entity clock is port (
    clk50in                : in std_logic;             -- 50 Mhz XTAL
    pb_in                : in std_logic_vector(3 downto 0);    -- 4 pushbutton inputs
    sw_in                : in std_logic_vector(7 downto 0);    -- 8 switch inputs
    digit_out            : out std_logic_vector(3 downto 0);    -- digit drivers
    led_out                : out std_logic_vector(7 downto 0);    -- 8 LEDs
    seg_out                : out std_logic_vector(7 downto 0));    -- segment drivers

end clock;

process (clk50, rst)
begin
if rst = '1' then
    seg <= (others => '1');
    digit <= (others => '1');
    cd <= (others => '0');
    curr <= (others => '0');
elsif clk50'event and clk50 = '1' then
    cd(2) <= '1';
    if khertz_en = '1' then
        cd(1 downto 0) <= cd(1 downto 0) + 1;
    end if;
    case cd(1 downto 0) is
        when "00" =>   curr <= bcdint(3 downto 0);   digit <= "1110";
        when "01" =>   curr <= bcdint(7 downto 4);   digit <= "1101";
        when "10" =>   curr <= bcdint(11 downto 8);  digit <= "1011";
        when others => curr <= bcdint(15 downto 12); digit <= "0111";
    end case;
    if cd(2) = '1' then
        case curr is
            when "0000" => seg <= "0000001" & dp;
            when "0001" => seg <= "1001111" & dp;
            when "0010" => seg <= "0010010" & dp;
            when "0011" => seg <= "0000110" & dp;
            when "0100" => seg <= "1001100" & dp;
            when "0101" => seg <= "0100100" & dp;
            when "0110" => seg <= "0100000" & dp;
            when "0111" => seg <= "0001111" & dp;
            when "1000" => seg <= "0000000" & dp;
            when others => seg <= "0000100" & dp;
        end case;
    else
        seg <= (others => '1');
    end if;
end if;
end process;