuit, and a write driver. The write boosting circuit boosts a first voltage and outputs a first control voltage in response to a control signal in a first operation mode, and boosts the first voltage and outputs a second control voltage in response to the control signal in a second operation mode and a third operation mode. The write driver is driven by the first control voltage in the first operation mode and writes data to a selected memory cell of the memory array.

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 one aspect, a semiconductor memory device includes a plurality of phase-change memory cells which are programmed according to a write current applied to the phase-change memory cells, a voltage boosting circuit which receives a first voltage and outputs a boosted voltage which is greater than the first voltage, and a write driver which receives the boosted voltage and which generates the write current from the boosted voltage. In another aspect, the write driver generates the write current corresponding to one of a set current pulse and a reset current pulse, and at least one of the set current pulse and the reset current pulse is gradually increased.

Abstract: A semiconductor memory device includes: phase-change memory cells whose states change to a set resistance state or a reset resistance state in response to an applied current pulse; a set pulse driving circuit outputting a set current pulse having first through n-th stages in response to a first control signal and a set control signal wherein current amounts of the first through n-th stages are sequentially reduced and are all greater than a reference current amount; a reset pulse driving circuit outputting a reset current pulse in response to a second control signal; a pull-down device activating the set pulse driving circuit and the reset pulse driving circuit in response to a third control signal; and a write driver control circuit outputting the first through third control signals in response to write data, a set pulse width control signal, and a reset pulse width control signal.

Abstract: Phase change memory devices having cell diodes and related methods are provided, where the phase change memory devices include a semiconductor substrate of a first conductivity type and a plurality of parallel word lines disposed on the semiconductor substrate, the word lines have a second conductivity type different from the first conductivity type and have substantially flat top surfaces, a plurality of first semiconductor patterns are one-dimensionally arrayed on each word line along a length direction of the word line, the first semiconductor patterns have the first conductivity type or the second conductivity type, second semiconductor patterns having the first conductivity type are stacked on the first semiconductor patterns, an insulating layer is provided on the substrate having the second semiconductor patterns, the insulating layer fills gap regions between the word lines, gap regions between the first semiconductor patterns and gap regions between the second semiconductor patterns, a plurality of p