Patent application number | Description | Published |
20090323402 | SPIN-TRANSFER TORQUE MEMORY SELF-REFERENCE READ METHOD - A spin-transfer torque memory apparatus and self-reference read schemes are described. One method of self-reference reading a spin-transfer torque memory unit includes applying a first read current through a magnetic tunnel junction data cell and forming a first bit line read voltage, the magnetic tunnel junction data cell having a first resistance state and storing the first bit line read voltage in a first voltage storage device. Then applying a low resistance state polarized write current through the magnetic tunnel junction data cell, forming a low second resistance state magnetic tunnel junction data cell. A second read current is applied through the low second resistance state magnetic tunnel junction data cell to forming a second bit line read voltage. The second bit line read voltage is stored in a second voltage storage device. The method also includes comparing the first bit line read voltage with the second bit line read voltage to determine whether the first resistance state of the magnetic tunnel junction data cell was a high resistance state or low resistance state. | 12-31-2009 |
20090323403 | SPIN-TRANSFER TORQUE MEMORY NON-DESTRUCTIVE SELF-REFERENCE READ METHOD - A spin-transfer torque memory apparatus and non-destructive self-reference read schemes are described. One method of self-reference reading a spin-transfer torque memory unit includes applying a first read current through a magnetic tunnel junction data cell and forming a first bit line read voltage and storing the first bit line read voltage in a first voltage storage device. The magnetic tunnel junction data cell has a first resistance state. Then the method includes applying a second read current thorough the magnetic tunnel junction data cell having the first resistance state and forming a second bit line read voltage and storing the second bit line read voltage in a second voltage storage device. The first read current is less than the second read current. Then the stored first bit line read voltage is compared with the stored second bit line read voltage to determine whether the first resistance state of the magnetic tunnel junction data cell was a high resistance state or low resistance state. | 12-31-2009 |
20100008134 | TRANSMISSION GATE-BASED SPIN-TRANSFER TORQUE MEMORY UNIT - A transmission gate-based spin-transfer torque memory unit is described. The memory unit includes a magnetic tunnel junction data cell electrically coupled to a bit line and a source line. A NMOS transistor is in parallel electrical connection with a PMOS transistor and they are electrically connected with the source line and the magnetic tunnel junction data cell. The magnetic tunnel junction data cell is configured to switch between a high resistance state and a low resistance state by passing a polarized write current through the magnetic tunnel junction data cell. The PMOS transistor and the NMOS transistor are separately addressable so that a first write current in a first direction flows through the PMOS transistor and a second write current in a second direction flows through the NMOS transistor. | 01-14-2010 |
20100014347 | DIODE ASSISTED SWITCHING SPIN-TRANSFER TORQUE MEMORY UNIT - A memory unit includes a magnetic tunnel junction data cell electrically coupled to a bit line and a source line. The magnetic tunnel junction data cell is configured to switch between a high resistance state and a low resistance state by passing a polarized write current through the magnetic tunnel junction data cell. A transistor is electrically between the magnetic tunnel junction data cell and the bit line or source line and a diode is in thermal or electrical contact with the magnetic tunnel junction data cell to assist in resistance state switching. | 01-21-2010 |
20100034017 | OSCILLATING CURRENT ASSISTED SPIN TORQUE MAGNETIC MEMORY - A memory unit having a spin torque memory cell with a ferromagnetic free layer, a ferromagnetic pinned layer and a spacer layer therebetween, with the free layer having a switchable magnetization orientation with a switching threshold. A DC current source is electrically connected to the spin torque memory cell to cause spin transfer torque in the free layer. An AC current source is electrically connected to the spin torque memory cell to produce an oscillatory polarized current capable of spin transfer torque via resonant coupling with the free layer. | 02-11-2010 |
20100037020 | PIPELINED MEMORY ACCESS METHOD AND ARCHITECTURE THEREFORE - A memory array and a method for accessing a memory array including: receiving an address from a host related to relevant data; accessing a first module based on the address received from the host, wherein accessing the first module includes: decoding the address for the first module; enabling a wordline based on the decoded address for the first module and sensing the contents of one or more bits at the decoded address for the first module; and outputting information regarding the first module; and accessing a second module based on the address received from the host, wherein accessing the second module includes: decoding the address for the second module; enabling a wordline based on the decoded address for the second module and sensing the contents of one or more bits at the decoded address for the second module; and outputting information regarding the second module, wherein the step of decoding the address for the second module occurs while the step of enabling a wordline based on the decoded address for the first module and sensing the contents of one or more bits at the decoded address for the first module occurs. | 02-11-2010 |
20100037102 | FAULT-TOLERANT NON-VOLATILE BUDDY MEMORY STRUCTURE - Various embodiments of the present invention are generally directed to an apparatus and method for providing a fault-tolerant non-volatile buddy memory structure, such as a buddy cache structure for a controller in a data storage device. A semiconductor memory array of blocks of non-volatile resistive sense memory (RSM) cells is arranged to form a buddy memory structure comprising a first set of blocks in a first location of the array and a second set of blocks in a second location of the array configured to redundantly mirror the first set of blocks. A read circuit decodes a fault map which identifies a defect in a selected one of the first and second sets of blocks and concurrently outputs data stored in the remaining one of the first and second sets of blocks responsive to a data read operation upon said buddy memory structure. | 02-11-2010 |
20100057984 | MEMORY HIERARCHY CONTAINING ONLY NON-VOLATILE CACHE - A storage system that includes non-volatile main memory; non-volatile read cache; non-volatile write cache; and a data path operably coupled between the non-volatile write cache and the non-volatile read cache, wherein the storage system does not include any volatile cache and methods for retrieving and writing data throughout this memory hierarchy system. | 03-04-2010 |
20100058125 | DATA DEVICES INCLUDING MULTIPLE ERROR CORRECTION CODES AND METHODS OF UTILIZING - A method of utilizing at least one block of data, wherein the at least one block of data includes a plurality of cells for storing data and at least one error flag bit, the method including: scanning the block of data for errors; determining the error rate of the block of data; and applying an error correction code to data being read from or written to a cell within the at least one block of data, wherein the error correction code is applied based on the error rate, wherein a weak error correction code is applied when the error rate is below an error threshold, and a strong error correction code is applied when the error rate is at or above the error threshold. | 03-04-2010 |
20100067281 | VARIABLE WRITE AND READ METHODS FOR RESISTIVE RANDOM ACCESS MEMORY - Variable write and read methods for resistance random access memory (RRAM) are disclosed. The methods include initializing a write sequence and verifying the resistance state of the RRAM cell. If a write pulse is needed, then two or more write pulses are applied through the RRAM cell to write the desired data state to the RRAM cell. Each subsequent write pulse has substantially the same or greater write pulse duration. Subsequent write pulses are applied to the RRAM cell until the RRAM cell is in the desired data state or until a predetermined number of write pulses have been applied to the RRAM cell. A read method is also disclosed where subsequent read pulses are applied through the RRAM cell until the read is successful or until a predetermined number of read pulses have been applied to the RRAM cell. | 03-18-2010 |
20100067282 | MEMORY ARRAY WITH READ REFERENCE VOLTAGE CELLS - The present disclosure relates to memory arrays with read reference voltage cells. In particular the present disclosure relates to variable resistive memory cell apparatus and arrays that include a high resistance state reference memory cell and a low resistance state reference memory cell that provides a reliable average reference voltage on chip to compare to a read voltage of a selected memory cell and determine if the selected memory cell is in the high resistance state or low resistance state. These memory arrays are particularly suitable for use with spin-transfer torque memory cells and resolves many systematic issues related to generation of a reliable reference voltage. | 03-18-2010 |
