Abstract: Various embodiments are directed to an apparatus comprising a semiconductor memory array with non-volatile memory unit cells arranged into a NAND block. Each of the unit cells comprises a resistive sense element connected in parallel with a switching element. The resistive sense elements are connected in series to form a first serial path, and the switching elements are connected in series to form a second serial path parallel to the first serial path. Each resistive sense element is serially connected to an adjacent resistive sense element in the block by a tortuous conductive path having a portion that extends substantially vertically between said elements to provide operational isolation therefor.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: Apparatus and associated method for transferring data to memory, such as resistive sense memory (RSM). In accordance with some embodiments, input data comprising a sequence of logical states are transferred to a block of memory by concurrently writing a first logical state from the sequence to each of a first plurality of unit cells during a first write step, and concurrently writing a second logical state from the sequence to each of a second non-overlapping plurality of unit cells during a second write step.

Abstract: 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.

Abstract: 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.

Abstract: Apparatus and associated method for asymmetric write current compensation for resistive sense memory (RSM) cells, such as but not limited to spin-torque transfer random access memory (STRAM) or resistive random access memory (RRAM) cells. In accordance with some embodiments, an RSM cell includes an RSM element coupled to a switching device. The switching device has a plurality of terminals. A control circuit compensates for asymmetric write characteristics of the RSM cell by limiting a range of voltage differentials across the terminals so as to be equal to or less than a magnitude of a source voltage applied to the switching device, thereby providing bi-directional write currents of substantially equal magnitude through the RSM element.

Abstract: 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.