State charts and Graphical `languages'

Synthesis from diagrams (especially UML/SysML) is useful:

• Full schematic entry at the gate level was once popular,
• Still popular for high-level system block diagrams,
• Also popular for state transition diagrams.

The stategraph general form is:

stategraph graph_name()
{
  state statename0 (subgraph_name, subgraph_entry_state), ... : 

        entry:  statement;
        exit:   statement;
        body: statement;

        statement;
        ...            // implied 'body:' statements
        statement;
 
        c1 -> statename1: statement;
        c2 -> statename2: statement;
        c3 -> exit(good);
        ...

        exit(good) -> statename3: statement;
        exit(bad) -> statename4: statement;
      
        ...


   endstate

   state statename2:
   ...
   ...
   endstate


   state abort: // A special state that can be 
                  // forced remotely (also called disable).
		  
   ...

}