Unwanted voltages on ADC(A3,A6,A7) with UART communication in msp430f2254

Hi,

     In my application iam sending the ADC voltages through UART
communication, here the problem is, with out UART initialisation the ADC's
perfectly working, but while initialising UART by default the ADC pins
getting 3.2 Volts(VCC).

Can any one help me out , why these voltage are coming on those pins
(A3,A6,A7)  with UART initialisation.below is my UART initilisation code.

I am using msp430f2254 controller.

 

 void serial_init()
  {
  
    P3SEL =  0x00;                            // configuring as GPIO pins
    P3DIR =  0xFF;
    P3SEL |= 0x30;                            // port3 4,5 are configured
as uart
    P3OUT =  0xc0;                            //
    UCA0CTL1 |= UCSWRST;
    BCSCTL1 = CALBC1_16MHZ;
    DCOCTL  = CALDCO_16MHZ;
    BCSCTL1 |= XTS+XT2OFF;                    // set in high freq mode and
Crystal2 Off
    BCSCTL3 &= XCAP_0;
    BCSCTL3 |= LFXT1S_2;                      // set for 3-16MHz crystal
for high freq mode
    UCA0CTL1 |= UCSSEL_2;                     // CLK = SMCLK
    UCA0CTL0 = 0x00;                          
    UCA0BR0 =  0x82;                          // 16MHz/9600 = 1666.6
    UCA0BR1 =  0x06;               
   // UCA0MCTL = UCBRS1 + UCBRS0;               // Modulation UCBRSx = 3
    UCA0MCTL = UCBRS0;
    UCA0CTL1 &= ~UCSWRST;
   
  }


Thanks in Advance,

Regards

Manohar