Abstract: In order to provide a highly reliable crossbar circuit that enables salvation of reversal of a resistive state of a variable resistance element, the semiconductor device has a configuration obtained by parallelly arranging two unit elements, each including variable-resistance two-terminal elements connected in series, the semiconductor device being provided with: a unit element group being connected to a first wiring and a second wiring; a first programming driver that changes, via the first wiring, a resistive state of the two-terminal element constituting the unit element group; a first selection transistor being connected to the first wiring and the first programming driver; a second programming driver that changes, via the second wiring, a resistive state of the two-terminal element constituting the unit element group; and a second selection transistor being connected to the second wiring and the second programming driver.

Abstract: A memory device comprising a memory array of a plurality of memory bit cells; a read reference system comprising four or more reference memory bit cells in a reference column of the memory array; wherein a first bit cell of the reference memory bit cells is always selected; wherein a bitline of the first bit cell of the reference memory bit cells is connected to a bitline of a first subset of the reference memory bit cells, and a select line of the first bit cell of the reference memory bit cells is connected to a reference select signal; wherein a select line of each of the first subset of the reference memory bit cells and a second subset of the reference memory bit cells are coupled together; and wherein a bitline blref of the second subset of the reference memory bit cells outputs a read reference signal.

Abstract: A semiconductor memory cell and arrays of memory cells are provided In at least one embodiment, a memory cell includes a substrate having a top surface, the substrate having a first conductivity type selected from a p-type conductivity type and an n-type conductivity type; a first region having a second conductivity type selected from the p-type and n-type conductivity types, the second conductivity type being different from the first conductivity type, the first region being formed in the substrate and exposed at the top surface; a second region having the second conductivity type, the second region being formed in the substrate, spaced apart from the first region and exposed at the top surface; a buried layer in the substrate below the first and second regions, spaced apart from the first and second regions and having the second conductivity type; a body region formed between the first and second regions and the buried layer, the body region having the first conductivity type; a gate positioned between the

Abstract: A bit cell driving mechanism is disclosed. The mechanism includes a bit cell which includes a first magnetic tunnel junction (MTJ) cell, including a pinned layer, a non-magnetic layer, a free layer having two magnetic regions separated by a laterally moveable domain wall, and a spin-hall metal layer configured to receive an electrical current therethrough which causes the DW to move laterally. The mechanism also includes a second MTJ cell coupled to the first MTJ cell as well as an interconnect driver configured to provide electrical current to the first MTJ cell during a write operation.

Abstract: A magnetic structure includes a magnetic tunnel junction based on a synthetic antiferromagnetic free layer which is regulated by an electric field, and a spin-orbit layer located below the magnetic tunnel junction. The transformation from the antiferromagnetic coupling to the ferromagnetic coupling of the free layer based on a synthetic antiferromagnetic multilayer structure is controlled by an electric field. A spin-orbit torque magnetic random access memory, which includes the magnetic structure, is able to realize stable data writing under the combined interaction of electric field and current, and has advantages of simple structure for scaling, ultralow power consumption, ultrahigh speed of switching, radiation resistance and non-volatility.

Abstract: True random number generation (TRNG) circuits are presented which employ magnetic tunnel junction (MTJ) elements that can change magnetization state probabilistically in response to application of electrical pulses. Some implementations include pulse generators which apply perturbation sequences to the MTJ elements. The MTJ elements responsively produce randomized outputs related to changes in magnetization states. Probability compensators are included which monitor for deviations in measured probabilities in the randomized outputs from a target probability. The probability compensators make adjustments to the perturbation sequences to influence probabilistic changes in the magnetization states of the MTJ elements and bring the measured probabilities to within a predetermined deviation from the target probability.

Abstract: A memory device according to an embodiment includes: a plurality of memory cells including a storage element having a first and second terminals; a reference resistor having a third and fourth terminals; a first current source electrically connected to the first terminal of the storage element in the selected memory cell; a second current source electrically connected to the third terminal; and a determination circuit that determines the greater one among a resistance value of a storage element of selected one and a resistance value of the reference resistor, the resistance value of the reference resistor being smaller than a middle value between a mean value of first resistance values obtained from the storage elements in the high-resistance state and a mean value of second resistance values obtained from the storage elements in the low-resistance state, and greater than the mean value of the second resistance values.

