MSP430F6779: Uart not able to RX using driver lib example

I am trying the echo example i am able transmit but not able receive. The RX interrupt fag is not getting high to trigger interrupt

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//******************************************************************************
//!  EUSCI_A0 External Loopback test using EUSCI_A_UART_init API
//!
//!  Description: This demo connects TX to RX of the MSP430 UART
//!  The example code shows proper initialization of registers
//!  and interrupts to receive and transmit data.
//!
//!  ACLK = BRCLK = 32.768kHz, MCLK = SMCLK = DCO/8 = ~1MHz
//!
//!
//!            Tested on MSP430F67791A
//!             -----------------
//!       RST -|     P3.0/UCA0RXD|----|
//!            |                 |    |
//!            |                 |    |
//!            |     P3.1/UCA0TXD|----|
//!            |                 |
//!
//! This example uses the following peripherals and I/O signals.  You must
//! review these and change as needed for your own board:
//! - UART peripheral
//! - GPIO Port peripheral (for UART pins)
//! - UCA0TXD
//! - UCA0RXD
//!
//! This example uses the following interrupt handlers.  To use this example
//! in your own application you must add these interrupt handlers to your
//! vector table.
//! - USCI_A0_VECTOR.
//******************************************************************************
#include "driverlib.h"

uint16_t i;
uint8_t RXData = 0, TXData = 0;
uint8_t check = 0;

void main(void)
{
    // stop watchdog
    WDT_A_hold(WDT_A_BASE);

    //Set external clock frequency to 32.768 KHz
    UCS_setExternalClockSource(32768, 0);
    //Set ACLK=XT1
    UCS_initClockSignal(UCS_ACLK, UCS_XT1CLK_SELECT, UCS_CLOCK_DIVIDER_1);
    //Start XT1 with no time out
    UCS_turnOnLFXT1(UCS_XT1_DRIVE_0, UCS_XCAP_3);

    //Configure UART pins (UCA0TXD/UCA0SIMO, UCA0RXD/UCA0SOMI)
    //Set P3.0 and P3.1 as Module Function Input
    GPIO_setAsPeripheralModuleFunctionInputPin(
        GPIO_PORT_P3,
        GPIO_PIN0 + GPIO_PIN1
        );

    // Configure UART
    EUSCI_A_UART_initParam param = {0};
    param.selectClockSource = EUSCI_A_UART_CLOCKSOURCE_ACLK;
    param.clockPrescalar = 3;
    param.firstModReg = 0;
    param.secondModReg = 92;
    param.parity = EUSCI_A_UART_NO_PARITY;
    param.msborLsbFirst = EUSCI_A_UART_LSB_FIRST;
    param.numberofStopBits = EUSCI_A_UART_ONE_STOP_BIT;
    param.uartMode = EUSCI_A_UART_MODE;
    param.overSampling = EUSCI_A_UART_LOW_FREQUENCY_BAUDRATE_GENERATION;

    if (STATUS_FAIL == EUSCI_A_UART_init(EUSCI_A0_BASE, &param)) {
        return;
    }

    EUSCI_A_UART_enable(EUSCI_A0_BASE);

    EUSCI_A_UART_clearInterrupt(EUSCI_A0_BASE,
                         EUSCI_A_UART_RECEIVE_INTERRUPT);

    // Enable USCI_A0 RX interrupt
    EUSCI_A_UART_enableInterrupt(EUSCI_A0_BASE,
          EUSCI_A_UART_RECEIVE_INTERRUPT);                     // Enable interrupt

    __enable_interrupt();
    while (1)
    {
        TXData = TXData+1;                      // Increment TX data
        // Load data onto buffer
        EUSCI_A_UART_transmitData(EUSCI_A0_BASE,
                           TXData);
        while(check != 1);
        check = 0;
    }
}
//******************************************************************************
//
//This is the USCI_A0 interrupt vector service routine.
//
//******************************************************************************
#if defined(__TI_COMPILER_VERSION__) || defined(__IAR_SYSTEMS_ICC__)
#pragma vector=USCI_A0_VECTOR
__interrupt
#elif defined(__GNUC__)
__attribute__((interrupt(USCI_A0_VECTOR)))
#endif
void EUSCI_A0_ISR(void)
{
  switch(__even_in_range(UCA0IV,USCI_UART_UCTXCPTIFG))
  {
    case USCI_NONE: break;
    case USCI_UART_UCRXIFG:
       RXData = EUSCI_A_UART_receiveData(EUSCI_A0_BASE);
      if(!(RXData == TXData))                   // Check value
      {
        while(1);
      }
      check =1;
      break;
    case USCI_UART_UCTXIFG: break;
    case USCI_UART_UCSTTIFG: break;
    case USCI_UART_UCTXCPTIFG: break;
  }
}