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
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();
}