library ieee;
use ieee.std_logic_1164.all;

entity DISP_MUX is
  port(EXP_TIME   : in integer; -- range needed
       NO_PICS    : in integer; -- range needed
       SHOW_TIME  : in std_ulogic;
       -- add ERROR port
       DISP_PHOTO : out integer;); -- range needed
end DISP_MUX;

architecture RTL of DISP_MUX is
begin
  process(NO_PICS, EXP_TIME...) -- complete sensitivity list!!
  begin
    -- add ERROR condition
    if SHOW_TIME = '1' then
      -- output = exposure time
    else
      -- output = picture count
    end if;
  end process;
end RTL;