Complex synchronous digital systems can be implemented on FPGAs (Field Programmable Gate Arrays), but due to the global clock, might have problems with clock skew, performance degradation and increased of power consumed. An alternative to these designs is the asynchronous paradigm that solves the problems related to the clock. However it is difficult to design asynchronous circuits, especially in the FPGA platform. This work presents in the style of asynchronous FSM (finite state machine) + data-path a method that implements asynchronous digital systems on FPGAs. The proposed method uses the tools of paradigm synchronous, thus synthesizes without the knowledge of asynchronous logic. Our method synthesizes the asynchronous FSM by direct mapping from the conventional state transition graph. Through a case study, it is shown the simplicity of the proposed methodology.