查看“STM32CubeMX系列教程20:Nand Flash”的源代码



<b>一、Nand Flash 简介</b>
<b>
</b>
        Flash 中文名字叫闪存，是一种长寿命的非易失性（断电数据不丢失）的存储器。可以对称为块的存储器单元块进行擦写和再编程，在进行写入操作之前必须先执行擦除。功能性分为两种：


NOR Flash：允许随机存取存储器上的任何区域，以编码应用为主，其功能多与运算相关
Nand Flash：主要功能是存储资料，适合储存卡之类的大量数据的存储。


本章以K9F1G08U0E芯片为例讲解Nand Flash。如下为此芯片的数据手册：



<a class="attach" href="portal.php?mod=attachment&amp;id=507" target="_blank">K9F1G08U0E.pdf



<b>二、Nand Flash存储结构</b>
<b>
</b>


[[File:112308jakhbuzhshbujasx.png]]



        一个Nand Flash由多个块(Block)组成，每个块里面又包含很多页(page)。每个页对应一个空闲区域/冗余区域(spare area),这个区域不是用来存储数据的，用于放置数据的校验值检测和纠错的。


块，是Nand Flash的擦除操作的基本/最小单位。

页，是Nand Flash的写入操作的基本/最小的单位。


从上图可知，K91FG080U0E包含1024 Blocks，每个Block包含 64 Pages，每个Page包含2K Bytes数据空间 + 64 Bytes冗余空间。故总大小=1024 Blocks  x 64 Pages x (2K+ 64) B = (1024 + 32) MBits = 1G Bits。



K91G08U0E功能框图如下：


[[File:112308ks6spadqa3kq9zbw.png]]



<b>三、Nand Flash引脚功能说明</b>
<b>
</b>


[[File:112309dzvhjxzjda42zj34.png]]



[[File:112309g3ezgkg84gggqgss.png]]


上图是常见的Nand Flash所拥有的引脚(Pin)所对应的功能，简单翻译如下：
<ol style="font-family: 'Microsoft YaHei', 微软雅黑; line-height: 1.5; background-color: rgb(255, 255, 255);">* I/O0 ~ I/O7：用于输入地址/数据/命令，输出数据* CLE：Command Latch Enable，命令锁存使能，在输入命令之前，要先在模式寄存器中，设置CLE使能* ALE：Address Latch Enable，地址锁存使能，在输入地址之前，要先在模式寄存器中，设置ALE使能* CE#：Chip Enable，芯片使能，在操作Nand Flash之前，要先选中此芯片，才能操作* RE#：Read Enable，读使能，在读取数据之前，要先使CE＃有效。* WE#：Write Enable，写使能,在写取数据之前，要先使WE＃有效。* WP#：Write Protect，写保护* R/B#:Ready/Busy Output,就绪/忙,主要用于在发送完编程/擦除命令后,检测这些操作是否完成,忙,表示编程/擦除操作仍在进行中,就绪表示操作完成.*  Vcc：Power，电源* Vss：Ground，接地* N.C：Non-Connection,未定义，未连接</ol>
（字母上面带横杠说明引脚是低电平有效，为书写方便，在字母后面加“#”表示）


<b>四、可变存储控制器(FMC)</b>
<b>
</b>
        FMC,即可变存储控制器，为STM32系列单片机的接口，本章就是通过这个接口控制NAND FLAHS。FMC 功能块可连接：同步/异步静态存储器、 SDRAM 存储器和 NAND Flash。其主要用途有：
* 将 AHB 数据通信事务转换为适当的外部器件协议* 满足外部存储器器件的访问时间要求
        
        说得复杂一点，FMC个功能就是将读写stm32内部地址操作转换为输出满足外部存储器的时序读写外部存储器。例如对STM32内部Ox8000 0000地址写入一个数据，FMC控制器会控制对应的管脚输出一个满足Nand Flash的时序，发送一个数据到Nand Flash设备。同理读取读取内部的寄存器，也会生成一个时序从Nand Flash读取一个数据。因此通过FMC控制外设非常简单，只需读写STM32内部寄存器即可实现对外部存储器的读写操作。我们只需配置好FMC时序寄存器,使产生的时序满足外部存储器的访问时间要求。




