MSP430F6638IPZR

I am using this chip MSP430F6638IPZR. I have a board on which this chip can be mounted and programmed. There is also a MSP430 USB-Debug-Interface MSP-FET430UIF. I know that the maximum software configurable supply voltage that this USB-Debug-Interface can handle is between 1.8 V to 3.6 V at 100 mA. I am trying to work with a sample program from the Texas instruments folder list. The code is as follows:

//******************************************************************************

//  MSP430F66x Demo - ADC12, Using the Internal Reference

//

//  Description: This example shows how to use the internal reference of REF

//  module using the ADC12 control registers.

//  The ADC12 uses the internal 2.5V reference and performs a single conversion

//  on channel A0. The conversion results are stored in ADC12MEM0. Test by

//  applying a voltage to channel A0, then setting and running to a break point

//  at the "__no_operation()" instruction. To view the conversion results,

//  open an ADC12 register window in debugger and view the contents of ADC12MEM0

//                MSP430F66x

//             -----------------

//         /|\|                 |

//          | |                 |

//          --|RST              |

//            |                 |

//     Vin -->|P6.0/CB0/A0      |

//            |                 |

//

//   Priya Thanigai

//   Texas Instruments Inc.

//   Nov 2009

//   Built with IAR Embedded Workbench Version: 4.20 & Code Composer Studio V4.0

//******************************************************************************

#include <msp430f6638.h>

void main(void)

{

  volatile unsigned int i;

  WDTCTL = WDTPW+WDTHOLD;                   // Stop watchdog timer

  P6SEL |= 0x01;                            // Enable A/D channel A0

  REFCTL0 &= ~REFMSTR;                      // Reset REFMSTR to hand over control to

                                            // ADC12_A ref control registers

  ADC12CTL0 = ADC12ON+ADC12SHT02+ADC12REFON+ADC12REF2_5V;

                                            // Turn on ADC12, Sampling time

                                            // On Reference Generator and set to

                                            // 2.5V

  ADC12CTL1 = ADC12SHP;                     // Use sampling timer

  ADC12MCTL0 = ADC12SREF_1;                 // Vr+=Vref+ and Vr-=AVss

  for ( i=0; i<0x30; i++);                  // Delay for reference start-up

  ADC12CTL0 |= ADC12ENC;                    // Enable conversions

  while (1)

  {

    ADC12CTL0 |= ADC12SC;                   // Start conversion

    while (!(ADC12IFG & BIT0));

    __no_operation();                       // SET BREAKPOINT HERE

  }

}

The above code says that the ADC12 uses the internal 2.5 V reference and performs a single conversion on channel A0 and we can test it by applying a voltage to channel A0. Now my doubt is, what is the voltage range that can be applied to channel A0???  I mean what is the range of voltage that this chip can perform Analog to Digital Conversion on ??????

Thanks in advance :)