In this paper, we are concerned by the elaboration of generic development steps for the code generation for synchronous languages. Our aim is to provide a correct by construction solution. For that purpose, we adopt a refinement-based approach where proof obligations for each step guarantee properties preservation. We use the Event-B formal method. We start with a big step semantics specified by an Event-B machine. Through a sequence of refinements, expressed as Event-B refinement machines, we end up with a code generation step which implements a small step semantics preserving the properties of the big step semantics.