void AT91F_SET_Security (void)
{
if(!(AT91C_BASE_MC->MC_FSR & AT91C_MC_SECURITY))
{
// Write the Errase All command
AT91C_BASE_MC->MC_FCR = ( AT91C_MC_CORRECT_KEY | AT91C_MC_FCMD_SET_SECURITY ) ;

// Wait the and of command
//AT91F_Flash_Ready();
while ((AT91C_BASE_MC->MC_FSR & AT91C_MC_FRDY) != AT91C_MC_FRDY ) {};
}
return ;
}

int main(void)
{
AT91F_SET_Security ();
.....
.....
}