面向嵌入式闪存存储系统的系统纵向优化关键技术研究

Embedded NAND flash memory systems have many benefits, including good random access performance, low power consumption, shock resistance and small form size. However, there are two key issues in this kind of storage systems, performance and reliability, which hold back their further development. First, with the development of applications, users' requirements become more complicated; the storage systems need to be designed with new challenges. Second, with the development of flash memory technology, flash memory's performance and reliability become worse. Based on these observations, the design of embedded NAND flash memory systems with high reliability and good performance becomes the key challenges for their further development. In this project, different from all of previous works, we propose cross layer techniques to improve the reliability and performance of embedded NAND flash memory systems. Specifically, we propose to design cross layer write activity reduction techniques and cross layer write amplification reduction techniques. First, based on the cross layer characteristics, we propose to design two models: cross layer write activity characteristic model and cross layer write amplification characteristic model. Based on these models, we propose the reliability and performance improvement approaches: cross layer write activity reduction techniques and cross layer write amplification reduction techniques. The results of this project will provide new directions for performance and reliability optimization of flash memory in embedded systems and further improvement the development and applications of flash memory.

嵌入式闪存存储系统具有诸多优点，包括随机访问性能好、功耗低、无振动以及尺寸较小。然而此类系统普遍存在可靠性和性能问题，导致其进一步发展受到严重阻碍。首先，随着应用复杂度的增加，存储设计要求增加；其次，随着闪存发展，可靠性和性能不断变差，因此优化嵌入式闪存存储系统可靠性和性能成为其继续发展至关重要的研究课题。本项目突破传统思维，从嵌入式闪存存储系统纵向设计角度展开研究，研究通过设计纵向的写减少技术和纵向的写放大优化技术两个角度改善系统性能和可靠性。首先，根据系统纵向特征，构建以系统纵向访存行为为基础的写操作行为模型和写放大模型，为嵌入式闪存系统的纵向优化提供基础框架。然后在此基础上开展基于系统纵向的写减少优化技术研究和系统纵向的写放大优化技术研究，最终达到系统性能和可靠性的优化。本项目成果将为闪存存储设备在嵌入式系统中的性能和寿命优化提供全新思路，为各类闪存存储设备的进一步应用提供技术支撑。

嵌入式闪存存储系统具有诸多优点，包括随机访问性能好、功耗低、无振动以及尺寸较小。然而此类系统普遍存在可靠性和性能问题，导致其进一步发展受到严重阻碍。首先，随着应用复杂度的增加，存储设计要求增加；其次，随着闪存发展，可靠性和性能不断变差，因此优化嵌入式闪存存储系统可靠性和性能成为其继续发展至关重要的研究课题。本项目突破传统思维，从嵌入式闪存存储系统纵向设计角度展开研究，研究通过设计纵向的写减少技术和纵向的写放大优化技术两个角度改善系统性能和可靠性。首先，根据系统纵向特征，构建了以系统纵向访存行为为基础的写操作行为模型和写放大模型，为嵌入式闪存系统的纵向优化提供了基础框架。然后在此基础上开展了基于系统纵向的写减少优化技术研究和系统纵向的写放大优化技术研究，优化了系统性能和可靠性。通过本项目的实施，我们为闪存存储设备在嵌入式系统中的性能和寿命优化提供了全新思路，为各类闪存存储设备的进一步应用提供了技术支撑。