/* Code borrowed from http://forum.arduino.cc/index.php?topic=289190.0
Awesome work Mark T!*/


__attribute__ ((section (".ramfunc")))
void _EEFC_ReadUniqueID( unsigned int * pdwUniqueID )
{
    unsigned int status ;
 
    /* Send the Start Read unique Identifier command (STUI) by writing the Flash Command Register with the STUI command.*/
    EFC1->EEFC_FCR = (0x5A << 24) | EFC_FCMD_STUI;
    do
    {
        status = EFC1->EEFC_FSR ;
    } while ( (status & EEFC_FSR_FRDY) == EEFC_FSR_FRDY ) ;

    /* The Unique Identifier is located in the first 128 bits of the Flash memory mapping. So, at the address 0x400000-0x400003. */
    pdwUniqueID[0] = *(uint32_t *)IFLASH1_ADDR;
    pdwUniqueID[1] = *(uint32_t *)(IFLASH1_ADDR + 4);
    pdwUniqueID[2] = *(uint32_t *)(IFLASH1_ADDR + 8);
    pdwUniqueID[3] = *(uint32_t *)(IFLASH1_ADDR + 12);

    /* To stop the Unique Identifier mode, the user needs to send the Stop Read unique Identifier
       command (SPUI) by writing the Flash Command Register with the SPUI command. */
    EFC1->EEFC_FCR = (0x5A << 24) | EFC_FCMD_SPUI ;

    /* When the Stop read Unique Unique Identifier command (SPUI) has been performed, the
       FRDY bit in the Flash Programming Status Register (EEFC_FSR) rises. */
    do
    {
        status = EFC1->EEFC_FSR ;
    } while ( (status & EEFC_FSR_FRDY) != EEFC_FSR_FRDY ) ;
}

void setup ()
{
    Serial.begin (9600) ;

    unsigned int adwUniqueID[5] ;
    WDT_Disable( WDT ) ;

    Serial.println("Reading 128 bits unique identifier \n\r" ) ;
    _EEFC_ReadUniqueID( adwUniqueID ) ;

    Serial.print ("ID: ") ;
    for (byte b = 0 ; b < 4 ; b++)
      Serial.print ((unsigned int) adwUniqueID [b], HEX) ;
    Serial.println () ;
}



void loop() {
  // put your main code here, to run repeatedly:

}