Erasing external FLASH

问题

I'm working with a MCF51EM256 Freescale microcontroller and I've some problems to store data in the external flash memory to make it persistent.

I need to store this struct:

typedef struct {
  ui64_s Ea_ps; 
  ui64_s Ea_ng;  
  ui64_s Er_q1;
  ui64_s Er_q2;
  ui64_s Er_q3;
  ui64_s Er_q4;
  uint16 F_ea;
  uint16 F_er;
}Ws_EnergyAcc64;

Where:

typedef union{    
  uint64 v;
  uint32 p[2];  
} ui64_s;

and:

typedef unsigned long long int uint64;
typedef unsigned long int uint32;
typedef unsigned short int uint16;

In order to do this, I've implemented this function:

void Save_Flash_WsEnergyAcc(long addr, Ws_EnergyAcc64* Acc) {

  // WsEnergyAcc struct needs 56 bytes in Flash

  uint32 F_ea_32 = (uint32) Acc->F_ea;
  uint32 F_er_32 = (uint32) Acc->F_er;

  Flash_Erase(addr);
  Flash_Erase(addr + 4);
  Flash_Burst(addr, 2, Acc->Ea_ps.p);

  Flash_Erase(addr + 8);
  Flash_Erase(addr + 12);
  Flash_Burst(addr + 8, 2, Acc->Ea_ng.p);

  Flash_Erase(addr + 16);
  Flash_Erase(addr + 20);
  Flash_Burst(addr + 16, 2, Acc->Er_q1.p);

  Flash_Erase(addr + 24);
  Flash_Erase(addr + 28);
  Flash_Burst(addr + 24, 2, Acc->Er_q2.p);

  Flash_Erase(addr + 32);
  Flash_Erase(addr + 36);
  Flash_Burst(addr + 32, 2, Acc->Er_q3.p);

  Flash_Erase(addr + 40);
  Flash_Erase(addr + 44);
  Flash_Burst(addr + 40, 2, Acc->Er_q4.p);

  Flash_Erase(addr + 48);
  Flash_Burst(addr + 48, 2, &F_ea_32);

  Flash_Erase(addr + 52);
  Flash_Burst(addr + 52, 2, &F_er_32);

}

Where "Flash_Burst" and "Flash_Erase":

#define FLASH_MASS_ERASE_CMD  0x41
#define FLASH_ERASE_CMD       0x40
#define FLASH_PROGRAM_CMD     0x20
#define FLASH_BURST_CMD       0x25

/* Macros to call the function using the different features */
#define Flash_Erase(Address) \
      Flash_Cmd((UINT32)Address, (UINT16)1, (UINT32*)CUSTOM_ROM_ADDRESS, FLASH_ERASE_CMD)

#define Flash_Burst(Address, Size, DataPtr) \
      Flash_Cmd((UINT32)Address, (UINT16)Size, (UINT32*)DataPtr, FLASH_BURST_CMD)

UINT8 /*far*/ 
Flash_Cmd(UINT32 FlashAddress, 
      UINT16 FlashDataCounter, 
      UINT32 *pFlashDataPtr, 
      UINT8 FlashCommand)
{
  /* Check to see if FACCERR or PVIOL is set */
  if (FSTAT &0x30)  
  {         
      /* Clear Flags if set*/
      FSTAT = 0x30;  
  }

  if (FlashDataCounter)
  {
    do
    {
        /* Wait for the Last Busrt Command to complete */
        while(!(FSTAT&FSTAT_FCBEF_MASK)){};/*wait until termination*/

        /* Write Data into Flash*/
        (*((volatile unsigned long *)(FlashAddress))) = *pFlashDataPtr;
        FlashAddress += 4;
        pFlashDataPtr++;

        /* Write Command */
        FCMD = FlashCommand;

        /* Put FCBEF at 1 */
        FSTAT = FSTAT_FCBEF_MASK;

        asm (NOP);
        asm (NOP);
        asm (NOP);

         /* Check if Flash Access Error or Protection Violation Error are Set */
        if (FSTAT&0x30)
        {     
          /* If so, finish the function returning 1 to indicate error */
          return (1);
        }

    }while (--FlashDataCounter);
  }
  /* wait for the last command to complete */
  while ((FSTAT&FSTAT_FCCF_MASK)==0){};/*wait until termination*/

  /* Return zero to indicate that the function executed OK */
  return (0);
}

I also defined:

extern unsigned char __CUSTOM_ROM[];
extern unsigned char __CUSTOM_ROM_SIZE[];

#define CUSTOM_ROM_ADDRESS      (unsigned long int)__CUSTOM_ROM
#define CUSTOM_ROM_SIZE         (unsigned long int)__CUSTOM_ROM_SIZE

I don't understand what is CUSTOM_ROM_ADDRESS, and it causes a link error in my project:

C:/Freescale/CW MCU    v10.6.4/MCU/ColdFire_Tools/Command_Line_Tools/mwldmcf|Linker|Error
>Undefined : "__CUSTOM_ROM"

I think it could be the data wich is stored in the erased address, and I tryed to do something like this (instead Flash_Erase(address)):

void EraseFlash(long addr) {

    uint32 eraseData = 0xFFFFFFFF;
    Flash_Cmd((uint32)addr, (uint16)1, (uint32*)&eraseData, 0x40);

}

It works in the first execution of "Save_Flash_WsEnergyAcc", but I cannot explain why it blocks the MCU the next times.

¿Can someone tell me what I'm doing wrong? Thank you all!

回答1:

The MCF51EM256 Freescale microcontroller only allows erase flash memory by 1024 bytes sectors.

If I call the Erase function each time I want to write the flash memory the MCU will be blocked.

来源：https://stackoverflow.com/questions/36260611/erasing-external-flash