File reading and writing method based on flash storage medium

Abstract

The invention discloses a file read-write method on the basis of a FLASH storage medium, relates to the technical field of file systems and solves the technical problem of improving the safety operation times of a file. The method comprises the following steps of: distributing a 256-byte storage area for each table item of a FAT (file allocation table), distributing a 8192-byte storage area for each directory entry of a directory area and sequentially and uniformly dividing each directory entry of the directory area into 256 subarea blocks; and when the file is operated each time, only executing the write operation on one byte of the corresponding FAT table item, only executing the write operation on one subarea block of the corresponding directory entry, executing the erasing operation for once after the write operation is executed for each FAT table item for 256 times, and executing the erasing operation for once after the write operation is executed for each directory entry for 256 times. According to the file read-write method provided by the invention, the safety operation times of the file can be increased and the service life of the FLASH storage medium is prolonged.

Description

technical field [0001] The invention relates to the technology of the file system, in particular to the technology of a method for reading and writing files based on a FLASH storage medium. Background technique [0002] In the power automation industry, there are various embedded products, which often need to store various monitoring data. Generally, for the convenience of use, various file systems are introduced, the most common one is the FAT file system, which is divided into three file systems: FAT12, FAT16, and FAT32 according to the manageable capacity. Among various embedded products, the most economical and common media for storing large-capacity data are FLASH chips, SD cards, U disks, etc. These storage media have the advantages of large capacity and low cost on the one hand, and on the other hand There is also a feature that is obviously different from computer hard drives, that is, the number of life spans is limited. The general technical index is 10,000 times ...

AI Technical Summary

Problems solved by technology

In this way, conventional file systems based on FLASH chips, SD cards, and U disks cannot meet the requirements. People usually choose to use SRAM chips or ferroelectric RAM chips to store these data.

Although SRAM chips and ferroelectric RAM chips have no limit on the number of erasing and writing times, their capacity is small and expensive, generally below 1M bytes, even a few large-capacity SRAM chips, and their single-chip capacity will not exceed 8M, while FLASH The capacity of chips, SD cards, and U disks can easily reach hundreds of megabytes, several gigabytes, or even tens of gigabytes

If you use SRAM chips or ferroelectric RAM chips to store large-capacity data, you must use many pieces of SRAM chips or ferroelectric RAM chips to put together, so not only will the cost increase sharply, but also limited by product space, sometimes it is impossible to do it. to large capacity