Flash Mem. Read/Write

Question

Using SerialPort communication between PC and MSP430F5438A. It's C# on the PC side and Code Composer Studio (CCS) on the MSP430 side. I'm sending "Hello World!" to MCU. I set the flash pointer to address 0x20000:

unsigned long *Flash_ptr= 0x20000;               // Initialize Flash pointer

then I write to flash (This procedure repeat itself as the number of the chars in the string or the text file):

void write_SegC(char data)
{
 //__disable_interrupt();                  // 5xx Workaround: Disable global
                                        // interrupt while erasing. Re-Enable
                                        // GIE if needed
 FCTL3 = FWKEY;                            // Clear Lock bit
 FCTL1 = FWKEY+ERASE;                      // Set Erase bit
 *(unsigned int *)Flash_ptr = 0;           // Dummy write to erase Flash seg
 FCTL1 = FWKEY+WRT;                        // Set WRT bit for write operation
 while(!(WAIT & FCTL3));
 *Flash_ptr++ = data;                   // Write value to flash


 FCTL1 = FWKEY;                            // Clear WRT bit
 FCTL3 = FWKEY+LOCK;                       // Set LOCK bit
 }

And then send it back to PC:

void read_SegC(void)
{
  unsigned long i;
  Flash_ptr=0x20000;
  for(i = 0; i < 8; i++)
  {
      while(!(WAIT & FCTL3));
      while(!(UCA1IFG & UCTXIFG));
      UCA1TXBUF=*Flash_ptr++;                 // Write long int to Flash
  }
}

what I get in PC: 2d!Wo

instead of: Hello World! which means I just get some chars of the string! the rest are garbage. What I did wrong?

Answer 1

You need to add a busy check prior to moving on and writing to the next location. Something along these lines should appear after writing at each location.

while(FCTL3 & BUSY){};

Where busy is defined as 0x01 - We're checking to see if FCTL3 Bit 0 is set.

Here is my flash write method in its entirety:

/*!
* \brief Writes an array of 8 bit unsigned integers to the flash.
* \param[in]     p_data  pointer to the data to write
* \param[in,out] p_flash starting address to write to
* \param[in]     count   size of the array to write
*
* \warning This function cannot be used to write to INFO A
*/
void flash_write(const uint8_t * p_data, uint8_t * p_flash, uint16_t count)
{

    FCTL3 = FWKEY;                  // Clear Lock bit and set the
                                    // Flash write password of FCTL3
    FCTL1 = FWKEY + WRT;            // Enable byte/word write mode and set the
                                    // Flash write password of FCTL1
    while (count > 0u){
        while (FCTL3 & BUSY)        // Wait if the flash is busy
        {}
        *p_flash = *p_data; // Write to Flash
        p_flash++;
        p_data++;
        count--;
    }
    FCTL1 = FWKEY;                  // Clear write bit
    FCTL3 = FWKEY + LOCK;           // Set LOCK bit
}