library IEEE; use IEEE.std_logic_1164.all; use IEEE.std_logic_arith.all; entity vadd is port ( A, B: in UNSIGNED (7 downto 0); C: in SIGNED (7 downto 0); D: in STD_LOGIC_VECTOR (7 downto 0); S: out UNSIGNED (8 downto 0); T: out SIGNED (8 downto 0); U: out SIGNED (7 downto 0); V: out STD_LOGIC_VECTOR (8 downto 0) ); end vadd; architecture vadd_arch of vadd is begin S <= ('0' & A) + ('0' & B); T <= A + C; U <= C + SIGNED(D); V <= C - UNSIGNED(D); end vadd_arch;