[[File:112310bgvl73mmql3v9oza.png]]



        FMC框图如上图，所有外部存储器共享地址、数据和控制信号， 但有各自的片选信号。 FMC 一次只能访问一个外部器件。其中FMC_A[25:0]，FMC_D[31:00]为地址线和数据线，由于Nand Flash地址线和数据线复用，故配置时地址线和数据线是一样的。Nand Flash接口如下图(摘自Open746I-C原理图)。




[[File:112310ll3vlhh9kh39lvs9.png]]



[[File:112311wop3p2loryuwywup.png]]





FMC的存储区域外部储存分配图如图。其中Nand Flash为储存区域3，4x64MB。起始地址为0x8000 0000。




[[File:112311a1zniqxdi24umjmn.png]]



<b style="font-family: 微软雅黑; font-size: 14px;">五、Nand Flash控制时序</b>

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<b>       </b> 和前面介绍的串行Nor Flash芯片W25Q128FV类似，Nand Flash也是通过指令控制的，在这里简单讲解一下Nand Flash的控制时序，讲解这部分只要是为了加深对Nand Flash的了解，和学习看时序图，实际编程的时候是不需要用到的，这部分ST公司已经提供nand flash的库了，我们只需调用函数控制Nand flash即可，不需要再理会底层。
   下面为Nand Flash操作指令:


[[File:112312o9us90jjecs66zok.png]]



        如下编程操作和读操作的时序。首先先拉低NCE片选，只有选中芯片才能让他工作。
 Nand Flash是通过 ALE/CLE 来区分数据线上的数据是命令(CLE有效)，地址(ALE有效)还是数据(CLE/ALE都无效)。通过NWE/NRE来区分数据线上的数据是写操作(NWE有效)还是读操作(NRE有效)。


[[File:112312to7yioyqmmgquqs5.png]]



[[File:112313n1cgmojngcco6px8.png]]

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下面为发送命令的时序图，已经对应的时间参数表：


[[File:112314yrrv8ok5oonzjqtn.png]]



[[File:112315q33li3g3vh323ja2.png]]






用FMC控制Nand Flash 我们只需要知道访问波形图中的四个时间参数既可。


[[File:112315dvivv2z9vx2jyvrg.png]]


从上这三个图我们可以知道：
        MEMxSET = tCLS - tWP >= 0ns
        MEMxWAIT = tWP  >= 12ns
        MEMxHOLED = tCLH >= 5ns
        MEMxHIZ = tCLS - tDS >= 0ns


<b style="font-family: 微软雅黑; font-size: 14px;">六、新建工程</b>

<b style="font-family: 微软雅黑; font-size: 14px;">    <b style="font-size: 14px;">   复制串口printf的工程，修改文件夹名。击STM32F746I.ioc打开STM32cubeMX的工程文件重新配置，选择NCE3开启NAND Flash,数据地址线选择8 bits，Ready or Busy选择 NWAIT。</b></b>
<b style="font-family: 微软雅黑; font-size: 14px;">    </b>
[[File:112315y8r8k6nryre8xgky.png]]



FMC配置NAND Flash如下：使能ECC校验，建立保存等待等时间参数设置可以见上一节的时序图时间参数。
FMC是挂载到AHB时钟线上，频率等于系统时钟频率，即216M，时钟周期为 1 /216 MHz = ~4.6ns。
NAND属性信息根据前面介绍的K91FG080U0E存储结构配置。




[[File:112315vxpd2r05j9rc4cop.png]]



生成报告以及代码，编译程序。在fmc.c文件中可以看到初始化函数。在stm32f7xx_hal_nand.h头文件中可以看到NAND Flash的操作函数。



声明变量: RxBuffer，TxBnffer为读写缓存，大小可以Nand flash一页的长度；NAND_ID储存ID信息，WriteReadAddr为存储Nand Flash操作地址。



<syntaxhighlight lang="python">
/* USER CODE BEGIN PV */</syntaxhighlight>
<syntaxhighlight lang="python">
/* Private variables ---------------------------------------------------------*/</syntaxhighlight>
<syntaxhighlight lang="python">
/* for K9F1G08 */</syntaxhighlight>
<syntaxhighlight lang="python">
#define NAND_PAGE_SIZE             ((uint16_t)0x0800) /* 2 * 1024 bytes per page w/o Spare Area */</syntaxhighlight>
 
