ARM学习笔记－－NAND Flash控制器

小咪咪 2022-03-26 13:52 221阅读 0赞

摘自：《嵌入式Linux应用开发完全手册》——韦东山

一、NAND Flash介绍和NAND Flash控制器的使用

NAND Flash在嵌入式系统中的作用，相当于PC上的硬盘

常见的Flash有NOR Flash和NAND Flash，NOR Flash上进行读取的效率非常高，但是擦除和写操作的效率很低，容量一般比较小；NAND Flash进行擦除和写操作的效率更高，并且容量更大。一般NOR Flash用于存储程序，NAND Flash用于存储数据。

1）NAND Flash的物理结构

笔者用的开发板上NAND Flash型号是K9F1G08，大小为128M，下图为它的封装和外部引脚

![201004111728211471.jpg][]

\* NandFlash接口信号较少

\*数据宽度只有8Bit，没有地址总线。地址和数据总线复用，串行读取

<table style="border-bottom:medium none; border-left:medium none; width:395.25pt; border-collapse:collapse; border-top:medium none; border-right:medium none"> 
 <tbody> 
 <tr> 
 <td style="border-bottom:black 1pt solid; border-left:black 1pt solid; padding-bottom:0cm; background-color:transparent; padding-left:5.4pt; width:55.05pt; padding-right:5.4pt; border-top:black 1pt solid; border-right:black 1pt solid; padding-top:0cm"> 信号名称 </td> 
 <td style="border-bottom:black 1pt solid; border-left:#d4d0c8; padding-bottom:0cm; background-color:transparent; padding-left:5.4pt; width:12cm; padding-right:5.4pt; border-top:black 1pt solid; border-right:black 1pt solid; padding-top:0cm"> 信号描述 </td> 
 </tr> 
 <tr> 
 <td style="border-bottom:black 1pt solid; border-left:black 1pt solid; padding-bottom:0cm; background-color:transparent; padding-left:5.4pt; width:55.05pt; padding-right:5.4pt; border-top:#d4d0c8; border-right:black 1pt solid; padding-top:0cm"> IO[7..0] </td> 
 <td style="border-bottom:black 1pt solid; border-left:#d4d0c8; padding-bottom:0cm; background-color:transparent; padding-left:5.4pt; width:12cm; padding-right:5.4pt; border-top:#d4d0c8; border-right:black 1pt solid; padding-top:0cm"> 数据总线 </td> 
 </tr> 
 <tr> 
 <td style="border-bottom:black 1pt solid; border-left:black 1pt solid; padding-bottom:0cm; background-color:transparent; padding-left:5.4pt; width:55.05pt; padding-right:5.4pt; border-top:#d4d0c8; border-right:black 1pt solid; padding-top:0cm"> CE# </td> 
 <td style="border-bottom:black 1pt solid; border-left:#d4d0c8; padding-bottom:0cm; background-color:transparent; padding-left:5.4pt; width:12cm; padding-right:5.4pt; border-top:#d4d0c8; border-right:black 1pt solid; padding-top:0cm"> 片选信号(Chip Select)，低电平有效 </td> 
 </tr> 
 <tr> 
 <td style="border-bottom:black 1pt solid; border-left:black 1pt solid; padding-bottom:0cm; background-color:transparent; padding-left:5.4pt; width:55.05pt; padding-right:5.4pt; border-top:#d4d0c8; border-right:black 1pt solid; padding-top:0cm"> WE# </td> 
 <td style="border-bottom:black 1pt solid; border-left:#d4d0c8; padding-bottom:0cm; background-color:transparent; padding-left:5.4pt; width:12cm; padding-right:5.4pt; border-top:#d4d0c8; border-right:black 1pt solid; padding-top:0cm"> 写有效(Write Enable)，低电平表示当前总线操作是写操作 </td> 
 </tr> 
 <tr> 
 <td style="border-bottom:black 1pt solid; border-left:black 1pt solid; padding-bottom:0cm; background-color:transparent; padding-left:5.4pt; width:55.05pt; padding-right:5.4pt; border-top:#d4d0c8; border-right:black 1pt solid; padding-top:0cm"> RE# </td> 
 <td style="border-bottom:black 1pt solid; border-left:#d4d0c8; padding-bottom:0cm; background-color:transparent; padding-left:5.4pt; width:12cm; padding-right:5.4pt; border-top:#d4d0c8; border-right:black 1pt solid; padding-top:0cm"> 读有效(Read Enable)，低电平表示当前总线操作是读操作 </td> 
 </tr> 
 <tr> 
 <td style="border-bottom:black 1pt solid; border-left:black 1pt solid; padding-bottom:0cm; background-color:transparent; padding-left:5.4pt; width:55.05pt; padding-right:5.4pt; border-top:#d4d0c8; border-right:black 1pt solid; padding-top:0cm"> CLE </td> 
 <td style="border-bottom:black 1pt solid; border-left:#d4d0c8; padding-bottom:0cm; background-color:transparent; padding-left:5.4pt; width:12cm; padding-right:5.4pt; border-top:#d4d0c8; border-right:black 1pt solid; padding-top:0cm"> 命令锁存(Command Latch Enable)信号，写操作时给出此信号表示写命令 </td> 
 </tr> 
 <tr> 
 <td style="border-bottom:black 1pt solid; border-left:black 1pt solid; padding-bottom:0cm; background-color:transparent; padding-left:5.4pt; width:55.05pt; padding-right:5.4pt; border-top:#d4d0c8; border-right:black 1pt solid; padding-top:0cm"> ALE </td> 
 <td style="border-bottom:black 1pt solid; border-left:#d4d0c8; padding-bottom:0cm; background-color:transparent; padding-left:5.4pt; width:12cm; padding-right:5.4pt; border-top:#d4d0c8; border-right:black 1pt solid; padding-top:0cm"> 地址/数据锁存(Address Latch Enable)信号，写操作时给出此信号表示写地址或数据 </td> 
 </tr> 
 <tr> 
 <td style="border-bottom:black 1pt solid; border-left:black 1pt solid; padding-bottom:0cm; background-color:transparent; padding-left:5.4pt; width:55.05pt; padding-right:5.4pt; border-top:#d4d0c8; border-right:black 1pt solid; padding-top:0cm"> WP# </td> 
 <td style="border-bottom:black 1pt solid; border-left:#d4d0c8; padding-bottom:0cm; background-color:transparent; padding-left:5.4pt; width:12cm; padding-right:5.4pt; border-top:#d4d0c8; border-right:black 1pt solid; padding-top:0cm"> 写保护(Write Protect)信号 </td> 
 </tr> 
 <tr> 
 <td style="border-bottom:black 1pt solid; border-left:black 1pt solid; padding-bottom:0cm; background-color:transparent; padding-left:5.4pt; width:55.05pt; padding-right:5.4pt; border-top:#d4d0c8; border-right:black 1pt solid; padding-top:0cm"> R/B </td> 
 <td style="border-bottom:black 1pt solid; border-left:#d4d0c8; padding-bottom:0cm; background-color:transparent; padding-left:5.4pt; width:12cm; padding-right:5.4pt; border-top:#d4d0c8; border-right:black 1pt solid; padding-top:0cm"> 忙(Read/Busy)信号 </td> 
 </tr> 
 </tbody> 
</table>

