44. Flash operation program

1. Read half word (16 bits) function

//Read the half word (16-bit data) of the specified address

//faddr: read address (this address must be a multiple of 2!!)

//Return value: corresponding data.

u16 STMFLASH_ReadHalfWord(u32 faddr)

{

return *(vu16*)faddr; 

}

2. Direct writing without checking

// Write without checking

//WriteAddr: starting address

//pBuffer: data pointer

//NumToWrite: half-word (16-bit) number   

void STMFLASH_Write_NoCheck(u32 WriteAddr,u16 *pBuffer,u16 NumToWrite)   

{  

u16 i;

for(i=0;i

{

FLASH_ProgramHalfWord(WriteAddr,pBuffer[i]);

   WriteAddr+=2; //Address increases by 2. Write one half word at a time (16-bit number)

}  

} 

3. Read data of specified length from specified address

//Read data of specified length starting from the specified address

//ReadAddr: starting address

//pBuffer: data pointer

//NumToWrite: half-word (16-bit) number

void STMFLASH_Read(u32 ReadAddr,u16 *pBuffer,u16 NumToRead)  

{

u16 i;

for(i=0;i

{

pBuffer[i]=STMFLASH_ReadHalfWord(ReadAddr); //Read 2 bytes.

ReadAddr+=2; //Offset 2 bytes.

}

}

4. Write data of specified length starting from the specified address

Program ideas

//Write data of specified length starting from the specified address

//WriteAddr: starting address (this address must be a multiple of 2!!)

//pBuffer: data pointer

//NumToWrite: half-word (16-bit) number (that is, the number of 16-bit data to be written.)

#if STM32_FLASH_SIZE<256

#define STM_SECTOR_SIZE 1024 // bytes

#else 

#define STM_SECTOR_SIZE 2048

#endif  

u16 STMFLASH_BUF[STM_SECTOR_SIZE/2]; // up to 2K bytes

void STMFLASH_Write(u32 WriteAddr,u16 *pBuffer,u16 NumToWrite)

{

u32 secpos; //sector address

u16 secoff; //Inside sector offset address (16-bit word calculation)

u16 secremain; // Remaining addresses in the sector (16-bit word calculation)   

  u16 i;    

u32 offaddr; // remove the address after 0X08000000

if(WriteAddr=(STM32_FLASH_BASE+1024*STM32_FLASH_SIZE)))return;//Illegal address, first determine whether the address to be written is an illegal address

FLASH_Unlock(); //Unlock

offaddr=WriteAddr-STM32_FLASH_BASE; //actual offset address.

secpos=offaddr/STM_SECTOR_SIZE; //sector address 0~127 for STM32F103RBT6, determine which page or sector

secoff=(offaddr%STM_SECTOR_SIZE)/2; //Offset within the sector (2 bytes as the basic unit.)

secremain=STM_SECTOR_SIZE/2-secoff; //Sector remaining space size   

if(NumToWrite<=secremain)secremain=NumToWrite; //Not larger than the sector range

while(1) 

{

STMFLASH_Read(secpos*STM_SECTOR_SIZE+STM32_FLASH_BASE,STMFLASH_BUF,STM_SECTOR_SIZE/2); //Read the contents of the entire sector and read it into STMFLASH_BUF

for(i=0;i

{

if(STMFLASH_BUF[secoff+i]!=0XFFFF)break;//need to erase    

}

If (i) the check above is aborted midway, i must be less than secretmain, otherwise if all checks are successful, i should be equal to secretmain.

{

FLASH_ErasePage(secpos*STM_SECTOR_SIZE+STM32_FLASH_BASE);//Erase this sector

                        for(i=0;i

{

STMFLASH_BUF[i+secoff]=pBuffer[i]; //Write the data to be updated to the array

}

STMFLASH_Write_NoCheck(secpos*STM_SECTOR_SIZE+STM32_FLASH_BASE,STMFLASH_BUF,STM_SECTOR_SIZE/2);//Write the entire sector  

}

               else STMFLASH_Write_NoCheck(WriteAddr,pBuffer,secremain);//Write what has been erased, directly write to the remaining area of ​​the sector.   

if(NumToWrite==secremain)break;//Writing is finished

                else //Writing is not finished

{

secpos++; //Increase the sector address by 1

secoff=0; //Offset position is 0  

  pBuffer+=secremain; //Pointer offset

WriteAddr+=secremain; //write address offset   

  NumToWrite-=secremain; //Number of bytes (16 bits) decreases

if(NumToWrite>(STM_SECTOR_SIZE/2))secremain=STM_SECTOR_SIZE/2; //The next sector cannot be written completely

else secremain=NumToWrite; //The next sector can be written

}  

};

FLASH_Lock(); //Lock

}