I am trying to read 10 bit resolution voltages pins AN0 and AN2 on a 16F616. I see on the data sheet that ADCON0 bits 5 – 2 can be used to configure a fixed voltage reference of 0.6V or 1.2V. Is this equivalent to setting up an external voltage reference on the VREF pin? If so, how would I set bit 6 of the ADCON0 register to use this internal reference, or have I misunderstood this thing completely?