0 clk=0, data=1111, clear=1111, state=0000
                  10 clk=0, data=1111, clear=0000, state=0000
                  20 clk=1, data=1111, clear=0000, state=0000
                  21 clk=1, data=1111, clear=0000, state=1111
                  30 clk=0, data=1111, clear=0010, state=1101
                  40 clk=0, data=1010, clear=0000, state=1101
                  50 clk=1, data=1010, clear=0000, state=1101
                  51 clk=1, data=1010, clear=0000, state=1010
                  60 clk=0, data=1010, clear=0000, state=1010