how to write flash memory in stm32f030

1// You can write into flash page but can not over write erase page before write again.
2//https://stackoverflow.com/questions/47373317/how-to-write-erase-on-chip-flash-continuously-in-stm32f030-family
3uint32_t pageAddress = 0x08008000;
4  uint16_t buffer = 0xdddd;          // data buffer
5  HAL_HAL_StatusTypeDef  status;
6
7  while(1)
8  { 
9     HAL_FLASH_Unlock();              // unlock the flash memory in ST
10     //FLASH_PageErase(pageAddress); 
11     status=HAL_FLASH_Program(FLASH_TYPEPROGRAM_HALFWORD, pageAddress, 
12     buffer);
13     HAL_FLASH_Lock();                // Flash memory locked
14  }
15