2）K9F1G08功能结构图如下

![201004111730385042.jpg][]

K9F1G08内部结构有下面一些功能部件

①X-Buffers Latches & Decoders：用于行地址

②X-Buffers Latches & Decoders：用于列地址

③Command Register：用于命令字

④Control Logic & High Voltage Generator：控制逻辑及产生Flash所需高压

⑤Nand Flash Array：存储部件

⑥Data Register & S/A：数据寄存器，读、写页时，数据存放此寄存器

⑦Y-Gating

⑧I/O Buffers & Latches

⑨Global Buffers

⑩Output Driver

3）NAND Flash 存储单元组织结构图如下：

![201004111745084806.jpg][]

K9F1G08容量为1056Mbit，分为65536行（页）、2112列，每一页大小为2kb，外加64字节的额外空间，这64字节的额外空间的列地址为2048-2111

命令、地址、数据都通过IO0-IO7输入/输出，写入命令、地址或数据时，需要将WE、CE信号同时拉低，数据在WE信号的上升沿被NAND FLash锁存；命令锁存信号CLE、地址锁存信号ALE用来分辨、锁存命令或地址。

K9F1G08有128MB的存储空间，需要27位地址，以字节为单位访问Flash时，需要4个地址序列

NandFlash地址结构

\* NandFlash设备的存储容量是以页(Page)和块(Block)为单位的。

\* Page=528Byte (512Byte用于存放数据，其余16Byte用于存放其他信息，如块好坏的标记、块的逻辑地址、页内数据的ECC校验和等)。

\* Block=32Page

\*容量为64MB的NandFlash存储结构为：512Byte×32Page×4096Block

\* NandFlash以页为单位进行读和编程（写）操作，一页为512Byte；以块为单位进行擦除操作，一块为512Byte\*32page=16KB

\*对于64MB的NAND设备，需要26根地址线，由于NAND设备数据总线宽度是8位的，因此必须经过4个时钟周期才能把全部地址信息接收下来

<table style="border-bottom:medium none; border-left:medium none; border-collapse:collapse; border-top:medium none; border-right:medium none"> 
 <tbody> 
 <tr> 
 <td style="border-bottom:black 1pt solid; border-left:black 1pt solid; padding-bottom:0cm; background-color:transparent; padding-left:5.4pt; width:85.3pt; padding-right:5.4pt; border-top:black 1pt solid; border-right:black 1pt solid; padding-top:0cm"> &nbsp; </td> 
 <td style="border-bottom:black 1pt solid; border-left:#d4d0c8; padding-bottom:0cm; background-color:transparent; padding-left:5.4pt; width:42.6pt; padding-right:5.4pt; border-top:black 1pt solid; border-right:black 1pt solid; padding-top:0cm"> I/O7 </td> 
 <td style="border-bottom:black 1pt solid; border-left:#d4d0c8; padding-bottom:0cm; background-color:transparent; padding-left:5.4pt; width:42.6pt; padding-right:5.4pt; border-top:black 1pt solid; border-right:black 1pt solid; padding-top:0cm"> I/O6 </td> 
 <td style="border-bottom:black 1pt solid; border-left:#d4d0c8; padding-bottom:0cm; background-color:transparent; padding-left:5.4pt; width:42.6pt; padding-right:5.4pt; border-top:black 1pt solid; border-right:black 1pt solid; padding-top:0cm"> I/O5 </td> 
 <td style="border-bottom:black 1pt solid; border-left:#d4d0c8; padding-bottom:0cm; background-color:transparent; padding-left:5.4pt; width:42.6pt; padding-right:5.4pt; border-top:black 1pt solid; border-right:black 1pt solid; padding-top:0cm"> I/O4 </td> 
 <td style="border-bottom:black 1pt solid; border-left:#d4d0c8; padding-bottom:0cm; background-color:transparent; padding-left:5.4pt; width:42.6pt; padding-right:5.4pt; border-top:black 1pt solid; border-right:black 1pt solid; padding-top:0cm"> I/O3 </td> 
 <td style="border-bottom:black 1pt solid; border-left:#d4d0c8; padding-bottom:0cm; background-color:transparent; padding-left:5.4pt; width:42.6pt; padding-right:5.4pt; border-top:black 1pt solid; border-right:black 1pt solid; padding-top:0cm"> I/O2 </td> 
 <td style="border-bottom:black 1pt solid; border-left:#d4d0c8; padding-bottom:0cm; background-color:transparent; padding-left:5.4pt; width:42.6pt; padding-right:5.4pt; border-top:black 1pt solid; border-right:black 1pt solid; padding-top:0cm"> I/O1 </td> 
 <td style="border-bottom:black 1pt solid; border-left:#d4d0c8; padding-bottom:0cm; background-color:transparent; padding-left:5.4pt; width:42.6pt; padding-right:5.4pt; border-top:black 1pt solid; border-right:black 1pt solid; padding-top:0cm"> I/O0 </td> 
 </tr> 
 <tr> 
 <td style="border-bottom:black 1pt solid; border-left:black 1pt solid; padding-bottom:0cm; background-color:transparent; padding-left:5.4pt; width:85.3pt; padding-right:5.4pt; border-top:#d4d0c8; border-right:black 1pt solid; padding-top:0cm"> 第一个周期 </td> 
 <td style="border-bottom:black 1pt solid; border-left:#d4d0c8; padding-bottom:0cm; background-color:transparent; padding-left:5.4pt; width:42.6pt; padding-right:5.4pt; border-top:#d4d0c8; border-right:black 1pt solid; padding-top:0cm"> A7 </td> 
 <td style="border-bottom:black 1pt solid; border-left:#d4d0c8; padding-bottom:0cm; background-color:transparent; padding-left:5.4pt; width:42.6pt; padding-right:5.4pt; border-top:#d4d0c8; border-right:black 1pt solid; padding-top:0cm"> A6 </td> 
