anchor.diff:     method Bool notFull();
      method Action push(Bit#(8) num);
      method Action pop(Bit#(8) num);
  -   interface Reg#(Bit#(40)) bufferfirst;
  -   interface Reg#(Bit#(40)) bufferlast;
  +   interface Reg#(DmaAddrSize) bufferfirst;
  +   interface Reg#(DmaAddrSize) bufferlast;
      interface Reg#(Bool) enable;
      interface RingBufferConfig configifc;
  +   interface Reg#(DmaMemHandle) memhandle;
   endinterface
   
   interface RingBufferConfig;
  
positive.code:       else if (regist == 2) rbufferfirst <= addr;
        else if (regist == 3) rbufferlast <= addr;
        else if (regist == 4) rbuffermask <= addr;
        else renable <= (addr[0] != 0);
     endmethod
     
  
negative.code:    interface Reg bufferfirst = rbufferfirst;
     interface Reg bufferlast = rbufferlast;
     interface Reg enable = renable;
     interface Reg memhandle = rmemhandle;
  
  endmodule
  