Among the several techniques available to inject faults, SWIFI is commonly recognized as the one with more potential. The scope of SWIFI injectors may look very narrow at first glance: software has access to processor registers, memory, addressable ASICs and not much more in the system. However, by gaining full control of the processor functions and being able to manipulate the information that it processes, SWIFI tools can emulate a much larger set of hardware fault types than expected at first - examples include faults in the address bus, arithmetic unit, and memory, among other functional units. The main advantages of SWIFI, in comparison with other techniques, are a lower complexity (since no dedicated hardware or very detailed models are required) and increased portability.