Abstract: A MRAM device includes a spin valve containing a reference layer having a fixed magnetization direction, a free layer, and a nonmagnetic metallic barrier layer located between the reference layer and the free layer, a metallic assist structure configured to provide rotating spin transfer torque to the free layer to assist the free layer switching during programming, and a first nonmagnetic metallic spacer layer located between the free layer and the metallic assist structure.

Abstract: A memory structure includes a first memory array with two transistor-two variable resistor memory cells and a second memory array with one transistor-one variable resistor memory cells, which are each selectively operable in read, write and standby modes. The first memory array and the second memory array are interleaved so that, when the second memory operates in the read mode, the first memory array automatically and concurrently operates in a reference mode. A method of operating the memory structure includes, when the second memory array operates in the read mode, automatically and concurrently operating the first memory array in the reference mode so that the first memory array generates and outputs a statistical reference voltage, which is between the low and high voltages of a nominal memory cell within the second memory array and which is employed by the second memory array to sense a stored data value.

Abstract: The present invention is directed to a magnetic structure including a first seed layer, a second seed layer formed on top of the first seed layer, and a third seed layer made of chromium or iridium formed on top of the second seed layer. One of the first and second seed layers comprises cobalt, iron, and boron. The other one of the first and second seed layers is made of iridium, rhodium, cobalt, platinum, palladium, nickel, ruthenium, or rhenium. The magnetic structure further includes a magnetic fixed layer structure formed on top of the third seed layer and having an invariable magnetization direction substantially perpendicular to a layer plane thereof. The magnetic fixed layer structure includes layers of a magnetic material interleaved with layers of a transition metal. The transition metal may be nickel, platinum, palladium, or iridium.

Abstract: The present disclosure generally relates to semiconductor structures and, more particularly, to a single path memory sense amplifier circuit and methods of manufacture. The circuit includes a sense amplifier circuit comprising a plurality of self-aligned transistors in a single sensing path; and a memory array connected to the sense amplifier circuit by the single sensing path.

Abstract: Subject matter disclosed herein relates to memory devices and, more particularly, to programming a memory cell.

Abstract: A nonvolatile memory cell includes a layered structure body formed by layering a storage layer that stores information in accordance with a magnetization direction and a magnetization fixed layer that defines a magnetization direction of the storage layer; and a heating layer that heats the magnetization fixed layer to control a magnetization direction of the magnetization fixed layer.

Abstract: A radio frequency (RF) switch includes a phase-change material (PCM) and a heating element underlying an active segment of the PCM, the PCM and heating element being situated over a substrate. A contact dielectric is over the PCM. PCM contacts have upper portions and uniform plate slot lower portions. The uniform plate slot lower portions have a total plate resistance RPLATE, and a total plate slot interface resistance RPLATE-INT. The upper portions have a total capacitance CUPPER to the uniform plate slot lower portions, and the PCM has a total capacitance CPCM to the substrate. The uniform plate slot lower portions significantly reduce a product of (RPLATE+RPLATE-INT) and (CUPPER+CPCM). As an alternative to the uniform plate slot lower portions, PCM contacts have segmented lower portions. The segmented lower portions significantly reduce CUPPER.

Abstract: A semiconductor integrated circuit of an embodiment includes: first to fifth wiring lines; a first OTP memory element including a first and second terminals connected to the first and second wiring lines; a first p-channel transistor including a source and drain terminals connected to the first and third wiring line, and a gate terminal receiving a first control signal; a first n-channel transistor including a source and drain terminals connected to the first and fourth wiring lines, and a gate terminal receiving a second control signal; a second p-channel transistor including a source and drain terminals connected to the second and third wiring lines, and a gate terminal receiving a third control signal; and a second n-channel transistor including a source and drain terminals connected to the second and fifth wiring lines, and a gate terminal receiving a fourth control signal.

Abstract: The present disclosure relates to a structure which includes a merged write driver circuit with a first device next to a first memory array and a second device next to a second memory array, and the merged write driver circuit being configured to share a write driver line between the first device and the second device.

Abstract: Circuits and methods for programming a MTJ stack of an MRAM cell minimizes a ferromagnetic free layer or pinned layer polarization reversal due to back-hopping. The programming begins by applying a first segment of the segment of the write pulse at a first write voltage level for a first time period to program the MTJ stack. A second segment of the segment of the write pulse at a second write voltage level that is less than the first write voltage level is applied to the magnetic tunnel junction stack for a second time period to correct the polarization of the MTJ when the MTJ stack has reversed polarization during the first time period. The second segment of the segment of the write pulse may be a ramp, or multiple ramps, or have a quiescent period between it and the first segment of the write pulse.

