library ieee;
use ieee.std_logic_1164.all;
use ieee.std_logic_arith.all;
use ieee.std_logic_unsigned.all;

entity s3_display1234 is 
    port ( CLKIN : in std_logic;
           AN3 : inout std_logic;
           AN2 : inout std_logic;
           AN1 : inout std_logic;
           AN0 : inout std_logic;
           LED : out std_logic_vector(6 downto 0));
end s3_display1234;


architecture behavioral of s3_display1234 is 
signal CTR : STD_LOGIC_VECTOR(12 downto 0);
begin
  Process (CLKIN)
  begin
    if CLKIN'event and CLKIN = '1' then
      if (CTR="0000000000000") then
        if (AN0='0') then 
          AN0 <= '1';
          LED <= "0000110";           -- cifra 3
          AN1 <= '0';
        elsif (AN1='0') then 
          AN1 <= '1'; 
          LED <= "0010010";             -- cifra 2
          AN2 <= '0';
        elsif (AN2='0') then 
          AN2 <= '1';
          LED <= "1001111";             -- cifra 1
          AN3 <= '0';
        elsif (AN3='0') then 
          AN3 <= '1';
          LED <= "1001100";             -- cifra 4
          AN0 <= '0';
        else        
          LED <= "1001100";             -- cifra 4
          AN0 <= '0';
        end if;
      end if;
      CTR<=CTR+"0000000000001";
      if (CTR > "1000000000000") then   -- num. ajunge la 2^13
        CTR<="0000000000000";
      end if;
    end if; -- CLK'event and CLK = '1' 
  End Process;
End Behavioral;