Abstract: Dependability plays an important role in the design of nanometer-scale processors and application-specific processors exposed to harsh environments such as cosmic rays. Fault injection is employed to characterize the soft error sensitivity and validate the integrated fault tolerance mechanisms in a fault-tolerant processor. With Godson-1 processor as the research prototype, a novel fault injection technique is presented, which can perform fast and continuous simulation-based fault injections to the subjected processor by running two synthesizable processor RTL models simultaneously. Based on this technique, about 30,0000 soft errors are injected into Godson-1 and the soft error sensitivity of Godson-1 is further investigated to direct the design of a fault-tolerant and dependable Godson-1 processor with good statistical significance.