<syntaxhighlight lang="python">
NAND_IDTypeDef NAND_ID;</syntaxhighlight>
<syntaxhighlight lang="python">
NAND_AddressTypeDef WriteReadAddr;</syntaxhighlight>
 
<syntaxhighlight lang="python">
static</syntaxhighlight> <syntaxhighlight lang="python">
uint8_t TxBuffer [NAND_PAGE_SIZE];</syntaxhighlight>
<syntaxhighlight lang="python">
static</syntaxhighlight> <syntaxhighlight lang="python">
uint8_t RxBuffer [NAND_PAGE_SIZE];</syntaxhighlight>
<syntaxhighlight lang="python">
uint16_t i;</syntaxhighlight>
<syntaxhighlight lang="python">
/* USER CODE END PV */</syntaxhighlight>
<syntaxhighlight lang="python">

</syntaxhighlight>
<syntaxhighlight lang="python">
</syntaxhighlight>添加应用程序，程序中先读取Nand Flash ID,然后配置操作地址，对页进行擦除，写，读等操作。



<syntaxhighlight lang="python">
</syntaxhighlight>
<syntaxhighlight lang="python">

<code style="color: rgb(221, 17, 68); font-family: Consolas, 'Bitstream Vera Sans Mono', 'Courier New', Courier, monospace !important; font-size: 1em !important;">  </syntaxhighlight><syntaxhighlight lang="python">
/* USER CODE BEGIN 2 */</syntaxhighlight>
<syntaxhighlight lang="python">
  </syntaxhighlight><syntaxhighlight lang="python">
printf</syntaxhighlight><syntaxhighlight lang="python">
(</syntaxhighlight><syntaxhighlight lang="python">
"\r\nNandFlash Example \r\n\r\n"</syntaxhighlight><syntaxhighlight lang="python">
);</syntaxhighlight>
<syntaxhighlight lang="python">
    </syntaxhighlight> 
<syntaxhighlight lang="python">
  </syntaxhighlight><syntaxhighlight lang="python">
/* Read the NAND memory ID */</syntaxhighlight>                                                                  
<syntaxhighlight lang="python">
  </syntaxhighlight><syntaxhighlight lang="python">
HAL_NAND_Read_ID(&amp;hnand1, &amp;NAND_ID);</syntaxhighlight>
 
