Patent classifications
G11C2013/0073
Data-based polarity write operations
Methods, systems, and devices for data-based polarity write operations are described. A write command may cause a set of data to be written to a set of memory cells. To write the set of data, a write operation that applies voltages across the memory cells based on a logic state of data to be written to the memory cells may be used. During a first interval of the write operation, a voltage may be applied across a memory cell based on a logic state of a data bit to be written to the memory cell. During a second interval of the write operation, a voltage may be applied across the memory cell based on an amount of charge conducted by the memory cell during the first interval.
DATA STORAGE BASED ON DATA POLARITY
Methods, systems, and devices for storing and reading data at a memory device are described. A memory device may utilize one or more storage states to store data within a data word. The memory device may exhibit higher data leakage or more power consumption when storing or reading a first storage state compared to storing or reading one or more other storage states. In some cases, the memory device may generate a second data word corresponding to a first data word by modifying each symbol type of the first data word to generate a different symbol type for the second data word. A memory device may reduce the occurrence of a storage state associated with large data leakage, or high-power consumption, or both. Further, the memory device may generate and store an indicator indicating the transformation of a corresponding data word.
Systems and techniques for accessing multiple memory cells concurrently
Techniques are provided for accessing two memory cells of a memory tile concurrently. A memory tile may include a plurality of self-selecting memory cells addressable using a row decoder and a column decoder. A memory controller may access a first self-selecting memory cell of the memory tile using a first pulse having a first polarity to the first self-selecting memory cell. The memory controller may also access a second self-selecting memory cell of the memory tile concurrently with accessing the first self-selecting memory cell using a second pulse having a second polarity different than the first polarity. The memory controller may determine characteristics of the pulses to mitigate disturbances of unselected self-selecting memory cells of the memory tile.
Modified write voltage for memory devices
Methods, systems, and devices for a modified write voltage for memory devices are described. In an example, the memory device may determine a first set of memory cells to be switched from a first logic state (e.g., a SET state) to a second logic state (e.g., a RESET state) based on a received write command. The memory device may perform a read operation to determine a subset of the first set of memory cells (e.g., a second set of memory cells) having a conductance threshold satisfying a criteria based on a predicted drift of the memory cells. The memory device may apply a RESET pulse to each of the memory cells within the first set of memory cells, where the RESET pulse applied to the second set of memory cells is modified to decrease voltage threshold drift in the RESET state.
Programming memory cells using asymmetric current pulses
The present disclosure includes apparatuses and methods for programming memory cells using asymmetric current pulses. An embodiment includes a memory having a plurality of self-selecting memory cells, and circuitry configured to program a self-selecting memory cell of the memory by applying a first current pulse or a second current pulse to the self-selecting memory cell, wherein the first current pulse is applied for a longer amount of time than the second current pulse and the first current pulse has a lower amplitude than the second current pulse.
PUF with dissolvable conductive paths
The generation of “fingerprints”, also called challenge-response pairs (CRPs) of Physically Unclonable Functions (PUFs), can often stress electronic components, leaving behind traces that can be exploited by crypto-analysts. A non-intrusive method to generate CRPs based on Resistive RAMs may instead be used, which does not disturb the memory cells. The injection of small electric currents (magnitude of nanoAmperes) in each cell causes the resistance of each cell to drop abruptly by several orders of magnitudes through the formation of temporary conductive paths in each cell. A repeated injection of currents into the same cell, results in an almost identical effect in resistance drop for a single cell. However, due to the small physical variations which occur during manufacturing, the cells are significantly different from each other, in such a way that a group of cells can be used as a basis for PUF authentication.
Self-selecting memory cells configured to store more than one bit per memory cell
Systems, methods and apparatus to program a memory cell to have a threshold voltage to a level representative of one value among more than two predetermined values. A first voltage pulse is driven across the memory cell to cause a predetermined current to go through the memory cell. The first voltage pulse is sufficient to program the memory cell to a level representative of a first value. To program the memory cell to a level representative of a second value, a second voltage pulse, different from the first voltage pulse, is driven across the memory cell within a time period of residual poling in the memory cell caused by the first voltage pulse.
PROGRAMMING TECHNIQUES FOR POLARITY-BASED MEMORY CELLS
Methods, systems, and devices for programming techniques for polarity-based memory cells are described. A method may include writing memory cells to an intermediate state based on receiving a write command. Writing the intermediate state may include applying a first pulse having a first polarity to the memory cell. The method may include isolating a first access line coupled with the memory cell from a voltage source based on applying the first pulse. The method may also include applying a second pulse to a second access line coupled with the memory cell based on isolating the first access line.
MEMORY DEVICE
According to one embodiment, a memory device includes a first wiring line, a second wiring line, a memory cell connected between the first and second wiring lines, including a resistance change memory element having first and second resistance states, and a two-terminal switching element connected in series to the resistance change memory element, and a voltage application circuit which applies a write voltage signal having a first polarity and setting a desired resistance state to the resistance change memory element, to the memory cell, and applies, after the write voltage signal is applied to the memory cell, a second polarity voltage signal having a magnitude that prevents the two-terminal switching element from being set to the on-state, to the memory cell.
METHOD FOR PROGRAMMING AN ARRAY OF RESISTIVE MEMORY CELLS
A method for programming at least one resistive memory cell of an array of resistive memory cells, includes a sequence of N programming cycles, N being an integer greater than or equal to 2, each programming cycle including a set procedure and a reset procedure, each set procedure including the application of a set technique chosen among a plurality of set techniques, the method including acquiring a bit error ratio value corresponding to each programming cycle for each set technique; and at each programming cycle, applying the set technique having the lowest bit error ratio value corresponding to the programming cycle.