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

entity counters_3 is
    port(C, ALOAD : in std_logic;
         D : in std_logic_vector(3 downto 0);
         Q : out std_logic_vector(3 downto 0));
end counters_3;

architecture archi of counters_3 is
    signal tmp: std_logic_vector(3 downto 0);
begin
    process (C, ALOAD, D)
    begin
        if (ALOAD='1') then
            tmp <= D;
        elsif (C'event and C='1') then
            tmp <= tmp + 1;
        end if;
    end process;

    Q <= tmp;

end archi;