Embedded Flash Storage Management System Design

Flash memory has become an important data storage medium for various embedded devices due to its non-volatile,high performance and low power consumption.The characteristics of flash memory write-and-write and the erase life limit limit that embedded devices cannot directly manage them using traditional file systems,but must rely on flash memory management systems.At present,the research on the flash translation layer mainly focuses on prolonging the life and improving the performance,and does not consider the case that the embedded system has less hardware resources.In order to reduce the resource consumption of the flash translation layer and extend the service life of the flash memory device,this paper deeply studies the address mapping and garbage collection of the flash translation layer,and designs a heat correlation conversion layer(HAST)based on the hybrid mapping algorithm.The main work includes the following aspects:(1)A cold-hot block identification algorithm based on circular queue is designed.The algorithm uses the cyclic queue to calculate the access frequency of the logic block.Calculate a heat value for each logical block,and set the heat value with the system.The thresholds are compared to identify the hot and cold logic blocks.(2)Based on the characteristics of hybrid address mapping,a log block sharing strategy is designed to share the log blocks of logical cold blocks to other data blocks,thereby improving the utilization of physical blocks.The logical hot block exclusive log block reduces unnecessary merge operations and improves the read and write efficiency of the flash memory.(3)Considering the correlation between the data block and the log block and the heat value of the logical block in the garbage collection al-gorithm,reducing the total number of merges improves the efficiency of garbage collection,thereby improving the read and write performance.(4)The HAST algorithm was simulated on the FlashSim simulation platform and evaluated using a variety of trace files.The algorithm was implemented on the Tiny6410 embedded development board and evaluated using PostMark software.Simulation experiments show that the HAST algorithm designed in this paper is more effective than the DFTL algorithm,the FAST algorithm and the FRW algorithm in terms of resource occupancy and extended lifetime.Hardware experiments show that the algorithm has high compatibility with EXT4 and FAT32 file systems,and can accurately and quickly manage data under the above two file systems.