Uhm, just calculate how many Bits you need for your RAMs/ROMs, check the
datasheet of your exact FPGA (there are many Spartan 3A types in various
And then you should know if your data will fit into the memory or not.
If your data is smaller than the FPGA block RAM it should work fine.
If your data size larger than the FPGA block RAM then you'll get a
problem or have to use a bigger FPGA.
Spartan 3A isn't a DSP. It's an FPGA.
You can build a DSP into an FPGA if you want.
Also make sure that you really need all this data - maybe it can be
optimized. Maybe you can use some symmetry of the data or compress it
using some simple algorithm.
Without knowing what you want to do it's really hard to tell if it will
work or not.