To provide a semiconductor device with a novel structure. The semiconductor device includes an accelerator. The accelerator includes a first memory circuit, a second memory circuit, and an arithmetic circuit. The first memory circuit includes a first transistor. The second memory circuit includes a second transistor. Each of the first transistor and the second transistor includes a semiconductor layer including a metal oxide in a channel formation region. The arithmetic circuit includes a third transistor. The third transistor includes a semiconductor layer including silicon in a channel formation region. The first transistor and the second transistor are provided in different layers. The layer including the first transistor is provided over a layer including the third transistor. The layer including the second transistor is provided over the layer including the first transistor. The data retention characteristics of the first memory circuit are different from those of the second memory circuit.

Methods, systems, and devices for triggering a refresh for non-volatile memory are described. A host system may communicate with a memory system, where the host system and memory system may be included within a vehicle (e.g., an automotive system). The host system may receive an indication that the vehicle is powering down and may enter a power off state in response to the indication. The host system may detect a trigger (e.g., using a time or temperature input) to switch back to a power on state while the vehicle is powered down, the trigger associated with performing a refresh operation at the memory system. The host system may enter the power on state and may transmit a power on command to the memory system. The memory system may perform the refresh operation on one or more memory cells while the vehicle remains in the powered down state.

A memory device is provided to include: a plurality of memory cells; a peripheral circuit configured to perform an operation on the plurality of memory cells; a temperature circuit configured to measure a temperature of the memory device; a monitoring component configured to generate, based on whether a measured temperature is within a reference range, monitoring information representing an operation mode that is either a normal mode in which the operation is performed or a protection mode in which the operation is suspended; and an operation controller configured to output a signal for controlling the operation according to the monitoring information. The monitoring component is further configured to store the monitoring information and output the monitoring information to the operation controller in response to receiving the measured temperature from the temperature circuit.

A current operating characteristic value of a unit of the memory device is identified. An operating characteristic threshold value is identified from a set of operating characteristic thresholds, where the current operating characteristic value satisfies an operating characteristic threshold criterion that is based on the operating characteristic threshold value. A set of write-to-read (W2R) delay time thresholds that corresponds to the operating characteristic threshold value is identified from a plurality of sets of W2R delay time thresholds. Each of the W2R delay time thresholds in the set is associated with a corresponding read voltage level. A W2R delay time threshold associated with a W2R delay time threshold criterion is identified from the set of W2R delay time thresholds, where the W2R threshold criterion is satisfied by a current W2R delay time of the memory sub-system. A read voltage level associated with the identified W2R delay time threshold is identified.

A memory controller component of a memory system stores memory access requests within a transaction queue until serviced so that, over time, the transaction queue alternates between occupied and empty states. The memory controller transitions the memory system to a low power mode in response to detecting the transaction queue is has remained in the empty state for a predetermined time. In the transition to the low power mode, the memory controller disables oscillation of one or more timing signals required to time data signaling operations within synchronous communication circuits of one or more attached memory devices and also disables one or more power consuming circuits within the synchronous communication circuits of the one or more memory devices.

A memory controller component of a memory system stores memory access requests within a transaction queue until serviced so that, over time, the transaction queue alternates between occupied and empty states. The memory controller transitions the memory system to a low power mode in response to detecting the transaction queue is has remained in the empty state for a predetermined time. In the transition to the low power mode, the memory controller disables oscillation of one or more timing signals required to time data signaling operations within synchronous communication circuits of one or more attached memory devices and also disables one or more power consuming circuits within the synchronous communication circuits of the one or more memory devices.

A system including a stack of two or more layers of volatile memory, such as layers of a 3D stacked DRAM memory, places data in the stack based on a temperature or a refresh rate. When a threshold is exceeded, data are moved from a first region to a second region in the stack, the second region having one or both of a second temperature lower than a first temperature of the first region or a second refresh rate lower than a first refresh rate of the first region.

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.

An example memory sub-system to receive a request to execute a read operation associated with data of a memory unit of a memory sub-system. A time after program associated with the data is determined. The time after program is compared to a threshold time level to determine if a first condition is satisfied or a second condition is satisfied. The memory sub-system selects one of a first set of read offset values based on the time after program in response to satisfying the first condition, or a second set of read offset values based on a data state metric measurement in response to satisfying the second condition.

An example memory sub-system to receive a request to execute a read operation associated with data of a memory unit of a memory sub-system. A time after program associated with the data is determined. The time after program is compared to a threshold time level to determine if a first condition is satisfied or a second condition is satisfied. The memory sub-system selects one of a first set of read offset values based on the time after program in response to satisfying the first condition, or a second set of read offset values based on a data state metric measurement in response to satisfying the second condition.