stm32 内部flash

嵌入式闪存

闪存存储器有主存储块和信息块组成

大容量产品主存储块最大为64K×64位，每个存储块划分为256个2K字节的页

编程和擦除闪存

闪存编程一次可以写入16位(半字)

闪存擦除操作可以按页面擦除或完全擦除(全擦除)。全擦除不影响信息块

编程过程

页擦除过程

操作步骤

1.解锁

2.读操作

3.擦除操作

4.写操作

5.获取FLASH状态

6.锁定

举例

#define STM32_FLASH_BASE    0x08000000
#define STM32_PAGE_NUM      256
#define STM32_PAGE_SIZE     (2 * 1024)

void FLASH_read(u16 *buf, u32 addr, u16 num)
{
    u16 i;

    for(i = 0; i < num / 2; i++)
    {
        buf[i] = *((u16*)addr + i);
    }
}

void FLASH_page_write(u16 *buf, u32 addr)
{
    u16 i;
    FLASH_Status s;

    for(i = 0; i < STM32_PAGE_SIZE / 2; i++)
    {
        s = FLASH_ProgramHalfWord(addr + i * 2, buf[i]); //地址+2
        if(s != FLASH_COMPLETE)
        {
            LCD_ShowString(10, 100, tftlcd_data.width, tftlcd_data.height, 16, "FLASH_page_write failed.");
        }
    }
}

u16 FLASH_BUF[STM32_PAGE_SIZE / 2];
void FLASH_write(u16 *buf, u32 addr, u16 num)
{
    u16 i;
    u16 *b = buf;
    u32 a = addr;
    u16 n = num;
    u32 pos;
    u16 offset;
    FLASH_Status s;

    FLASH_Unlock();

    a -= STM32_FLASH_BASE; //FLASH实际地址
    pos = a / STM32_PAGE_SIZE; //页地址
    offset = a % STM32_PAGE_SIZE; //页偏移
    n = STM32_PAGE_SIZE - offset; //页剩余

    if(num < n)
    {
        n = num;
    }

    while(1)
    {
        FLASH_read(FLASH_BUF, pos * STM32_PAGE_SIZE + STM32_FLASH_BASE, STM32_PAGE_SIZE); //读页

        for(i = 0; i < n / 2; i++)
        {
            FLASH_BUF[i + offset / 2] = b[i];
        }

        s = FLASH_ErasePage(pos * STM32_PAGE_SIZE + STM32_FLASH_BASE); //擦除页
        if(s != FLASH_COMPLETE)
        {
            LCD_ShowString(10, 80, tftlcd_data.width, tftlcd_data.height, 16, "FLASH_ErasePage failed.");
            break;
        }

        FLASH_page_write(FLASH_BUF, pos * STM32_PAGE_SIZE + STM32_FLASH_BASE); //写页

        if(n == num) //结束标志
        {
            break;
        }

        num -= n;
        b += n;
        pos++;
        offset = 0;
        if(num > STM32_PAGE_SIZE)
        {
            n = STM32_PAGE_SIZE;
        }
        else
        {
            n = num;
        }
    }

    FLASH_Lock();
}