20100080053 | STATIC SOURCE PLANE IN STRAM - The present disclosure relates to a memory array including a plurality of magnetic tunnel junction cells arranged in an array. Each magnetic tunnel junction cell is electrically coupled between a bit line and a source line. The magnetic tunnel junction cell is configured to switch between a high resistance state and a low resistance state by passing a write current passing though the magnetic tunnel junction cell. A transistor is electrically between the magnetic tunnel junction cell and the source line. A word line is electrically coupled to a gate of the transistor. The source line is a common source line for the plurality of magnetic tunnel junctions. | 04-01-2010 |
20100085110 | Integrated Circuit Active Power Supply Regulation - Method and apparatus for compensating for voltage fluctuations on a voltage supply line in an integrated circuit device. In accordance with some embodiments, the apparatus includes a voltage fluctuation sensor which senses a voltage on the supply line, and a compensation circuit comprising a switch and a charge storage device (CSD). The switch actively connects the CSD to the supply line when the voltage sensed by the voltage fluctuation sensor passes outside a predetermined voltage range. | 04-08-2010 |
20100085795 | Asymmetric Write Current Compensation - An apparatus and method for compensating for asymmetric write current in a non-volatile unit cell. The unit cell comprises a switching device and an asymmetric resistive sense element (RSE), such as an asymmetric resistive random access memory (RRAM) element or an asymmetric spin-torque transfer random access memory (STRAM) element. The RSE is physically oriented within the unit cell relative to the switching device such that a hard direction for programming the RSE is aligned with an easy direction of programming the unit cell, and an easy direction for programming the RSE is aligned with a hard direction for programming the unit cell. | 04-08-2010 |
20100085796 | Enhancing Read and Write Sense Margins in a Resistive Sense Element - An apparatus and method for enhancing read and write sense margin in a memory cell having a resistive sense element (RSE), such as but not limited to a resistive random access memory (RRAM) element or a spin-torque transfer random access memory (STRAM) element. The RSE has a hard programming direction and an easy programming direction. A write current is applied in either the hard programming direction or the easy programming direction to set the RSE to a selected programmed state. A read circuit subsequently passes a read sense current through the cell in the hard programming direction to sense the selected programmed state of the cell. | 04-08-2010 |
20100085797 | DUAL STAGE SENSING FOR NON-VOLATILE MEMORY - A method and apparatus for accessing a non-volatile memory cell. In some embodiments, a memory block provides a plurality of memory cells arranged into rows and columns. A read circuit is configured to read a selected row of the memory block by concurrently applying a control voltage to each memory cell along the selected row and, for each column, using a respective local sense amplifier and a column sense amplifier to successively differentiate a voltage across the associated memory cell in said column to output a programmed content of the row. | 04-08-2010 |
20100085803 | ELECTRONIC DEVICES UTILIZING SPIN TORQUE TRANSFER TO FLIP MAGNETIC ORIENTATION - Electronic devices that include (i) a magnetization controlling structure; (ii) a tunnel barrier structure; and (iii) a magnetization controllable structure including: a first polarizing layer; and a first stabilizing layer, wherein the tunnel barrier structure is between the magnetization controlling structure and the magnetization controlling structure and the first polarizing layer is between the first stabilizing layer and the tunnel barrier structure, wherein the electronic device has two stable overall magnetic configurations, and wherein a first unipolar current applied to the electronic device will cause the orientation of the magnetization controlling structure to reverse its orientation and a second unipolar current applied to the electronic device will cause the magnetization controllable structure to switch its magnetization in order to obtain one of the two stable overall magnetic configurations, wherein the second unipolar current has an amplitude that is less than the first unipolar current. | 04-08-2010 |
20100085805 | MAGNETIC RANDOM ACCESS MEMORY (MRAM) UTILIZING MAGNETIC FLIP-FLOP STRUCTURES - Non-volatile magnetic random access memory (MRAM) devices that include magnetic flip-flop structures that include a magnetization controlling structure; a first tunnel barrier structure; and a magnetization controllable structure that includes a first polarizing layer; and a first stabilizing layer, wherein the first tunnel barrier structure is between the magnetization controllable structure and the magnetization controlling structure and the first polarizing layer is between the first stabilizing layer and the first tunnel barrier structure, wherein the magnetic flip-flop device has two stable overall magnetic configurations, and wherein a first unipolar current applied to the device will cause the orientation of the magnetization controlling structure to reverse its orientation and a second unipolar current applied to the electronic device will cause the magnetization controllable structure to switch its magnetization so that the device reaches one of the two stable overall magnetic configurations, wherein the second unipolar current has an amplitude that is less than the first unipolar current; a second tunnel barrier structure and a reference layer, wherein the second tunnel barrier structure is between the magnetic flip-flop device and the reference layer. MRAM cells that include such devices and arrays including such cells are also disclosed. | 04-08-2010 |
20100090687 | DOMAIN WALL MOVEMENT ON MAGNETIC STRIP TRACKS - Magnetic shift tracks or magnetic strips, to which application of a rotating magnetic field or by rotation of the strip itself allows accurate determination of domain wall movement. One particular embodiment is a method of determining a position of a domain wall in a magnetic strip. The method includes applying a rotating magnetic field to the magnetic strip, the magnetic field rotating around a longitudinal axis of the magnetic strip, and after applying the magnetic field, determining a displacement of the domain wall to a second position. | 04-15-2010 |
20100091546 | HIGH DENSITY RECONFIGURABLE SPIN TORQUE NON-VOLATILE MEMORY - One time programmable memory units include a magnetic tunnel junction cell electrically coupled to a bit line and a word line. The magnetic tunnel junction cell is pre-programmed to a first resistance state, and is configured to switch only from the first resistance state to a second resistance state by passing a voltage across the magnetic tunnel junction cell. In some embodiments, a transistor is electrically coupled between the magnetic tunnel junction cell and the word line or the bit line. In other embodiments, a device having a rectifying switching characteristic, such as a diode or other non-ohmic device, is electrically coupled between the magnetic tunnel junction cell and the word line or the bit line. Methods of pre-programming the one time programmable memory units and reading and writing to the units are also disclosed. | 04-15-2010 |
20100091550 | Voltage Reference Generation with Selectable Dummy Regions - Various embodiments of the present invention are generally directed to an apparatus and associated method for generating a reference voltage with dummy resistive sense element regions. A first resistance distribution is obtained for a first dummy region of resistance sense elements and a second resistance distribution is obtained for a second dummy region of resistive sense elements. A user resistive sense element from a user region is assigned to a selected resistive sense element of one of the first or second dummy regions in relation to the first and second resistance distributions. | 04-15-2010 |
20100091562 | TEMPERATURE DEPENDENT SYSTEM FOR READING ST-RAM - A memory device that includes at least one memory cell, the memory cell includes: a magnetic tunnel junction (MTJ); and a transistor, wherein the transistor is operatively coupled to the MTJ; a bit line; a source line; and a word line, wherein the memory cell is operatively coupled between the bit line and the source line, and the word line is operatively coupled to the transistor; a temperature sensor; and control circuitry, wherein the temperature sensor is operatively coupled to the control circuitry and the control circuitry and temperature sensor are configured to control a current across the memory cell. | 04-15-2010 |
20100095050 | COMPUTER MEMORY DEVICE WITH STATUS REGISTER - Method and apparatus for operating a memory device with a status register. In some embodiments, the memory device has a plurality of individually programmable non-volatile memory cells comprised of at least a resistive sense memory. The memory device engages an interface and maintains a status register in some embodiments by logging at least an error or busy signal during data transfer operations. | 04-15-2010 |
20100095052 | DATA UPDATING IN NON-VOLATILE MEMORY - Various embodiments of the present invention are generally directed to an apparatus and associated method for updating data in a non-volatile memory array. In accordance with some embodiments, a memory block is formed with a plurality of types of memory cell sectors arranged in data pages of a first type and log pages of a second type that can be updated in-place. A first updated sector is written to a first log page while maintaining an outdated sector in an original data page, and overwritten with a second updated sector. | 04-15-2010 |