 <td style="border-bottom:black 1pt solid; border-left:#d4d0c8; padding-bottom:0cm; background-color:transparent; padding-left:5.4pt; width:42.6pt; padding-right:5.4pt; border-top:#d4d0c8; border-right:black 1pt solid; padding-top:0cm"> A5 </td> 
 <td style="border-bottom:black 1pt solid; border-left:#d4d0c8; padding-bottom:0cm; background-color:transparent; padding-left:5.4pt; width:42.6pt; padding-right:5.4pt; border-top:#d4d0c8; border-right:black 1pt solid; padding-top:0cm"> A4 </td> 
 <td style="border-bottom:black 1pt solid; border-left:#d4d0c8; padding-bottom:0cm; background-color:transparent; padding-left:5.4pt; width:42.6pt; padding-right:5.4pt; border-top:#d4d0c8; border-right:black 1pt solid; padding-top:0cm"> A3 </td> 
 <td style="border-bottom:black 1pt solid; border-left:#d4d0c8; padding-bottom:0cm; background-color:transparent; padding-left:5.4pt; width:42.6pt; padding-right:5.4pt; border-top:#d4d0c8; border-right:black 1pt solid; padding-top:0cm"> A2 </td> 
 <td style="border-bottom:black 1pt solid; border-left:#d4d0c8; padding-bottom:0cm; background-color:transparent; padding-left:5.4pt; width:42.6pt; padding-right:5.4pt; border-top:#d4d0c8; border-right:black 1pt solid; padding-top:0cm"> A1 </td> 
 <td style="border-bottom:black 1pt solid; border-left:#d4d0c8; padding-bottom:0cm; background-color:transparent; padding-left:5.4pt; width:42.6pt; padding-right:5.4pt; border-top:#d4d0c8; border-right:black 1pt solid; padding-top:0cm"> A0 </td> 
 </tr> 
 <tr> 
 <td style="border-bottom:black 1pt solid; border-left:black 1pt solid; padding-bottom:0cm; background-color:transparent; padding-left:5.4pt; width:85.3pt; padding-right:5.4pt; border-top:#d4d0c8; border-right:black 1pt solid; padding-top:0cm"> 第二个周期 </td> 
 <td style="border-bottom:black 1pt solid; border-left:#d4d0c8; padding-bottom:0cm; background-color:transparent; padding-left:5.4pt; width:42.6pt; padding-right:5.4pt; border-top:#d4d0c8; border-right:black 1pt solid; padding-top:0cm"> A15 </td> 
 <td style="border-bottom:black 1pt solid; border-left:#d4d0c8; padding-bottom:0cm; background-color:transparent; padding-left:5.4pt; width:42.6pt; padding-right:5.4pt; border-top:#d4d0c8; border-right:black 1pt solid; padding-top:0cm"> A14 </td> 
 <td style="border-bottom:black 1pt solid; border-left:#d4d0c8; padding-bottom:0cm; background-color:transparent; padding-left:5.4pt; width:42.6pt; padding-right:5.4pt; border-top:#d4d0c8; border-right:black 1pt solid; padding-top:0cm"> A13 </td> 
 <td style="border-bottom:black 1pt solid; border-left:#d4d0c8; padding-bottom:0cm; background-color:transparent; padding-left:5.4pt; width:42.6pt; padding-right:5.4pt; border-top:#d4d0c8; border-right:black 1pt solid; padding-top:0cm"> A12 </td> 
 <td style="border-bottom:black 1pt solid; border-left:#d4d0c8; padding-bottom:0cm; background-color:transparent; padding-left:5.4pt; width:42.6pt; padding-right:5.4pt; border-top:#d4d0c8; border-right:black 1pt solid; padding-top:0cm"> A11 </td> 
 <td style="border-bottom:black 1pt solid; border-left:#d4d0c8; padding-bottom:0cm; background-color:transparent; padding-left:5.4pt; width:42.6pt; padding-right:5.4pt; border-top:#d4d0c8; border-right:black 1pt solid; padding-top:0cm"> A10 </td> 
 <td style="border-bottom:black 1pt solid; border-left:#d4d0c8; padding-bottom:0cm; background-color:transparent; padding-left:5.4pt; width:42.6pt; padding-right:5.4pt; border-top:#d4d0c8; border-right:black 1pt solid; padding-top:0cm"> A9 </td> 
 <td style="border-bottom:black 1pt solid; border-left:#d4d0c8; padding-bottom:0cm; background-color:transparent; padding-left:5.4pt; width:42.6pt; padding-right:5.4pt; border-top:#d4d0c8; border-right:black 1pt solid; padding-top:0cm"> A8 </td> 
 </tr> 
 <tr> 
 <td style="border-bottom:black 1pt solid; border-left:black 1pt solid; padding-bottom:0cm; background-color:transparent; padding-left:5.4pt; width:85.3pt; padding-right:5.4pt; border-top:#d4d0c8; border-right:black 1pt solid; padding-top:0cm"> 第三个周期 </td> 
