The evolvable hardware (EHW) is widely used in the design of fault-tolerant system. Fault-tolerant system is really a real-time system, and the recovery time is necessary in fault detection and recovery. However, when applying EHW, real-time characteristic is usually ignored. In this paper, a fault-tolerant strategy based on EHW is proposed. The recovery time, predicted by the fault tree analysis (FTA), is considered as a constraint condition. A configuration library is set up in the design phase to accelerate the repair process of the anticipated faults. An evolvable algorithm (EA) based on similarity is applied to evolve the repair circuit for the unanticipated faults. When the library reaches the upper, the target system is reconfigured by the EA-repair technology. Extensive experiments are conducted to show that our method can improve the fault-tolerance of the system while satisfying the real-time requirement on FPGA platform. In a long run system, our method can keep a higher fault recovery rate.
