MSP430F5529: ADC12 A4 doesn't work

Hi,

I'm trying to do an ADC single-channel single-conversion of A4 (P6.4) on the MSP430F5529.

I used `MSP430F55xx_adc_05.c` from `slac300k MSP430F55xx_Code_Examples` which samples A0 (P6.0):

int main(void)
{
  WDTCTL = WDTPW+WDTHOLD;                   // Stop watchdog timer
  P6SEL |= 0x01;                            // Enable A/D channel A0
  ADC12CTL0 = ADC12ON+ADC12SHT0_2;          // Turn on ADC12, set sampling time
  ADC12CTL1 = ADC12SHP;                     // Use sampling timer
  ADC12MCTL0 = ADC12SREF_2;                 // Vr+ = VeREF+ (ext) and Vr-=AVss
  ADC12CTL0 |= ADC12ENC;                    // Enable conversions

  while (1)
  {
    ADC12CTL0 |= ADC12SC;                   // Start conversion-software trigger
    while (!(ADC12IFG & BIT0));
    __no_operation();                       // SET BREAKPOINT HERE
  }
}

I tried to run the example and saw that the everything is working and I'm reading 0 when it is connected to GND and 4096 when connected to VCC.

I changed it as follows in order to sample A4 (P6.4):

volatile unsigned int result;

void main() {
//    setup();

    WDTCTL = WDTPW+WDTHOLD;                   // Stop watchdog timer
    P6SEL |= 0x10;                            // Enable A/D channel A0
    ADC12CTL0 = ADC12ON+ADC12SHT0_2;          // Turn on ADC12, set sampling time
    ADC12CTL1 = ADC12SHP;                     // Use sampling timer
    ADC12MCTL0 = ADC12INCH_4 | ADC12SREF_2;                 // Vr+ = VeREF+ (ext) and Vr-=AVss
    ADC12CTL0 |= ADC12ENC;                    // Enable conversions

    while (1)
    {
    ADC12CTL0 |= ADC12SC;                   // Start conversion-software trigger
    while (!(ADC12IFG & BIT0));
    result = ADC12MEM0;
    __no_operation();                       // SET BREAKPOINT HERE
    }
}

However, it doesn't work...
When I read the value in result, I see that the value is 0 always.
Also, when I try and hookup the pin to 3.3V, the board resets...
It looks like I haven't configured the pin right, and that it is tied to GND (it will also explain the reset when hooking up to 3.3V), but I haven't found the mistake in the code...

I got the same behavior using the driverlib.
Also, I get this behavior also on an MSP430F5529 Launchpad and also on some other propriety MSP430F5529 board.



Thanks a lot!