 <td style="border-bottom:black 1pt solid; border-left:#d4d0c8; padding-bottom:0cm; background-color:transparent; padding-left:5.4pt; width:42.6pt; padding-right:5.4pt; border-top:#d4d0c8; border-right:black 1pt solid; padding-top:0cm"> A23 </td> 
 <td style="border-bottom:black 1pt solid; border-left:#d4d0c8; padding-bottom:0cm; background-color:transparent; padding-left:5.4pt; width:42.6pt; padding-right:5.4pt; border-top:#d4d0c8; border-right:black 1pt solid; padding-top:0cm"> A22 </td> 
 <td style="border-bottom:black 1pt solid; border-left:#d4d0c8; padding-bottom:0cm; background-color:transparent; padding-left:5.4pt; width:42.6pt; padding-right:5.4pt; border-top:#d4d0c8; border-right:black 1pt solid; padding-top:0cm"> A21 </td> 
 <td style="border-bottom:black 1pt solid; border-left:#d4d0c8; padding-bottom:0cm; background-color:transparent; padding-left:5.4pt; width:42.6pt; padding-right:5.4pt; border-top:#d4d0c8; border-right:black 1pt solid; padding-top:0cm"> A20 </td> 
 <td style="border-bottom:black 1pt solid; border-left:#d4d0c8; padding-bottom:0cm; background-color:transparent; padding-left:5.4pt; width:42.6pt; padding-right:5.4pt; border-top:#d4d0c8; border-right:black 1pt solid; padding-top:0cm"> A19 </td> 
 <td style="border-bottom:black 1pt solid; border-left:#d4d0c8; padding-bottom:0cm; background-color:transparent; padding-left:5.4pt; width:42.6pt; padding-right:5.4pt; border-top:#d4d0c8; border-right:black 1pt solid; padding-top:0cm"> A18 </td> 
 <td style="border-bottom:black 1pt solid; border-left:#d4d0c8; padding-bottom:0cm; background-color:transparent; padding-left:5.4pt; width:42.6pt; padding-right:5.4pt; border-top:#d4d0c8; border-right:black 1pt solid; padding-top:0cm"> A17 </td> 
 <td style="border-bottom:black 1pt solid; border-left:#d4d0c8; padding-bottom:0cm; background-color:transparent; padding-left:5.4pt; width:42.6pt; padding-right:5.4pt; border-top:#d4d0c8; border-right:black 1pt solid; padding-top:0cm"> A16 </td> 
 </tr> 
 <tr> 
 <td style="border-bottom:black 1pt solid; border-left:black 1pt solid; padding-bottom:0cm; background-color:transparent; padding-left:5.4pt; width:85.3pt; padding-right:5.4pt; border-top:#d4d0c8; border-right:black 1pt solid; padding-top:0cm"> 第四个周期 </td> 
 <td style="border-bottom:black 1pt solid; border-left:#d4d0c8; padding-bottom:0cm; background-color:transparent; padding-left:5.4pt; width:42.6pt; padding-right:5.4pt; border-top:#d4d0c8; border-right:black 1pt solid; padding-top:0cm"> &nbsp; </td> 
 <td style="border-bottom:black 1pt solid; border-left:#d4d0c8; padding-bottom:0cm; background-color:transparent; padding-left:5.4pt; width:42.6pt; padding-right:5.4pt; border-top:#d4d0c8; border-right:black 1pt solid; padding-top:0cm"> &nbsp; </td> 
 <td style="border-bottom:black 1pt solid; border-left:#d4d0c8; padding-bottom:0cm; background-color:transparent; padding-left:5.4pt; width:42.6pt; padding-right:5.4pt; border-top:#d4d0c8; border-right:black 1pt solid; padding-top:0cm"> &nbsp; </td> 
 <td style="border-bottom:black 1pt solid; border-left:#d4d0c8; padding-bottom:0cm; background-color:transparent; padding-left:5.4pt; width:42.6pt; padding-right:5.4pt; border-top:#d4d0c8; border-right:black 1pt solid; padding-top:0cm"> &nbsp; </td> 
 <td style="border-bottom:black 1pt solid; border-left:#d4d0c8; padding-bottom:0cm; background-color:transparent; padding-left:5.4pt; width:42.6pt; padding-right:5.4pt; border-top:#d4d0c8; border-right:black 1pt solid; padding-top:0cm"> &nbsp; </td> 
 <td style="border-bottom:black 1pt solid; border-left:#d4d0c8; padding-bottom:0cm; background-color:transparent; padding-left:5.4pt; width:42.6pt; padding-right:5.4pt; border-top:#d4d0c8; border-right:black 1pt solid; padding-top:0cm"> &nbsp; </td> 
 <td style="border-bottom:black 1pt solid; border-left:#d4d0c8; padding-bottom:0cm; background-color:transparent; padding-left:5.4pt; width:42.6pt; padding-right:5.4pt; border-top:#d4d0c8; border-right:black 1pt solid; padding-top:0cm"> A25 </td> 
 <td style="border-bottom:black 1pt solid; border-left:#d4d0c8; padding-bottom:0cm; background-color:transparent; padding-left:5.4pt; width:42.6pt; padding-right:5.4pt; border-top:#d4d0c8; border-right:black 1pt solid; padding-top:0cm"> A24 </td> 
 </tr> 
 </tbody> 
</table>

