STM32 Flash für Retain nutzen

uint8_t *p = 0x08040000; //z.B. lesen

void Flash_Unlock(){

  FLASH->KEYR = 0x45670123;

  FLASH->KEYR = 0xCDEF89AB;

}

void Flash_Lock(){

  FLASH->CR |= FLASH_CR_LOCK;

}

void Flash_Erase(uint8_t ucSector){

  while(FLASH->SR & FLASH_SR_BSY);

  FLASH->CR |= FLASH_CR_SER;

  FLASH->CR |= (ucSector << 3);

  FLASH->CR |= FLASH_CR_STRT;

  while(FLASH->SR & FLASH_SR_BSY);

}

void Flash_Write(uint8_t * pucSrc, uint8_t * pucDest, uint16_t usSize){

  while(FLASH->SR & FLASH_SR_BSY);

  FLASH->CR |= FLASH_CR_PG;

  while(usSize-- > 0){

    *pucDest++ = *pucSrc++;

  }

  while(FLASH->SR & FLASH_SR_BSY);

}