EEPW论坛

//4Kbytes为一个Sector
//16个扇区为1个Block
//W25X16
//容量为2M字节,共有32个Block,512个Sector

//初始化SPI FLASH的IO口
void SPI_Flash_Init(void)
{
 RCC->APB2ENR|=1<<2;       //PORTA时钟使能     
 //这里
 GPIOA->CRL&=0XFFF000FF;
 GPIOA->CRL|=0X00033300;//PA2.3.4 推挽     
 GPIOA->ODR|=0X7<<2;    //PA2.3.4上拉
 SPIx_Init();     //初始化SPI
} 

//读取SPI_FLASH的状态寄存器
//BIT7  6   5   4   3   2   1   0
//SPR   RV  TB BP2 BP1 BP0 WEL BUSY
//SPR:默认0,状态寄存器保护位,配合WP使用
//TB,BP2,BP1,BP0:FLASH区域写保护设置
//WEL:写使能锁定
//BUSY:忙标记位(1,忙;0,空闲)
//默认:0x00
u8 SPI_Flash_ReadSR(void)  
{ 
 u8 byte=0;  
 SPI_FLASH_CS=0;                            //使能器件  
 SPIx_ReadWriteByte(W25X_ReadStatusReg);    //发送读取状态寄存器命令   
 byte=SPIx_ReadWriteByte(0Xff);             //读取一个字节 
 SPI_FLASH_CS=1;                            //取消片选    
 return byte;  
}
//写SPI_FLASH状态寄存器
//只有SPR,TB,BP2,BP1,BP0(bit 7,5,4,3,2)可以写!!!
void SPI_FLASH_Write_SR(u8 sr)  
{  
 SPI_FLASH_CS=0;                            //使能器件  
 SPIx_ReadWriteByte(W25X_WriteStatusReg);   //发送写取状态寄存器命令   
 SPIx_ReadWriteByte(sr);               //写入一个字节 
 SPI_FLASH_CS=1;                            //取消片选           
}  
//SPI_FLASH写使能 
//将WEL置位  
void SPI_FLASH_Write_Enable(void)  
{
 SPI_FLASH_CS=0;                            //使能器件  
    SPIx_ReadWriteByte(W25X_WriteEnable);      //发送写使能 
 SPI_FLASH_CS=1;                            //取消片选           
}
//SPI_FLASH写禁止 
//将WEL清零 
void SPI_FLASH_Write_Disable(void)  
{ 
 SPI_FLASH_CS=0;                            //使能器件  
    SPIx_ReadWriteByte(W25X_WriteDisable);     //发送写禁止指令   
 SPI_FLASH_CS=1;                            //取消片选           
}       
//读取芯片ID W25X16的ID:0XEF14
u16 SPI_Flash_ReadID(void)
{
 u16 Temp = 0;  
 SPI_FLASH_CS=0;       
 SPIx_ReadWriteByte(0x90);//发送读取ID命令    
 SPIx_ReadWriteByte(0x00);     
 SPIx_ReadWriteByte(0x00);     
 SPIx_ReadWriteByte(0x00);        
 Temp|=SPIx_ReadWriteByte(0xFF)<<8; 
 Temp|=SPIx_ReadWriteByte(0xFF); 
 SPI_FLASH_CS=1;       
 return Temp;
}        
//读取SPI FLASH 
//在指定地址开始读取指定长度的数据
//pBuffer:数据存储区
//ReadAddr:开始读取的地址(24bit)
//NumByteToRead:要读取的字节数(最大65535)
void SPI_Flash_Read(u8* pBuffer,u32 ReadAddr,u16 NumByteToRead)  
{
  u16 i;                   
 SPI_FLASH_CS=0;                            //使能器件  
    SPIx_ReadWriteByte(W25X_ReadData);         //发送读取命令  
    SPIx_ReadWriteByte((u8)((ReadAddr)>>16));  //发送24bit地址   
    SPIx_ReadWriteByte((u8)((ReadAddr)>>8));  
    SPIx_ReadWriteByte((u8)ReadAddr);  
    for(i=0;i<NumByteToRead;i++)
 {
        pBuffer[i]=SPIx_ReadWriteByte(0XFF);   //循环读数 
    }
 SPI_FLASH_CS=1;                            //取消片选           
} 
//SPI在一页(0~65535)内写入少于256个字节的数据
//在指定地址开始写入最大256字节的数据
//pBuffer:数据存储区
//WriteAddr:开始写入的地址(24bit)
//NumByteToWrite:要写入的字节数(最大256),该数不应该超过该页的剩余字节数!!! 
void SPI_Flash_Write_Page(u8* pBuffer,u32 WriteAddr,u16 NumByteToWrite)
{
  u16 i; 
    SPI_FLASH_Write_Enable();                  //SET WEL
 SPI_FLASH_CS=0;                            //使能器件  
    SPIx_ReadWriteByte(W25X_PageProgram);      //发送写页命令  
    SPIx_ReadWriteByte((u8)((WriteAddr)>>16)); //发送24bit地址   
    SPIx_ReadWriteByte((u8)((WriteAddr)>>8));  
    SPIx_ReadWriteByte((u8)WriteAddr);  
    for(i=0;i<NumByteToWrite;i++)SPIx_ReadWriteByte(pBuffer[i]);//循环写数 
 SPI_FLASH_CS=1;                            //取消片选
 SPI_Flash_Wait_Busy();        //等待写入结束
}
//无检验写SPI FLASH
//必须确保所写的地址范围内的数据全部为0XFF,否则在非0XFF处写入的数据将失败!
//具有自动换页功能
//在指定地址开始写入指定长度的数据,但是要确保地址不越界!
//pBuffer:数据存储区
//WriteAddr:开始写入的地址(24bit)
//NumByteToWrite:要写入的字节数(最大65535)
//CHECK OK
void SPI_Flash_Write_NoCheck(u8* pBuffer,u32 WriteAddr,u16 NumByteToWrite)  
{       
 u16 pageremain;   
 pageremain=256-WriteAddr%256; //单页剩余的字节数       
 if(NumByteToWrite<=pageremain)pageremain=NumByteToWrite;//不大于256个字节
 while(1)
 {   
  SPI_Flash_Write_Page(pBuffer,WriteAddr,pageremain);
  if(NumByteToWrite==pageremain)break;//写入结束了
   else //NumByteToWrite>pageremain
  {
   pBuffer+=pageremain;
   WriteAddr+=pageremain; 

