The XLR8 board schematic is available as part of the User Manual which can be found here:
We also have a single-page pin map that provides a cross-reference to the FPGA pins:
If you want to take a look at the top-level Verilog, you can install the XLR8BuildTemplate library via the Arduino IDE or download it directly from our Github repository here:
The top-level is located in /XLR8BuildTemplate-master/extras/rtl/.
The specific location of this file will be different, if you installed it via Arduino, depending upon what platform you are using – Mac, Windows, Linux.
Does this address your question?