$--$ Multiplexor is a device to select different

$--$ inputs to outputs. we use $3$ bits vector to

$--$ describe its $\frac{\text{I}}{O}$ ports

library ieee;

use ieee.std$\_$logic$\_1164.$all;

entity Mux is

port $($ I$3$: in std$\_$logic$\_$vector$(2$ downto $0)$;

I$2$: in std$\_$logic$\_$vector$(2$ downto $)$;

I$1$: in std$\_$logic$\_$vector$(2$ downto $0)$;

I$0$: in std$\_$logic$\_$vector$(2$ downto $0)$;

S: $,$ in std$\_$logic$\_$vector$(1$ downto $0$