Methods and systems for controlling refresh operations of a memory device. A method disclosed herein includes receiving, by a refresh controller of the memory device, a refresh command from a host for performing the refresh operation on a plurality of memory rows. The method further includes selecting, by the refresh controller, at least one memory row from the plurality of memory rows for the refresh operation using a refresh-row selection circuitry. The at least one memory row is selected by performing digital reading or analog reading of at least one row condition cell (RCC) and at least one supplemental cell that are connected to each memory row of the memory rows. The method further includes performing, by the refresh controller, the refresh operation on the selected at least one memory row.

An integrated circuit includes a primary memory array with cells switchable between first and second states. The circuit also includes sacrificial memory cells; each fabricated to be switchable between the first and second states and associated with at least one row of the primary array. A controller is configured to detect a write operation to a row of the primary array, stress a sacrificial cell associated with the row and detect a failure of the associated sacrificial cell. The sacrificial cells are fabricated to have lower write-cycle endurance than cells of the primary array or are subjected to more stress. Failure of a row of the primary array is predicted based, at least in part, on a detected failure of the associated sacrificial cell.

Methods, systems, and devices for imprint recovery for memory arrays 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.

The low end operating voltage of an integrated circuit is adjusted. Oscillations are counted at a ring oscillator on the integrated circuit over a designated period of clock cycles. Based on the number of oscillations, a prediction model associated with a first set of device degradation data and a second set of static random-access memory (SRAM) low end operating voltage data is used to select a low end operating voltage limit for a processor on the integrated circuit. The low end operating voltage of the processor is set based on the selected low end operating voltage limit. These steps are repeated multiple times during operation of the processor. A method of testing integrated circuits to provide the data employed to produce the prediction model is also provided.

A method and a device for testing a memory chip are provided. The method includes: writing test data into memory cells of a memory chip to-be-tested; reading stored data from the memory cells; and generating a test result of the memory chip to-be-tested according to the test data and the stored data; a word line turn-on voltage tested in the memory chip to-be-tested being greater than a standard bit line and word line turn-on voltage of the memory chip to-be-tested, and/or a sense amplification time tested in the memory chip to-be-tested being greater than a standard sense amplification time of the memory chip to-be-tested.

Embodiments relate to a test method, a computer apparatus, and a computer-readable storage medium. The test method includes: writing first data into a target memory cell; performing reverse writing on the target memory cell; reading second data stored in the target memory cell after the reverse writing; determining whether the second data are the same as the first data; and determining that write recovery time of the target memory cell fails when the second data are the same as the first data. The present disclosure can make an effective test of determining whether the write recovery time fails.

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.

Methods and systems for testing memory systems are disclosed. A refresh rate for a test system including a number of memory devices may be controlled based on estimated power scenario of a memory system design. In response to performance of a number of refresh operations on the memory devices and based on the refresh rate, one or more conditions of the test system may be monitored to generate estimated performance data for the memory system design.

A method of characterizing an error in a NAND flash memory, and an error estimation method and a storage system control method using the same are provided. The method of characterizing an error in a NAND flash memory characterizes an error source of the NAND flash memory using a center distance between one pattern and another pattern among a plurality of patterns in a threshold voltage distribution of NAND flash memory cells as a parameter.

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.