CCS/MSP430FR2155: I2C working fine when debugging and but stuck in Continuous run

Part Number:MSP430FR2155

Tool/software: Code Composer Studio

I am trying to communicate through I2C in MSP430FR2155 as master device and Arduino Uno as slave device .

when I am debugging my code and execute program line by line the Code works and send data to Arduino.

but when I start continuous mode the code get stuck in while loop and communication stops. I am using standard driver provided from ti web sites.

void EUSCI_B_I2C_masterSendSingleByte(uint16_t baseAddress,
                                      uint8_t txData)
{
    //Store current TXIE status
    uint16_t txieStatus = HWREG16(baseAddress + OFS_UCBxIE) & UCTXIE;

    //Disable transmit interrupt enable
    HWREG16(baseAddress + OFS_UCBxIE) &= ~(UCTXIE);

    //Send start condition.
    HWREG16(baseAddress + OFS_UCBxCTLW0) |= UCTR + UCTXSTT;

    //Poll for transmit interrupt flag.
    while(!(HWREG16(baseAddress + OFS_UCBxIFG) & UCTXIFG))
    {
        ;
    }

    //Send single byte data.
    HWREG16(baseAddress + OFS_UCBxTXBUF) = txData;

    //Poll for transmit interrupt flag.
    while(!(HWREG16(baseAddress + OFS_UCBxIFG) & UCTXIFG))
    {
        ;
    }

    //Send stop condition.
    HWREG16(baseAddress + OFS_UCBxCTLW0) |= UCTXSTP;

    //Clear transmit interrupt flag before enabling interrupt again
    HWREG16(baseAddress + OFS_UCBxIFG) &= ~(UCTXIFG);

    //Reinstate transmit interrupt enable
    HWREG16(baseAddress + OFS_UCBxIE) |= txieStatus;
}

the execution stuck at 

while(!(HWREG16(baseAddress + OFS_UCBxIFG) & UCTXIFG))...

any suggestion?