Patent classifications
G11C2211/406
Partial refresh technique to save memory refresh power
In a conventional memory subsystem, a memory controller issues explicit refresh commands to a DRAM memory device to maintain integrity of the data stored in the memory device when the memory device is in an auto-refresh mode. A significant amount of power may be consumed to carry out the refresh. To address this and other issues, it is proposed to allow a partial refresh in the auto-refresh mode in which the refreshing operation may be skipped for a subset of the memory cells. Through such selective refresh skipping, the power consumed for auto-refreshes may be reduced. Operating system kernels and memory drivers may be configured to determine areas of memory for which the refreshing operation can be skipped.
SCAN OPTIMIZATION FROM STACKING MULTIPLE RELIABILITY SPECIFICATIONS
A variety of applications can include systems and/or methods of optimizing results from scanning a memory device, where the memory device has stacked multiple reliability specifications. Information about a block of multiple blocks of a memory device can be logged, where the information is associated with a combination of reliability specifications. A refresh of the block can be triggered based on exceeding a threshold condition for the combination of reliability specifications. Additional apparatus, systems, and methods are disclosed.
MEMORY WITH PARTIAL ARRAY REFRESH
Memory devices and systems with partial array refresh control over memory regions in a memory array, and associated methods, are disclosed herein. In one embodiment, a memory system includes a memory controller and a memory device operably connected to the memory controller. The memory device includes (i) a memory array having a plurality of memory cells arranged in a plurality of memory regions and (ii) inhibit circuitry. In some embodiments, the inhibit circuitry is configured to disable one or more memory regions of the plurality of memory regions from receiving refresh commands such that memory cells of the one or more memory regions are not refreshed during refresh operations of the memory device. In these and other embodiments, the memory controller is configured to track memory regions that include utilized memory cells and/or to write data to the memory regions in accordance with a programming sequence of the memory device.
REFRESH-RELATED ACTIVATION IMPROVEMENTS
Methods, systems, and devices for refresh-related activation in memory are described. A memory device may conduct a refresh operation to preserve the integrity of data. A refresh operation may be associated with a refresh time where the memory device is unable to execute or issue any commands (e.g., access commands). By posting (e.g., saving) one or more commands and/or row addresses during the refresh time, the memory device may be configured to execute the saved commands and/or re-open one or more rows associated with the saved row addresses at a later time (e.g., upon completion of the refresh operation). Accordingly, fewer commands may be issued to activate the memory cells after the refresh time.
Apparatuses and methods for access based refresh timing
Embodiments of the disclosure are drawn to apparatuses and methods for scheduling targeted refreshes in a memory device. Memory cells in a memory device may be volatile and may need to be periodically refreshed as part of an auto-refresh operation. In addition, certain rows may experience faster degradation, and may need to undergo targeted refresh operations, where a specific targeted refresh address is provided and refreshed. The rate at which targeted refresh operations need to occur may be based on the rate at which memory cells are accessed. The memory device may monitor accesses to a bank of the memory, and may use a count of the accesses to determine if an auto-refresh address or a targeted refresh address will be refreshed.
APPARATUSES AND METHODS FOR ACCESS BASED REFRESH TIMING
Embodiments of the disclosure are drawn to apparatuses and methods for scheduling targeted refreshes in a memory device. Memory cells in a memory device may be volatile and may need to be periodically refreshed as part of an auto-refresh operation. In addition, certain rows may experience faster degradation, and may need to undergo targeted refresh operations, where a specific targeted refresh address is provided and refreshed. The rate at which targeted refresh operations need to occur may be based on the rate at which memory cells are accessed. The memory device may monitor accesses to a bank of the memory, and may use a count of the accesses to determine if an auto-refresh address or a targeted refresh address will be refreshed.
METHOD AND APPARATUS FOR INTERRUPTING MEMORY BANK REFRESH
A memory controller includes a state machine that initiates a memory refresh of a DRAM (having a number of banks) by sending thereto a refresh command. Responsive to receiving the command, the DRAM may perform a per-bank refresh in which individual ones of the banks are refreshed in succession, one at a time. Upon receiving a high priority transaction, a determination is made as to the number of memory banks that have currently been refreshed in the per-bank refresh. If the number of banks refreshed is less than a threshold value, the per-bank refresh is aborted.
Memory with partial array refresh
Memory devices and systems with partial array refresh control over memory regions in a memory array, and associated methods, are disclosed herein. In one embodiment, a memory device includes a memory array having a first memory region and a second memory region. The memory device is configured to write data to the memory array in accordance with a programming sequence by initially writing data to unutilized memory cells of the first memory region before initially writing data to unutilized memory cells of the second memory region. The memory device is further configured to determine that the data stored on the first and/or second memory regions is not consolidated, and to consolidate at least a portion of the data by rewriting the portion of the data to physically or logically contiguous memory cells of the first memory region and/or the second memory region.
Method and apparatus for interrupting memory bank refresh
A memory controller includes a state machine that initiates a memory refresh of a DRAM (having a number of banks) by sending thereto a refresh command. Responsive to receiving the command, the DRAM may perform a per-bank refresh in which individual ones of the banks are refreshed in succession, one at a time. Upon receiving a high priority transaction, a determination is made as to the number of memory banks that have currently been refreshed in the per-bank refresh. If the number of banks refreshed is less than a threshold value, the per-bank refresh is aborted.
METHOD AND APPARATUS FOR ADAPTIVE DATA RETENTION MANAGEMENT IN NON-VOLATILE MEMORY
Aspects of the disclosure provide systems and methods for adaptive data retention management in non-volatile memory. A solid state device (SSD) includes non-volatile memory (NVM) for storing data. The SSD is configured to determine a temperature of the NVM. If the temperature of the NVM is below a predetermined temperature, the SSD maintains a data retention refresh rate of the data stored in the NVM. If the temperature of the NVM is equal to or above the predetermined temperature, the SSD adjusts the data retention refresh rate at a first rate and then a second rate, each adjustment based on the temperature of the NVM. The first rate and the second rate are different, for example, the second rate is less than the first rate.