Abstract: Systems, methods and apparatus to implement bipolar read retry. In response to a determination that a first result of reading a set of memory cells using a first magnitude of read voltage is erroneous, a second magnitude of read voltage, greater than the first magnitude, is identified for the bipolar read retry. In the retry, a controller uses voltage drivers to apply, to the set of memory cells, first voltages of the second magnitude in a first polarity to obtain a second result of reading the set of memory cells and, after the second result is generated and in parallel with decoding the second result, apply second voltages of the second magnitude in a second polarity, opposite to the first polarity.

Abstract: An output, representing synaptic weights of a neural network can be received from first memory elements. The output can be compared to a known correct output. A random number can be generated with a tuned bias via second memory elements. The weights can be updated based on the random number and a difference between the output and the known correct output.

Abstract: The present disclosure includes apparatuses, methods, and systems for performing refresh operations on memory cells. A memory can include a group of memory cells and one or more additional memory cells whose data state is indicative of whether to refresh the group of memory cells. Circuitry is configured to apply a first voltage pulse to the group of memory cells to sense a data state of the memory cells of the group, apply, while the first voltage pulse is applied to the group of memory cells, a second voltage pulse having a greater magnitude than the first voltage pulse to the one or more additional memory cells to sense a data state of the one or more additional memory cells, and determine whether to perform a refresh operation on the group of memory cells based on the sensed data state of the one or more additional memory cells.

Abstract: 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.

Abstract: Methods, systems, and devices for adjustable programming pulses for a multi-level cell are described. A memory device may modify a characteristic of a programming pulse for an intermediate logic state based on a metric of reliability of associated memory cells. The modified characteristic may increase a read window and reverse a movement of a shifted threshold voltage distribution (e.g., by moving the threshold voltage distribution farther from one or more other voltage distributions). The metric of reliability may be determined by performing test writes may be a quantity of cycles of use for the memory cells, a bit error rate, and/or a quantity of reads of the first state. The information associated with the modified second pulse may be stored in fuses or memory cells, or may be implemented by a memory device controller or circuitry of the memory device.

Abstract: Systems, methods and apparatus to program memory cells to an intermediate state. A first voltage pulse is applied in a first polarity across each respective memory cell among the memory cells to move its threshold voltage in the first polarity to a first voltage region representative of a first value. A second voltage pulse is then applied in a second polarity to further move its threshold voltage in the first polarity to a second voltage region representative of a second value and the intermediate state. A magnitude of the second voltage pulse applied for the memory cells is controlled by increasing the magnitude in increments until the memory cells are sensed to be conductive. Optionally, prior to the first voltage pulse, a third voltage pulse is applied in the second polarity to cancel or reduce a drift in threshold voltages of the respective memory cell.

Abstract: 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.

Abstract: Some embodiments include apparatuses and methods operating the apparatuses. One of the apparatuses includes a first data line located over a substrate, a second data line located over the first data line, a third data line located over the second data line and electrically separated from the first and second data lines, and a memory cell coupled to the first, second, and third data lines. The memory cell includes a first material between the first and second data lines and electrically coupled to the first and second data lines; a second material located over the first data line and the first material, the second material electrically separated from the first material and electrically coupled to the third data line; and a memory element electrically coupled to the second material and electrically separated from the first material and first and second data lines.

Abstract: 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.

Abstract: Systems, methods and apparatus to determine a programming mode of a set of memory cells without having bit values stored in the memory cells to include an identifier of the programming mode. During the test of which of the memory cells in the set is in a lowest voltage region, which is a common operation for reading the memory cells programmed in different mode, the statistics of the memory cells found to be in the lowest voltage region can be compared to the known, different behaviors of the memory cell set programmed in different modes. A match with the behavior of one of the modes can be used to identify the matching mode as the programming mode of the set of memory cells.

Abstract: Methods, systems, and devices for restoring memory cell threshold voltages are described. A memory device may perform a write operation on a memory cell during which a logic state is stored at the memory cell. Upon detecting satisfaction of a condition, the memory device may perform a read refresh operation on the memory cell during which the threshold voltage of the memory cell may be modified. In some cases, the duration of the read refresh operation may be longer than the duration of a read operation performed by the memory device on the memory cell or on a different memory cell.

Abstract: Methods, systems, and devices for dynamic read voltage techniques are described. In some examples, a memory device may include one or more partitions made up of multiple disjoint subsets of memory arrays. The memory device may receive a read command to read the one or more partitions and enter a drift determination phase. During the drift determination phase, the memory device may concurrently apply a respective voltage of a set of voltages to each disjoint subset and determine a quantity of memory cells in each disjoint subset that have a threshold voltage below the applied voltage. Based on a comparison between the determined quantity of memory cells and a predetermined quantity of memory cells, the memory device may select a voltage from the set of voltages and utilize the selected voltage to read the one or more partitions.

