read and write data from internal memory

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//******************************************************************************
//  MSP430G2xx1 Demo - Flash In-System Programming, Copy SegC to SegD
//
//  Description: This program first erases flash seg C, then it increments all
//  values in seg C, then it erases seg D, then copies seg C to seg D.
//  Assumed MCLK 771kHz - 1428kHz.
//  //* Set Breakpoint on NOP in the Mainloop to avoid Stressing Flash *//
//
//               MSP430G2xx1
//            -----------------
//        /|\|              XIN|-
//         | |                 |
//         --|RST          XOUT|-
//           |                 |
//
//  D. Dang
//  Texas Instruments Inc.
//  October 2010
//  Built with CCS Version 4.2.0 and IAR Embedded Workbench Version: 5.10
//******************************************************************************

#include <msp430.h>

char  value;                                // 8-bit value to write to segment A

// Function prototypes
void write_SegC (char value);
void copy_C2D (void);

int main(void)
{
  WDTCTL = WDTPW + WDTHOLD;                 // Stop watchdog timer
  if (CALBC1_1MHZ==0xFF)					// If calibration constants erased
  {											
    while(1);                               // do not load, trap CPU!!	
  }
  DCOCTL = 0;                               // Select lowest DCOx and MODx settings
  BCSCTL1 = CALBC1_1MHZ;                    // Set DCO to 1MHz
  DCOCTL = CALDCO_1MHZ;
  FCTL2 = FWKEY + FSSEL0 + FN1;             // MCLK/3 for Flash Timing Generator
  value = 0;                                // initialize value

  while(1)                                  // Repeat forever
  {
    write_SegC(value++);                    // Write segment C, increment value
    copy_C2D();                             // Copy segment C to D
    _NOP();                                 // SET BREAKPOINT HERE
  }
}

void write_SegC (char value)
{
  char *Flash_ptr;                          // Flash pointer
  unsigned int i;

  Flash_ptr = (char *) 0x1040;              // Initialize Flash pointer
  FCTL1 = FWKEY + ERASE;                    // Set Erase bit
  FCTL3 = FWKEY;                            // Clear Lock bit
  *Flash_ptr = 0;                           // Dummy write to erase Flash segment

  FCTL1 = FWKEY + WRT;                      // Set WRT bit for write operation

  for (i=0; i<64; i++)
  {
    *Flash_ptr++ = value;                   // Write value to flash
  }

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

void copy_C2D (void)
{
  char *Flash_ptrC;                         // Segment C pointer
  char *Flash_ptrD;                         // Segment D pointer
  unsigned int i;

  Flash_ptrC = (char *) 0x1040;             // Initialize Flash segment C pointer
  Flash_ptrD = (char *) 0x1000;             // Initialize Flash segment D pointer
  FCTL1 = FWKEY + ERASE;                    // Set Erase bit
  FCTL3 = FWKEY;                            // Clear Lock bit
  *Flash_ptrD = 0;                          // Dummy write to erase Flash segment D
  FCTL1 = FWKEY + WRT;                      // Set WRT bit for write operation

  for (i=0; i<64; i++)
  {
    *Flash_ptrD++ = *Flash_ptrC++;          // copy value segment C to segment D
  }

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