CMCON0 and ANSEL registers

[HighTechPower]

Hi. Recently I designed a circuit with PIC12F683. It's pins not working properly until I declare CMCON0 register although I'm not using it's internal comparator. Is it not true that to declare pins as digital or analog I have to use either CMCON0 or ANSEL register and not both. However when I omit the CMCON0 line in code below then circuit does not work properly (e.g. POWER_GOOD pin does not go high). I'm using ADC that is why I have declared ANSEL register.

#define POWER_GOOD GP0

void init_micro (void)
{
    OSCCON = 0b01100111;
    TRISIO = 0b00001010;
    CMCON0 = CMCON0 | 0b00000100;
    ANSEL = 0b01010010;
    GPIO = 0b00000000;
    POWER_GOOD = TRUE;
    __delay_ms(100);
}

 

[FvM]

Is it not true that to declare pins as digital or analog I have to use either CMCON0 or ANSEL register and not both.

To use a GPIO as digital input, both ANSx and respective comparator function have to be disabled. In case of GP0, digital output function doesn't depend on CMCON0 and ANSEL setting, it does however for GP2. Regarding your findings, either you confused GP0 with GP2, or the datasheet is incorrect.