library ieee;
use ieee.std_logic_1164.all;
use ieee.std_logic_arith.all;
use ieee.std_logic_unsigned.all;
entity h31 is  
port(cp,rst,EN:in std_logic;
         seg:out std_logic_vector(6 downto 0);
         op:out std_logic;
         indata:In Std_Logic_Vector(3 downto 0));
end h31;
architecture rtl of h31 is
type state is(s0,s1,s2,s3,s4,s5,s6,s7,s8,s9);
signal presentstate:state;
signal nextstate:state;
signal qn:std_logic_vector(3 downto 0);
begin
    switchtonextstate:process(cp,rst,EN)
begin
If rst='1' Then presentstate<=s0;
   elsif cp'event and cp='1'then
     if EN<='0' Then
     presentstate<=nextstate;
     else
case indata is
    When"0000"=> presentstate<=s0;
    When"0001"=> presentstate<=s1;
    When"0010"=> presentstate<=s2;
    When"0011"=> presentstate<=s3;
    When"0100"=> presentstate<=s4;
    When"0101"=> presentstate<=s5;
    When"0110"=> presentstate<=s6;
    When"0111"=> presentstate<=s7;
    When"1000"=> presentstate<=s8;
    When"1001"=> presentstate<=s9;
    When others=> null;
end case;
   end if;
end if;
end process switchtonextstate;
changestatemode:process(presentstate)
begin
     case presentstate is
           when s0=>nextstate<=s1;
              qn<="0000";
              op<='0';
           when s1=>nextstate<=s2;
              qn<="0001";
              op<='0';
           when s2=>nextstate<=s3;
              qn<="0010";
              op<='0';
           when s3=>nextstate<=s4;
              qn<="0011";
              op<='0';
           when s4=>nextstate<=s5;
              qn<="0100";
              op<='0';
           when s5=>nextstate<=s6;
              qn<="0101";
              op<='0';
           when s6=>nextstate<=s7;
              qn<="0110";
              op<='0';
           when s7=>nextstate<=s8;
              qn<="0111";
              op<='0';
           when s8=>nextstate<=s9;
              qn<="1000";
              op<='0';
            when s9=>nextstate<=s0;
             qn<="1001";
              op<='1';
           When others=>null;
        end case;
      case qn is
    When "0000"=>seg<="0111111";
       When "0001"=>seg<="0000110";
       When "0010"=>seg<="1011011";
       When "0011"=>seg<="1001111";
       When "0100"=>seg<="1100110";
       When "0101"=>seg<="1101101";
       When "0110"=>seg<="1111101";
       When "0111"=>seg<="0000111";
       When "1000"=>seg<="1111111";
       When "1001"=>seg<="1101111";
       When Others=>NULL;
end case;