Very deep submicron and nanometer technologies have increased notably integrated circuit (IC) sensitiveness to radiation. Soft errors are currently appearing into ICs working at earth surface. Therefore, hardened circuits are currently required in many applications where Fault Tolerance (FT) was not a requirement in the very near past. The use of CAD tools, for the generation and the validation of fault tolerant circuits, will allow designers to obtain hardened devices in a cost-effective way with short development times and with high reliability results. While automatic insertion of fault tolerant structures in designs is already possible, automatic evaluation with an optimum time-cost relation is still needed. In this sense, the use of platform FPGAs for the emulation of single-event upset effects (SEU) is gaining attention in order to speed up the fault tolerance evaluation. In this work, a new emulation system for the evaluation of FT with respect to SEU effects is proposed. This solution gets profit of hardware resources for accelerating the FT evaluation. It is analysed and compared with respect to other emulation techniques. The proposed solution provides not only short times but also low cost in area for FT validation, giving better results than pure software or hardware solutions.