anchor.diff:     {0, 0, 1, 0, 0, 0, 1, 0, 0, 1, 0, 0, 0, 1, 0, 0, 1, 0, 0, 0, 1, 0, 0, 1, 0, 0, 0, 1, 0, 0, 1},     // Mode 29
      {0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 1},     // Mode 28
      {0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1},     // Mode 27
  -   {0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0},     // Mode 26
  +   {0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0},     // Mode 26,  1
      {0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0},     // Mode 25
      {0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0},     // Mode 24
      {0, 0, 1, 0, 0, 0, 1, 0, 0, 1, 0, 0, 0, 1, 0, 0, 1, 0, 0, 0, 1, 0, 0, 1, 0, 0, 0, 1, 0, 0, 0},     // Mode 23
  
positive.code:          tmpLeft = takeAt(1, x.top);
           tmpTop  = cons(x.top[0], x.left);
        end
        reg_i  <= (mode == 32) ? (tagged Invalid) : (tagged Valid IntraRef_t {left:tmpLeft, top:tmpTop});
  
        moded1 <= mode;
        mode   <= mode + 1;
        stage0 <= tagged Valid y;
        cnt1   <= (mode < 16) ? ~0 : 0;
  
negative.code:    interface io_in  =  interface Put; 
                             method Action put(IntraRef_t x) if (!isValid(reg_i));
                                reg_i <= tagged Valid x;
                                Bit#(14) sum = 0;
                                for(Integer i = 0; i < 32; i = i + 1) begin
                                   sum = sum + zeroExtend(x.left[i]) + zeroExtend(x.top[1+i]);
                                end
                                dcVal <= truncate(sum >> 6);
                             endmethod
                        endinterface;
     interface io_out = toGet(fifo_o);
  