CCS/TM4C1294NCPDT: UART TTL to RS 485 Protocol

#define USER_LED1  GPIO_PIN_0
#define USER_LED2  GPIO_PIN_1

//*****************************************************************************
//
// The error routine that is called if the driver library encounters an error.
//
//*****************************************************************************
#ifdef DEBUG
void
__error__(char *pcFilename, uint32_t ui32Line)
{
}
#endif

//*****************************************************************************
//
// Main 'C' Language entry point.  Toggle an LED using TivaWare.
//
//*****************************************************************************
int
main(void)
{
    uint32_t ui32SysClock;

    //
    // Run from the PLL at 120 MHz.
    //
    ui32SysClock = SysCtlClockFreqSet((SYSCTL_XTAL_25MHZ |
                                       SYSCTL_OSC_MAIN |
                                       SYSCTL_USE_PLL |
                                       SYSCTL_CFG_VCO_480), 120000000);

    //
    // Enable and wait for the port to be ready for access
    //
    SysCtlPeripheralEnable(SYSCTL_PERIPH_GPION);
    while(!SysCtlPeripheralReady(SYSCTL_PERIPH_GPION))
    {
    }

    //
    // Configure the GPIO port for the LED operation.
    //
    GPIOPinTypeGPIOOutput(GPIO_PORTN_BASE, (USER_LED1|USER_LED2));

    //
    // Loop Forever
    //
    while(1)
    {
        //
        // Turn on the LED
        //
        GPIOPinWrite(GPIO_PORTN_BASE, (USER_LED1|USER_LED2), USER_LED1);

        //
        // Delay for a bit
        //
        SysCtlDelay(ui32SysClock/6);

        //
        // Turn on the LED
        //
        GPIOPinWrite(GPIO_PORTN_BASE, (USER_LED1|USER_LED2), USER_LED2);

        //
        // Delay for a bit
        //
        SysCtlDelay(ui32SysClock/6);
    }
}