   NumByteToWrite-=pageremain;     //减去已经写入了的字节数
   if(NumByteToWrite>256)pageremain=256; //一次可以写入256个字节
   else pageremain=NumByteToWrite;    //不够256个字节了
  }
 };    
}
//写SPI FLASH 
//在指定地址开始写入指定长度的数据
//该函数带擦除操作!
//pBuffer:数据存储区
//WriteAddr:开始写入的地址(24bit)
//NumByteToWrite:要写入的字节数(最大65535)      
u8 SPI_FLASH_BUF[4096];
void SPI_Flash_Write(u8* pBuffer,u32 WriteAddr,u16 NumByteToWrite)  
{
 u32 secpos;
 u16 secoff;
 u16 secremain;   
  u16 i;   

 secpos=WriteAddr/4096;//扇区地址 0~511 for w25x16
 secoff=WriteAddr%4096;//在扇区内的偏移
 secremain=4096-secoff;//扇区剩余空间大小  

 if(NumByteToWrite<=secremain)secremain=NumByteToWrite;//不大于4096个字节
 while(1)
 { 
  SPI_Flash_Read(SPI_FLASH_BUF,secpos*4096,4096);//读出整个扇区的内容
  for(i=0;i<secremain;i++)//校验数据
  {
   if(SPI_FLASH_BUF[secoff+i]!=0XFF)break;//需要擦除    
  }
  if(i<secremain)//需要擦除
  {
   SPI_Flash_Erase_Sector(secpos);//擦除这个扇区
   for(i=0;i<secremain;i++)    //复制
   {
    SPI_FLASH_BUF[i+secoff]=pBuffer[i];  
   }
   SPI_Flash_Write_NoCheck(SPI_FLASH_BUF,secpos*4096,4096);//写入整个扇区 

  }else SPI_Flash_Write_NoCheck(pBuffer,WriteAddr,secremain);//写已经擦除了的,直接写入扇区剩余区间.       
  if(NumByteToWrite==secremain)break;//写入结束了
  else//写入未结束
  {
   secpos++;//扇区地址增1
   secoff=0;//偏移位置为0  