20100095057 | NON-VOLATILE RESISTIVE SENSE MEMORY ON-CHIP CACHE - Various embodiments of the present invention are generally directed to an apparatus and associated method for a non-volatile resistive sense memory on-chip cache. In accordance with some embodiments, a processing circuit is formed on a first semiconductor substrate. A second semiconductor substrate is affixed to the first semiconductor substrate to form an encapsulated integrated chip package, wherein a non-volatile storage array of resistive sense memory (RSM) cells is formed on the second semiconductor substrate to cache data used by the processing circuit. | 04-15-2010 |
20100096611 | VERTICALLY INTEGRATED MEMORY STRUCTURES - A device including a transistor that includes a source region; a drain region; and a channel region, wherein the channel region electrically connects the source region and the drain region along a channel axis; and a memory cell, wherein the memory cell is disposed adjacent the drain region so that the channel axis runs through the memory cell. | 04-22-2010 |
20100097852 | MRAM DIODE ARRAY AND ACCESS METHOD - A memory unit includes a magnetic tunnel junction data cell is electrically coupled to a bit line and a source line. The magnetic tunnel junction data cell is configured to switch between a high resistance state and a low resistance state by passing a write current through the magnetic tunnel junction data cell. A first diode is electrically between the magnetic tunnel junction data cell and the source line and a second diode is electrically between the magnetic tunnel junction data cell and the source line. The first diode and second diode are in parallel electrical connection, and having opposing forward bias directions. | 04-22-2010 |
20100100857 | GENERIC NON-VOLATILE SERVICE LAYER - Method and apparatus for constructing and operating an integrated circuit in an electronic device. In some embodiments, a generic service layer is integrated in a three dimensional integrated circuit and tested using a testing pattern stored in a non-volatile memory. The generic service layer is reconfigured to a permanent non-testing functional component of the integrated circuit. | 04-22-2010 |
20100103728 | SPIN-TRANSFER TORQUE MEMORY SELF-REFERENCE READ AND WRITE ASSIST METHODS - A spin-transfer torque memory apparatus and self-reference read and write assist schemes are described. One method of self-reference reading a spin-transfer torque memory unit includes applying a first read current through a magnetic tunnel junction data cell and forming a first bit line read voltage and storing the first bit line read voltage. A magnetic field is applied through the free magnetic layer the forming a magnetic field modified magnetic tunnel junction data cell, the magnetic field rotates the magnetization orientation of the free magnetic layer without switching a resistance state of the magnetic tunnel junction data cell. Then a second read current is applied thorough the magnetic field modified magnetic tunnel junction data cell forming a second bit line read voltage and the bit line read voltage is stored and compared with the first bit line read voltage to determine whether the first resistance state of the magnetic tunnel junction data cell was a high resistance state or low resistance state. Methods of applying a destabilizing magnetic field to the MTJ and then writing the desired resistance state are also disclosed. | 04-29-2010 |
20100103729 | SPIN-TRANSFER TORQUE MEMORY SELF-REFERENCE READ AND WRITE ASSIST METHODS - A spin-transfer torque memory apparatus and self-reference read and write assist schemes are described. One method of self-reference reading a spin-transfer torque memory unit includes applying a first read current through a magnetic tunnel junction data cell and forming a first bit line read voltage and storing the first bit line read voltage. A magnetic field is applied through the magnetic tunnel junction data cell forming a magnetic field modified magnetic tunnel junction data cell. Then a second read current is applied thorough the magnetic field modified magnetic tunnel junction data cell forming a second bit line read voltage and the bit line read voltage is stored and compared with the first bit line read voltage to determine whether the first resistance state of the magnetic tunnel junction data cell was a high resistance state or low resistance state. Methods of applying a magnetic field to the MTJ and then writing the desired resistance state are also disclosed. | 04-29-2010 |
20100109656 | Magnetic Tunnel Junction and Memristor Apparatus - A magnetic memory device includes a magnetic tunnel junction having a free magnetic layer having a magnetization orientation that is switchable between a high resistance state magnetization orientation and a low resistance state magnetization orientation and a memristor solid state element electrically coupled to the magnetic tunnel junction. The memristor has a device response that is an integrated voltage versus an integrated current. | 05-06-2010 |
20100109660 | Tunable Random Bit Generator with Magnetic Tunnel Junction - A random number generator device that utilizes a magnetic tunnel junction. An AC current source is in electrical connection to the magnetic tunnel junction to provide an AC current having an amplitude and a frequency through the free layer of the magnetic tunnel junction, the AC current configured to switch the magnetization orientation of the free layer via thermal magnetization. A read circuit is used to determine the relative orientation of the free layer magnetization in relation to the reference layer magnetization orientation. | 05-06-2010 |
20100110760 | Resistive Sense Memory Calibration for Self-Reference Read Method - Resistive memory calibration for self-reference read methods are described. One method of self-reference reading a resistive memory unit includes setting a plurality of resistive memory units to a first resistive data state. The resistive memory units forms a memory array. Reading a sensed resistive data state for each resistive memory unit by applying a first read current and a second read current through each resistive memory unit and then comparing voltages formed by the first read current and the second read current to determine the sensed resistive data state for each resistive memory unit. Then the method includes adjusting the first or the second read current, read voltages, or storage device capacitance for each resistive memory unit where the sensed resistive data state was not the same as the first resistive data state until the sensed resistive data state is the same as the first resistive data state. | 05-06-2010 |
20100110761 | Spatial Correlation of Reference Cells in Resistive Memory Array - The present disclosure relates to methods of selectively placing a reference column or reference row in a memory array. The method includes measuring a resistance state resistance value for a plurality of variable resistive memory cells within a memory array and mapping a location of each measured variable resistive memory cell to form a map of the resistance state resistance values for a plurality of variable resistive memory cells within a memory array. Then a column or row is selected to be a reference column or reference row based on the map of the resistance state resistance value for a plurality of variable resistive memory cells within a memory array, to minimize read operation errors, and forming a variable resistive memory cell memory array. | 05-06-2010 |
20100110762 | WRITE METHOD WITH VOLTAGE LINE TUNING - A method of writing to a resistive sense memory unit includes applying a first voltage across a resistive sense memory cell and a semiconductor transistor to write a first data state to the resistive sense memory cell. The first voltage forms a first write current for a first time duration through the resistive sense memory cell in a first direction. Then the method includes applying a second voltage across the resistive sense memory cell and the transistor to write a second data state to the resistive sense memory cell. The second voltage forms a second write current for a second duration through the resistive sense memory cell in a second direction. The second direction opposes the first direction, the first voltage has a different value than the second voltage, and the first duration is substantially the same as the second duration. | 05-06-2010 |
20100110763 | Write Current Compensation Using Word Line Boosting Circuitry - Apparatus and method for write current compensation in a non-volatile memory cell, such as but not limited to spin-torque transfer random access memory (STRAM) or resistive random access memory (RRAM). In accordance with some embodiments, a non-volatile memory cell has a resistive sense element (RSE) coupled to a switching device, the RSE having a hard programming direction and an easy programming direction opposite the hard programming direction. A voltage boosting circuit includes a capacitor which adds charge to a nominal non-zero voltage supplied by a voltage source to a node to generate a temporarily boosted voltage. The boosted voltage is applied to the switching device when the RSE is programmed in the hard programming direction. | 05-06-2010 |
20100110784 | STRAM with Self-Reference Read Scheme - Self-reference reading a magnetic tunnel junction data cell methods are disclosed. An illustrative method includes applying a read voltage across a magnetic tunnel junction data cell and forming a read current. The magnetic tunnel junction data cell has a first resistance state. The read voltage is sufficient to switch the magnetic tunnel junction data cell resistance. The method includes detecting the read current and determining if the read current remains constant during the applying step. If the read current remains constant during the applying step, then the first resistance state of the magnetic tunnel junction data cell is the resistance state that the read voltage was sufficient to switch the magnetic tunnel junction data cell to. | 05-06-2010 |