\*可以这么说，第一个时钟周期给出的是目标地址在一个page内的偏移量，而后三个时钟周期给出的是页地址。

\*由于一个页内有512Byte，需要9bit的地址寻址，而第一个时钟周期只给出了低8bit，最高位A8由不同的读命令(Read Mode2)来区分的。

4）. **NandFlash的命令**

![\[ARM笔记\]存储器扩展连接理解(S3C2410为例)—NandFlash - Fantity Wei - Footprint][ARM_S3C2410_NandFlash - Fantity Wei - Footprint]

NAND Flash访问方法

NAND Flash硬件连接如下图：

![201004111631128652.jpg][]

NAND Flash和S3C2440的连线包括，8个IO引脚，5个使能信号（nWE、ALE、CLE、nCE、nRE）、1个状态引脚（R/B）、1个写保护引脚（nWP）。地址、数据和命令都是在这些使能信号的配合下，通过8个IO引脚传输。写地址、数据、命令时，nCE、nWE信号必须为低电平，它们在 nWE信号的上升沿被锁存。命令锁存使能信号CLE和地址锁存使能信号ALE用来区别IO引脚上传输的是命令还是地址。

命令字及操作方法

操作NAND Flash时，先传输命令，然后传输地址，最后读写数据，这个期间要检查Flash的状态。K9F1G08容量为128MB，需要一个27位的地址，发出命令后，后面要紧跟着4个地址序列。

下图为K9F1G08的命令字

![201004112037412468.jpg][]

下图为K9F1G08的地址序列

![201004111816106632.jpg][]

