基于闪存设备分区的新型虚拟EEPROM设备的设计与研究

针对当前嵌入式系统对于低成本迫切需求，研究并设计了一种基于闪存设备（NAND FLASH）的新型虚拟EEPROM（Virtual EEPROM）设备。该设备被虚拟为操作系统NAND设备分区使用，使用数据备份机制确保数据信息安全性。针对NAND只支持页面单元的编程操作，使用缓冲区日志更新的方法，高效地解决Virtual EEPROM字节编程问题。最后通过设计损益均衡层实现NAND存储块的统一管理，对坏块和寿命问题进行大幅优化。分析结果表明，Virtual EEPROM具备NAND快速编程特性，擦写寿命较EEPROM有很大优势。该设计架构具备很好的系统兼容性，可以扩展移植于多种嵌入式平台。

Design and research of novel virtual EEPROM based on NAND flash device partition

In this paper, an novel virtual EEPROM based on flash device was designed, which focused on the current urgent need for low-cost in embedded systems especially, The virtual EEPROM was used as NAND device part in embedded Operating System (OS), which used data backup mechanism to ensure data security. Considering that NAND only supports page programming, a method of log update based on memory buffer was employed to realize byte programming in Virtual EEPROM. Finally, to achieve unified management of NAND block, a wear leveling was designed, meanwhile, issues of bad block and Program/Erase cycle were greatly optimized. The result shows that the Virtual EEPROM has fast programming characteristics of NAND, as well as a great advantage of endurance over the EEPROM. The design has good compatibility and can be widely transplanted in various embedded platforms.