So, I got my new plug-in boards, and I soldered on the SD card slot, plugged it into my sparkfun fpga board, and... didn't work GRRRR. I'm still not sure what's wrong, the same exact code works fine on my de2 board if i wire it up to my plug-in board.
I have a header that breaks out all the sd card pins and on the logic analyzer everything looks fine, except the SD card never puts any responses out on the DAT0 line. My first guess would be something going on with the power supply, which was suspiciously at 3.2v (should be 3.3), but I kind of wrote it off as well within the tolerances. eventually I thought it might be a good idea to maybe bypass the sparkfun power supplies and power the io directly from my bench supply.
This turned out to be a bad idea, as now the FPGA is thoroughly fried. Maybe there was something wrong with it from the get-go? I'm not sure. I put in an order to overnight me a new one to recieve on Friday. I am not feeling very hopeful though... I'm not really sure how to debug the problem further. I'll probably ping some of the lab techs for ideas.