20100110785 | Memory Cell With Proportional Current Self-Reference Sensing - Various embodiments of the present invention are generally directed to a method and apparatus for sensing a programmed state of a memory cell, such as a spin-torque transfer random access memory (STRAM) cell. A first read current is applied to the memory cell to generate a first voltage. A second read current is subsequently applied to the memory cell to generate a second voltage, with the second read current being proportional in magnitude to the first read current. A comparison is made between the first and second voltages to determine the programmed state of the memory cell. | 05-06-2010 |
20100118587 | RESISTIVE SENSE MEMORY ARRAY WITH PARTIAL BLOCK UPDATE CAPABILITY - Various embodiments of the present invention are generally directed to a method and apparatus for carrying out a partial block update operation upon a resistive sense memory (RSM) array, such as formed from STRAM or RRAM cells. The RSM array is arranged into multi-cell blocks (sectors), each block having a physical block address (PBA). A first set of user data is written to a selected block at a first PBA. A partial block update operation is performed by writing a second set of user data to a second block at a second PBA, the second set of user data updating a portion of the first set of user data in the first PBA. The first and second blocks are thereafter read to retrieve the second set of user data and a remaining portion of the first set of user data. | 05-13-2010 |
20100118588 | VOLTAGE REFERENCE GENERATION FOR RESISTIVE SENSE MEMORY CELLS - Various embodiments of the present invention are generally directed to an apparatus and associated method for generating a reference voltage for a resistive sense memory (RSM) cell, such as an STRAM cell. A dummy reference cell used to generate a reference voltage to sense a resistive state of an adjacent RSM cell. The dummy reference cell comprises a switching device, a resistive sense element (RSE) programmed to a selected resistive state, and a dummy resistor coupled to the RSE. A magnitude of the reference voltage is set in relation to the selected resistive state of the RSE and the resistance of the dummy resistor. | 05-13-2010 |
20100118602 | DOUBLE SOURCE LINE-BASED MEMORY ARRAY AND MEMORY CELLS THEREOF - A memory array includes a plurality of first and second source, lines overlapping a plurality of bit lines, and a plurality of magnetic storage elements, each coupled to a corresponding first and second source line and to a corresponding bit line. Current may be driven, in first and second directions, through each magnetic element, for example, to program the elements. Diodes may be incorporated to avert sneak paths in the memory array. A first diode may be coupled between each magnetic element and the corresponding first source line, the first diode being biased to allow read and write current flow through the magnetic element, from the corresponding first source line; and a second diode may be coupled between each magnetic element and the corresponding second source line, the second diode being reverse-biased to block read and write current flow through the magnetic element, from the corresponding second source line. | 05-13-2010 |
20100128519 | NON VOLATILE MEMORY HAVING INCREASED SENSING MARGIN - A non volatile memory assembly that includes a reference element having: a reference component; and a reference transistor, wherein the reference component is electrically connected to the reference transistor, and the reference transistor controls the passage of current across the reference component; and at least one non volatile memory element having: a non volatile memory cell, having at least a low and a high resistance state; and an output that electrically connects the reference element with the at least one non volatile memory element, wherein the reference transistor and the memory transistor are activated by a reference gate voltage and a memory gate voltage respectively, and the reference gate voltage and the memory gate voltage are not the same. | 05-27-2010 |
20100153646 | MEMORY HIERARCHY WITH NON-VOLATILE FILTER AND VICTIM CACHES - Various embodiments of the present invention are generally directed to an apparatus and method for non-volatile caching of data in a memory hierarchy of a data storage device. In accordance with some embodiments, a pipeline memory structure is provided to store data for use by a controller. The pipeline has a plurality of hierarchical cache levels each with an associated non-volatile filter cache and a non-volatile victim cache. Data retrieved from each cache level are respectively promoted to the associated non-volatile filter cache. Data replaced in each cache level are respectively demoted to the associated non-volatile victim cache. | 06-17-2010 |
20100177551 | BIT SET MODES FOR A RESISTIVE SENSE MEMORY CELL ARRAY - Various embodiments of the present invention are generally directed to a method and apparatus for providing different bit set modes for a resistive sense memory (RSM) array, such as a spin-torque transfer random access memory (STRAM) or resistive random access memory (RRAM) array. In accordance with some embodiments, a group of RSM cells in a non-volatile semiconductor memory array is identified for application of a bit set operation. A bit set value is selected from a plurality of bit set values each separately writable to the RSM cells to place said cells in a selected resistive state. The selected bit set value is thereafter written to at least a portion of the RSM cells in the identified group. | 07-15-2010 |
20100177552 | TABLE-BASED REFERENCE VOLTAGE CHARACTERIZATION SCHEME - Method and apparatus for reading data from a non-volatile memory cell, such as a modified STRAM cell. In some embodiments, at least a first and second memory cell are read for a plurality of resistance values that are used to select and store a voltage reference for each memory cell. | 07-15-2010 |
20100177554 | BIPOLAR CMOS SELECT DEVICE FOR RESISTIVE SENSE MEMORY - A resistive sense memory apparatus includes a bipolar select device having a semiconductor substrate and a plurality of transistors disposed in the semiconductor substrate and forming a row or transistors. Each transistor includes an emitter contact and a collector contact. Each collector contact is electrically isolated from each other and each emitter contact is electrically isolated from each other. A gate contact extends along a channel region between the emitter contact and a collector contact. A base contact is disposed within the semiconductor substrate such that the emitter contact and a collector contact is between the gate contact and the base contact. A resistive sense memory cells is electrically coupled to each collector contact or emitter contact and a bit line. | 07-15-2010 |
20100177562 | COMPUTER MEMORY DEVICE WITH MULTIPLE INTERFACES - Various embodiments are generally directed to a method and apparatus associated with operating a first memory device with multiple interfaces and a status register. In some embodiments, a first interface is engaged by a host. A memory device that has a plurality of memory cells comprised of at least a magnetic tunneling junction and a spin polarizing magnetic material is connected to a second interface. A status register is maintained by logging at least an error or busy signal during data transfer operations through the first and second interfaces. | 07-15-2010 |
20100188883 | Simultaneously Writing Multiple Addressable Blocks of User Data to a Resistive Sense Memory Cell Array - Method and apparatus are disclosed for storing data to non-volatile resistive sense memory (RSM) memory cells of a semiconductor memory array, including but not limited to resistive random access memory (RRAM) and spin-torque transfer random access memory (STTRAM or STRAM) cells. In accordance with various embodiments, a plurality of addressable data blocks from a host device are stored in a buffer. At least a portion of each of the addressable data blocks are serially transferred to a separate register of a plurality of registers. The transferred portions of said addressable data blocks are thereafter simultaneously transferred from the registers to selected RSM cells of the array. | 07-29-2010 |
20100195380 | Non-Volatile Memory Cell with Precessional Switching - A method and apparatus for writing data to a non-volatile memory cell, such as a spin-torque transfer random access memory (STRAM) memory cell. In some embodiments, a selected resistive state is written to a magnetic tunneling structure by applying a succession of indeterminate write pulses thereto until the selected resistive state is verified. | 08-05-2010 |
20100220512 | PROGRAMMABLE POWER SOURCE USING ARRAY OF RESISTIVE SENSE MEMORY CELLS - Various embodiments of the present invention are generally directed to an apparatus comprising a programmable power source which uses an array of resistive sense memory cells, such as but not limited to STRAM or RRAM cells, to provide a controlled power bias to a load, such as but not limited to a micro-oscillator. In some embodiments, the programmable power source incorporates an array of serially connected resistive sense memory cells. A selectively controllable power level is applied by the programmable power source to a load in relation to a control input which selectively programs at least selected ones of the memory cells to a selected resistance state. | 09-02-2010 |
