Abstract: Devices and techniques for correcting for power loss in NAND memory devices are disclosed herein. The NAND memory devices may comprise a number of physical pages. For example, a memory controller may detect a power loss indicator at the NAND flash memory. The memory controller may identify a last-written physical page and determine whether the last-written physical page comprises more than a threshold number of low-read-margin cells. If the last-written physical page comprises more than the threshold number of low-read-margin cells, the memory controller may provide a programming voltage to at least the low-read-margin cells.

Abstract: A variety of applications can include apparatus and/or methods of operating the apparatus that include a memory device having read levels that can be calibrated. A calibration controller implemented with the memory device can trigger a read level calibration based on inputs from one or more trackers monitoring parameters associated with the memory device and a determination of an occurrence of at least one event from a set of events related to the monitored parameters. The monitored parameters can include parameters related to a selected time interval and measurements of read, erase, or write operations of the memory device. Additional apparatus, systems, and methods are disclosed.

Abstract: Devices and techniques for NAND cell encoding to improve data integrity are disclosed herein. A high-temperature indicator is obtained and a write operation is received. The write operation is then performed on a NAND cell using a modified encoding in response to the high-temperature indicator. The modified encoding includes a reduced number of voltage distribution positions from an unmodified encoding without changing voltage distribution widths, where each voltage distribution corresponds to a discrete set of states an encoding.

Abstract: Devices and techniques for voltage degradation aware NAND array management are disclosed herein. Voltage to a NAND device is monitored to detect a voltage event. A history of voltage events is modified with the voltage event. A voltage condition is observed from the history of voltage events. An operational parameter of a NAND array in the NAND device is then modified in response to the voltage condition.

Abstract: Devices and techniques temperature sensitive NAND programming are disclosed herein. A device controller can receive a command to write data to a component of the device. A temperature can be obtained in response to the command, and the temperature can be combined with a temperature compensation value to calculate a verification level. The command can then be executed in accordance with the verification level.

Abstract: Devices and techniques for managing partial superblocks in a NAND device are described herein. A set of superblock candidates is calculated. Here, a superblock may have a set of blocks that share a same position in each plane in each die of a NAND array of the NAND device. A set of partial super block candidates is also calculated. A partial superblock candidate is a superblock candidate that has at least one plane that has a bad block. A partial superblock use classification may then be obtained. Superblocks may be established for the NAND device by using members of the set of superblock candidates after removing the set of partial superblock candidates from the set of superblock candidates. Partial superblocks may then be established for classes of data in the NAND device according to the partial superblock use classification.

Abstract: Disclosed in some examples, are methods, systems, and machine readable mediums which compensate for read-disturb effects by shifting the read voltages used to read the value in a NAND cell based upon a read counter. For example, the NAND memory device may have a read counter that corresponds to a group of NAND cells (e.g., a page, a block, a superblock). Anytime a NAND cell in the group is read, the read counter may be incremented. The read voltage, Vread, may be adjusted based on the read counter to account for the read disturb voltage.

Abstract: Devices and techniques for detecting power loss in NAND memory devices are disclosed herein. A memory controller may calibrate a first read level for a first physical page of a number of physical pages from an initial first read level position to a calibrated first read level position. The first read level may be between a first threshold voltage distribution corresponding to a first logical state of the at least four logical states and a second threshold voltage distribution corresponding to a second logical state of the at least four logical states. Also, the first threshold voltage distribution may be a highest threshold voltage distribution for the first physical page. The memory controller may calibrate a second read level for the first physical page that is lower than the first read level from an initial second read level position to a calibrated first read level position.

Abstract: Disclosed in some examples are methods, systems, memory devices, and machine readable mediums for performing an erase page check. For example, in response to an unexpected (e.g., an asynchronous) shutdown, the memory device may have one or more cells that did not finish programming. The memory device may detect these cells and erase them or mark them for erasure.

Abstract: Devices and techniques for correcting for power loss in NAND memory devices are disclosed herein. The NAND memory devices may comprise a number of physical pages. For example, a memory controller may detect a power loss indicator at the NAND flash memory. The memory controller may identify a last-written physical page and determine whether the last-written physical page comprises more than a threshold number of low-read-margin cells. If the last-written physical page comprises more than the threshold number of low-read-margin cells, the memory controller may provide a programming voltage to at least the low-read-margin cells.

