Storage Management Design On NAND Flash

With the development of the information technology and the promotion of the digital products,at present the embedded system has become the focus in the area of the computer technology research and application. As the complexity of the embedded system is boosted,more and more data will be stored and managed. NAND Flash has the character of high storage density and high storage speed,so it has been applied as storage medium widely in the field of the embedded system. In the industry of mobile telephone, the functions provided by mobile telephone are more and more complete,and there are more and more applications to be installed,what's more, with the development of the multimedia,there will be more kind of and higher quality of multimedia files which need to be stored and applied,all above will result in that the number of files that need to be managed as well as storage space is larger and larger,but as a handheld device,it possesses so limited resource,it needs a mature filesystem to administrate its related files,and The FAT (File Allocation Table) file system supported by Microsoft corporation is quite matur,it has been accepted generally in the embedded system which has limited resource for the character of being concise and efficient.It becomes an significative topic for how to combine FAT with NAND Flash effectively.NAND Flash has a fatal innate vulnerability of Erased mechanism and various kind of bad blocks which becomes the main obstacle in its application, as NAND Flash has its unique hardware character,we can not put it into use without any adjustment.In this paper,we design and implement an embedded file system on NAND Flash which is based on Microsoft corporation's FAT file system,it solves the above problems very well. We make some modifications on conventional FAT in order to be betterly suited to the embedded devices,e.g. adding the construct of mapping table.At the same time,we have described how to deal with the bad blocks and the Wear balance in detail. So far this design has been applied in a lot of mobile in the market,a mass of users and long-time running prove its reliability.