Systems, methods and apparatus to read target memory cells having an associated reference memory cell configured to be representative of drift or changes in the threshold voltages of the target memory cells. The reference cell is programmed to a predetermined threshold level when the target cells are programmed to store data. In response to a command to read the target memory cells, estimation of a drift of the threshold voltage of the reference is performed in parallel with applying an initial voltage pulse to read the target cells. Based on a result of the drift estimation, voltage pulses used to read the target cells can be modified and/or added to account for the drift estimated using the reference cell.

A neuromorphic hardware apparatus based on a resistive memory array includes a resistive memory array in which a plurality of synaptic resistor elements are arranged. Each synaptic resistor element is changed in its resistance value depending on a voltage pulse applied thereto and stores the resistance value for a predetermined time. The apparatus also includes a neuron circuit configured to receive an output signal from the resistive memory array and to output a voltage signal to another resistive memory array. The neuron circuit includes a temperature compensation unit, which compensates for an output voltage of the resistive memory array on the basis of an operating temperature of the resistive memory array. Even when a resistive memory array outputs an abnormal output depending on an operating temperature, by compensating a neuron circuit for an input value, it is possible to prevent an operation error from occurring.

A method includes determining a first memory access count threshold for a first word line of a block of memory cells and determining a second memory access count threshold for a second word line of the block of memory cells. The second memory access count threshold can be greater than the first memory access count threshold. The method can further include incrementing a memory block access count corresponding to the block of memory cells that includes the first word line and the second word line in response to receiving a memory access command and refreshing the first word line when the memory block access count corresponding to the block of memory cells is equal to the first memory access count threshold.

A system includes a memory device storing groups of managed units and a processing device operatively coupled to the memory device. The processing device is to, during power on of the memory device, perform including: causing a read operation to be performed at a subset of a group of managed units; determining a bit error rate related to data read from the subset of the group of managed units; and in response to the bit error rate satisfying a threshold criterion, causing a rewrite of the data stored at the group of managed units.

A current operating characteristic value of a unit of the memory device is identified. An operating characteristic threshold value is identified from a set of operating characteristic thresholds, where the current operating characteristic value satisfies an operating characteristic threshold criterion that is based on the operating characteristic threshold value. A set of write-to-read (W2R) delay time thresholds that corresponds to the operating characteristic threshold value is identified from a plurality of sets of W2R delay time thresholds. Each of the W2R delay time thresholds in the set is associated with a corresponding read voltage level. A W2R delay time threshold associated with a W2R delay time threshold criterion is identified from the set of W2R delay time thresholds, where the W2R threshold criterion is satisfied by a current W2R delay time of the memory sub-system. A read voltage level associated with the identified W2R delay time threshold is identified.

A method for resetting an array of RAM cells by applying a sequence of N reset operations, the method including at a first reset operation, defining a first reset technique and performing the first reset operation; at a j-th reset operation of a N-1 subsequent reset operations, j being an integer between 2 and N, if a correction yield of the reset technique used at the (j-1)-th reset operation fulfils a predefined condition, applying the reset technique used at the (j-1)-th reset operation to perform the j-th reset operation, if the correction yield does not fulfil the predefined condition, defining a new reset technique and applying the new reset technique to perform the j-th reset operation, the correction yield being a cumulative correction yield or a relative correction yield, the correction yield for the N reset operations being measured prior to the first reset operation.

A processing device of a memory sub-system is configured to determine a current refresh frequency associated with the memory device, the current refresh frequency specifying a rate of performing refresh operations on data stored at the memory device; compute an updated refresh frequency by updating the current refresh frequency based on a criterion reflecting a result of comparing one or more operating parameters of the memory device to their respective threshold values; and perform a refresh operation on data stored at the memory device according to the updated refresh frequency.

Methods, systems, and devices for write operation techniques for memory systems are described. In some memory systems, write operations performed on target memory cells of the memory device may disturb logic states stored by one or more adjacent memory cells. Such disturbances may cause reductions in read margins when accessing one or more memory cells, or may cause a loss of data in one or more memory cells. The described techniques may reduce aspects of logic state degradation by supporting operational modes where a host device, a memory device, or both, refrains from writing information to a region of a memory array, or inhibits write commands associated with write operations on a region of a memory array.

First signaling indicative of instructions to enter a self-refresh (SREF) mode can be received concurrently by a plurality of memory dies. Responsive to a memory die of the plurality of memory dies entering the SREF mode, self-refreshing of memory banks of the memory die can be delayed, at the memory die and based on fuse states of an array of fuses of the memory die, an amount of time relative to receipt of the signaling by the memory die. Delaying self-refreshing of memory banks of memory dies in a staggered, or asynchronous, manner can evenly distribute power consumption of the memory dies so that the likelihood of an associated power spike is reduced or eliminated.

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.