进程语句的一个实例 例:2-4译码器的进程描述 a: in std logic vector(I downto 0); f: out std logic vector (3 downto O) process(a) begin f(0)<= not a(1)and not a(0); f(1)<=not a(1)and a(0) f(2)<=a(1)and not a(0) f(3)<=a(1)anda(0) end process;进程语句的一个实例 例：2-4译码器的进程描述 a: in std_logic_vector (1 downto 0); f: out std_logic_vector (3 downto 0) ; ……… process(a) begin f(0) <= not a(1) and not a(0); f(1) <= not a(1) and a(0); f(2) <= a(1) and not a(0); f(3) <= a(1) and a(0); end process; ………