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US 8,275,945 B2Granted
Mitigation of flash memory latency and bandwidth limitations via a write activity log and buffer
AssigneeSpansion LLC
InventorTzungren Allan Tzeng
Life of this patent
Estimating the term…
Abstract
A memory system is provided. The system includes a controller that regulates read and write access to one or more FLASH memory devices that are employed for random access memory applications. A buffer component operates in conjunction with the controller to regulate read and write access to the one or more FLASH devices. Wear leveling components along with read and write processing components are provided to facilitate efficient operations of the FLASH memory devices.
Claims18
A memory system, comprising:
- a controller that regulates read and write timing access to one or more FLASH memory devices employed for random access memory applications and to a dynamic random access memory (DRAM) buffer component that operates as a data staging area for incoming system writes by receiving, during a data burst, incoming write data for the one or more FLASH memory devices, wherein the controller reads write data from the DRAM buffer component and application data from the one or more FLASH memory devices;
- a memory management unit that updates the one or more FLASH memory devices with the incoming system writes received by the DRAM buffer component at a frequency selected to sustain a frequently written sector in the DRAM buffer as a function of a capacity of the DRAM buffer component and provided at least one sector being cached in the DRAM buffer component before the one or more FLASH memory device are updated;
- and
- wherein the memory management unit maintains a sector-based write activity log and determines whether to move respective data of the incoming write data from the DRAM buffer component to the one or more FLASH memory devices during a background operation based at least in part on buffer write activity recorded in the sector-based write activity log at a time determined based on at least one of write times associated with the one or more FLASH memory devices, bandwidth of the one or more FLASH memory devices, or sector size associated with the one or more FLASH memory devices,
- wherein the memory management unit is bypassed for incoming system writes related to a low write demand application;
- and
- wherein during the data burst the incoming write data is written to the DRAM buffer component at a high rate over a short period of time and the write data is moved at a slower rate to the one or more FLASH memory devices during the background operation.
4 more elements
A memory system, comprising:
- means for receiving data at a random access device during a data burst, wherein the data is incoming write data for a FLASH memory device;
- means for controlling write access to ath_.ee FLASH memory device and reading write data from the random access device and application data from the FLASH memory device;
- means for accessing a computer bus to communicate with the FLASH memory device;
- and means for transferring data from the random access device to the FLASH memory device;
- wherein the means for controlling maintains a sector-based write activity log and determines whether to move respective data of the incoming write data from the random access device to the FLASH memory device based at least in part on a frequently written sector being retained in the random access device as long as possible based on a data capacity of the random access device component, at least one sector being cached in the random access device component before the one or more FLASH memory device are updated, a buffer write activity recorded in the sector-based write activity log at a time determined based on at least one of write times associated with the FLASH memory device, bandwidth of the FLASH memory device, or sector size associated with the FLASH memory device
- wherein the means for controlling is bypassed for incoming system writes related to a low write demand application;
- and
- wherein during the data burst the incoming write data is written to the random access device component at a high rate over a short period of time and the write data is moved at a slower rate to the FLASH memory device during the background operation.
5 more elements
Dependencies are inferred from the claim text.