alucontrol.vhd

来自「MIPS处理器VHDL代码」· VHDL 代码 · 共 47 行

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-- Company: 
-- Engineer: 
-- 
-- Create Date:    12:18:53 09/17/2007 
-- Design Name: 
-- Module Name:    alucontrol - Behavioral 
-- Project Name: 
-- Target Devices: 
-- Tool versions: 
-- Description: 
--
-- Dependencies: 
--
-- Revision: 
-- Revision 0.01 - File Created
-- Additional Comments: 
--
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library IEEE; 
use IEEE.STD_LOGIC_1164.all;
entity alucontrol is  --ALU 控制译码器
    port(aluop:   in  STD_LOGIC_VECTOR(1 downto 0);
	      funct:   in  STD_LOGIC_VECTOR(5 downto 0);
	      alucont: out STD_LOGIC_VECTOR(2 downto 0));
end;

architecture synth of alucontrol is
begin
   process(aluop, funct) 
	begin
	case aluop is 
	    when "00" => alucont <= "010";
	    when "01" => alucont <= "110";
	    when others => case funct is 
				when "100000" => alucont <= "010";
				when "100010" => alucont <= "110";
				when "100100" => alucont <= "000";
				when "100101" => alucont <= "001";
				when "101010" => alucont <= "111";
				when others   => alucont <= "---";
			   end case;
	end case;
   end process;
end;