Overview
NAND flash 128Mb到2Tb的设备用于存储数据和代码. 低密度NAND闪存是机顶盒等应用的理想选择, digital televisions (DTVs), 和dsc，而高密度NAND闪存最常用于像ssd这样的数据密集型应用, tablets, and USB drives. 人们一直在努力降低NAND设备的每GB成本, 因此，设备的生命周期往往更短，更频繁的工艺光刻收缩. NAND requires a controller, either internal or external, 以及用于纠错码(ECC)的专用固件, bad block management, and wear leveling.
NAND主要有两种类型:原始的和管理的. Raw NAND有不同的口味, including single-level cell (SLC), multilevel cell (MLC), 三层薄层和四层薄层. Raw NAND需要外部管理，但成本最低/GB NAND闪存可用. 托管NAND将内存管理集成到封装中，简化了设计过程.
Raw NAND
Raw NAND提供最低的每比特成本，但需要一个外部主机控制器(不包含在封装中)来执行所有的管理功能(例如.g., ECC, FTL).
Single-Level Cell (SLC)
- One bit per cell; high performance and write endurance; designed for high-end, high-density, 关键任务系统需要NAND高性能标准和可靠性，降低成本并不是主要驱动因素
Serial NAND
- 低密度SLC器件，具有类似nor的串行接口，简化系统设计
Multilevel Cell (MLC)
- Two bits per cell; a good balanced of performance and write endurance for a wide range of cost-sensitive, high-density applications
Embedded MLC+ NAND
- Uses special programming algorithms to extend write endurance; typically used in high-write workloads like time shifting (pausing live TV)
Triple-Level Cell (TLC)
- Three bits per cell; high cell density, but lower performance and endurance specifications; most often used in mass storage consumer applications (e.g.(客户端ssd, USB驱动器或SD卡)，具有非常高的成本敏感性
Quad-Level Cell (QLC)
- Four bits per cell; high cell density, but impact on latency more than throughput; most often used in applications that demand high-density mass storage (e.g.(企业应用程序)具有成本敏感性
Managed NAND
Managed NAND 提供更简单的解决方案并加快上市时间，因为控制器嵌入在封装中以处理磨损均衡, bad block management and ECC.
e.MMC Memory
- High-capacity NAND flash device combined with a high-speed MultiMediaCard (MMC) controller in a single BGA package; suitable for designers looking for a fully managed device and ease of design for MMC-like, 用于广泛网络的应用程序到应用程序的互操作性, industrial, and automotive applications
On-die ECC NAND
- Hybrid between raw and fully managed NAND; ECC is integrated while wear leveling and bad block management are handled by the host controller
Solid State Drives (SSDs)
- 基于nand的驱动器，提高可靠性, reduce power, 并提供比硬盘驱动器(hdd)更快的性能。
Embedded USB Solutions
- 嵌入式USB通过一个简单的通用串行总线(USB)连接器为网络和嵌入式应用带来SSD的密度和可靠性. 嵌入式USB在物理上小于1.8-inch HDD, 实现成本远低于最便宜的硬盘驱动器, 当它主动读取或写入数据时，只消耗330兆瓦的电力, 而且启动速度比大多数硬盘都快.
Universal Flash Storage (UFS)
- UFS是一种高性能存储接口，适用于需要更快顺序的应用程序 & 随机性能优于eMMC，功耗低
安全数字卡(SD)， Micro SD/USB
- SD,microSD卡和USB闪存驱动器是理想的应用程序，需要闪存易于拆卸或安装
NAND for MCPs
- 越来越多的NAND闪存被用于多芯片封装(mcp)中，它与各种形式的移动LPDRAM配对. NAND/LPDRAM mcp的密度为SLC NAND的1GB至4GB, e的1GB至8GB.MMC™ Embedded Memory.
Conclusion
对各种基于NAND闪存的存储解决方案的基本了解可以帮助设计人员做出明智的决定，确定为特定设计指定哪种NAND闪存器件. 本文对每种NAND闪存选项的一般描述有助于说明是什么使它们比其他应用程序更适合某些应用程序. 沙巴体育安卓版下载每种内存类型的更多技术信息可以在我们网站的沙巴体育结算平台部分找到.
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