tests/6-rot/rot.v

module top(input clk, output D1, output D2, output D3, output D4, output D5);

   reg ready = 0;
   reg [3:0] rot;

   always @(posedge clk) begin
      if (ready)
         begin
            rot <= {rot[2:0], rot[3]};
         end
      else
        begin
           ready <= 1;
           rot <= 4'b0001;
        end
   end

   assign D1 = rot[0];
   assign D2 = rot[1];
   assign D3 = rot[2];
   assign D4 = rot[3];
   assign D5 = 1;
endmodule // top