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 method includes determining a first memory access count threshold for a first word line of a block of memory cells and determining a second memory access count threshold for a second word line of the block of memory cells. The second memory access count threshold can be greater than the first memory access count threshold. The method can further include incrementing a memory block access count corresponding to the block of memory cells that includes the first word line and the second word line in response to receiving a memory access command and refreshing the first word line when the memory block access count corresponding to the block of memory cells is equal to the first memory access count threshold.

A memory system has a memory, a first substrate on which the memory is mounted and which is set to a temperature of −40[° C.] or lower, a controller configured to control the memory; and a second substrate on which the controller is mounted, which is set to a temperature of −40[° C.] or higher, and which transmits and receives a signal to and from the first substrate via a signal transmission cable.

Methods, systems, and devices for triggering a refresh for non-volatile memory are described. A host system may communicate with a memory system, where the host system and memory system may be included within a vehicle (e.g., an automotive system). The host system may receive an indication that the vehicle is powering down and may enter a power off state in response to the indication. The host system may detect a trigger (e.g., using a time or temperature input) to switch back to a power on state while the vehicle is powered down, the trigger associated with performing a refresh operation at the memory system. The host system may enter the power on state and may transmit a power on command to the memory system. The memory system may perform the refresh operation on one or more memory cells while the vehicle remains in the powered down state.

A memory device is provided to include: a plurality of memory cells; a peripheral circuit configured to perform an operation on the plurality of memory cells; a temperature circuit configured to measure a temperature of the memory device; a monitoring component configured to generate, based on whether a measured temperature is within a reference range, monitoring information representing an operation mode that is either a normal mode in which the operation is performed or a protection mode in which the operation is suspended; and an operation controller configured to output a signal for controlling the operation according to the monitoring information. The monitoring component is further configured to store the monitoring information and output the monitoring information to the operation controller in response to receiving the measured temperature from the temperature circuit.

A system includes a memory device storing groups of managed units and a processing device operatively coupled to the memory device. The processing device is to, during power on of the memory device, perform including: causing a read operation to be performed at a subset of a group of managed units; determining a bit error rate related to data read from the subset of the group of managed units; and in response to the bit error rate satisfying a threshold criterion, causing a rewrite of the data stored at the group of managed units.

A current operating characteristic value of a unit of the memory device is identified. An operating characteristic threshold value is identified from a set of operating characteristic thresholds, where the current operating characteristic value satisfies an operating characteristic threshold criterion that is based on the operating characteristic threshold value. A set of write-to-read (W2R) delay time thresholds that corresponds to the operating characteristic threshold value is identified from a plurality of sets of W2R delay time thresholds. Each of the W2R delay time thresholds in the set is associated with a corresponding read voltage level. A W2R delay time threshold associated with a W2R delay time threshold criterion is identified from the set of W2R delay time thresholds, where the W2R threshold criterion is satisfied by a current W2R delay time of the memory sub-system. A read voltage level associated with the identified W2R delay time threshold is identified.

A memory device includes a memory cell array including a plurality of memory cells on which a programming loop is executed a plurality of times; a voltage generator configured to apply a verifying voltage to the memory cells, for verifying at least one programming state of the memory cells; and a voltage controller configured to control the voltage generator to change a level of the verifying voltage as a program loop count increases, based on temperature information about a temperature inside or outside the memory device.

A processing device of a memory sub-system is configured to determine a current refresh frequency associated with the memory device, the current refresh frequency specifying a rate of performing refresh operations on data stored at the memory device; compute an updated refresh frequency by updating the current refresh frequency based on a criterion reflecting a result of comparing one or more operating parameters of the memory device to their respective threshold values; and perform a refresh operation on data stored at the memory device according to the updated refresh frequency.

A nonvolatile semiconductor memory device comprises a cell unit including a first and a second selection gate transistor and a memory string provided between the first and second selection gate transistors and composed of a plurality of serially connected electrically erasable programmable memory cells operative to store effective data; and a data write circuit operative to write data into the memory cell, wherein the number of program stages for at least one of memory cells on both ends of the memory string is lower than the number of program stages for other memory cells, and the data write circuit executes the first stage program to the memory cell having the number of program stages lower than the number of program stages for the other memory cells after the first stage program to the other memory cells.