I have a board with three Spartan3s on it. Right now, under sources in project, I have the project name, then xc3s400-4pq208, and under that top1-behavioral(top1.vhd), top2-behavioral(top2.vhd), top3-behavioral(top3.vhd)
and stuf under those like the top1.ucf, etc.
So what happens if one of the Xilinx parts gets upgraded or downgrade in speed or size? Can I assign the xc3s400 spec to each top level design?