Abstract: Portions of data stored in a three dimensional memory array are selected based on their locations for calculation of redundancy data. Locations are selected so that no two portions in a set of portions for a given calculation are likely to become uncorrectable at the same time. Selected portions may be separated by at least one word line and separated by at least one string in a block.

Abstract: When data from a portion of a three dimensional NAND memory array is determined to be uncorrectable by Error Correction Code (ECC), a determination is made as to whether data is uncorrectable by ECC throughout some unit that is larger than the portion. If modified read conditions provide ECC correctable data, the modified read conditions are recorded for subsequent reads of the larger unit.

Abstract: Memory hole diameter in a three dimensional memory array may be calculated from characteristics that are observed during programming. Suitable operating parameters may be selected for operating a block based on memory hole diameters. Hot counts of blocks may be adjusted according to memory hole size so that blocks that are expected to fail earlier because of small memory holes are more lightly used than blocks with larger memory holes.

Abstract: Erasing memory cells in certain 3-D NAND charge-storage memory arrays is achieved by rapidly charging vertical conductors using Gate Induced Drain Leakage (GIDL) current generated in select transistors. When bit line voltage drops below its nominal value, select line voltage is controlled to maintain a constant voltage difference between bit line voltage and select line voltage thus maintaining a gate-drain voltage difference in select transistors that provides sufficient GIDL current for erase.

Abstract: In a charge trapping memory, data that would otherwise be likely to remain adjacent to unwritten word lines is written three times, along three immediately adjacent word lines. The middle copy is protected from charge migration on either side and is considered a safe copy for later reading. Dummy data may be programmed along a number of word lines to format a block for good data retention.

Abstract: In a nonvolatile memory, hybrid blocks are initially written with only lower page data. The hybrid blocks later have middle and upper page data written. For high speed writes, data is written to a hybrid block and two or more Single Level Cell (SLC) blocks. The data from the SLC blocks are copied to the hybrid block at a later time in a folding operation.

Abstract: Techniques, related to a flash memory device having a non-volatile memory array (NVM), for recovering from a write interrupt resulting from host-supplied memory voltage fault are disclosed. A memory controller is configured to control a response to an occurrence of the write-interrupt, the response including writing to the NVM, after the memory voltage is verified as being within an acceptable range, one or more of a safe copy of a portion of a first sector of upper-page data and a safe copy of a portion of a second sector of lower-page data, and terminating the write interrupt. Terminating the write-interrupt may include receiving new data from the host while avoiding sending an error message to the host.

Abstract: A data storage device includes a memory and a controller. In a particular embodiment, a method is performed in the data storage device. The method is performed during a read threshold voltage update operation and includes determining a first read threshold voltage of a set of storage elements of a memory according to a first technique and determining a second read threshold voltage of the set of storage elements of the memory according to a second technique. The first read threshold voltage is different from the second read threshold voltage, and the first technique is different from the second technique.

Abstract: A memory system or flash card may include a multi-level cell block with multiple states. Before the upper page is written, an intermediate state may be shifted to prevent or minimize overlapping of the states from the corresponding lower page. A write abort during the writing of the upper page will not result in a loss of data from the corresponding lower page.

Abstract: A memory system or flash card may include safe zone blocks where data is written in case of an error condition, such as a write abort. The system may utilize predetermined risk zones when selecting the data that is written to the safe zone blocks. For example, data written to a lower page may be one example of data that is a predetermined risk. Upon receiving a write command, the data that is written to a lower page may be written to a safe zone either in parallel or after the write operation.

Abstract: A memory system or flash card may be initialized from a protected block of flash memory as a backup process. If there is an error during regular card initialization and the firmware for the card cannot be loaded, the card may be inaccessible to a user. Booting with a protected block of memory may be used to load a different version of the firmware that can still initialize the card despite the error from loading the other firmware.