Abstract: A variety of applications can include apparatus and/or methods that include tracking data temperatures of logical block addresses for a memory device by operating multiple accumulators by one or more data temperature analyzers to count host writes to ranges of logical block addresses. Data temperature for data written by a host is a measure of how frequently data at a logical block address is overwritten. In various embodiments, tracking can include staggering the start of counting by each of the multiple accumulators to provide subsequent binning of logical block addresses bands into temperature zones, which can achieve better data segregation. Data having a logical block address received from a host can be routed to a block associated with a temperature zone based on the binning provided by the staggered operation of the multiple accumulators by one or more data temperature analyzers. Additional apparatus, systems, and methods are disclosed.

Abstract: Devices and techniques for NAND temperature data management are disclosed herein. A command to write data to a NAND component in the NAND device is received at a NAND controller of the NAND device. A temperature corresponding to the NAND component is obtained in response to receiving the command. The command is then executed to write data to the NAND component and to write a representation of the temperature. The data is written to a user portion and the representation of the temperature is written to a management portion that is accessible only to the controller and segregated from the user portion.

Abstract: Devices and techniques for a flash memory block retirement policy are disclosed herein. In an example embodiment, a first memory block is removed from service in response to encountering a read error in the first memory block that exceeds a first error threshold. Recoverable data is copied from the first memory block to a second memory block. During each of multiple iterations, the first memory block is erased and programmed, and each page of the first memory block is read. In response to none of the pages exhibiting a read error that exceeds a second error threshold during the multiple iterations, the first memory block is returned to service.

Abstract: Devices and techniques temperature sensitive NAND programming are disclosed herein. A device controller can receive a command to write data to a component of the device. A temperature can be obtained in response to the command, and the temperature can be combined with a temperature compensation value to calculate a verification level. The command can then be executed in accordance with the verification level.

Abstract: Devices and techniques for read voltage calibration of a flash-based storage system based on host IO operations are disclosed. In an example, a memory device includes a NAND memory array having groups of multiple blocks of memory cells, and a memory controller to optimize voltage calibration for reads of the memory array. In an example, the optimization technique includes monitoring read operations occurring to a respective block, identifying a condition to trigger a read level calibration based on the read operations, and performing the read level calibration for the respective block or a memory component that includes the respective block. In a further example, the calibration is performed based on a threshold voltage to read the respective block, which may be considered when the threshold voltage to read the respective block is evaluated within a sampling operation performed by the read level calibration.

Abstract: Devices and techniques for voltage degradation aware NAND array management are disclosed herein. Voltage to a NAND device is monitored to detect a voltage event. A history of voltage events is modified with the voltage event. A voltage condition is observed from the history of voltage events. An operational parameter of a NAND array in the NAND device is then modified in response to the voltage condition.

Abstract: Devices and techniques for a flash memory block retirement policy are disclosed herein. In an example embodiment, a first memory block is removed from service in response to encountering a read error in the first memory block that exceeds a first error threshold. Recoverable data is copied from the first memory block to a second memory block. During each of multiple iterations, the first memory block is erased and programmed, and each page of the first memory block is read. In response to none of the pages exhibiting a read error that exceeds a second error threshold during the multiple iterations, the first memory block is returned to service.

Abstract: Devices and techniques for initiating and controlling preemptive idle time read scans in a flash based storage system are disclosed. In an example, a memory device includes a NAND memory array and a memory controller to schedule and initiate read scans among multiple locations of the memory array, with such read scans being preemptively triggered during an idle (background) state of the memory device, thus reducing host latency during read and write operations in an active (foreground) state of the memory device. In an example, the optimization technique includes scheduling a read scan operation, monitoring an active or idle state of host IO operations, and preemptively initiating the read scan operation when entering an idle state, before the read scan operation is scheduled to occur. In further examples, the read scan may preemptively occur based on time-based scheduling, frequency-based conditions, or event-driven conditions triggering the read scan.

Abstract: Disclosed in some examples are methods, systems, memory devices, and machine readable mediums for performing an erase page check. For example, in response to an unexpected (e.g., an asynchronous) shutdown, the memory device may have one or more cells that did not finish programming. The memory device may detect these cells and erase them or mark them for erasure.

Abstract: Devices and techniques for voltage degradation aware NAND array management are disclosed herein. Voltage to a NAND device is monitored to detect a voltage event. A history of voltage events is modified with the voltage event. A voltage condition is observed from the history of voltage events. An operational parameter of a NAND array in the NAND device is then modified in response to the voltage condition.