      pBuffer+=secremain;  //指针偏移
   WriteAddr+=secremain;//写地址偏移   
      NumByteToWrite-=secremain;    //字节数递减
   if(NumByteToWrite>4096)secremain=4096; //下一个扇区还是写不完
   else secremain=NumByteToWrite;   //下一个扇区可以写完了
  } 
 };   
}
//擦除整个芯片
//整片擦除时间:
//W25X16:25s
//W25X32:40s
//W25X64:40s
//等待时间超长...
void SPI_Flash_Erase_Chip(void)  
{                                            
    SPI_FLASH_Write_Enable();                  //SET WEL
    SPI_Flash_Wait_Busy();  
   SPI_FLASH_CS=0;                            //使能器件  
    SPIx_ReadWriteByte(W25X_ChipErase);        //发送片擦除命令 
 SPI_FLASH_CS=1;                            //取消片选           
 SPI_Flash_Wait_Busy();          //等待芯片擦除结束
}  
//擦除一个扇区
//Dst_Addr:扇区地址 0~511 for w25x16
//擦除一个山区的最少时间:150ms
void SPI_Flash_Erase_Sector(u32 Dst_Addr)  
{  
 Dst_Addr*=4096;
    SPI_FLASH_Write_Enable();                  //SET WEL  
    SPI_Flash_Wait_Busy();  
   SPI_FLASH_CS=0;                            //使能器件  
    SPIx_ReadWriteByte(W25X_SectorErase);      //发送扇区擦除指令
    SPIx_ReadWriteByte((u8)((Dst_Addr)>>16));  //发送24bit地址   
    SPIx_ReadWriteByte((u8)((Dst_Addr)>>8));  
    SPIx_ReadWriteByte((u8)Dst_Addr); 
 SPI_FLASH_CS=1;                            //取消片选           
    SPI_Flash_Wait_Busy();          //等待擦除完成
} 
//等待空闲
void SPI_Flash_Wait_Busy(void)  
{  
 while ((SPI_Flash_ReadSR()&0x01)==0x01);   // 等待BUSY位清空
} 
//进入掉电模式
void SPI_Flash_PowerDown(void)  
{
   SPI_FLASH_CS=0;                            //使能器件  
    SPIx_ReadWriteByte(W25X_PowerDown);        //发送掉电命令 
 SPI_FLASH_CS=1;                            //取消片选           
    delay_us(3);                               //等待TPD 
}  
//唤醒
void SPI_Flash_WAKEUP(void)  
{ 
   SPI_FLASH_CS=0;                            //使能器件  
    SPIx_ReadWriteByte(W25X_ReleasePowerDown);   //  send W25X_PowerDown command 0xAB   
 SPI_FLASH_CS=1;                            //取消片选           
    delay_us(3);                               //等待TRES1
}   

#define SPI_FLASH_CS PAout(2)  //选中FLASH     
////////////////////////////////////////////////////////////////////////////
//W25X40读写
#define FLASH_ID 0XEF12           //W25X系列的FLASH从数据手册找到ID
//指令表
#define W25X_WriteEnable  0x06
#define W25X_WriteDisable  0x04
#define W25X_ReadStatusReg  0x05
#define W25X_WriteStatusReg  0x01
#define W25X_ReadData   0x03
#define W25X_FastReadData  0x0B
#define W25X_FastReadDual  0x3B
#define W25X_PageProgram  0x02
#define W25X_BlockErase   0xD8
#define W25X_SectorErase  0x20
#define W25X_ChipErase   0xC7
#define W25X_PowerDown   0xB9
#define W25X_ReleasePowerDown 0xAB
#define W25X_DeviceID   0xAB
#define W25X_ManufactDeviceID 0x90
#define W25X_JedecDeviceID  0x9F

void SPI_Flash_Init(void);
u16  SPI_Flash_ReadID(void);       //读取FLASH ID
u8  SPI_Flash_ReadSR(void);        //读取状态寄存器
void SPI_FLASH_Write_SR(u8 sr);   //写状态寄存器
void SPI_FLASH_Write_Enable(void);  //写使能
void SPI_FLASH_Write_Disable(void); //写保护
void SPI_Flash_Read(u8* pBuffer,u32 ReadAddr,u16 NumByteToRead);   //读取flash
void SPI_Flash_Write(u8* pBuffer,u32 WriteAddr,u16 NumByteToWrite);//写入flash
void SPI_Flash_Erase_Chip(void);       //整片擦除
void SPI_Flash_Erase_Sector(u32 Dst_Addr);//扇区擦除
void SPI_Flash_Wait_Busy(void);           //等待空闲
void SPI_Flash_PowerDown(void);           //进入掉电模式
void SPI_Flash_WAKEUP(void);     //唤醒

详情请登录网友——正点原子官方论坛http://www.openedv.com/forums/list.htm或下载《STM32不完全手册V2.0》
源代码：实验16 SPI实验.rar


注意：我板上用的是W25X40（虽然图片上显示W25X16），查到FLASH_ID是0XEF12。