K9F1G08有2112列，所以必须使用A0-A11共12位来寻址，有65535行，所以必须使用A12-A27共16位来寻址。

3）S3C2440 NAND Flash控制器介绍

NAND Flash的读写操作次序如下：

①设置NFCONF配置NAND Flash

②向NFCMD寄存器写入命令

③向NFADDR寄存器写入地址

④读写数据：通过寄存器NFSTAT检测NAND Flash的状态，在启动某个操作后，应该检测R/nB信号以确定该操作是否完成、是否成功。

下面介绍这些寄存器：

①NFCONF：配置寄存器

用来设置NAND Flash的时序参数，设置数据位宽，设置是否支持其他大小的页等。

②NFCONT：控制寄存器

用来使能NAND Flash控制器、使能控制引脚信号nFCE、初始化ECC，锁定NAND Flash等功能

③NFCMD：命令寄存器

用来发送Flash操作命令

④NFADDR：地址寄存器

用来向Flash发送地址信号

⑤NFDATA：数据寄存器

读写此寄存器启动对NAND Flash的读写数据操作

⑥NFSTAT：状态寄存器

0：busy，1：ready

二、NAND Flash控制器操作实例：读Flash

1）读NAND Flash的步骤

①设置NFCONF

在HCLK=100Mhz的情况下，TACLS=0，TWRPH0=3，TWRPH1=0，则

NFCONF = 0x300

使能NAND Flash控制器、禁止控制引脚信号nFCE，初始化ECC

NFCONT = (1<<4) | (1<<1) | (1<<0)

②操作NAND Flash前，复位

NFCONT &= ~(1<<1)        发出片选信号

NFCMD = 0xff        reset命令

然后循环查询NFSTAT位0，直到等于1，处于就绪态

最后禁止片选信号，在实际使用时再使能

NFCONT |= 0x2        禁止NAND Flash

③发出读命令

NFCONT &= ~(1<<1)        发出片选信号

NFCMD = 0        读命令

④发出地址信号

⑤循环查询NFSTAT，直到等于1

⑥连续读NFDATA寄存器，得到一页数据

⑦最后禁止NAND Flash片选信号

NFCONT |= (1<<1)

2）代码详解

本实例的目的是把一部分代码存放在NAND Flash地址4096之后，当程序启动后通过NAND Flash控制器读出代码，执行。

连接脚本 nand.lds

SECTIONS \{

firtst  0x00000000 : \{ head.o init.o nand.o\}

second 0x30000000 : AT(4096) \{ main.o \}

head.o init.o nand.o三个文件运行地址为0，生成的镜像文件偏移地址也为0

main.0的运行地址为0x30000000，生成的镜像文件偏移地址为4096

@\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*

@ File：head.s

@ 功能：设置SDRAM，将程序复制到SDRAM，然后跳到SDRAM继续执行

@\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*

.text

.global \_start

\_start:

@函数disable\_watch\_dog, memsetup, init\_nand, nand\_read\_ll在init.c中定义

ldr     sp, =4096               @设置堆栈

bl      disable\_watch\_dog       @关WATCH DOG

bl      memsetup                @初始化SDRAM

bl      nand\_init               @初始化NAND Flash

@将NAND Flash中地址4096开始的1024字节代码(main.c编译得到)复制到SDRAM中

@nand\_read\_ll函数需要3个参数：

ldr     r0,     =0x30000000     @1. 目标地址=0x30000000，这是SDRAM的起始地址

mov     r1,     \#4096           @2.  源地址   = 4096，连接的时候，main.c中的代码都存在NAND Flash地址4096开始处

mov     r2,     \#2048           @3.  复制长度= 2048(bytes)，对于本实验的main.c，这是足够了

bl      nand\_read               @调用C函数nand\_read

ldr     sp, =0x34000000         @设置栈

ldr     lr, =halt\_loop          @设置返回地址

ldr     pc, =main               @b指令和bl指令只能前后跳转32M的范围，所以这里使用向pc赋值的方法进行跳转

halt\_loop:

b       halt\_loop

init.c 用于初始化操作

/\* WOTCH DOG register \*/

\#define WTCON(\*(volatile unsigned long \*)0x53000000)

/\* SDRAM regisers \*/

\#define MEM\_CTL\_BASE0x48000000

void disable\_watch\_dog();

void memsetup();

/\*上电后，WATCH DOG默认是开着的，要把它关掉 \*/

void disable\_watch\_dog()

WTCON= 0;

/\* 设置控制SDRAM的13个寄存器 \*/

void memsetup()

int i = 0;

unsigned long \*p = (unsigned long \*)MEM\_CTL\_BASE;

/\* SDRAM 13个寄存器的值 \*/

unsigned long  const    mem\_cfg\_val\[\]=\{ 0x22011110,     //BWSCON

0x00000700,     //BANKCON0

0x00000700,     //BANKCON1

0x00000700,     //BANKCON2

0x00000700,     //BANKCON3

0x00000700,     //BANKCON4

0x00000700,     //BANKCON5

0x00018005,     //BANKCON6

0x00018005,     //BANKCON7

0x008C07A3,     //REFRESH

0x000000B1,     //BANKSIZE

0x00000030,     //MRSRB6

0x00000030,     //MRSRB7

\};

for(; i < 13; i++)

p\[i\] = mem\_cfg\_val\[i\];

nand.c 用于操作nand flash

\#define BUSY            1

\#define NAND\_SECTOR\_SIZE\_LP    2048        //K9F1G08使用2048+64列

\#define NAND\_BLOCK\_MASK\_LP     (NAND\_SECTOR\_SIZE\_LP - 1)

typedef unsigned int S3C24X0\_REG32;

typedef struct \{

S3C24X0\_REG32   NFCONF;