Abstract: The present disclosure includes apparatuses and methods for sensing a resistive memory cell. A number of embodiments include performing a sensing operation on a memory cell to determine a current value associated with the memory cell, applying a programming signal to the memory cell, and determining a data state of the memory cell based on the current value associated with the memory cell before applying the programming signal and a current value associated with the memory cell after applying the programming signal.

Abstract: Magnetic random access memory (MRAM) devices are provided. The MRAM devices may include a magnetic tunnel junction (MTJ) including a free layer and a pinned layer sequentially stacked in a vertical direction and a conductive layer adjacent to the free layer of the MTJ. The conductive layer may include a horizontal portion and first and second protruding portions that protrude away from the horizontal portion and are spaced apart from each other in a horizontal direction that is perpendicular to the vertical direction. A side of the free layer and a side of the horizontal portion may form a straight side.

Abstract: A method of forming a memory cell with a high aspect ratio metal via formed underneath a metal tunnel junction (MTJ) and the resulting device are provided. Embodiments include a device having a metal via formed underneath a metal tunnel junction (MTJ) in a memory cell, and the metal via has an aspect ratio smaller than 2.

Abstract: A method of manufacturing an array of magnetic random access memory cells includes writing to a magnetic random access memory cell. The writing to a memory cell includes determining an optimum write current for the array of memory cells, and applying the optimum write current to a first memory cell in the array. A first read current is applied to the first memory cell to determine whether a magnetic orientation of the first memory cell has changed in response to applying the optimum write current. A second write current is applied to the first memory cell when the magnetic orientation of the first memory cell has not changed. The second write current is different from the optimum write current. A second read current is applied to the first memory cell to determine whether the magnetic orientation of the first memory cell changed in response to applying the second write current.

Abstract: A multilayered magnetic free layer structure is provided that includes a first magnetic free layer and a second magnetic free layer separated by a non-magnetic layer in which the second magnetic free layer has higher magnetic damping (greater than 0.01) as compared with the first magnetic free layer. Such a multilayered magnetic free layer structure substantially reduces the switching current needed to reorient the magnetization of the magnetic free layers. The higher magnetic damping value of the second magnetic free layer as compared to the first magnetic free layer improves the switching speed of the magnetic free layers and thus reduces, and even eliminates, write errors.

Abstract: A magnetoresistive memory architecture in one aspect includes a plurality of bit lines each coupled to two or more respective columns of magnetoresistive memory cells, and a plurality of source lines each coupled to a respective one of the columns of memory cells. A given memory cell can be accessed by biasing a selected word line, a selected bit line, and a selected source line coupled to corresponding column of memory cells coupled to the selected bit line, and by counter biasing one or more selected source lines coupled to one or more other columns of memory cells coupled to the selected bit line.

Abstract: A magnetoresistive memory device includes a memory cell including a magnetic tunnel junction element, a detector to detect a current value writable in units of the memory cell, a current value storage area, and a current controller. The current value storage area stores at least one of a maximum value and a minimum value of the writable current value detected by the detector. The current controller performs at least one control operation of an operation of controlling a write current value of the memory cell based on the maximum value and an operation of controlling a read current value of the memory cell based on the minimum value.

Abstract: A device includes a metal layer comprising a plurality of bottom electrode features. The device further includes a Magnetic Tunnel Junction (MTJ) stack layer comprising a plurality of MTJ stack features, each of the MTJ stack features disposed on a top surface of one of the plurality of bottom electrode features. The device further includes sidewall structures that extend along side surfaces of both the bottom electrode features and the MTJ stack features.

Abstract: A magnetic detection circuit for a magnetic random access memory (MRAM) is provided. The magnetic detection circuit includes a sensing array including a plurality of sensing cells and a controller. Each of the sensing cells includes a first magnetic tunnel junction (MTJ) device. The controller is configured to access the first MRAM cells to detect the external magnetic field strength of the MRAM. The controller determines whether to stop the write operation of a plurality of memory cells of the MRAM according to the external magnetic field strength of the MRAM, and each of the memory cells includes a second MTJ device. The first MTJ device is smaller than the second MTJ device.

