In this paper, we deal with a design flow that makes easier the design of complex digital systems and allows their fast prototyping, This design flow is based on Petri Nets (PN) and components. The PN-based approach allows for high level analysis, the component aspect favors modularity and reusability, and automatic translation of PN into VHDL enables safe and fast prototyping. To support this design flow, a software tool has been created: HIgh LEvel hardware COmponent Programming (HILECOP). We applied this methodology and its associated software tool to realize prototypes of biomedical devices. Indeed, in the context of functional rehabilitation by means of functional electrical stimulation, it has been used to create a prototype of an implantable stimulator which is briefly exposed, communicating according to a given protocol stack.