I am a little bit confused reading the datasheet so far for xmega A series devices. It seems you need to place AREF for port A and AREF for port B if you want to utilize both the port pins. On top of that once you use PA0 as AREF you have just lost a pin for measuring an analog input...so now you can only measure 7 inputs instead of 8. Am I correct?
Also how is the differential measurements done? I dont understand. Lets say I have 3 phase (for BLDC motors) I want to measure (differential) between each phase and the motor ground which is not necessarily the power supply ground. Since I will be using a shunt resistor for current measurements.
How could this arrangement work?