<syntaxhighlight lang="python">
  </syntaxhighlight><syntaxhighlight lang="python">
printf</syntaxhighlight><syntaxhighlight lang="python">
(</syntaxhighlight><syntaxhighlight lang="python">
"Nand Flash ID = 0x%02X,0x%02X,0x%02X,0x%02X  "</syntaxhighlight><syntaxhighlight lang="python">
,NAND_ID.Maker_Id, NAND_ID.Device_Id,</syntaxhighlight>
<syntaxhighlight lang="python">
                                                 </syntaxhighlight><syntaxhighlight lang="python">
NAND_ID.Third_Id, NAND_ID.Fourth_Id );</syntaxhighlight>
<syntaxhighlight lang="python">
  </syntaxhighlight><syntaxhighlight lang="python">
if</syntaxhighlight> <syntaxhighlight lang="python">
((NAND_ID.Maker_Id == 0xEC) &amp;&amp; (NAND_ID.Device_Id == 0xF1)</syntaxhighlight>
<syntaxhighlight lang="python">
        </syntaxhighlight><syntaxhighlight lang="python">
&amp;&amp; (NAND_ID.Third_Id == 0x80) &amp;&amp; (NAND_ID.Fourth_Id == 0x15))</syntaxhighlight>
<syntaxhighlight lang="python">
  </syntaxhighlight><syntaxhighlight lang="python">
{</syntaxhighlight>
<syntaxhighlight lang="python">
        </syntaxhighlight><syntaxhighlight lang="python">
printf</syntaxhighlight><syntaxhighlight lang="python">
(</syntaxhighlight><syntaxhighlight lang="python">
"Type = K9F1G08U0A\r\n"</syntaxhighlight><syntaxhighlight lang="python">
);</syntaxhighlight>
<syntaxhighlight lang="python">
  </syntaxhighlight><syntaxhighlight lang="python">
}</syntaxhighlight>
<syntaxhighlight lang="python">
  </syntaxhighlight><syntaxhighlight lang="python">
else</syntaxhighlight> <syntaxhighlight lang="python">
if</syntaxhighlight> <syntaxhighlight lang="python">
((NAND_ID.Maker_Id == 0xEC) &amp;&amp; (NAND_ID.Device_Id == 0xF1)</syntaxhighlight>
<syntaxhighlight lang="python">
        </syntaxhighlight><syntaxhighlight lang="python">
&amp;&amp; (NAND_ID.Third_Id == 0x00) &amp;&amp; (NAND_ID.Fourth_Id == 0x95))</syntaxhighlight>
<syntaxhighlight lang="python">
  </syntaxhighlight><syntaxhighlight lang="python">
{</syntaxhighlight>
<syntaxhighlight lang="python">
        </syntaxhighlight><syntaxhighlight lang="python">
printf</syntaxhighlight><syntaxhighlight lang="python">
(</syntaxhighlight><syntaxhighlight lang="python">
"Type = K9F1G08U0B\r\n"</syntaxhighlight><syntaxhighlight lang="python">
);     </syntaxhighlight>
<syntaxhighlight lang="python">
  </syntaxhighlight><syntaxhighlight lang="python">
}</syntaxhighlight>
<syntaxhighlight lang="python">
  </syntaxhighlight><syntaxhighlight lang="python">
else</syntaxhighlight> <syntaxhighlight lang="python">
if</syntaxhighlight> <syntaxhighlight lang="python">
((NAND_ID.Maker_Id == 0xAD) &amp;&amp; (NAND_ID.Device_Id == 0xF1)</syntaxhighlight>
<syntaxhighlight lang="python">
        </syntaxhighlight><syntaxhighlight lang="python">
&amp;&amp; (NAND_ID.Third_Id == 0x80) &amp;&amp; (NAND_ID.Fourth_Id == 0x1D))</syntaxhighlight>
<syntaxhighlight lang="python">
  </syntaxhighlight><syntaxhighlight lang="python">
{</syntaxhighlight>
<syntaxhighlight lang="python">
        </syntaxhighlight><syntaxhighlight lang="python">
printf</syntaxhighlight><syntaxhighlight lang="python">
(</syntaxhighlight><syntaxhighlight lang="python">
"Type = HY27UF081G2A\r\n"</syntaxhighlight><syntaxhighlight lang="python">
);       </syntaxhighlight>
<syntaxhighlight lang="python">
  </syntaxhighlight><syntaxhighlight lang="python">
}</syntaxhighlight>
<syntaxhighlight lang="python">
  </syntaxhighlight><syntaxhighlight lang="python">
else</syntaxhighlight>
<syntaxhighlight lang="python">
  </syntaxhighlight><syntaxhighlight lang="python">
{</syntaxhighlight>
<syntaxhighlight lang="python">
        </syntaxhighlight><syntaxhighlight lang="python">
printf</syntaxhighlight><syntaxhighlight lang="python">
(</syntaxhighlight><syntaxhighlight lang="python">
"Type = Unknow\r\n"</syntaxhighlight><syntaxhighlight lang="python">
);</syntaxhighlight>
<syntaxhighlight lang="python">
  </syntaxhighlight><syntaxhighlight lang="python">
}</syntaxhighlight>
<syntaxhighlight lang="python">
    </syntaxhighlight> 
<syntaxhighlight lang="python">
  </syntaxhighlight><syntaxhighlight lang="python">
/* NAND memory address to write to */</syntaxhighlight>
<syntaxhighlight lang="python">
  </syntaxhighlight><syntaxhighlight lang="python">
WriteReadAddr.Zone = 0x00;</syntaxhighlight>
<syntaxhighlight lang="python">
  </syntaxhighlight><syntaxhighlight lang="python">
WriteReadAddr.Block = 0x00;</syntaxhighlight>
<syntaxhighlight lang="python">
  </syntaxhighlight><syntaxhighlight lang="python">
WriteReadAddr.Page = 0x00;</syntaxhighlight>
 