S3C24X0\_REG32   NFCONT;

S3C24X0\_REG32   NFCMD;

S3C24X0\_REG32   NFADDR;

S3C24X0\_REG32   NFDATA;

S3C24X0\_REG32   NFMECCD0;

S3C24X0\_REG32   NFMECCD1;

S3C24X0\_REG32   NFSECCD;

S3C24X0\_REG32   NFSTAT;

S3C24X0\_REG32   NFESTAT0;

S3C24X0\_REG32   NFESTAT1;

S3C24X0\_REG32   NFMECC0;

S3C24X0\_REG32   NFMECC1;

S3C24X0\_REG32   NFSECC;

S3C24X0\_REG32   NFSBLK;

S3C24X0\_REG32   NFEBLK;

\} S3C2440\_NAND;         //此结构体存储操作NAND Flash相关寄存器

typedef struct \{

void (\*nand\_reset)(void);

void (\*wait\_idle)(void);

void (\*nand\_select\_chip)(void);

void (\*nand\_deselect\_chip)(void);

void (\*write\_cmd)(int cmd);

void (\*write\_addr)(unsigned int addr);

unsigned char (\*read\_data)(void);

\}t\_nand\_chip;        //存储nand相关操作的函数地址

static S3C2440\_NAND \* s3c2440nand = (S3C2440\_NAND \*)0x4e000000;        //s2c2440nand控制器地址

static t\_nand\_chip nand\_chip;

/\* 供外部调用的函数 \*/

void nand\_init(void);

void nand\_read(unsigned char \*buf, unsigned long start\_addr, int size);

/\* NAND Flash操作的总入口, 它们将调用S3C2440的相应函数 \*/

static void nand\_reset(void);

static void wait\_idle(void);

static void nand\_select\_chip(void);

static void nand\_deselect\_chip(void);

static void write\_cmd(int cmd);

static void write\_addr(unsigned int addr);

static unsigned char read\_data(void);

/\* S3C2440的NAND Flash处理函数 \*/

static void s3c2440\_nand\_reset(void);

static void s3c2440\_wait\_idle(void);

static void s3c2440\_nand\_select\_chip(void);

static void s3c2440\_nand\_deselect\_chip(void);

static void s3c2440\_write\_cmd(int cmd);

static void s3c2440\_write\_addr(unsigned int addr);

static unsigned char s3c2440\_read\_data(void);

/\* S3C2440的NAND Flash操作函数 \*/

/\* 复位 \*/

static void s3c2440\_nand\_reset(void)

s3c2440\_nand\_select\_chip();

s3c2440\_write\_cmd(0xff);  // 复位命令

s3c2440\_wait\_idle();

s3c2440\_nand\_deselect\_chip();

/\* 等待NAND Flash就绪 \*/

static void s3c2440\_wait\_idle(void)

int i;

volatile unsigned char \*p = (volatile unsigned char \*)&s3c2440nand->NFSTAT;

while(!(\*p & BUSY))        //\*p=1表示就绪，跳出循环

for(i=0; i<10; i++);

/\* 发出片选信号 \*/

static void s3c2440\_nand\_select\_chip(void)

int i;

s3c2440nand->NFCONT &= ~(1<<1);

for(i=0; i<10; i++);

/\* 取消片选信号 \*/

static void s3c2440\_nand\_deselect\_chip(void)

s3c2440nand->NFCONT |= (1<<1);

/\* 发出命令 \*/

static void s3c2440\_write\_cmd(int cmd)

volatile unsigned char \*p = (volatile unsigned char \*)&s3c2440nand->NFCMD;

\*p = cmd;

/\* 发出地址 \*/

static void s3c2440\_write\_addr\_lp(unsigned int addr)

int i;

volatile unsigned char \*p = (volatile unsigned char \*)&s3c2440nand->NFADDR;

int col, page;

col = addr & NAND\_BLOCK\_MASK\_LP;        //取得列地址

page = addr / NAND\_SECTOR\_SIZE\_LP;        //取得行地址

\*p = col & 0xff; /\* 列地址 A0~A7 \*/

for(i=0; i<10; i++);

\*p = (col >> 8) & 0x0f;  /\* 列地址 A8~A11 \*/

for(i=0; i<10; i++);

\*p = page & 0xff; /\* 行地址 A12~A19 \*/

for(i=0; i<10; i++);

\*p = (page >> 8) & 0xff; /\* 行地址 A20~A27 \*/

for(i=0; i<10; i++);

\*p = (page >> 16) & 0x03; /\* 行地址 A28~A29 \*/

for(i=0; i<10; i++);

