Aggressor rows may be detected by comparing access count values of word lines to a threshold value. Based on the comparison, a word line may be determined to be an aggressor row. The threshold value may be dynamically generated, such as a random number generated by a random number generator. In some examples, a random number may be generated each time an activation command is received. Responsive to detecting an aggressor row, a targeted refresh operation may be performed.

A processing device of a memory sub-system is configured to determine, for a memory unit of the memory device, a plurality of write disturb counts associated with the memory unit, wherein each of the plurality of write disturb (WD) count is associated with a corresponding write disturb direction; compute, for the memory unit, a weighted WD count reflecting the plurality of write disturb counts; determine whether the weighted WD count meets a criterion; and responsive to determining that the weighted WD count meets the criterion, perform a refresh operation on the memory unit.

A processing device of a memory sub-system is configured to determine, for a memory unit of the memory device, a plurality of write disturb counts associated with the memory unit, wherein each of the plurality of write disturb (WD) count is associated with a corresponding write disturb direction; compute, for the memory unit, a weighted WD count reflecting the plurality of write disturb counts; determine whether the weighted WD count meets a criterion; and responsive to determining that the weighted WD count meets the criterion, perform a refresh operation on the memory unit.

A semiconductor memory apparatus includes a first memory cell array, a second memory cell array, and a hammering control circuit. The first memory cell array includes a first row hammer memory cell. The second memory cell array includes a second row hammer memory cell. The hammering control circuit controls the number of active operations on a first word line to be stored in the second row hammer memory cell and controls the number of active operations on a second word line to be stored in the first row hammer memory cell.

Systems and methods for detecting a row hammer in a memory comprising a plurality of memory cells arranged in a plurality of rows may include: a plurality of detection cells in a subject row of memory cells, the detection cells to be set to respective initial states and configured to transition to a state different from their initial states in response to activations of memory cells in an adjacent row of memory cells; a comparison circuit to compare current states of the detection cells with initial states of the detection cells and to determine whether any of the detection cells have a current state that is different from their corresponding initial states; and a trigger circuit to trigger a refresh of the memory cells in the subject row based on a detection of detection cells in the subject row having current states that are different from their corresponding initial states.

Systems and methods for detecting a row hammer in a memory comprising a plurality of memory cells arranged in a plurality of rows may include: a plurality of detection cells in a subject row of memory cells, the detection cells to be set to respective initial states and configured to transition to a state different from their initial states in response to activations of memory cells in an adjacent row of memory cells; a comparison circuit to compare current states of the detection cells with initial states of the detection cells and to determine whether any of the detection cells have a current state that is different from their corresponding initial states; and a trigger circuit to trigger a refresh of the memory cells in the subject row based on a detection of detection cells in the subject row having current states that are different from their corresponding initial states.

A memory component includes a memory core comprising dynamic random access memory (DRAM) storage cells and a first circuit to receive external commands. The external commands include a read command that specifies transmitting data accessed from the memory core. The memory component also includes a second circuit to transmit data onto an external bus in response to a read command and pattern register circuitry operable during calibration to provide at least a first data pattern and a second data pattern. During the calibration, a selected one of the first data pattern and the second data pattern is transmitted by the second circuit onto the external bus in response to a read command received during the calibration. Further, at least one of the first and second data patterns is written to the pattern register circuitry in response to a write command received during the calibration.

A memory component includes a memory core comprising dynamic random access memory (DRAM) storage cells and a first circuit to receive external commands. The external commands include a read command that specifies transmitting data accessed from the memory core. The memory component also includes a second circuit to transmit data onto an external bus in response to a read command and pattern register circuitry operable during calibration to provide at least a first data pattern and a second data pattern. During the calibration, a selected one of the first data pattern and the second data pattern is transmitted by the second circuit onto the external bus in response to a read command received during the calibration. Further, at least one of the first and second data patterns is written to the pattern register circuitry in response to a write command received during the calibration.

A hammer refresh row address detector includes a control logic unit that receives a row address applied along with an active command, to increase a hit count stored in a corresponding entry when the row address is present in candidate aggressor row addresses stored in n entries. The control logic determines a candidate aggressor row address stored in an entry in which the hit count equals a threshold value to be a target aggressor row address. The control logic generates a victim row address adjacent to the target aggressor row address as a hammer refresh row address to accompany a hammer refresh command. The control logic increases the miss count value when the row address is not present in the candidate aggressor row addresses stored in the n entries and no hit count within the n entries is identical to the miss count value.

A hammer refresh row address detector includes a control logic unit that receives a row address applied along with an active command, to increase a hit count stored in a corresponding entry when the row address is present in candidate aggressor row addresses stored in n entries. The control logic determines a candidate aggressor row address stored in an entry in which the hit count equals a threshold value to be a target aggressor row address. The control logic generates a victim row address adjacent to the target aggressor row address as a hammer refresh row address to accompany a hammer refresh command. The control logic increases the miss count value when the row address is not present in the candidate aggressor row addresses stored in the n entries and no hit count within the n entries is identical to the miss count value.