Abstract: Systems, methods and apparatus to implement bipolar read retry. In response to a determination that a first result of reading a set of memory cells using a first magnitude of read voltage is erroneous, a second magnitude of read voltage, greater than the first magnitude, is identified for the bipolar read retry. In the retry, a controller uses voltage drivers to apply, to the set of memory cells, first voltages of the second magnitude in a first polarity to obtain a second result of reading the set of memory cells and, after the second result is generated and in parallel with decoding the second result, apply second voltages of the second magnitude in a second polarity, opposite to the first polarity.

Abstract: Some embodiments include apparatuses and methods of forming the apparatuses. One of the apparatuses includes a first data line located in a first level of the apparatus; a second data line located in a second level of the apparatus; a first memory cell located in a third level of the apparatus between the first and second levels, the first memory cell including a first transistor coupled to the first data line, and a second transistor coupled between the first data line and a charge storage structure of the first transistor; and a second memory cell located in a fourth level of the apparatus between the first and second levels, the second memory cell including a third transistor coupled to the second data line, and a fourth transistor coupled between the second data line and a charge storage structure of the third transistor, the first transistor coupled in series with the third transistor between the first and second data lines.

Abstract: Systems, methods and apparatus to determine a programming mode of a set of memory cells that store an indicator of the programming mode. In response to a command to read the memory cells in a memory device, a first read voltage is applied to the memory cells to identify a first subset of the memory cells that become conductive under the first read voltage. The determination of the first subset is configured as an operation common to different programming modes. Based on whether the first subset of the memory cell includes one or more predefined memory cells, the memory device determines a programming mode of memory cells. Once the programming mode is identified from the common operation, the memory device can further execute the command to determine a data item stored, via the programming mode, in the memory cells.

Abstract: Systems, methods, and apparatus related to memory devices. In one approach, a memory device has a memory array including memory cells. A controller of the memory device evaluates background leakage in order to select a write voltage to apply to a memory cell when performing a programming operation. The write voltage is dynamically selected from two or more write voltages. These write voltages include a first write voltage that is a normal or default voltage, and a second write voltage that is a boosted write voltage. The controller applies a pre-sensing voltage and pre-read voltage to the memory cell, and determines first and second respective currents that result from applying these voltages. In response to determining that the first current exceeds a first threshold (indicating background leakage), and the second current is below a second threshold that is greater than the first threshold (indicating that the memory cell does not snap), the controller selects the second (boosted) write voltage.

Abstract: Systems, methods and apparatus to determine, in response to a command to write data into a set of memory cells, a programming mode of a set of memory cell to optimize performance in retrieving the data back from the set of memory cells. For example, based on usages of a memory region containing the memory cell set, a predictive model can be used to identify a combination of an amount of redundant information to be stored into the memory cells in the set and a programming mode of the memory cells to store the redundant information. Increasing the amount of redundant information can increase error recovery capability but increase bit error rate and/or increase time to read. The predictive model is trained to predict the combination to optimize read performance.

Abstract: Systems, methods and apparatus to determine a programming mode of a set of memory cells without having bit values stored in the memory cells to include an identifier of the programming mode. During the test of which of the memory cells in the set is in a lowest voltage region, which is a common operation for reading the memory cells programmed in different mode, the statistics of the memory cells found to be in the lowest voltage region can be compared to the known, different behaviors of the memory cell set programmed in different modes. A match with the behavior of one of the modes can be used to identify the matching mode as the programming mode of the set of memory cells.

Abstract: An example apparatus includes a three-dimensional (3D) memory array including a sense line and a plurality of vertical stacks. Each respective on of the vertical stacks includes a different respective portion of the sense line, a first memory cell coupled to that portion of the sense line, a second memory cell coupled to that portion of the sense line, a first access line coupled to the first memory cell and a second access line coupled to the second memory cell. The first and second access lines are perpendicular to the sense line.

Abstract: Methods, systems, and devices for accessing a multi-level memory cell are described. The memory device may perform a read operation that includes pre-read portion and a read portion to access the multi-level memory cell. During the pre-read portion, the memory device may apply a plurality of voltages to a plurality of memory cells to identify a likely distribution of memory cells storing a first logic state. During the read portion, the memory device may apply a first read voltage to a memory cell based on performing the pre-read portion. The memory device may apply a second read voltage to the memory cell during the read portion that is based on the first read voltage. The memory device may determine the logic state stored by the memory cell based on applying the first read voltage and the second read voltage.