/\* 读取数据 \*/

static unsigned char s3c2440\_read\_data(void)

volatile unsigned char \*p = (volatile unsigned char \*)&s3c2440nand->NFDATA;

return \*p;

/\* 在第一次使用NAND Flash前，复位一下NAND Flash \*/

static void nand\_reset(void)

nand\_chip.nand\_reset();

static void wait\_idle(void)

nand\_chip.wait\_idle();

static void nand\_select\_chip(void)

int i;

nand\_chip.nand\_select\_chip();

for(i=0; i<10; i++);

static void nand\_deselect\_chip(void)

nand\_chip.nand\_deselect\_chip();

static void write\_cmd(int cmd)

nand\_chip.write\_cmd(cmd);

static void write\_addr(unsigned int addr)

nand\_chip.write\_addr(addr);

static unsigned char read\_data(void)

return nand\_chip.read\_data();

/\* 初始化NAND Flash \*/

void nand\_init(void)

\#define TACLS   0

\#define TWRPH0  3

\#define TWRPH1  0

nand\_chip.nand\_reset         = s3c2440\_nand\_reset;

nand\_chip.wait\_idle          = s3c2440\_wait\_idle;

nand\_chip.nand\_select\_chip   = s3c2440\_nand\_select\_chip;

nand\_chip.nand\_deselect\_chip = s3c2440\_nand\_deselect\_chip;

nand\_chip.write\_cmd          = s3c2440\_write\_cmd;

nand\_chip.write\_addr         = s3c2440\_write\_addr\_lp;

nand\_chip.read\_data          = s3c2440\_read\_data;

/\* 设置时序 \*/

s3c2440nand->NFCONF = (TACLS<<12)|(TWRPH0<<8)|(TWRPH1<<4);

/\* 使能NAND Flash控制器, 初始化ECC, 禁止片选 \*/

s3c2440nand->NFCONT = (1<<4)|(1<<1)|(1<<0);

/\* 复位NAND Flash \*/

nand\_reset();

/\* 读函数 用于把nand flash中代码复制到sdram中\*/

void nand\_read(unsigned char \*buf, unsigned long start\_addr, int size)

int i, j;

if ((start\_addr & NAND\_BLOCK\_MASK\_LP) || (size & NAND\_BLOCK\_MASK\_LP)) \{

return ;     /\* 地址或长度不对齐 \*/

/\* 选中芯片 \*/

nand\_select\_chip();

for(i=start\_addr; i < (start\_addr + size);) \{

/\* 发出READ命令 \*/

write\_cmd(0);

/\* 写地址 \*/

write\_addr(i);

write\_cmd(0x30);

wait\_idle();

for(j=0; j < NAND\_SECTOR\_SIZE\_LP; j++, i++) \{

\*buf = read\_data();

buf++;

/\* 取消片选信号 \*/

nand\_deselect\_chip();

return ;

main.c 很简单，点灯

\#defineGPBCON(\*(volatile unsigned long \*)0x56000010)

\#defineGPBDAT(\*(volatile unsigned long \*)0x56000014)

\#defineGPB5\_out(1<<(5\*2))

\#defineGPB6\_out(1<<(6\*2))

\#defineGPB7\_out(1<<(7\*2))

\#defineGPB8\_out(1<<(8\*2))

void  wait(unsigned long dly)

for(; dly > 0; dly--);

int main(void)

unsigned long i = 0;

GPBCON = GPB5\_out|GPB6\_out|GPB7\_out|GPB8\_out; // 将LED1-4对应的GPB5/6/7/8四个引脚设为输出

GPBDAT = ~(1<<5) | ~(1<<7) | ~(1<<8);

while(1)\{

wait(30000);

GPBDAT = (~(i<<5));// 根据i的值，点亮LED1-4

if(++i == 16)

i = 0;

return 0;

最后是Makefile

objs := head.o init.o nand.o main.o

nand.bin : $(objs)

arm-linux-ld -Tnand.lds\-o nand\_elf $^

arm-linux-objcopy -O binary -S nand\_elf $@

arm-linux-objdump -D -m arm  nand\_elf > nand.dis

%.o:%.c

arm-linux-gcc -Wall -c -O2 -o $@ $<

%.o:%.S

arm-linux-gcc -Wall -c -O2 -o $@ $<

clean:

rm -f  nand.dis nand.bin nand\_elf \*.o

[201004111728211471.jpg]: http://www.sectop.com/upload/2010/4/201004111728211471.jpg
[201004111730385042.jpg]: http://www.sectop.com/upload/2010/4/201004111730385042.jpg
[201004111745084806.jpg]: http://www.sectop.com/upload/2010/4/201004111745084806.jpg
[ARM_S3C2410_NandFlash - Fantity Wei - Footprint]: http://img389.ph.126.net/opZ9q8zst_pPDoUnUb9W7g==/1048212813271642750.jpg
[201004111631128652.jpg]: http://www.sectop.com/upload/2010/4/201004111631128652.jpg
[201004112037412468.jpg]: http://www.sectop.com/upload/2010/4/201004112037412468.jpg
[201004111816106632.jpg]: http://www.sectop.com/upload/2010/4/201004111816106632.jpg