<syntaxhighlight lang="python">
  </syntaxhighlight><syntaxhighlight lang="python">
/* Erase the NAND first Block */</syntaxhighlight>
<syntaxhighlight lang="python">
  </syntaxhighlight><syntaxhighlight lang="python">
HAL_NAND_Erase_Block(&amp;hnand1,&amp;WriteReadAddr);</syntaxhighlight>
 
<syntaxhighlight lang="python">
  </syntaxhighlight><syntaxhighlight lang="python">
/* Fill the buffer to send */</syntaxhighlight>
<syntaxhighlight lang="python">
  </syntaxhighlight><syntaxhighlight lang="python">
for</syntaxhighlight> <syntaxhighlight lang="python">
(i = 0; i < NAND_PAGE_SIZE; i++ )</syntaxhighlight>
<syntaxhighlight lang="python">
  </syntaxhighlight><syntaxhighlight lang="python">
{</syntaxhighlight>
<syntaxhighlight lang="python">
     </syntaxhighlight><syntaxhighlight lang="python">
TxBuffer[i] = i;</syntaxhighlight>
<syntaxhighlight lang="python">
  </syntaxhighlight><syntaxhighlight lang="python">
}</syntaxhighlight>
 
<syntaxhighlight lang="python">
  </syntaxhighlight><syntaxhighlight lang="python">
/* Write data to FMC NAND memory */</syntaxhighlight>
<syntaxhighlight lang="python">
  </syntaxhighlight><syntaxhighlight lang="python">
HAL_NAND_Write_Page(&amp;hnand1, &amp;WriteReadAddr, TxBuffer, 1);</syntaxhighlight>
<syntaxhighlight lang="python">
  </syntaxhighlight><syntaxhighlight lang="python">
printf</syntaxhighlight><syntaxhighlight lang="python">
(</syntaxhighlight><syntaxhighlight lang="python">
"\r\nWritten to the number of£º \r\n"</syntaxhighlight><syntaxhighlight lang="python">
);</syntaxhighlight>
<syntaxhighlight lang="python">
  </syntaxhighlight><syntaxhighlight lang="python">
for</syntaxhighlight><syntaxhighlight lang="python">
(i = 0; i < 2048; i++)</syntaxhighlight>
<syntaxhighlight lang="python">
      </syntaxhighlight><syntaxhighlight lang="python">
printf</syntaxhighlight><syntaxhighlight lang="python">
(</syntaxhighlight><syntaxhighlight lang="python">
"0x%02X \r"</syntaxhighlight><syntaxhighlight lang="python">
,TxBuffer[i]);</syntaxhighlight>
 
<syntaxhighlight lang="python">
  </syntaxhighlight><syntaxhighlight lang="python">
HAL_Delay(100);</syntaxhighlight>
<syntaxhighlight lang="python">
  </syntaxhighlight><syntaxhighlight lang="python">
/* Read data from FMC NAND memory */</syntaxhighlight>
<syntaxhighlight lang="python">
  </syntaxhighlight><syntaxhighlight lang="python">
HAL_NAND_Read_Page(&amp;hnand1, &amp;WriteReadAddr, RxBuffer, 1);</syntaxhighlight>
<syntaxhighlight lang="python">
  </syntaxhighlight><syntaxhighlight lang="python">
printf</syntaxhighlight><syntaxhighlight lang="python">
(</syntaxhighlight><syntaxhighlight lang="python">
"\r\nRead receive: \r\n"</syntaxhighlight><syntaxhighlight lang="python">
);</syntaxhighlight>
<syntaxhighlight lang="python">
  </syntaxhighlight><syntaxhighlight lang="python">
for</syntaxhighlight><syntaxhighlight lang="python">
(i = 0; i < 2048; i++)</syntaxhighlight>
<syntaxhighlight lang="python">
      </syntaxhighlight><syntaxhighlight lang="python">
printf</syntaxhighlight><syntaxhighlight lang="python">
(</syntaxhighlight><syntaxhighlight lang="python">
"0x%02X \r"</syntaxhighlight><syntaxhighlight lang="python">
,RxBuffer[i]); </syntaxhighlight></code>