20100228912 | Non-Volatile Memory With Hybrid Index Tag Array - Various embodiments of the present invention are generally directed to an apparatus and associated method for a non-volatile memory with a hybrid index tag array. In accordance with some embodiments, a memory device has a word memory array formed of non-volatile resistive sense memory (RSM) cells, a first index array formed of volatile content addressable memory (CAM) cells, and a second index array formed of non-volatile RSM cells. The memory device is configured to output word data from the word memory array during a data retrieval operation when input request data matches tag data stored in the first index array, and to copy tag data stored in the second index array to the first index array during a device reinitialization operation. | 09-09-2010 |
20100232206 | NON-VOLATILE MEMORY READ/WRITE VERIFY - An apparatus and associated method for writing data to a non-volatile memory cell, such as a resistive random access memory (RRAM) cell. In some embodiments, a control circuitry is configured to write a logic state to a resistive sense element while simultaneously verifying the logic state of the resistive sense element. | 09-16-2010 |
20100232211 | MEMORY ARRAY WITH READ REFERENCE VOLTAGE CELLS - The present disclosure relates to memory arrays with read reference voltage cells. In particular the present disclosure relates to variable resistive memory cell apparatus and arrays that include a high resistance state reference memory cell and a low resistance state reference memory cell that provides a reliable average reference voltage on chip to compare to a read voltage of a selected memory cell and determine if the selected memory cell is in the high resistance state or low resistance state. These memory arrays are particularly suitable for use with spin-transfer torque memory cells and resolves many systematic issues related to generation of a reliable reference voltage. | 09-16-2010 |
20100238700 | Quiescent Testing of Non-Volatile Memory Array - A method and apparatus for testing an array of non-volatile memory cells, such as a spin-torque transfer random access memory (STRAM). In some embodiments, an array of memory cells having a plurality of unit cells with a resistive sense element and a switching device has a row decoder and a column decoder connected to the plurality of unit cells. A test circuitry sends a non-operational test pattern through the array via the row and column decoders with a quiescent supply current to identify defects in the array of memory cells. | 09-23-2010 |
20100238712 | VARIABLE WRITE AND READ METHODS FOR RESISTIVE RANDOM ACCESS MEMORY - Variable write and read methods for resistance random access memory (RRAM) are disclosed. The methods include initializing a write sequence and verifying the resistance state of the RRAM cell. If a write pulse is needed, then two or more write pulses are applied through the RRAM cell to write the desired data state to the RRAM cell. Each subsequent write pulse has substantially the same or greater write pulse duration. Subsequent write pulses are applied to the RRAM cell until the RRAM cell is in the desired data state or until a predetermined number of write pulses have been applied to the RRAM cell. A read method is also disclosed where subsequent read pulses are applied through the RRAM cell until the read is successful or until a predetermined number of read pulses have been applied to the RRAM cell. | 09-23-2010 |
20100246250 | Pipeline Sensing Using Voltage Storage Elements to Read Non-Volatile Memory Cells - Various embodiments are generally directed to a method and apparatus for carrying out a pipeline sensing operation. In some embodiments, a read voltage from a first memory cell is stored in a voltage storage element (VSE) and compared to a reference voltage to identify a corresponding memory state of the first memory cell while a second read voltage from a second memory cell is stored in a second VSE. In other embodiments, bias currents are simultaneously applied to a first set of memory cells from the array while read voltages generated thereby are stored in a corresponding first set of VSEs. The read voltages are sequentially compared with at least one reference value to serially output a logical sequence corresponding to the memory states of the first set of memory cells while read voltages are stored for a second set of memory cells in a second set of VSEs. | 09-30-2010 |
20100246251 | Predictive Thermal Preconditioning and Timing Control for Non-Volatile Memory Cells - A method and apparatus for using thermal preconditioning to write data to a non-volatile memory cell, such as a spin-torque transfer random access memory (STRAM) memory cell. In some embodiments, a logical state is written to an unconditioned non-volatile first memory cell associated with a first block address. Thermal preconditioning is concurrently applied to a non-volatile second memory cell associated with a second block address selected in response to the first block address. | 09-30-2010 |
20100302839 | STATIS SOURCE PLANE IN STRAM - A memory array includes a plurality of magnetic tunnel junction cells arranged in a 2 by 2 array. Each magnetic tunnel junction cell is electrically coupled between a bit line and a source line and each magnetic tunnel junction cell electrically coupled to a transistor. Each magnetic tunnel junction cell is configured to switch between a high resistance state and a low resistance state by passing a write current passing though the magnetic tunnel junction cell. A first word line is electrically coupled to a gate of first set of two of the transistors and a second word line is electrically coupled to a gate of a second set of two of the transistors. The source line is a common source line for the plurality of magnetic tunnel junctions. | 12-02-2010 |
20100315865 | DIODE ASSISTED SWITCHING SPIN-TRANSFER TORQUE MEMORY UNIT - A memory array includes a cross-point array of bit and source lines. A memory is disposed at cross-points of the cross-point array. The memory unit includes a magnetic tunnel junction data cell electrically coupled to a bit line and a source line. The magnetic tunnel junction data cell is configured to switch between a high resistance state and a low resistance state by passing a polarized write current through the magnetic tunnel junction data cell. A transistor is electrically between the magnetic tunnel junction data cell and the bit line or source line and a diode is in thermal or electrical contact with the magnetic tunnel junction data cell to assist in resistance state switching. | 12-16-2010 |
20100321994 | MEMORY SELF-REFERENCE READ AND WRITE ASSIST METHODS - A magnetic tunnel junction memory apparatus and self-reference read and write assist schemes are described. One method of self-reference reading a magnetic tunnel junction memory unit includes applying a first read current through a magnetic tunnel junction data cell to form a first bit line read voltage, then applying a first magnetic field through the magnetic tunnel junction data cell forming a magnetic field modified magnetic tunnel junction data cell, and then applying a second read current thorough the magnetic field modified magnetic tunnel junction data cell to form a second bit line read voltage. The first read current being less than the second read current. Then comparing the first bit line read voltage with the second bit line read voltage to determine whether the magnetic tunnel junction data cell was in a high resistance state or a low resistance state. Methods of applying a magnetic field to the MTJ and then writing the desired resistance state are also disclosed. | 12-23-2010 |
20110007588 | Defective Bit Scheme for Multi-Layer Integrated Memory Device - Various embodiments of the present invention are generally directed to an apparatus and associated method for handling defective bits in a multi-layer integrated memory device. In accordance with some embodiments, the multi-layer integrated memory device is formed from a plurality of vertically stacked semiconductor layers each having a number of storage sub-arrays and redundant sub-arrays. Each semiconductor layer is tested to determine a defect rate for each array, and a defective portion of a first semiconductor layer having a relatively higher defect rate is stored to a redundant sub-array of a second semiconductor layer having a relatively lower defect rate. | 01-13-2011 |
20110026317 | SPIN-TRANSFER TORQUE MEMORY SELF-REFERENCE READ AND WRITE ASSIST METHODS - A spin-transfer torque memory apparatus and self-reference read and write assist schemes are described. One method of self-reference reading a spin-transfer torque memory unit includes applying a first read current through a magnetic tunnel junction data cell and forming a first bit line read voltage. A magnetic field is applied through the free magnetic layer the forming a magnetic field modified magnetic tunnel junction data cell. Then a second read current is applied thorough the magnetic field modified magnetic tunnel junction data cell forming a second bit line read voltage and compared with the first bit line read voltage to determine whether the first resistance state of the magnetic tunnel junction data cell was a high resistance state or low resistance state. Methods of applying a destabilizing magnetic field to the MTJ and then writing the desired resistance state are also disclosed. | 02-03-2011 |
