A nonvolatile memory device includes processing circuitry configured to apply a sub-voltage to the first word lines, determine a desired first read voltage based on a threshold voltage distribution of a plurality of first memory cells connected to the first word lines, apply the sub-voltage to the second word lines, determine a desired second read voltage based on a threshold voltage distribution of a plurality of second memory cells connected to the second word lines, apply the desired first read voltage to the first word lines while simultaneously reading the first memory cells connected to the first word lines, and apply the desired second read voltage different from the desired first read voltage to the second word lines while simultaneously reading the second memory cells connected to the second word lines.

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.

Various examples are directed to memory systems comprising a component and a processing device. The memory system may comprise a plurality of blocks. A first portion of the plurality of blocks may be retired and a second portion of the plurality of blocks may be unretired. The processing device receives a sanitize operation for the plurality of blocks. The processing device initiates a first erase cycle at a first retired block of the plurality of blocks. The processing device determines that the first erase cycle was not successful and sets an erase indicator to false.

Various examples are directed to memory systems comprising a component and a processing device. The memory system may comprise a plurality of blocks. A first portion of the plurality of blocks may be retired and a second portion of the plurality of blocks may be unretired. The processing device receives a sanitize operation for the plurality of blocks. The processing device initiates a first erase cycle at a first retired block of the plurality of blocks. The processing device determines that the first erase cycle was not successful and sets an erase indicator to false.

A memory device includes a plurality of memory blocks, and a control circuit. A selected memory block of the plurality of memory blocks comprises a top select gate, a bottom select gate, a plurality of word lines, a common-source line, and a P-well. The control circuit performs an erasing and verification method, wherein the erasing and verification method includes erasing the selected memory block during an erasing stage; and maintaining the bottom select gate to be turned on during a maintaining period before the top select gate are turned on during a verification stage.

An operating method of a non-volatile memory device including a plurality of memory cells respectively connected to a plurality of word lines is provided. The operating method includes applying an erase detect voltage to a selected word line of the plurality of word lines to perform an erase detect operation on memory cells connected to the selected word line in response to a program command, applying a program voltage to the selected word line after the erase detect operation, and counting a number of undererased cells of the memory cells on which the erase detect operation has been performed.

A memory device includes a plurality of memory blocks, and a control circuit. A selected memory block of the plurality of memory blocks comprises a top select gate, a bottom select gate, a plurality of word lines, a common-source line, and a P-well. The control circuit performs an erasing and verification method, wherein the erasing and verification method includes erasing the selected memory block during an erasing stage; and maintaining the bottom select gate to be turned on during a maintaining period before the top select gate are turned on during a verification stage.

A memory device, a memory system, and/or a method of operating a memory system includes measuring, using processing circuitry, an erase program interval (EPI) of a memory group included in a non-volatile memory (NVM), the EPI being a time period from an erase time point to a program time point of the memory group, determining, using the processing circuitry, a plurality of program modes based on a number of data bits stored in each memory cell of the memory group, selecting, using the processing circuitry, a program mode for the memory group from the plurality of program modes, based on the measured EPI of the memory group, and performing, using the processing circuitry, a program operation on the memory group corresponding to the selected program mode.

A method of operating a storage device, including; performing, by a non-volatile memory, an erase operation on a block of memory in the non-volatile memory, where the non-volatile memory is coupled to a controller; receiving, by the non-volatile memory, a host-transaction within a first time period, where, the non-volatile memory is coupled to a host device; and suspending, by the non-volatile memory, an erase operation in response to receiving the host-transaction by: determining the erase operation has completed a charge phase; and suspending the erase operation during a pulse phase of the erase operation. The method additionally includes the non-volatile memory maintaining a loop counter and a pulse counter, where: the loop counter increments in response to completion of an erase loop, and the pulse counter increments in response to completion of an erase pulse, where the erase pulse is applied during a pulse phase of the erase operation.

A nonvolatile memory device includes processing circuitry configured to apply a sub-voltage to the first word lines, determine a desired first read voltage based on a threshold voltage distribution of a plurality of first memory cells connected to the first word lines, apply the sub-voltage to the second word lines, determine a desired second read voltage based on a threshold voltage distribution of a plurality of second memory cells connected to the second word lines, apply the desired first read voltage to the first word lines while simultaneously reading the first memory cells connected to the first word lines, and apply the desired second read voltage different from the desired first read voltage to the second word lines while simultaneously reading the second memory cells connected to the second word lines.