Design Entry

[bwiec]

Why not just use concatenation operators?

[rcingham · Accepted solution]

quagga: process (Clk, Reset) is
begin
  if (Reset = '1') then
    Internal <= (others => '0');
  elsif rising_edge(Clk) then
    Internal <= In_D & In_C & In_B & In_A;
  end if;
end process quagga;

 Actually, the asynchronous reset is non-preferred, but is only moderately harmful.