library IEEE;
use IEEE.std_logic_1164.all;
entity mux4 is port (
a, b, c, d : in std_logic_vector (7 downto 0);
sel : in std_logic_vector (1 downto 0);
outmux : out std_logic_vector (7 downto 0));
end mux4;
architecture behavior of mux4 is begin
process (a, b, c, d, sel)
begin
case sel is
when "00" => outmux <= a;
when "01" => outmux <= b;
when "10" => outmux <= c;
when others => outmux <= d; -- case statement must be complete
end case;
end process;
end behavior;