[Schematic Info]

13 minutes ago, zygot said:

Tip: Don't solicit random responses to questions about PCB design questions if you are new at this, and hoping that someone answers questions that you haven't thought of. Also don't copy someone else's designs. Do read any literature that you can get a hold of regarding board design considerations from device vendors. There's plenty available and you should not restrict your search to one vendors. Do you homework before starting a PCB design not after trying to bring up new boards that are having problems. The first topic on your list would be power supplies.

Thank you for your "tip", let me clarify. I am not copying designs, I pasted an image to show as reference.. The question is simply regarding the VCCAUX on the schematic and what purpose it serves for the FPGA.

I did not ask specific questions regarding PCBs. Please consider questions rather than comments first. 

[Schematic Info]

On the schematic for the Arty S7-50 there is a VCC1V8 going to VCCAUX as shown below.

 

What is the purpose of VCCAUX? Some documentation I've read on the board label it as 1.8V power supply for auxiliary circuits as shown below.

 

Does auxiliary circuitry imply internal to the FPGA?

Is this voltage to VCCAUX needed for the FPGA functionality?

Can this pin be used via a 3.3V or 1.0V supply?

 

This is my first time designing a custom PCB which is why I am wondering if these voltages are necessary.

Thank you!