Provided are a memory device and a memory system performing request-based refresh, and an operating method of the memory device. The operating method includes: determining a weak row by counting an activated number of at least one row; requesting for refresh on the weak row based on a result of the determining; and performing target refresh on the weak row upon receiving a refresh command according to the requesting.

A memory storage apparatus having a plurality of operating modes is provided. The memory storage apparatus includes a memory control circuit and a memory cell array circuit. The memory control circuit controls the memory storage apparatus to operate in one of the operating modes. The memory control circuit controls the memory storage apparatus to operate in a first operating mode and controls the memory storage apparatus to switch from the first operating mode to a second operating mode to refresh storage data of the memory cell array circuit. The memory storage apparatus operates in a third operating mode to refresh storage data in the memory storage apparatus. An operating voltage of the memory storage apparatus operating in the second operating mode is smaller than an operating voltage of the memory storage apparatus operating in the third operating mode.

A semiconductor memory device includes: a plurality of memory blocks; a plurality of bit-line sense amplifiers shared by neighboring memory blocks among the plurality of the memory blocks, and suitable for sensing and amplifying data read from memory cells coupled to activated word lines through bit lines, and outputting the amplified data through a plurality of segment data lines; a word line driver suitable for activating word lines of memory blocks that do not share the bit-line sense amplifiers during a test mode; and a weak cell detection circuit suitable for compressing the amplified data transferred through the plurality of the segment data lines for generating compressed data and detecting a weak cell based on the compressed data during the test mode.

A memory device includes a plurality of memory cells for storing data; a plurality of memory cells for storing data; a non-volatile memory unit; a test control unit suitable for detecting weak memory cells among the plurality of memory cells; a program control unit suitable for controlling addresses of the detected weak memory cells to be programmed in the non-volatile memory unit; and a refresh control unit suitable for refreshing the addresses stored in the non-volatile memory unit more frequently than other memory cells.

Apparatuses and methods for targeted row refreshes are disclosed herein. In an example apparatus, a predecoder receives a target row address and determines whether a target row of memory associated with the target row address is a primary or a redundant row of memory. The predecoder is further configured to cause one or more rows of memory physically adjacent the primary row of memory to be refreshed if the primary row is the target row or one or more rows of memory physically adjacent the redundant row of memory to be refreshed if the redundant row of memory is the target row of memory.

A memory device capable of optimizing a refresh cycle is provided. The memory device includes a monitor circuit capable of generating a signal serving as a trigger for a refresh operation. The monitor circuit includes a transistor and a capacitor. The monitor circuit has a function of sensing that a potential retained in the capacitor is lower than a reference potential, a function of generating a first signal and a second signal on the basis of the sensing result, and a function of turning on the transistor in response to the second signal and resetting the potential retained in the capacitor to an initialization state. It is possible to start refresh of a memory cell in response to the first signal.

Memory devices may send information related to refresh rates to a memory controller. The memory controller may instruct the memory devices to refresh based on the received information.

A semiconductor memory device includes: a weak cell controller for programming weak cell information, outputting the weak cell information in response to an initialization signal or a write end signal, and outputting a read end signal whenever the weak cell information is outputted; a memory cell array region that includes memory cells for storing data in response to a row active signal and a column selection signal, and includes a first cell region for storing the weak cell information; an information transfer control circuit for generating a column address based on a column counting signal generated by using the read end signal, and generating a row address whenever the column counting signal reaches a predetermined value in response to the initialization signal; a row circuit for enabling the row active signal; and a column circuit for outputting the column selection signal by decoding the column address.

Systems, devices and methods are disclosed. In an embodiment of one such method, a method of decoding received command signals, the method comprises decoding the received command signals in combination with a signal provided to a memory address node at a first clock edge of a clock signal to generate a plurality of memory control signals. The received command signals, in combination with the signal provided to the memory address node at the first clock edge of the clock signal, represent a memory command. Furthermore, the signal provided to the memory address node at a second clock edge of the clock signal is not decoded in combination with the received command signals. The memory command may be a reduced power command and/or a no operation command.

Devices, systems, and methods include an active mode to accommodate read/write operations of a memory device and a self-refresh mode to accommodate recharging of voltage levels representing stored data when read/write operations are idle. At least one register source provides a first voltage level and a second voltage level that is less than the first voltage level. With such a configuration, during the active mode, the memory device operates at the first voltage level as provided by the at least one register source, and during the self-refresh mode, the memory device operates at the second voltage level as provided by the at least one register source.