Is there a certification or some authority that decides if a soft core is fault tolerant or not?
Another question. I've seen that LEON3-FT is radiation tolerant only when implemented on the RTAX Actel FPGA. Is that right?
Excuse me but I'm confused about it because somebody speaks about LEON3-FT (fault tolerant) for space applications, where it is more correct to say radiation tolerant?
And, the last question...is there somebody that knows another soft core "radiation tolerant" (for space application)?
The Actel is not fault tolerant. It is resistant to radiation in the first place. This is because of the way it is design.
Xilinx has some documentation on radiation link text.
I have done satellite FPGA work and don't know of any certification body. Some discussion of the general issue is at link text.
A fault tolerant design will be a start. However since the configuration memory can be corrupted in a SRAM-based design (Xilinx, Altera, Lattice), you have to worry about that too.