Abstract: A device is disclosed including a first resistive storage element, a first access transistor having a first terminal coupled to the first resistive storage element at a first node, a second resistive storage element, a second access transistor having a first terminal coupled to the second resistive storage element at a second node, and a write assist transistor having a first terminal coupled to the first node and a second terminal coupled to the second node.

Abstract: A magnetic tunnel junction (MTJ) is disclosed wherein first and second interfaces of a free layer (FL) with a first metal oxide (Hk enhancing layer) and second metal oxide (tunnel barrier), respectively, produce perpendicular magnetic anisotropy (PMA) to increase thermal stability. In some embodiments, a capping layer that is a conductive metal nitride such as MoN contacts an opposite surface of the Hk enhancing layer with respect to the first interface to reduce interdiffusion of oxygen and nitrogen compared with a TiN capping layer and maintain an acceptable resistance×area (RA) product. In other embodiments, the capping layer may comprise an insulating nitride such as AlN that is alloyed with a conductive metal to minimize RA. Furthermore, a metallic buffer layer may be inserted between the capping layer and Hk enhancing layer. As a result, electrical shorts are reduced and the magnetoresistive ratio is increased.

Abstract: To provide a high-speed, large-scale non-volatile skyrmion random access memory that prevents incorrect writing and incorrect erasure, has a circuit with good storage-data sensitivity, generates smaller leakage current, and consumes less power. To provide a magnetic element for generating and erasing a skyrmion including: a first magnetic material thin film in which the skyrmion is generated and erased; a sensing element for sensing the skyrmion; and at least one of a first transistor for selecting the first magnetic material thin film, and a second transistor for selecting the skyrmion sensing element.

Abstract: A magnetic memory includes magnetoresistance effect elements, each of which includes a first ferromagnetic metal layer in which a magnetization direction is fixed, a second ferromagnetic metal layer for a magnetization direction to be changed, and a nonmagnetic layer provided between the first ferromagnetic metal layer and the second ferromagnetic metal layer, a first wiring connected to the first ferromagnetic metal layer of at least one magnetoresistance effect element, spin-orbit torque wirings, each of which is connected to each of the second ferromagnetic metal layers of the magnetoresistance effect elements and extend in a direction intersecting a lamination direction of the magnetoresistance effect element, one first control element connected to the first wiring, one second control element connected to each of first connection points of the spin-orbit torque wirings, and first cell selection elements, each of which is connected to each of second connection points of the spin-orbit torque wirings.

Abstract: A method is presented for integrating a resistive random access memory (ReRAM) device with vertical transistors on a single chip. The method includes forming a vertical field effect transistor (FET) including an epitaxial tip defining a drain terminal and forming the ReRAM device in direct contact with the epitaxial tip of the vertical FET such that a current conducting filament is formed at the epitaxial tip due to electric field enhancement.

Abstract: A method is provided for a reading memory even if there is a threshold voltage in an overlapped threshold voltage (VTH) region between a first state distribution and a second state distribution. The method includes ramping a bias on a memory cell a first time to determine a first threshold voltage (VTH1) of the memory cell and determining whether the VTH1 is within the overlapped VTH region. Upon determination that the memory cell is within the overlapped VTH region, the method further includes applying a write pulse to the memory cell; ramping a bias on the memory cell a second time to determine a second threshold voltage (VTH2); and determining the state of the memory cell prior to receiving the write pulse based on a comparison between the VTH1 and the VTH2.

Abstract: A magnetic storage device includes a plurality of first wires extending along a first direction and a plurality of second wires extending along a second direction different from the first direction. The plurality of second wires form a grid with the plurality of first wires. The magnetic storage device further includes a plurality of spin orbit torque magnetic random access memory (SOT-MRAM) devices. Each of the plurality of SOT-MRAM devices is disposed at a respective position on the grid. The magnetic storage device further includes write circuitry, including a transistor coupled to each respective first wire of the plurality of first wires, to apply a first write current along the respective first wire in the first direction, and readout circuitry to read a data value stored by a respective SOT-MRAM device.

