TM4C129XNCZAD: Interrupt driven Uart reception problem

Hi all Im working on Interrupt driven uart reception in tm4c129xnczad microcontroller , im working in code composer studio the problem is im not getting the uart reception and the isr handler is not triggered, I have attached my code here below

Any tho

//*****************************************************************************
//
// The UART interrupt handler.
//
//*****************************************************************************
void
UARTIntHandler(void)
{
    uint32_t ui32Status;
    GPIOPinWrite(GPIO_PORTF_BASE, GPIO_PIN_4, GPIO_PIN_4);
    //
    // Get the interrrupt status.
    //
    ui32Status = MAP_UARTIntStatus(UART0_BASE, true);

    //
    // Clear the asserted interrupts.
    //
    MAP_UARTIntClear(UART0_BASE, ui32Status);

    //
    // Loop while there are characters in the receive FIFO.
    //
    while(MAP_UARTCharsAvail(UART0_BASE))
    {
        //
        // Read the next character from the UART and write it back to the UART.
        //
        MAP_UARTCharPutNonBlocking(UART0_BASE,
                                   UARTCharGetNonBlocking(UART0_BASE));
    }
}
//*****************************************************************************
//
// Send a string to the UART.
//
//*****************************************************************************
void
UARTSend(const uint8_t *pui8Buffer, uint32_t ui32Count)
{
    //
    // Loop while there are more characters to send.
    //
    while(ui32Count--)
    {
        //
        // Write the next character to the UART.
        //
        MAP_UARTCharPutNonBlocking(UART0_BASE, *pui8Buffer++);
    }
}


void delayMs(uint32_t ui32Ms) {

	// 1 clock cycle = 1 / SysCtlClockGet() second
	// 1 SysCtlDelay = 3 clock cycle = 3 / SysCtlClockGet() second
	// 1 second = SysCtlClockGet() / 3
	// 0.001 second = 1 ms = SysCtlClockGet() / 3 / 1000

	SysCtlDelay(ui32Ms * (120000000 / 3 / 1000));
}

void delayUs(uint32_t ui32Us)
{
	SysCtlDelay(ui32Us * (120000000 / 3 / 1000000));
}
int main(void)
{
    volatile uint32_t ui32Loop;
    uint32_t ui32SysClock;


    ui32SysClock = MAP_SysCtlClockFreqSet((SYSCTL_XTAL_25MHZ |
                                               SYSCTL_OSC_MAIN |
                                               SYSCTL_USE_PLL |
                                               SYSCTL_CFG_VCO_240), 120000000);

        MAP_SysCtlPeripheralEnable(SYSCTL_PERIPH_GPIOA);

        MAP_GPIOPinConfigure(GPIO_PA0_U0RX);
    	MAP_GPIOPinTypeUART(GPIO_PORTA_BASE, GPIO_PIN_0);


    	MAP_GPIOPinConfigure(GPIO_PA1_U0TX);
    	MAP_GPIOPinTypeUART(GPIO_PORTA_BASE, GPIO_PIN_1);

    	 MAP_SysCtlPeripheralEnable(SYSCTL_PERIPH_UART0);

        MAP_UARTConfigSetExpClk(UART0_BASE, ui32SysClock, 115200,
                                (UART_CONFIG_WLEN_8 | UART_CONFIG_STOP_ONE |
                                 UART_CONFIG_PAR_NONE));

        MAP_IntEnable(INT_UART0);
        MAP_UARTIntEnable(UART0_BASE, UART_INT_RX | UART_INT_RT);

        MAP_UARTCharPutNonBlocking(UART0_BASE, 'a');


    //
    // Enable the GPIO port that is used for the on-board LED.
    //
    SysCtlPeripheralEnable(SYSCTL_PERIPH_GPION);


    //
    // Check if the peripheral access is enabled.
    //
    while(!SysCtlPeripheralReady(SYSCTL_PERIPH_GPION))
    {
    }

    SysCtlPeripheralEnable(SYSCTL_PERIPH_GPIOF);



    //
    // Check if the peripheral access is enabled.
    //
    while(!SysCtlPeripheralReady(SYSCTL_PERIPH_GPIOF))
    {
    }
    SysCtlPeripheralEnable(SYSCTL_PERIPH_GPIOE);
    while(!SysCtlPeripheralReady(SYSCTL_PERIPH_GPIOE))
    {
    }

    //
    // Enable the GPIO pin for the LED (PN0).  Set the direction as output, and
    // enable the GPIO pin for digital function.
    //
    GPIOPinTypeGPIOOutput(GPIO_PORTF_BASE, GPIO_PIN_4);
    GPIOPinTypeGPIOOutput(GPIO_PORTF_BASE, GPIO_PIN_3);
    GPIOPinTypeGPIOInput(GPIO_PORTF_BASE, GPIO_PIN_5);
    GPIOPinTypeGPIOOutput(GPIO_PORTE_BASE, GPIO_PIN_6);
    /*PORTF_DIR |= 0x0000003E;    //set PF1, PF2, PF3 as output
    PORTF_DEN |= 0x0000003E;    //enable PF1, PF2, PF3
    PORTF_DATA = 0;*/

    //
    // Loop forever.
    //
    while(1)
    {
        //
        // Turn on the LED.
        //
    	//MAP_UARTCharPutNonBlocking(UART0_BASE, 'a');
    	/*if(GPIOPinRead(GPIO_PORTF_BASE, GPIO_PIN_5))
    	{
    		GPIO_PORTF_AHB_DATA_R |= (GPIO_PIN_4);
    	}
    	else
    	{
    		GPIO_PORTF_AHB_DATA_R &= ~(GPIO_PIN_4);
    	}*/
       /* GPIOPinWrite(GPIO_PORTF_BASE, GPIO_PIN_4, GPIO_PIN_4);
        GPIOPinWrite(GPIO_PORTF_BASE, GPIO_PIN_3, GPIO_PIN_3);
        GPIOPinWrite(GPIO_PORTF_BASE, GPIO_PIN_5, GPIO_PIN_5);
        GPIOPinWrite(GPIO_PORTE_BASE, GPIO_PIN_6, GPIO_PIN_6);*/


        //
        // Delay for a bit.
        //
       /* for(ui32Loop = 0; ui32Loop < 2000000; ui32Loop++)
        {
        }*/
    	// PORTF_DATA |= (GPIO_PIN_4 | PF2 | PF3);
       // SysCtlDelay(5000000);
        delayUs(100);
        //
        // Turn off the LED.
        //
      //  GPIOPinWrite(GPIO_PORTF_BASE, GPIO_PIN_4, 0x0);
        /*GPIO_PORTF_AHB_DATA_R &= ~((GPIO_PIN_4));
        GPIOPinWrite(GPIO_PORTF_BASE, GPIO_PIN_3, 0x0);
        GPIOPinWrite(GPIO_PORTE_BASE, GPIO_PIN_6, 0x0);
        //PORTF_DATA &= ~(GPIO_PIN_4 | PF2 | PF3 );*/
        delayUs(100);
       // SysCtlDelay(5000000);
        //
        // Delay for a bit.
        //
       /* for(ui32Loop = 0; ui32Loop < 2000000; ui32Loop++)
        {
        }*/
    }

	return 0;
}