20110029714 | RESISTIVE SENSE MEMORY ARRAY WITH PARTIAL BLOCK UPDATE CAPABILITY - Various embodiments of the present invention are generally directed to a method and apparatus for carrying out a partial block update operation upon a resistive sense memory (RSM) array, such as formed from STRAM or RRAM cells. The RSM array is arranged into multi-cell blocks (sectors), each block having a physical block address (PBA). A first set of user data is written to a selected block at a first PBA. A partial block update operation is performed by writing a second set of user data to a second block at a second PBA, the second set of user data updating a portion of the first set of user data in the first PBA. The first and second blocks are thereafter read to retrieve the second set of user data and a remaining portion of the first set of user data. | 02-03-2011 |
20110058405 | Memory Cell With Proportional Current Self-Reference Sensing - Various embodiments of the present invention are generally directed to a method and apparatus for sensing a programmed state of a memory cell, such as a spin-torque transfer random access memory (STRAM) cell. A first read current is applied to the memory cell to generate a first voltage. A second read current is subsequently applied to the memory cell to generate a second voltage, with the second read current being proportional in magnitude to the first read current. A comparison is made between the first and second voltages to determine the programmed state of the memory cell. | 03-10-2011 |
20110058409 | MRAM DIODE ARRAY AND ACCESS METHOD - A memory unit includes a magnetic tunnel junction data cell is electrically coupled to a bit line and a source line. The magnetic tunnel junction data cell is configured to switch between a high resistance state and a low resistance state by passing a write current through the magnetic tunnel junction data cell. A first diode is electrically between the magnetic tunnel junction data cell and the source line and a second diode is electrically between the magnetic tunnel junction data cell and the source line. The first diode and second diode are in parallel electrical connection, and having opposing forward bias directions. The memory unit is configured to be precharged to a specified precharge voltage level and the precharge voltage is less than a threshold voltage of the first diode and second diode. | 03-10-2011 |
20110063901 | STATIC SOURCE PLANE IN STRAM - A memory array includes a plurality of magnetic tunnel junction cells arranged in a 2 by 2 array. Each magnetic tunnel junction cell is electrically coupled between a bit line and a source line and each magnetic tunnel junction cell electrically coupled to a transistor. Each magnetic tunnel junction cell is configured to switch between a high resistance state and a low resistance state by passing a write current passing though the magnetic tunnel junction cell. A first word line is electrically coupled to a gate of first set of two of the transistors and a second word line is electrically coupled to a gate of a second set of two of the transistors. The source line is a common source line for the plurality of magnetic tunnel junctions. | 03-17-2011 |
20110075471 | Enhancing Read and Write Sense Margins in a Resistive Sense Element - An apparatus and method for enhancing read and write sense margin in a memory cell having a resistive sense element (RSE), such as but not limited to a resistive random access memory (RRAM) element or a spin-torque transfer random access memory (STRAM) element. The RSE has a hard programming direction and an easy programming direction. A write current is applied in either the hard programming direction or the easy programming direction to set the RSE to a selected programmed state. A read circuit subsequently passes a read sense current through the cell in the hard programming direction to sense the selected programmed state of the cell. | 03-31-2011 |
20110080768 | WRITE CURRENT COMPENSATION USING WORD LINE BOOSTING CIRCUITRY - Apparatus and method for write current compensation in a non-volatile memory cell, such as but not limited to spin-torque transfer random access memory (STRAM) or resistive random access memory (RRAM). In accordance with some embodiments, a non-volatile memory cell has a resistive sense element (RSE) coupled to a switching device, the RSE having a hard programming direction and an easy programming direction opposite the hard programming direction. A voltage boosting circuit includes a capacitor which adds charge to a nominal non-zero voltage supplied by a voltage source to a node to generate a temporarily boosted voltage. The boosted voltage is applied to the switching device when the RSE is programmed in the hard programming direction. | 04-07-2011 |
20110080769 | Spatial Correlation of Reference Cells in Resistive Memory Array - The present disclosure relates to methods of selectively placing a reference column or reference row in a memory array. The method includes measuring a resistance state resistance value for a plurality of variable resistive memory cells within a memory array and mapping a location of each measured variable resistive memory cell to form a map of the resistance state resistance values for a plurality of variable resistive memory cells within a memory array. Then a column or row is selected to be a reference column or reference row based on the map of the resistance state resistance value for a plurality of variable resistive memory cells within a memory array, to minimize read operation errors, and forming a variable resistive memory cell memory array. | 04-07-2011 |
20110080782 | WRITE CURRENT COMPENSATION USING WORD LINE BOOSTING CIRCUITRY - Apparatus and method for write current compensation in a non-volatile memory cell, such as but not limited to spin-torque transfer random access memory (STRAM) or resistive random access memory (RRAM). In accordance with some embodiments, a non-volatile memory cell has a resistive sense element (RSE) coupled to a switching device, the RSE having a hard programming direction and an easy programming direction opposite the hard programming direction. A voltage boosting circuit includes a capacitor which adds charge to a nominal non-zero voltage supplied by a voltage source to a node to generate a temporarily boosted voltage. The boosted voltage is applied to the switching device when the RSE is programmed in the hard programming direction. | 04-07-2011 |
20110116303 | Magnetic Tunnel Junction and Memristor Apparatus - A magnetic memory device includes a magnetic tunnel junction having a free magnetic layer having a magnetization orientation that is switchable between a high resistance state magnetization orientation and a low resistance state magnetization orientation and a memristor solid state element electrically coupled to the magnetic tunnel junction. The memristor has a device response that is an integrated voltage versus an integrated current. | 05-19-2011 |
20110122679 | Resistive Sense Memory Calibration for Self-Reference Read Method - Resistive memory calibration for self-reference read methods are described. One method of self-reference reading a resistive memory unit includes setting a plurality of resistive memory units to a first resistive data state. The resistive memory units forms a memory array. Reading a sensed resistive data state for each resistive memory unit by applying a first read current and a second read current through each resistive memory unit and then comparing voltages formed by the first read current and the second read current to determine the sensed resistive data state for each resistive memory unit. Then the method includes adjusting the first or the second read current, read voltages, or storage device capacitance for each resistive memory unit where the sensed resistive data state was not the same as the first resistive data state until the sensed resistive data state is the same as the first resistive data state. | 05-26-2011 |
20110128778 | Predictive Thermal Preconditioning and Timing Control for Non-Volatile Memory Cells - A method and apparatus for using thermal preconditioning to write data to a non-volatile memory cell, such as a spin-torque transfer random access memory (STRAM) memory cell. In some embodiments, a logical state is written to an unconditioned non-volatile first memory cell associated with a first block address. Thermal preconditioning is concurrently applied to a non-volatile second memory cell associated with a second block address selected in response to the first block address. | 06-02-2011 |
20110134682 | VARIABLE WRITE AND READ METHODS FOR RESISTIVE RANDOM ACCESS MEMORY - Variable write and read methods for resistance random access memory (RRAM) are disclosed. The methods include initializing a write sequence and verifying the resistance state of the RRAM cell. If a write pulse is needed, then two or more write pulses are applied through the RRAM cell to write the desired data state to the RRAM cell. Each subsequent write pulse has substantially the same or greater write pulse duration. Subsequent write pulses are applied to the RRAM cell until the RRAM cell is in the desired data state or until a predetermined number of write pulses have been applied to the RRAM cell. A read method is also disclosed where subsequent read pulses are applied through the RRAM cell until the read is successful or until a predetermined number of read pulses have been applied to the RRAM cell. | 06-09-2011 |
