Implementation of DRFSM

We intend to develop extensions to GIJOE [4] by adding some facilities to allow drawing of DRFSM's and to generate the appropriate C code with a recursive call to some states with variable transition conditions. The required modifications will be accomplished in two phases:

• Drawing Phase.

• Code Generation Phase.

In the drawing phase a new arrow will be added (RTA) to represent a recursive call to any state. Also a notation for variable transition value will be added as shown in Figure 5.

In the code generation phase, it is very important to preserve backward compatibility; fortunately, that is easy since we can check for the existence of RTA's. If no RTA is found, then it is a FSM and the code generated for this machine will be the same as before. On the other hand, if any RTA is found, then the following steps are required:

• Collect all variable transitions to form the VTV.

• For each RTA in the figure build a user-defined function: Get_New_VTVto be filled by the user of GIJOE later, since this function is very application dependent, then its purpose is to get the values of the new vector to be used in the new level of recursion, and it will be called from the recursive state.

• All states' functions will have a parameter which is the VTV.

With these modifications backward compatibility is guaranteed and the implementation of any DRFSM is easily maintained. In Appendix A, a generated code for a DRFSM is shown.