A pseudo static random access memory including a plurality of memory chips and an information storing device is provided. The memory chips transmit a plurality of read/write data strobe signals to a memory controller by using a same bus. Regardless of whether a self refresh collision occurs in the memory chips, when the memory chips perform a read operation, read latency of the memory chips is set to be a fixed period that self refresh is allowed to be completed. The fixed period is greater than initial latency. The information storing device is configured to store information which defines the fixed period. The read/write data strobe signal indicates whether the self refresh collision occurs in the memory chips, and a level of the read/write data strobe signals is constant during the read latency. A method for operating a pseudo static random access memory is also provided.

A semiconductor device includes a cell array having an upper segment and a lower segment which are classified according to refresh units. The semiconductor device includes a first repair controller configured to output a first repair signal for controlling a repair operation of the upper segment based on a fuse address, a row address, a second control signal, and selection address being at a first level, and generate a first control signal for controlling a repair operation of the lower segment based on the fuse address, the row address, and selection address.

Embodiments of the disclosure are drawn to apparatuses and methods for timing refresh operations in a memory device. An apparatus may include an oscillator that provides a periodic signal to one or more refresh timer circuits. Each of the refresh timer circuits is associated with a respective memory bank in the memory device. The refresh timer may include a counter block and a control logic block. The control logic block may gate the periodic signal to the counter block. The counter block may count the row active signal time and the row precharge time. The counter signals may be used by the control logic block to output a number of pumps of a refresh operation.

A system for refresh operations in semiconductor memories, and an apparatus and method therefore, are described. The system includes, for example, memory cells in memory banks that are refreshed during a self-refresh operation or an auto refresh operation. The self-refresh operation includes a different number of refresh activations than the auto refresh operation. The system further includes a row control circuit configured to refresh the memory cells in the memory banks based on refresh control signals received from a refresh control circuit, the refresh control signals provided by the refresh control circuit based on internal control signals received by the refresh control circuit from a command control circuit. The auto refresh operation includes a per bank refresh operation configured to refresh a corresponding memory bank or an all-bank refresh operation configured to refresh all memory banks.

Apparatuses and methods for triggering row hammer address sampling are described. An example apparatus includes an oscillator circuit configured to provide a clock signal, and a filter circuit. The filter circuit includes a control circuit configured to receive pulses of the clock signal and provide an output signal that represents a count number by counting a number of pulses of the clock signal and control a probability of enabling the output signal based on the count number. The filter circuit further includes a logic gate configured to pass one of the pulses of the clock signal responsive to the output signal from the control circuit being enabled and filter another of the pulses responsive to the output signal from the control circuit being not enabled

In a control method, external data input to the pseudo static random access memory with a reference clock signal in a write operation are counted to generate a first count value. Data written to a dynamic memory array of the pseudo static random access memory with a built-in clock signal in the write operation are counted to generate a second count value. An initial cycle of the built-in clock signal is smaller than a cycle of the reference clock signal. The first count value is compared with the second count value. When the first count value is equal to the second count value, a write match signal is enabled. When the enabled write match signal is received, the write operation is converted from an asynchronous mode to a synchronous mode to adjust the cycle of the built-in clock signal to be equal to the cycle of the reference clock signal.

Apparatuses and methods for executing row hammer (RH) refresh are described. An example apparatus includes a RH control circuit to provide a row hammer address, and a refresh control circuit to perform a RH refresh operation on a memory address array related to the RH address. The RH control circuit includes first latches each to store an old row address used to access the memory and second latches provided correspondingly to the first latches each set to a state indicating whether the old row address stored in one of the first latches is valid. The RH control circuit further including a signal generator configured to assert a sample signal when a new row address to be used to access the memory array matches the old row address stored in any one of the first latches is valid based on a state of one of the second latches.

Disclosed herein is an apparatus that includes a memory cell array including a plurality of memory cells, a first counter circuit configured to periodically update a count value during a first operation mode, a burst clock generator configured to successively generate a burst pulse predetermined times when the count value indicates a predetermined value, and a row address control circuit configured to perform a refresh operation on the memory cell array in response to the burst pulse.

Embodiments of the disclosure are drawn to apparatuses and methods for timing refresh operations in a memory device. An apparatus may include an oscillator that provides a periodic signal to one or more refresh timer circuits. Each of the refresh timer circuits is associated with a respective memory bank in the memory device. The refresh timer may include a counter block and a control logic block. The control logic block may gate the periodic signal to the counter block. The counter block may count the row active signal time and the row precharge time. The counter signals may be used by the control logic block to output a number of pumps of a refresh operation.

Apparatuses and methods for triggering row hammer address sampling are described. An example apparatus includes an oscillator circuit configured to provide a clock signal, and a filter circuit. The filter circuit includes a control circuit configured to receive pulses of the clock signal and provide an output signal that represents a count number by counting a number of pulses of the clock signal and control a probability of enabling the output signal based on the count number. The filter circuit further includes a logic gate configured to pass one of the pulses of the clock signal responsive to the output signal from the control circuit being enabled and filter another of the pulses responsive to the output signal from the control circuit being not enabled