ENH: IP address selection

Select one of 4 possible IP addresses (.10.16 - .13.19) by putting jumpers on the PMOD connector. Default is still .10.16. Short PMOD pin 1+2 for .11.17, Pin 3+4 for .12.18 and both for .13.19 Do NOT try to short other pins...

If you want to synthesize the firmware yourself, this requires a small modification to one line of Verilog code in one of the SiTCP wrapper files. This has to be modified if you want to compile your own firmware. The uploaded bitfile will be ready to use.