An operation method of a nonvolatile memory device which includes a memory block having wordlines includes performing an erase on the memory block, performing a block verification on the memory block by using a 0-th erase verification voltage, performing a delta verification on the memory block by using a first erase verification voltage different from the 0-th erase verification voltage when a result of the block verification indicates a pass, and outputting information about an erase result of the memory block based on the result of the block verification or a result of the delta verification. The delta verification includes generating delta counting values respectively corresponding to wordline groups by using the first erase verification voltage, generating a delta value based on the delta counting values, and comparing the delta value and a first reference value.

The present disclosure relates to a method for accessing an array of memory cells, comprising the steps of storing user data in a plurality of memory cells of a memory array, storing, in a counter associated to the array of memory cells, count data corresponding to a number of bits in the user data having a predetermined first logic value, applying a read voltage to the memory cells to read the user data stored in the array of memory cells, applying the read voltage to the cells of the counter to read the count data stored in the counter and to provide a target value corresponding to the number of bits in the user data having the first logic value, wherein, during the application of the read voltage, the count data are read simultaneously to the user data in such a way that the target value is provided during the reading of the user data, and based on the target value of the counter, stopping the application of the read voltage when the number of bits in the user data having the first logic value corresponds to the target value. A related memory device and a related system are also disclosed.

A storage device includes 3D NAND including layers of multi-level cells. When a shutdown command is received, whether a block is partially written is evaluated. If so, dummy lines are written after the last written wordline of the block. Partially written blocks may be those having a fill percentage less than a threshold. The threshold may be a function of the PEC count of the block. If a maximum retention time is exceeded by data stored in a partially written block, dummy lines may also be written to the block.

A non-volatile memory includes a plurality of cells each individually capable of storing multiple bits of data including bits of multiple physical pages. A controller of the non-volatile memory issues a command to perform a programming pass for a physical page among the multiple physical pages. The controller determines whether or not the programming pass took less than a minimum threshold time and no program fail status indication was received. Based on determining the programming pass took less than a minimum threshold time and no program fail status indication was received, the controller detects an under-programming error and performs mitigation for the detected under-programming error.

Systems and methods for read level tracking and optimization are described. Pages from a wordline of a flash memory device read and the raw page data read from the wordline may be buffered in a first set of buffers. The raw page data for each of the pages may be provided to a decoder for decoding and the decoded page data for each of the pages buffered in a second set of buffers. First bin identifiers may be identified for memory cells of the wordline based on the raw page data and second bin identifiers may be identified for the memory cells of the wordline based on the decoded page data. Cell-level statistics may be accumulated based on the first bin identifiers and the second bin identifiers, and a gradient may be determined for respective read levels based on decoding results for each of the pages and the cell-level statistics. Settings for the read levels may be configured in the flash memory device based on the determined gradients.

A memory device includes a memory cell array including normal memory cells and redundant memory cells; first page buffers connected to the normal memory cells through first bit lines including a first bit line group and a second bit line group and arranged in a first area corresponding to the first bit lines in a line in a first direction; and second page buffers connected to the redundant memory cells through second bit lines including a third bit line group and a fourth bit line group and arranged in a second area corresponding to the second bit lines in a line in the first direction, wherein, when at least one normal memory cell connected to the first bit line group is determined as a defective cell, normal memory cells connected to the first bit line group are replaced with redundant memory cells connected to the third bit line group.

Disclosed is an operation method of a memory device that includes a plurality of memory cells stacked in a direction perpendicular to a substrate. The method includes performing first to (n−1)-th program loops on selected memory cells connected to a selected word line from among the plurality of memory cells, based on a first program parameter, and after the (n−1)-th program loop is performed, performing n-th to k-th program loops on the selected memory cells, based on a second program parameter different from the first program parameter. Herein, n is an integer greater than 1 and k is an integer greater than or equal to n. The first and second program parameters include information about at least two of a program voltage increment, a 2-step verify range, and a bit line forcing voltage used in the first to k-th program loops.

An operating method of a nonvolatile memory device includes receiving, at the nonvolatile memory device, a suspend command, suspending, at the nonvolatile memory device, a program operation being performed, in response to the suspend command, receiving, at the nonvolatile memory device, a resume command, and resuming, at the nonvolatile memory device, the suspended program operation in response to the resume command. The program operation includes program loops, each of which includes a bit line setup interval, a program interval, and a verify interval. In the program interval of each of the program loops, a level of a program voltage to be applied to selected memory cells of the nonvolatile memory device increases as much as a first voltage. A difference between a level of the program voltage finally applied s suspend and a level of the program voltage applied first after resume is different from the first voltage.

A control method applied in a storage device for dynamically adjusting a ratio of single-level cell (SLC) blocks and three-level cells (TLC) blocks is provided. A selection input is received. The number of SLC blocks and TLC blocks of a flash memory are adjusted according to the selection input. In response to the storage device being reset, the number of SLC blocks and TLC blocks of the flash memory are re-adjusted.

In one embodiment, an apparatus comprises a storage device comprising a NAND flash memory. The storage device is to receive a write request from a computing host, the write request to specify data to be written to the NAND flash memory; perform a number of program loops to program the data into a plurality of cells of the NAND flash memory, wherein a program loop comprises application of a program voltage to a wordline of the memory to change the threshold voltage of at least one cell of the plurality of cells; and wherein the number of program loops is to be determined prior to receipt of the write request and based on a distribution of threshold voltages of the cells or determined based on tracking a number of program errors for only a portion of the plurality of cells.