stm32 FLASH 模擬 EEPROM 詳解

//讀取指定地址的半字(16位數(shù)據(jù))
//faddr:讀地址(此地址必須為2的倍數(shù)!!)
//返回值:對應(yīng)數(shù)據(jù).
u16 STMFLASH_ReadHalfWord(u32 faddr)
{
return *(vu16*)faddr;
}


#if STM32_FLASH_WREN //如果使能了寫
//不檢查的寫入
//WriteAddr:起始地址
//pBuffer:數(shù)據(jù)指針
//NumToWrite:半字(16位)數(shù)
void STMFLASH_Write_NoCheck(u32 WriteAddr,u16 *pBuffer,u16 NumToWrite)
{
u16 i;
for(i=0;i<NumToWrite;i++)
{
FLASH_ProgramHalfWord(WriteAddr,pBuffer[i]);
WriteAddr+=2;//地址增加2.
}
}
//從指定地址開始寫入指定長度的數(shù)據(jù)
//WriteAddr:起始地址(此地址必須為2的倍數(shù)!!)
//pBuffer:數(shù)據(jù)指針
//NumToWrite:半字(16位)數(shù)(就是要寫入的16位數(shù)據(jù)的個數(shù).)
#if STM32_FLASH_SIZE<256
#define STM_SECTOR_SIZE 1024 //字節(jié)
#else
#define STM_SECTOR_SIZE 2048
#endif
u16 STMFLASH_BUF[STM_SECTOR_SIZE/2];//最多是2K字節(jié)
void STMFLASH_Write(u32 WriteAddr,u16 *pBuffer,u16 NumToWrite)
{
u32 secpos; //扇區(qū)地址
u16 secoff; //扇區(qū)內(nèi)偏移地址(16位字計算)
u16 secremain; //扇區(qū)內(nèi)剩余地址(16位字計算)
u16 i;
u32 offaddr; //去掉0X08000000后的地址
if(WriteAddr<STM32_FLASH_BASE||(WriteAddr>=(STM32_FLASH_BASE+1024*STM32_FLASH_SIZE)))return;//非法地址
FLASH_Unlock(); //解鎖
offaddr=WriteAddr-STM32_FLASH_BASE; //實際偏移地址.
secpos=offaddr/STM_SECTOR_SIZE; //扇區(qū)地址 0~127 for STM32F103RBT6
secoff=(offaddr%STM_SECTOR_SIZE)/2; //在扇區(qū)內(nèi)的偏移(2個字節(jié)為基本單位.)
secremain=STM_SECTOR_SIZE/2-secoff; //扇區(qū)剩余空間大小
if(NumToWrite<=secremain)secremain=NumToWrite;//不大于該扇區(qū)范圍
while(1)
{
STMFLASH_Read(secpos*STM_SECTOR_SIZE+STM32_FLASH_BASE,STMFLASH_BUF,STM_SECTOR_SIZE/2);//讀出整個扇區(qū)的內(nèi)容
for(i=0;i<secremain;i++)//校驗數(shù)據(jù)
{
if(STMFLASH_BUF[secoff+i]!=0XFFFF)break;//需要擦除
}
if(i<secremain)//需要擦除
{
FLASH_ErasePage(secpos*STM_SECTOR_SIZE+STM32_FLASH_BASE);//擦除這個扇區(qū)
for(i=0;i<secremain;i++)//復制
{
STMFLASH_BUF[i+secoff]=pBuffer[i];
}
STMFLASH_Write_NoCheck(secpos*STM_SECTOR_SIZE+STM32_FLASH_BASE,STMFLASH_BUF,STM_SECTOR_SIZE/2);//寫入整個扇區(qū)
}else STMFLASH_Write_NoCheck(WriteAddr,pBuffer,secremain);//寫已經(jīng)擦除了的,直接寫入扇區(qū)剩余區(qū)間.
if(NumToWrite==secremain)break;//寫入結(jié)束了
else//寫入未結(jié)束
{
secpos++; //扇區(qū)地址增1
secoff=0; //偏移位置為0
pBuffer+=secremain; //指針偏移
WriteAddr+=secremain; //寫地址偏移
NumToWrite-=secremain; //字節(jié)(16位)數(shù)遞減
if(NumToWrite>(STM_SECTOR_SIZE/2))secremain=STM_SECTOR_SIZE/2;//下一個扇區(qū)還是寫不完
else secremain=NumToWrite;//下一個扇區(qū)可以寫完了
}
};
FLASH_Lock();//上鎖
}
#endif


//從指定地址開始讀出指定長度的數(shù)據(jù)
//ReadAddr:起始地址
//pBuffer:數(shù)據(jù)指針
//NumToWrite:半字(16位)數(shù)
void STMFLASH_Read(u32 ReadAddr,u16 *pBuffer,u16 NumToRead)
{
u16 i;
for(i=0;i<NumToRead;i++)
{
pBuffer[i]=STMFLASH_ReadHalfWord(ReadAddr);//讀取2個字節(jié).
ReadAddr+=2;//偏移2個字節(jié).
}
}

//////////////////////////////////////////////////////////////////////////////////////////////////////
//WriteAddr:起始地址
//WriteData:要寫入的數(shù)據(jù)
void Test_Write(u32 WriteAddr,u16 WriteData)
{
STMFLASH_Write(WriteAddr,&WriteData,1);//寫入一個字
}