20110134688 | Asymmetric Write Current Compensation - An apparatus and method for compensating for asymmetric write current in a non-volatile unit cell. The unit cell comprises a switching device and an asymmetric resistive sense element (RSE), such as an asymmetric resistive random access memory (RRAM) element or an asymmetric spin-torque transfer random access memory (STRAM) element. The RSE is physically oriented within the unit cell relative to the switching device such that a hard direction for programming the RSE is aligned with an easy direction of programming the unit cell, and an easy direction for programming the RSE is aligned with a hard direction for programming the unit cell. | 06-09-2011 |
20110169114 | ELECTRONIC DEVICES UTILIZING SPIN TORQUE TRANSFER TO FLIP MAGNETIC ORIENTATION - Electronic devices that include (i) a magnetization controlling structure; (ii) a tunnel barrier structure; and (iii) a magnetization controllable structure including: a first polarizing layer; and a first stabilizing layer, wherein the tunnel barrier structure is between the magnetization controlling structure and the magnetization controlling structure and the first polarizing layer is between the first stabilizing layer and the tunnel barrier structure, wherein the electronic device has two stable overall magnetic configurations, and wherein a first unipolar current applied to the electronic device will cause the orientation of the magnetization controlling structure to reverse its orientation and a second unipolar current applied to the electronic device will cause the magnetization controllable structure to switch its magnetization in order to obtain one of the two stable overall magnetic configurations, wherein the second unipolar current has an amplitude that is less than the first unipolar current. | 07-14-2011 |
20110170342 | ELECTRONIC DEVICES UTILIZING SPIN TORQUE TRANSFER TO FLIP MAGNETIC ORIENTATION - Electronic devices that include (i) a magnetization controlling structure; (ii) a tunnel barrier structure; and (iii) a magnetization controllable structure including: a first polarizing layer; and a first stabilizing layer, wherein the tunnel barrier structure is between the magnetization controlling structure and the magnetization controlling structure and the first polarizing layer is between the first stabilizing layer and the tunnel barrier structure, wherein the electronic device has two stable overall magnetic configurations, and wherein a first unipolar current applied to the electronic device will cause the orientation of the magnetization controlling structure to reverse its orientation and a second unipolar current applied to the electronic device will cause the magnetization controllable structure to switch its magnetization in order to obtain one of the two stable overall magnetic configurations, wherein the second unipolar current has an amplitude that is less than the first unipolar current. | 07-14-2011 |
20110176360 | MAGNETIC RANDOM ACCESS MEMORY (MRAM) UTILIZING MAGNETIC FLIP-FLOP STRUCTURES - Non-volatile magnetic random access memory (MRAM) devices that include magnetic flip-flop structures that include a magnetization controlling structure; a first tunnel barrier structure; and a magnetization controllable structure that includes a first polarizing layer; and a first stabilizing layer, wherein the first tunnel barrier structure is between the magnetization controllable structure and the magnetization controlling structure and the first polarizing layer is between the first stabilizing layer and the first tunnel barrier structure, wherein the magnetic flip-flop device has two stable overall magnetic configurations, and wherein a first unipolar current applied to the device will cause the orientation of the magnetization controlling structure to reverse its orientation and a second unipolar current applied to the electronic device will cause the magnetization controllable structure to switch its magnetization so that the device reaches one of the two stable overall magnetic configurations, wherein the second unipolar current has an amplitude that is less than the first unipolar current; a second tunnel barrier structure and a reference layer, wherein the second tunnel barrier structure is between the magnetic flip-flop device and the reference layer. MRAM cells that include such devices and arrays including such cells are also disclosed. | 07-21-2011 |
20110194330 | MEMORY ARRAY WITH READ REFERENCE VOLTAGE CELLS - The present disclosure relates to memory arrays with read reference voltage cells. In particular the present disclosure relates to variable resistive memory cell apparatus and arrays that include a high resistance state reference memory cell and a low resistance state reference memory cell that provides a reliable average reference voltage on chip to compare to a read voltage of a selected memory cell and determine if the selected memory cell is in the high resistance state or low resistance state. These memory arrays are particularly suitable for use with spin-transfer torque memory cells and resolves many systematic issues related to generation of a reliable reference voltage. | 08-11-2011 |
20110194334 | DIODE ASSISTED SWITCHING SPIN-TRANSFER TORQUE MEMORY UNIT - A memory array includes a cross-point array of bit and source lines. A memory is disposed at cross-points of the cross-point array. The memory unit includes a magnetic tunnel junction data cell electrically coupled to a bit line and a source line. The magnetic tunnel junction data cell is configured to switch between a high resistance state and a low resistance state by passing a polarized write current through the magnetic tunnel junction data cell. A transistor is electrically between the magnetic tunnel junction data cell and the bit line or source line and a diode is in thermal or electrical contact with the magnetic tunnel junction data cell to assist in resistance state switching. | 08-11-2011 |
20110194337 | Non-Volatile Memory Cell With Precessional Switching - A method and apparatus for writing data to a non-volatile memory cell, such as a spin-torque transfer random access memory (STRAM) memory cell. In some embodiments, a selected resistive state is written to a magnetic tunneling structure by applying a succession of indeterminate write pulses thereto until the selected resistive state is verified. | 08-11-2011 |
20110228598 | TRANSMISSION GATE-BASED SPIN-TRANSFER TORQUE MEMORY UNIT - A transmission gate-based spin-transfer torque memory unit is described. The memory unit includes a magnetic tunnel junction data cell electrically coupled to a bit line and a source line. A NMOS transistor is in parallel electrical connection with a PMOS transistor and they are electrically connected with the source line and the magnetic tunnel junction data cell. The magnetic tunnel junction data cell is configured to switch between a high resistance state and a low resistance state by passing a polarized write current through the magnetic tunnel junction data cell. The PMOS transistor and the NMOS transistor are separately addressable so that a first write current in a first direction flows through the PMOS transistor and a second write current in a second direction flows through the NMOS transistor. | 09-22-2011 |
20110299324 | WRITE CURRENT COMPENSATION USING WORD LINE BOOSTING CIRCUITRY - Apparatus and method for write current compensation in a non-volatile memory cell, such as but not limited to spin-torque transfer random access memory (STRAM) or resistive random access memory (RRAM). In accordance with some embodiments, a non-volatile memory cell has a resistive sense element (RSE) coupled to a switching device, the RSE having a hard programming direction and an easy programming direction opposite the hard programming direction. A voltage boosting circuit includes a capacitor which adds charge to a nominal non-zero voltage supplied by a voltage source to a node to generate a temporarily boosted voltage. The boosted voltage is applied to the switching device when the RSE is programmed in the hard programming direction. | 12-08-2011 |
20120014168 | Dual Stage Sensing for Non-Volatile Memory - A method and apparatus for accessing a non-volatile memory cell. In some embodiments, a memory block provides a plurality of memory cells arranged into rows and columns. A read circuit is configured to read a selected row of the memory block by concurrently applying a control voltage to each memory cell along the selected row and, for each column, using a respective local sense amplifier and a column sense amplifier to successively differentiate a voltage across the associated memory cell in said column to output a programmed content of the row. | 01-19-2012 |
20120014175 | Magnetic Tunnel Junction and Memristor Apparatus - A magnetic memory device includes a magnetic tunnel junction having a free magnetic layer having a magnetization orientation that is switchable between a high resistance state magnetization orientation and a low resistance state magnetization orientation and a memristor solid state element electrically coupled to the magnetic tunnel junction. The memristor has a device response that is an integrated voltage versus an integrated current. | 01-19-2012 |
20120033482 | Bit Set Modes for a Resistive Sense Memory Cell Array - Various embodiments of the present invention are generally directed to a method and apparatus for providing different bit set modes for a resistive sense memory (RSM) array, such as a spin-torque transfer random access memory (STRAM) or resistive random access memory (RRAM) array. In accordance with some embodiments, a group of RSM cells in a non-volatile semiconductor memory array is identified for application of a bit set operation. A bit set value is selected from a plurality of bit set values each separately writable to the RSM cells to place said cells in a selected resistive state. The selected bit set value is thereafter written to at least a portion of the RSM cells in the identified group. | 02-09-2012 |
