FPGA:Cyclone V (5CEBA7F23C7N)
Can I use the input setting IO pin in the open state when it is not used?
There is a model where the FPGA circuit is common and the external circuit is different, so the settings are common.
You can also set this on an individual pin-by-pin basis using the Pin Planner. Right-click a pin in the Package View, go to Reserved Pins, and select an option.