BACKGROUND Erasable memories may have erasable elements that can become unreliable after a predetermined number of erase cycles. Thus, if one cell is erased dramatically more than other cells, that cell may be prone to earlier failure than the rest o…
BACKGROUND OF THE INVENTION Solid-state memory devices encompass rewritable non-volatile memory devices which may use electronic circuitry for storing data. Currently, solid-state memory devices start replacing conventional storage devices such as ha…
Techniques are presented that include determining, for data to be written to a nonvolatile memory, a location in the nonvolatile memory to which the data should be written based at least on one or more wear metrics corresponding to the location. The…
前面说过,闪存寿命是以P/E次数来计算的,而WL就是确保闪存内每个块被写入的次数相等的一种机制.若没有这个机制,SSD内的闪存颗粒就无法在同一时间内挂掉,那对用户来说就是灾难.       会出现这种情况的原因在于,用户在LBA空间里的数据更新速度是不同的,有部分是经常需要更新,而有些却长期不需要变更,因此若没有WL,很显然那些经常被更新的数据所在的闪存寿命会首先被消耗完毕,而不怎么需要变更的数据所在的闪存损耗就要小得多.为了避免出现这种状况,便需要WL这个机制来保持SSD内的每个闪存颗粒的磨损…
BACKGROUND OF THE INVENTION Conventional NAND Flash memories move data in the background to write over an entire span uniformly. The background data movement is called wear leveling. A process performing the background data movement is often referred…
参考:http://www.design-reuse.com/articles/24503/nand-flash-memory-embedded-systems.html Abstract : This paper presents fundamental information about NAND Flash memory used in Embedded Systems. It discusses various aspects of this storage media such as…
一.内存详解 NAND闪存阵列分为一系列128kB的区块(block),这些区块是 NAND器件中最小的可擦除实体.擦除一个区块就是把所有的位(bit)设置为"1"(而所有字节(byte)设置为FFh).有必要通过编程,将已擦除 的位从"1"变为"0".最小的编程实体是字节(byte).一些NOR闪存能同时执行读写操作(见下图1).虽然NAND不能同时执行读写操作,它可以采用称为"映射(shadowing)"的方法,在系统级实…
An I/O scheduler and a method for scheduling I/O requests to a solid-state drive (SSD) is disclosed. The I/O scheduler in accordance with the present disclosure bundles the write requests in such a form that the write requests in each bundle goes int…
FTL 1.百度百科 http://baike.baidu.com/link?url=HJ94Rz2Td83V8OW-6dD_h_P8CZb9VFR6HznPDopY_SFdfXDaMriYcBm1Xwpwrsnnv1HB1kSlFkYX0EjfNTcOfa 2.一些概念 http://www.pceva.com.cn/topic/Plextor/index.html 3.wiki :Flash memory controller http://en.wikipedia.org/wiki/Fla…
初学嵌入式Linux,感觉需要学习的东西太多了.把学习过程中的收获和问题记录在这里,算是一份经验吧.     前面利用开发板带的现成的东西step by step让Linux 2.4.19在开发板上跑起来了,对于开发的流程也有了一定的认识.现在想对每一步进行详细深入的探讨,好好学习一下,把笔记记录下来,省得忘记了.有些内容是从看过的书中摘要过来的,大部分是自己实践后的心得.我想记得详细点,也好为后面总结打好基础. 先谈一下对于嵌入式开发流程和嵌入式开发环境拓扑结构的认识. 刚开始比较盲目,看得书…