A memory access operation performed on a first memory unit of a memory device is detected. A counter associated with the first memory unit is modified. It is determined that the counter satisfies a threshold criterion, wherein the threshold criterion is based on a random or pseudo-random number within a margin of an average number of memory access operations. A refresh operation is performed on a second memory unit.

A temperature control method, a memory storage apparatus, and a memory control circuit unit are disclosed. The method includes: detecting a system parameter of the memory storage apparatus, and the system parameter reflects wear of a rewritable non-volatile memory module in the memory storage apparatus; determining a temperature control threshold value according to the system parameter; and performing a temperature reducing operation in response to a temperature of the memory storage apparatus reaching the temperature control threshold value to reduce the temperature of the memory storage apparatus.

An example memory sub-system includes a memory device and a processing device, operatively coupled to the memory device. The processing device is configured to identify a set of embedded servo cells stored on the memory device; determine a read voltage offset by performing read level calibration based on the set of embedded servo cells; and apply the read voltage offset for reading a memory page associated with the set of embedded servo cells.

A memory system includes: a semiconductor storage device including a memory cell array that includes memory cells and a temperature counter configured to increase a count value thereof at a rate that depends on a temperature of the memory cell array; and a memory controller configured to acquire the count value from the semiconductor storage device and reserve a refresh operation for a written memory cell of the memory cell array when a cumulative value of the count value, which is accumulated from when data was written to the memory cell to when the count value is acquired, exceeds a predetermined value.

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.

An operating method of a nonvolatile memory device for programming multi-page data, the operating method including: receiving the multi-page data from a memory controller; programming first page data among the multi-page data to first memory cells connected to a word line adjacent to a selected word line; reading previous page data previously stored in second memory cells connected to the selected word line based on a first sensing value and a second sensing value after programming the first page data; calculating a first fail bit number by comparing first bits of the previous page data read based on the first sensing value to second bits of the previous page data read based on the second sensing value; and programming the previous page data read from the second memory cells and second page data among the multi-page data to the second memory cells based on the first fail bit number.

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.

A memory system includes a memory device and a memory controller. The memory device includes a plurality of memory cells. The memory controller is configured to manage the memory device using a cell level assignment with respect to a plurality of memory cell levels, determine a cell count for each of the cell levels associated with original data of the memory device that is to be accessed, predict an error rate from the cell counts, and selectively adjust the cell level assignment based on the error rate.

A write operation performed on a first memory unit of a memory device is detected, wherein the first memory unit comprises one or more memory cells. Responsive to detecting the write operation, a value of a counter associated with the first memory unit is incremented. It is determined whether the value of the counter satisfies a threshold criterion, wherein the threshold criterion is based on a random or pseudo-random number within a defined range. Responsive to determining that the value of the counter satisfies the threshold criterion, a refresh operation is performed on a second memory unit.

A storage device includes a memory device including a first memory region, a second memory region, and a third memory region, the first memory region having a lowest bit-density relative to the second memory region and the third memory region, a second memory region having a medium bit-density relative to the first memory region and the third memory region, and a third memory region having a highest bit-density relative to the first memory region and the second memory region; and a controller configured to control the memory device The controller is configured to distribute data received from a host to the first to third memory regions based on attributes of the data, to determine a current state based on a data distribution amount for each of the first to third memory regions and a respective size of each of the first to third memory regions, and to perform an action of increasing or decreasing a size of the second memory region under the current state based on a reinforcement learning result for mitigating a reduction in lifespan of the third memory region.