1-to-4 Demultiplexer

The entity demux1_4 has one input (i_d) of type std_logic, a selector (i_sel) of type std_logic_vector(1 downto 0) and one output (o_q) of type std_logic_vector(3 downto 0).

Only the selected output receives the value of i_d, the others are '0'. "00" -> o_q(0)=i_d, "01" -> o_q(1)=i_d, "10" -> o_q(2)=i_d, "11" -> o_q(3)=i_d.