Question
Writing/Reading to flash
Posted on February 02, 2014 at 18:20
I have read the ST Flash programming manual and looked at the ST examples. I am using STM32F103VC.
I wrote some code to initialize and write/read from flash memory. This is just a test, but I end up in the hard fault handler so I must be accessing an invalid memory location or something. When debugging I can see that the flash is written in memory. So I think it might be the read function causing this? flash.c:#define FLASH_PAGE_SIZE ((uint16_t) 0x800)
#define BANK1_WRITE_START_ADDR ((uint32_t) 0x08008000) #define PAGES_TO_ERASE 2 static FLASH_Status flashStatus; static uint32_t currentAddress = BANK1_WRITE_START_ADDR + 4; bool_t Flash_Initialize(void) { uint8_t i; //Unlock flash bank 1. FLASH_UnlockBank1(); //Clear pending flags. FLASH_ClearFlag(FLASH_FLAG_EOP | FLASH_FLAG_PGERR | FLASH_FLAG_WRPRTERR); for(i = 0; i < PAGES_TO_ERASE; i++) { flashStatus = FLASH_ErasePage(BANK1_WRITE_START_ADDR + (FLASH_PAGE_SIZE * i)); if(flashStatus != FLASH_COMPLETE) { // FLASH_LockBank1(); return FALSE; } } // FLASH_LockBank1(); return TRUE; } bool_t Flash_Write(uint32_t data) { // FLASH_UnlockBank1(); flashStatus = FLASH_ProgramWord(currentAddress, data); // FLASH_LockBank1(); currentAddress += 4; if(flashStatus != FLASH_COMPLETE) return FALSE; if(Flash_Read( (currentAddress - 4) ) != data) return FALSE; return TRUE; } uint32_t Flash_Read(uint32_t address) { return (*(volatile uint32_t*) address); } main.c:status = Flash_Initialize();
if(status)
{
DEBUG(''Flash initialize OK'');
}
else
{
DEBUG(''Flash initialize FAILED'');
}
status = Flash_Write(0xAAAAAAAA);
if(status)
{
data = Flash_Read(0x08008000);
DEBUG(''Flash write and read back OK: %u\n'', data);
}
else
{
data = Flash_Read(0x08008000);
DEBUG(''Flash write and read back FAILED: %u\n'', data);
}