Patent classifications
G11C2211/4061
MEMORY DEVICE HAVING NON-UNIFORM REFRESH
An integrated circuit memory device includes an array of storage cells configured into multiple banks. Each bank includes multiple segments. Register storage stores per-segment values representing per-segment refresh parameters. Refresh logic refreshes each segment in accordance with the corresponding per-segment value.
TEMPERATURE INFORMED MEMORY REFRESH
Devices and techniques for temperature informed memory refresh are described herein. A temperature counter can be updated in response to a memory device write performed under an extreme temperature. Here, the write is performed on a memory device element in the memory device. The memory device element can be sorted above other memory device elements in the memory device based on the temperature counter. Once sorted to the top of these memory device elements, a refresh can be performed the memory device element.
APPARATUSES AND METHODS FOR STAGGERED TIMING OF SKIPPED REFRESH OPERATIONS
Embodiments of the disclosure are drawn to apparatuses and methods for staggering the timing of skipped refresh operations on a memory. Memory cells of memories may need to periodically perform refresh operations. In some instances, auto-refresh operations may be periodically skipped when charge retention characteristics of the memory cells of the memory exceed the auto-refresh frequency. To reduce peak current draw during refresh operations, the skipped refresh operations may be staggered across different portions of the memory. In one example, the skipped refresh operation may be staggered in time among memory dies of the memory to limit a number of memory dies that are performing an auto-refresh operation to a maximum number. In another example, the skipped refresh operation may be staggered in time among memory banks of a single memory array to limit a number of memory banks that are performing an auto-refresh operation to a maximum number.
Methods for row hammer mitigation and memory devices and systems employing the same
Memory devices and methods of operating memory devices in which refresh management operations can be scheduled on an as-needed basis for those memory portions where activity (e.g., activations in excess of a predetermined threshold) warrants a refresh management operation are disclosed. In one embodiment, an apparatus comprises a memory including a memory location, and circuitry configured to determine a count corresponding to a number of activations at the memory location, to schedule a refresh management operation for the memory location in response to the count exceeding a first predetermined threshold, and to decrease the count by an amount corresponding to the first predetermined threshold in response to executing the scheduled refresh management operation. The circuitry may be further configured to disallow, in response to determining that the count has reached a maximum permitted value, further activations at the memory location until after the count has been decreased.
Refresh rate control for a memory device
Methods, systems, and devices for refresh rate control for a memory device are described. For example, a memory array of a memory device may be refreshed according to a first set of refresh parameters, such as a refresh rate. The memory device may detect an event at the memory device associated with a reduction in data integrity. In some cases, the event may be associated with a temperature of the memory device, a voltage level detected at the memory device, an error event at the memory device, or the like. As a result of detecting the event, the memory device may adapt one or more of the set of refresh parameters, such as increasing the refresh rate for the memory array. In some cases, the memory device may adapt the set of refresh parameters by increasing a quantity of rows of the memory array that are refreshed during a refresh operation, decreasing a periodicity between refresh operations, or both.
Dynamic Refresh Rate Control
In an embodiment, a memory controller in an integrated circuit may generate refreshes for one or more DRAMs coupled to the integrated circuit according to a refresh rate. The integrated circuit may include one or more temperature sensors. A rate of change of the temperature may be determined from the temperature sensors. If the rate is greater than a threshold, the memory controller may generate refreshes according to a refresh rate specified by the DRAMs. If the rate is less than the threshold, the memory controller may generate refreshes at a reduced refresh rate.
Background interface training using secondary senses
The present disclosure generally relates to calibrating the communication with a memory device. To ensure proper calibration, interface training (IFT) needs to occur. IFT involves aligning the sampling point, which is an inflection point, of a clock signal with a data signal. The sampling point of the clock (i.e., the clock edge) needs to be located within the valid window of the data signal. The valid window of the data signal is the time in which the signal is guaranteed to be stable, i.e., after the signal has finished the signal transition time. If the sampling point is aligned with the inflection point of the data signal, then the data signal is not properly aligned. If the sampling point is aligned with the rising or falling edge of the data signal, the data may be obtained, but the data signal is misaligned and is dangerously close to being unreadable. To ensure properly aligning of the clock signal with the data signal, either additional clock signals or a faster clock signal can be used to ensure that misaligned data signals are identified and then properly aligned.
DRAM retention test method for dynamic error correction
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.
SIGNAL TIMING ALIGNMENT BASED ON A COMMON DATA STROBE IN MEMORY DEVICES CONFIGURED FOR STACKED ARRANGEMENTS
Disclosed are various embodiments related to stacked memory devices, such as DRAMs, SRAMs, EEPROMs, ReRAMs, and CAMs. For example, stack position identifiers (SPIDs) are assigned or otherwise determined, and are used by each memory device to make a number of adjustments. In one embodiment, a self-refresh rate of a DRAM is adjusted based on the SPID of that device. In another embodiment, a latency of a DRAM or SRAM is adjusted based on the SPID. In another embodiment, internal regulation signals are shared with other devices via TSVs. In another embodiment, adjustments to internally regulated signals are made based on the SPID of a particular device. In another embodiment, serially connected signals can be controlled based on a chip SPID (e.g., an even or odd stack position), and whether the signal is an upstream or a downstream type of signal.
Temperature informed memory refresh
Devices and techniques for temperature informed memory refresh are described herein. A temperature counter can be updated in response to a memory device write performed under an extreme temperature. Here, the write is performed on a memory device element in the memory device. The memory device element can be sorted above other memory device elements in the memory device based on the temperature counter. Once sorted to the top of these memory device elements, a refresh can be performed the memory device element.