library IEEE use IEEE.STD_LOGIC_1164.ALL use IEEE.STD_LOGIC_ARITH.ALL use IEEE.STD_LOGIC_UNSIGNED.ALL use ieee.numeric_std.all

16位MIPS指令集，VHDL实现，非常简单，非常粗暴(library ieee; use ieee.std_logic_1164.all; use ieee.std_logic_unsigned.all; use ieee.std_logic_arith.all;)

内含三个普通的四位加法器，adder，adder4-2，adder4-3(library ieee; use ieee.std_logic_1164.all; use ieee.numeric_std.all; entity full_adder is port( a,b,ci :in std_logic; s,co :out std_logic); end entity; architecture rtl of full_adder is begin s&