嵌入式系统中MLC闪存驱动研究

摘要

MLC闪存高密度、低成本的特点,适于做海量存储器.文中以在WinCE6.0平台下实现高性能的MLC闪存驱动为目的,介绍了ARM嵌入式系统中NAND FLASH控制器的工作原理;讨论了WinCE下闪存驱动可采用的两种架构,并在新的MDD、PDD闪存驱动架构下实现了该驱动;介绍并实现了双片操作命令操作;介绍了DMA的工作原理,并实现了DMA编程.测试表明,较之前传统架构及传统操作命令,写入速度提高1.8倍.读出速度提高1.3倍,可靠性也大幅提高.该设计方案可放应用于需要大容量存储的嵌入式系统中.%MLC NAND flash suitable to do mass storage because of its high-density and low cost. Tbe purpose of this article is to implement high performance of MLC NAND flash driver under WinCE6.0 system. Analyzed the working principle of NAND flash controller on ARM embedded system; Discussed two architectures of NAND flash driver can be used. And implemented the driver under the new driver architecture that consists of a model device driver (MDD) and platform-dependent driver (PDD); Discussed and implemented two-plane command operation. Analyzed the working principle of DMA, and implemented DMA program. Tests show that compared to traditional structure and command, the write speed increased by 1.8 times and the read speed enhancod 1.3 times, tbe relisbility is also greatly improved. This design can be applied to large storage of embedded system.