Abstract: Techniques are presented for ensuring alignment marks are available for use and patterning magnetoresistive devices following the deposition of layers used to form the magnetoresistive devices. In some cases, the plurality of layers corresponding to the magnetoresistive devices are selectively etched in order to expose the underlying alignment marks, whereas in other embodiments, the deposition of the plurality of layers is controlled by deposition tool tabs that prevent the materials from obscuring the underlying alignment marks.

Abstract: Provided are a magneto resistive effect element with a stable magnetization direction perpendicular to a film plane and with a controlled magnetoresistance ratio, and a magnetic memory using the magneto resistive effect element. Ferromagnetic layers of the magneto resistive effect element are formed from a ferromagnetic material containing at least one type of 3d transition metal such that the magnetoresistance ratio is controlled, and the film thickness of the ferromagnetic layers is controlled on an atomic layer level such that the magnetization direction is changed from a direction in the film plane to a direction perpendicular to the film plane.

Abstract: A memory includes: a dielectric fin formed over a substrate; and a pair of memory cells disposed along respective sidewalls of the dielectric fin, each of the pair of memory cells comprising: a first conductor layer; a selector layer; a resistive material layer; and a second conductor layer, wherein the first conductor layer, selector layer, resistive material layer, and second conductor layer each includes upper and lower boundaries, and at least one of the upper and lower boundaries is tilted away from one of the sidewalls of the dielectric fin by an angle.

Abstract: The present disclosure concerns a magnetic tunnel diode and a magnetic tunnel transistor. The magnetic tunnel diode may include two terminals for connecting to an electrical circuit as well as a tunnel junction. The magnetic tunnel transistor may include three terminals for connecting to an electrical circuit as well as a layer arrangement.

Abstract: According to one embodiment, there is provided a magnetic memory including a magnetic material column, a shift control circuit, and a write control circuit. The shift control circuit is connected to the magnetic material column. The write control circuit is configured to cause a current to flow through a write line passing near one end of the magnetic material column if writing data having a first value into the magnetic material column, and cause no current to flow through the write line if writing data having a second value into the magnetic material column.

Abstract: The present invention provides a memory device in which a lower electrode, a seed layer, synthetic antiferromagnetic (SyAF) layers, a separation layer, a magnetic tunnel junction, a capping layer, and an upper electrode are formed on a substrate in a laminated manner, wherein a diffusion barrier is formed between the magnetic tunnel junction and the capping layer. In addition, the present invention provides a memory device in which a lower electrode, a seed layer, SyAF layers, a separation layer, a magnetic tunnel junction, a capping layer, and an upper electrode are formed on a substrate in a laminated manner, wherein the seed layer is formed of a material that allows the SyAF layers to grow in the FCC (111) direction.

Abstract: A magnetic memory includes: first to third terminals; a conductive layer including first to fifth regions, the first region being electrically connected to the first terminal, the fifth region being electrically connected to the second terminal, and the third region being electrically connected to the third terminal; a first magnetoresistive element including a first magnetic layer, a second magnetic layer disposed between the second region and the first magnetic layer, and a first nonmagnetic layer disposed between the first and the second magnetic layer; a second magnetoresistive element including a third magnetic layer, a fourth magnetic layer disposed between the fourth region and the third magnetic layer, and a second nonmagnetic layer disposed between the third and the fourth magnetic layer; and a circuit flowing a write current between the first and the second terminal and between the second and the third terminal in a write operation.

Abstract: According to one embodiment, a nonvolatile memory device includes a memory cell including a first two-terminal resistance change memory element storing memory cell information, and a second two-terminal resistance change memory element, connected in series to the first two-terminal resistance change memory element, and functioning as a selector element, word and bit lines connected to the memory cell. When memory cell information is to be written, if the memory cell is a selected memory cell, the second two-terminal resistance change memory element is set to the low resistance state and, if the memory cell is an unselected memory cell, the second two-terminal resistance change memory element is set to the high resistance state.

Abstract: A spin current assisted magnetoresistance effect device includes: a spin current assisted magnetoresistance effect element including a magnetoresistance effect element part and a spin-orbit torque wiring; and a controller electrically connected to the spin current assisted magnetoresistance effect element. In a portion in which the magnetoresistance effect element part and the spin-orbit torque wiring are bonded, an STT inversion current flowing through the magnetoresistance effect element part and an SOT inversion current flowing through the spin-orbit torque wiring merge or are divided, and the controller is configured to be capable of performing control for applying the STT inversion current to the spin current assisted magnetoresistance effect element at the same time as an application of the SOT inversion current or a time application of the SOT inversion current.