20120087175 | Asymmetric Write Current Compensation - An apparatus and method for compensating for asymmetric write current in a non-volatile unit cell. The unit cell comprises a switching device and an asymmetric resistive sense element (RSE), such as an asymmetric resistive random access memory (RRAM) element or an asymmetric spin-torque transfer random access memory (STRAM) element. The RSE is physically oriented within the unit cell relative to the switching device such that a hard direction for programming the RSE is aligned with an easy direction of programming the unit cell, and an easy direction for programming the RSE is aligned with a hard direction for programming the unit cell. | 04-12-2012 |
20120106241 | SPIN-TRANSFER TORQUE MEMORY SELF-REFERENCE READ METHOD - A spin-transfer torque memory apparatus and self-reference read schemes are described. One method of self-reference reading a spin-transfer torque memory unit includes applying a first read current through a magnetic tunnel junction data cell and forming a first bit line read voltage, the magnetic tunnel junction data cell having a first resistance state and storing the first bit line read voltage in a first voltage storage device. Then applying a low resistance state polarized write current through the magnetic tunnel junction data cell, forming a low second resistance state magnetic tunnel junction data cell. A second read current is applied through the low second resistance state magnetic tunnel junction data cell to forming a second bit line read voltage. The second bit line read voltage is stored in a second voltage storage device. The method also includes comparing the first bit line read voltage with the second bit line read voltage to determine whether the first resistance state of the magnetic tunnel junction data cell was a high resistance state or low resistance state. | 05-03-2012 |
20120127787 | SPIN-TRANSFER TORQUE MEMORY NON-DESTRUCTIVE SELF-REFERENCE READ METHOD - A method of self-reference reading a spin-transfer torque memory unit includes applying a first read current through a magnetic tunnel junction data cell and forming a first bit line read voltage. The magnetic tunnel junction data cell has a first resistance state. Then the method includes applying a second read current thorough the magnetic tunnel junction data cell having the first resistance state. The first read current is less than the second read current. Then the first bit line read voltage is compared with the second bit line read voltage to determine whether the first resistance state of the magnetic tunnel junction data cell was a high resistance state or low resistance state. | 05-24-2012 |
20120147665 | Predictive Thermal Preconditioning and Timing Control for Non-Volatile Memory Cells - Method and apparatus for using thermal preconditioning to write data to a non-volatile memory cell. In accordance with some embodiments, a semiconductor memory has an array of non-volatile memory cells, and a control circuit which stores a first write command from a host to write data to said array. A write circuit flows a write current through an unconditioned first selected cell having a first block address associated with the first write command to write the first selected cell to a selected data state, and concurrently passes a thermal preconditioning current through a second selected cell having a second block address associated with the first block address. The write circuit further passes a thermal preconditioning current through a third selected cell having a third block address associated with the second block address in response to receipt by the control circuit of a second write command from the host associated with the second block address. | 06-14-2012 |
20120163065 | Spatial Correlation of Reference Cells in Resistive Memory Array - The present disclosure relates to methods of selectively placing a reference column or reference row in a memory array. The method includes measuring a resistance state resistance value for a plurality of variable resistive memory cells within a memory array and mapping a location of each measured variable resistive memory cell to form a map of the resistance state resistance values for a plurality of variable resistive memory cells within a memory array. Then a column or row is selected to be a reference column or reference row based on the map of the resistance state resistance value for a plurality of variable resistive memory cells within a memory array, to minimize read operation errors, and forming a variable resistive memory cell memory array. | 06-28-2012 |
20120224417 | DIODE ASSISTED SWITCHING SPIN-TRANSFER TORQUE MEMORY UNIT - A memory array includes a cross-point array of bit and source lines. A memory is disposed at cross-points of the cross-point array. The memory unit includes a magnetic tunnel junction data cell electrically coupled to a bit line and a source line. The magnetic tunnel junction data cell is configured to switch between a high resistance state and a low resistance state by passing a polarized write current through the magnetic tunnel junction data cell. A transistor is electrically between the magnetic tunnel junction data cell and the bit line or source line and a diode is in thermal or electrical contact with the magnetic tunnel junction data cell to assist in resistance state switching. | 09-06-2012 |
20120230093 | TRANSMISSION GATE-BASED SPIN-TRANSFER TORQUE MEMORY UNIT - A transmission gate-based spin-transfer torque memory unit is described. The memory unit includes a magnetic tunnel junction data cell electrically coupled to a bit line and a source line. A NMOS transistor is in parallel electrical connection with a PMOS transistor and they are electrically connected with the source line and the magnetic tunnel junction data cell. The magnetic tunnel junction data cell is configured to switch between a high resistance state and a low resistance state by passing a polarized write current through the magnetic tunnel junction data cell. The PMOS transistor and the NMOS transistor are separately addressable so that a first write current in a first direction flows through the PMOS transistor and a second write current in a second direction flows through the NMOS transistor. | 09-13-2012 |
20120243311 | Non-Sequential Encoding Scheme for Multi-Level Cell (MLC) Memory Cells - Apparatus and method for managing an array of multi-level cell (MLC) memory cells. In accordance with various embodiments, a non-sequential encoding scheme is selected that assigns a different multi-bit logical value to each of a plurality of available physical states of a selected MLC memory cell in relation to write effort associated with each of said plurality of physical states. Data are thereafter written to the selected MLC memory cell in relation to the selected non-sequential encoding scheme. In some embodiments, the MLC memory cell comprises a spin-torque transfer random access memory (STRAM) memory cell. In other embodiments, the MLC memory cell comprises an MLC flash memory cell. | 09-27-2012 |
20130003448 | MRAM DIODE ARRAY AND ACCESS METHOD - A memory unit includes a magnetic tunnel junction data cell is electrically coupled to a bit line and a source line. The magnetic tunnel junction data cell is configured to switch between a high resistance state and a low resistance state by passing a write current through the magnetic tunnel junction data cell. A first diode is electrically between the magnetic tunnel junction data cell and the source line and a second diode is electrically between the magnetic tunnel junction data cell and the source line. The first diode and second diode are in parallel electrical connection, and having opposing forward bias directions. The memory unit is configured to be precharged to a specified precharge voltage level and the precharge voltage is less than a threshold voltage of the first diode and second diode. | 01-03-2013 |
20130188420 | NON-DESTRUCTIVE SELF-REFERENCE SPIN-TRANSFER TORQUE MEMORY - A non-destructive self-reference spin-transfer torque memory unit is disclosed. | 07-25-2013 |
20130215674 | SPIN-TRANSFER TORQUE MEMORY SELF-REFERENCE READ METHOD - A spin-transfer torque memory apparatus and self-reference read schemes are described. One method of self-reference reading a spin-transfer torque memory unit includes applying a first read current through a magnetic tunnel junction data cell and forming a first bit line read voltage. Then applying a low resistance state polarized write current through the magnetic tunnel junction data cell, forming a low second resistance state magnetic tunnel junction data cell. A second read current is applied through the low second resistance state magnetic tunnel junction data cell to forming a second bit line read voltage. The method also includes comparing the first bit line read voltage with the second bit line read voltage to determine whether the first resistance state of the magnetic tunnel junction data cell was a high resistance state or low resistance state. | 08-22-2013 |
20140022837 | RANDOM BIT GENERATOR WITH MAGNETIC TUNNEL JUNCTION - Devices and methods for generating a random number that utilizes a magnetic tunnel junction are disclosed. An AC current source can be in electrical connection to a magnetic tunnel junction to provide an AC current to the magnetic tunnel junction. A read circuit can be used to determine a bit based on a state of the magnetic tunnel junction. A rate of production of the bits can be adjusted, such as by adjusting a frequency or amplitude of the AC current. A probability of obtaining a “0” or “1” bit can be managed, such as by an addition of DC biasing to the AC current. | 01-23-2014 |