A semiconductor memory device and a memory system are provided. The semiconductor memory device includes a fingerprint read signal generator configured to generate a fingerprint read signal in response to a refresh counting control signal, a memory cell array comprising a plurality of sub memory cell array blocks, a fingerprint output unit configured to receive data output from memory cells connected to one selected among a plurality of word lines and one selected among a plurality of bit lines of one among the plurality of sub memory cell array blocks in response to the fingerprint read signal to generate fingerprint data, and a pseudorandom number generator configured to perform a linear feedback shifting operation in response to an active command to generate sequence data, receive the fingerprint data in response to the fingerprint read signal, and generate the sequence data based on the fingerprint data.

Memory devices and systems with configurable die refresh stagger, and associated methods, are disclosed herein. In one embodiment, a memory system includes two or more memory dies. At least one memory die includes a fuse array storing refresh information that specifies a refresh group of the memory die. In these and other embodiments, at least one memory die includes a refresh group terminal and refresh group detect circuitry electrically connected to the refresh group terminal. The at least one memory die is configured to detect a refresh group of the memory die and to delay its refresh operation by a time delay corresponding to the refresh group. In this manner, refresh operations of the two or more memory dies can be staggered to reduce peak current demand of the memory system.

A memory device includes a memory cell array having a plurality of memory cells connected to wordlines and bitlines, a target row refresh logic configured to perform a refresh operation on at least one of target rows of the memory cell array in response to a refresh management mode command, a weak pattern detector that is activated according to a register update bit value included in the refresh management mode command and that outputs a risk level for each of the target rows, and a mode register circuit that updates at least one mode register value according to the risk level.

Embodiments of the disclosure are drawn to apparatuses and methods for a sequence of refreshing memory mats. During a refresh operation, wordlines of the memory may be refreshed in a sequence. Groups of wordlines may be organized into memory mats. In order to prevent noise, each time a wordline in a memory mat is refreshed, the next wordline to be refreshed may be in a mat which is not physically adjacent to the mat containing the previously refreshed wordline.

A memory device includes a memory cell array, a random bit generator, a comparator and a refresh controller. The memory cell array includes a plurality of memory cells coupled to a plurality of word-lines. The random bit generator generates a random binary code having a predetermined number of bits. The comparator compares the random binary code and a reference binary code to output a matching signal based on a result of the comparison. The refresh controller refreshes target memory cells from among the plurality of memory cells based on addresses accessed by a memory controller during a sampling period randomly determined based on the matching signal and a refresh command from the memory controller.

A semiconductor system including: an operation period adjusting circuit configured to generate operation information for adjusting an operation period, when an input count of an active command during a test mode period is equal to or more than a preset count; and a command generation circuit configured to adjust the input count of the active command applied to a semiconductor device during a preset period, by adjusting the operation period on the basis of the operation information.

A refresh tracking circuit and associated methods are disclosed herein. The tracking circuit may be configured to track a primary count value and a secondary count value based on addresses associated with received commands. The primary and secondary count values may be configured to control corresponding refresh operations respectively associated with a primary address and a secondary address.

Embodiments of the disclosure are drawn to apparatuses and methods for staggering the timing of skipped refresh operations on a memory. Memory cells of memories may need to periodically perform refresh operations. In some instances, auto-refresh operations may be periodically skipped when charge retention characteristics of the memory cells of the memory exceed the auto-refresh frequency. To reduce peak current draw during refresh operations, the skipped refresh operations may be staggered across different portions of the memory. In one example, the skipped refresh operation may be staggered in time among memory dies of the memory to limit a number of memory dies that are performing an auto-refresh operation to a maximum number. In another example, the skipped refresh operation may be staggered in time among memory banks of a single memory array to limit a number of memory banks that are performing an auto-refresh operation to a maximum number.

A memory module including at least one memory and a memory control circuit to control the at least one memory and to generate an internal operation request including an information regarding internal operation time when the memory module need the internal operation time. The memory control circuit is to transfer the internal operation request to an external device, to receive a first command from the external device in response to the internal operation request and including an information of whether the internal operation time is approved, and to perform the internal operation during the internal operation time based on the first command.

A row hammer preventing circuitry including: a first table storing a count value representing a hit count and an address bit of multiple entries, each entry corresponding to access-requested target rows; a second table including safe bits and a safe bit counter; and a row hammer preventing logic to identify masking entries, on which a masking comparison is to be performed, among the entries on the basis of the safe bit counter, to determine a hit or miss on the basis of whether other bits except an MSB among address bits of an access-requested target row match other bits except an MSB among address bits of the masking entries, and to generate a control signal indicating an additional refresh on rows adjacent to rows corresponding to a masking entry whose hit count is greater than a threshold value.