Abstract: An apparatus is provided which comprises: a first magnetic junction having a fixed magnetic layer and a 4-state free magnetic layer; a second magnetic junction having a fixed magnetic layer and a 4-state free magnetic layer; and a first layer of spin orbit coupling material adjacent to the first magnetic junction and the second magnetic junction via their respective 4-state free magnetic layers. Described is an apparatus which comprises a 4-state free magnetic layer; a layer of SOC material adjacent to the 4-state free magnetic layer; a first interconnect coupled to the layer of SOC material.

Abstract: A tunable resistance device and methods of forming the same include a magnetic fixed layer having a fixed magnetization, a magnetic free layer, and a non-magnetic conductive layer directly between the magnetic fixed layer and the magnetic free layer. The magnetic fixed layer, the magnetic free layer, and the non-magnetic conductive layer are formed in a lattice of wires, with each wire in the lattice being formed from a stack of the magnetic fixed layer, the magnetic free layer, and the non-magnetic conductive layer.

Abstract: A magnetic element is provided. The magnetic element includes a free magnetization layer having a surface area that is approximately 1,600 nm2 or less, the free magnetization layer including a magnetization state that is configured to be changed; an insulation layer coupled to the free magnetization layer, the insulation layer including a non-magnetic material; and a magnetization fixing layer coupled to the insulation layer opposite the free magnetization layer, the magnetization fixing layer including a fixed magnetization so as to be capable of serving as a reference of the free magnetization layer.

Abstract: In an embodiment, a cross-point array device includes a pillar-shaped structure disposed in an intersection region where a first conductive line overlaps a second conductive line. The pillar-shaped structure includes a resistance change material layer disposed between the first conductive line and the second conductive line. The pillar-shaped structure includes one or more conductive fuse material layers, each of which is disposed between the first or second conductive line and the resistance change material layer. The melting point of the conductive fuse material layer is higher than the melting point of the resistance change material layer.

Abstract: Spin-orbit-torque (SOT) segments are provided along the sides of free layers in magnetoresistive devices that include magnetic tunnel junctions. Current flowing through such SOT segments injects spin current into the free layers such that spin torque is applied to the free layers. The spin torque can be used as an assist to spin-transfer torque generated by current flowing vertically through the magnetic tunnel junction in order to improve the efficiency of the switching current applied to the magnetoresistive device.

Abstract: Disclosed is a method of manufacturing flash memory with a vertical cell stack structure. The method includes forming source lines in a cell area of a substrate having an ion-implanted well and forming an alignment mark relative to the source lines. The alignment mark is formed in the substrate outside the cell area of the substrate. After formation of the source lines, cell stacking layers are formed. After forming the cell stacking layers, cell pillars in the cell stacking layers are formed at locations relative to the previously formed source lines using the alignment mark to correctly locate the cell pillars.

Abstract: A magnetic memory cell includes a substrate having a memory region, a transistor within the memory region, a first dielectric layer disposed on the substrate, a landing pad in the first dielectric layer, a second dielectric layer covering the first dielectric layer and the landing pad, a cylindrical memory stack in the second dielectric layer, and a source line in the first dielectric layer. The first dielectric layer covers the memory region and the transistor. The landing pad is situated in a first horizontal plane and is coupled to a drain region of the transistor. The cylindrical memory stack has a bottom electrode connected to the landing pad and a top electrode electrically connected to a bit line. The source line is situated in a second horizontal plane and is connected to a source region of the transistor. The second horizontal plane is lower than the first horizontal plane.

Abstract: Embodiments relate generally to semiconductors and memory technology, and more particularly, to systems, integrated circuits, and methods to implement a memory architecture that includes local bit lines for accessing subsets of memory elements, such as memory elements based on third dimensional memory technology. In at least some embodiments, an integrated circuit includes a cross-point memory array formed above a logic layer. The cross-point memory array includes X-lines and Y-lines, of which at least one Y-line includes groups of Y-line portions. Each of the Y-line portions can be arranged in parallel with other Y-line portions within a group of the Y-line portions. Also included are memory elements disposed between a subset of the X-lines and the group of the Y-line portions. In some embodiments, a decoder is configured to select a Y-line portion from the group of Y-line portions to access a subset of the memory elements.