I'm looking at directly using the built in ADCs on the i.mx7 in our project.
In the Reference manual for the i.mx7d board it mentions the ADCX_inX pins w/ 2 ADCs and 4 inputs each. I see in the reference board schematic where these are connected to a header and brought into the CPU except for the one pin connected to the mikrobus.
It also mentions ADC_VREF[H/L] for the voltage high and low reference. I can't find these inputs in the reference schematic or the data sheet though. The only pins I see other than the inputs are the 1.8V power supply and pcap inputs.
So the question is, how does one set the reference voltage for the ADCs? I want to measure up to 12V for instance.