anchor.diff:     endmethod
   
      method Action capture ();
  -      sreg <= dreg;
  +      sreg <= v;
      endmethod
      
      method Action shift (bit d);
  
positive.code: module mkReadOnlyJtagReg#(a v)(JtagReg#(a))
     provisos(Bits#(a,asize), Add#(1,__a,asize));
     
     Reg#(a) dreg <- mkReg(v);
     Reg#(a) sreg <- mkReg(?);
     Reg#(bit) oreg <- mkReg(?);
     
  
negative.code:       oreg <= svalue[0];
     endmethod
     
     interface r = ?;
     interface tdo = regToReadOnly(oreg);
        
  endmodule
  