I am trying to program an RC-100 demo board, which contains a Spartan-II chip. The board is supposed to send three logic outputs to external devices through I/O pins provided on an expansion header. I am pretty sure I've coded the program correctly (only to the extent that it works as intended in simulation), but when I probe the I/O pins with a scope all I'm getting is what I assume is mains pick-up (50 Hz ~5Vpk-pk).
My probes have been calibrated; the probe and scope have adequate bandwidth (greater than 5x the signal bandwidth), and I get the same result whether I use the 'Auto-scale' function or manually set the 'Volts' and 'Time' division scales to the capture the expected waveforms. In the event that the source of the problem isn't my code, does anyone have any suggestions as to what I might be doing wrong?