anchor.diff:     
      interface PipeIn dac;
      
  -      method Action enq(Vector#(2, IQ) v);
  +      method Action enq(Vector#(2, OIQ) v);
   	 outfifo.enq(v);
         endmethod
         
  
positive.code: import DefaultValue::*;
  
  interface DiffOut;
     method Action _write(Bit#(1) v);
     method Bit#(1) read_p();
     method Bit#(1) read_n();
  endinterface 
  
negative.code:    path(I, O);
     path(I, OB);
  
    schedule (read_p, read_n) CF (read_p, read_n);
  
  endmodule: mkxOBUFDS
  