Methods, systems, and devices for imprint recovery management for memory systems are described. In some cases, memory cells may become imprinted, which may refer to conditions where a cell becomes predisposed toward storing one logic state over another, resistant to being written to a different logic state, or both. Imprinted memory cells may be recovered using a recovery or repair process that may be initiated according to various conditions, detections, or inferences. In some examples, a system may be configured to perform imprint recovery operations that are scaled or selected according to a characterized severity of imprint, an operational mode, environmental conditions, and other factors. Imprint management techniques may increase the robustness, accuracy, or efficiency with which a memory system, or components thereof, can operate in the presence of conditions associated with memory cell imprinting.

A method of operation in an integrated circuit (IC) memory device is disclosed. The method includes refreshing a first group of storage rows in the IC memory device at a first refresh rate. A retention time for each of the rows is tested. The testing for a given row under test includes refreshing at a second refresh rate that is slower than the first refresh rate. The testing is interruptible based on an access request for data stored in the given row under test.

Embodiments of the disclosure are drawn to apparatuses methods for checking redundancy information for row addresses prior to performing various refresh operations, such as auto refresh and targeted refresh operations. In some examples, refresh operations may be multi pump refresh operations. In some examples, a targeted refresh operation may be performed prior to an auto refresh operation responsive to a multi pump refresh operation. In some examples, redundancy information for the auto refresh operation may be performed, at least in part, during the targeted refresh operation. In some examples, refresh operations on word lines may be skipped when the redundancy information indicates the word line is defective or unused.

Methods, systems, and devices for imprint recovery for memory cells are described. In some cases, memory cells may become imprinted, which may refer to conditions where a cell becomes predisposed toward storing one logic state over another, resistant to being written to a different logic state, or both. Imprinted memory cells may be recovered using a recovery or repair process that may be initiated according to various conditions, detections, or inferences. In some examples, a system may be configured to perform imprint recovery operations that are scaled or selected according to a characterized severity of imprint, an operational mode, environmental conditions, and other factors. Imprint management techniques may increase the robustness, accuracy, or efficiency with which a memory system, or components thereof, can operate in the presence of conditions associated with memory cell imprinting.

A memory circuit includes: memory cells each including a storage transistor corresponding to a predetermined configuration; and a tracking circuit configured to elapse a variable waiting period during which a voltage on a first node decreases from a first level to a second level, the tracking circuit including a first finger circuit coupled between a first node of a tracking bit line and a reference voltage node, the first finger circuit including a first set of first tracking cells, each first tracking cell including a first shadow transistor corresponding to the predetermined configuration, gate terminals of the first shadow transistors being coupled with a tracking word line; and a second finger circuit coupled between the first node and the reference voltage node; and a first switch configured to adjust the variable waiting period by selectively coupling the second finger circuit in parallel with the first finger circuit.

A memory inspecting method and a memory inspecting system are proposed. The memory inspecting system includes a testing machine and a computer system. The memory inspecting method includes: performing a first data retention time test on a plurality of memory chips to obtain a plurality of first qualified memory chips; performing a second data retention time test on the first qualified memory chips to obtain a plurality of second qualified memory chips; performing a third data retention time test on the second qualified memory chips to obtain a plurality of third qualified memory chips. Performing a statistical analysis step on the third qualified memory chips according to a first data retention time, a second data retention time and a third data retention time of each of the third qualified memory chips is for obtaining at least one final qualified memory chip.

A method of testing using a memory test apparatus connected to a memory device includes receiving a test command. When the test command is a finite state machine (FSM) operation command, the memory device is tested in accordance with the FSM operation command, and an operation is performed to output a result depending on a pass/fail result. But, when the test command is a direct access command, an auto-operation test of input data is performed in a test region according to received address information, and a test result is output, which may include output data with fail information or the auto-operation.

Methods, systems, and devices for imprint recovery management for memory systems are described. In some cases, memory cells may become imprinted, which may refer to conditions where a cell becomes predisposed toward storing one logic state over another, resistant to being written to a different logic state, or both. Imprinted memory cells may be recovered using a recovery or repair process that may be initiated according to various conditions, detections, or inferences. In some examples, a system may be configured to perform imprint recovery operations that are scaled or selected according to a characterized severity of imprint, an operational mode, environmental conditions, and other factors. Imprint management techniques may increase the robustness, accuracy, or efficiency with which a memory system, or components thereof, can operate in the presence of conditions associated with memory cell imprinting.

An apparatus includes a memory circuit that includes a plurality of sub-arrays. The memory circuit is configured to implement a retention mode according to test information indicating voltage sensitivities for the plurality of sub-arrays. The apparatus also includes a voltage control circuit coupled to a power supply node. The voltage control circuit is configured, in response to activation of the retention mode for the plurality of sub-arrays, to generate, based on the test information, at least two different retention voltage levels for different ones of the plurality of sub-arrays. The at least two different retention voltage levels are lower than a power supply voltage level of the power supply node.

Methods, systems, and devices for staggered refresh counters for a memory device are described. The memory device may include a set of memory dies each coupled with a common command and address (CA) bus and each including a respective refresh counter. In response to a refresh command received over the CA bus, each memory die may refresh a set of memory cells based on a value output by the respective refresh counter for the memory die. The refresh counters for at least two of the memory dies of the memory device may be offset such that they indicate different values when a refresh command is received over the CA bus, and thus at least two of the memory dies may refresh memory cells in different sections of their respective arrays. Offsets between refresh counters may be based on different fuse settings associated with the different memory dies.