This paper presents a tool capable of automatically adding fault detection capabilities in software to protect the processors against transient faults. The tool implements a set of configurable software-based detection techniques over the assembly code of an unprotected program. The developed tool has been validated for two distinct processors: MIPS and LEON3. But it can be extended to other architectures and organizations by changing the configuration files. A fault injection campaign was performed and simulation results show high detection rates to both processors and a small increase in area and runtime.