except virtex-4 FX, which fpga can support the fpu ip core,especially with microblaze core ? does XC3S500E ? And the publication words says " spartan3E-fpga can build compact DSP ", I don't understand how to use the available ip core to build the compact DSP?
The Spartan 3E does support the FPU for the microblaze core. When you run through the Base System builder with our EDK tools, you can select the FPU as an option if you would like to use this in your EDK design with microblaze.
The compact DSP that is mentioned in the publication just means that some of the DSP cores such as MAC engines or parallel FIR filters will be more compact using the 18x18 multipliers rather than implementing the cores in regular fabric. It is just stating that the way that the filter is actually built in the part is more "compact".