anchor.diff:      // Interrupts
       method Action triggerExternalInterrupt = proc.triggerExternalInterrupt;
   
  +`ifdef CONFIG_RS232
       method Action sendUartChar(Bit#(8) x);
           simUart.rx.put(x);
       endmethod
  
positive.code: 
  interface ProcVerilator;
      // Processor Control
      method Action start(Bit#(64) startPc);
      method Action stop();
      method Action stallPipeline(Bool stall);
  
  
negative.code:         let x <- simUart.tx.get();
          $write("%c", x);
      endrule
  `endif
  
      // Processor Control
      method Action start;
          proc.start;
      endmethod
      method Action stop();
          proc.stop;
  