MSP430F5529: MSP-EXP430F5529LP UART problem

Hi All (again), I am trying to play around with UART on MSP-EXP430F5529LP (MSP5529 launch pad). I have configured my SMCLK to 4MHz and  try to configure the UART to run at 115,200kbps. I am starting simple by sending only one character 'A' (0x41). I have my scope hooked up to PIN3.3 and trigger to see the waveform to confirm my UART is doing what it supposed to

Here is my code to configure it:

#include <msp430f5529.h>

void ConfigUCS (void)
//Configure SMCLK to 4MHz
{
  P5SEL |= BIT2 | BIT3;//Configure IO as XT2 function
  UCSCTL6 &= ~XT2OFF;//Enable XT2

  UCSCTL4 |= SELA_2;//first configure ACLK source as REFCLK
  UCSCTL3 |= SELREF_2;//Configure FLLCLK source as REFCLK

  while (SFRIFG1 & OFIFG) {
    UCSCTL7 &= ~(XT2OFFG + XT1LFOFFG + DCOFFG);//Clear the three types of clock flags
                             //There are three flag bits that need to be cleared because any
                             //The flag bit will set OFIFG
    SFRIFG1 &= ~OFIFG;//Clear clock error flag
  }
  UCSCTL4 = UCSCTL4 & (~(SELS_7 | SELM_7)) | SELS_5 | SELM_5;//Configure SMCLK and MCLK clock sources as XT2
//P2SEL |= BIT2;
//P2DIR |= BIT2;//For measuring SMCLK
  return;
}

void ConfigURART (void)
{
    UCA0CTL1 |= UCSWRST; // Software reset of UCA0 module
    UCA0CTL0 |= UCMSB;   // Initialize control register UCA0XTL0
                         // default is no Parity / MSB first / 8bit / One stop bit / UART / Asynchrnoous mode

    UCA0CTL1 |= 0x00;    // Initialize control register UCA0CTL1
    UCA0CTL1 |= UCSSEL_2;// Set SMCLK (SMCLK is at 4MHz) to BRCLK.

    UCA0MCTL |= UCOS16;  // Oversampling mode
                         // N = 4,000,000/115,200 = 34.722
    UCA0BR1 |= 0x00;
    UCA0BR0 |= 0x02;     // UCBR0 = INT (N/16) = 2
    UCA0MCTL|= UCBRF1;   // UCBRF0 = 2
    UCA0MCTL|= UCBRS1 + UCBRS0; // UCBRS0 = 3

    P3SEL |= BIT3 + BIT4;// Port Configuration
    UCA0CTL1 &= ~UCSWRST; // Software reset of UCA0 module cleared
}

/**
 * main.c
 */
int main(void)
{
    ConfigUCS();
    ConfigURART();
    UCA0TXBUF = 'A';
}

SMCLK is configured properly as I can measure 4MHz clock on P2.2. However, when I put my scope on P3.3 (UCA0TXD), I got very weird waveform. The waveform almost suggested that there's something wrong on the hardware side. Did I make a mistake in the configuration or my hardware is somehow damaged?

Here is the scope capture:

C1 is a x10 probe at P3.3. To my understanding, the UART bus should be at 3.3V when no transmitting, but here I am seeing some garbage less than 200mV...Any ideas? Thanks.