picoblazeoutput.vhd

此为VHDL实现的路口红绿灯控制例子

--------------------------------------------------------------------------------
-- Company:		Steepest Ascent
-- Engineer:	James A Bowman
--
-- Create Date:   
-- Design Name:   picoblaze_traffic_light  
-- Module Name:   picoblazeoutput - Behavioral
-- Project Name:  XUP- PicoBlaze Traffic Light Example 
-- Target Device: XILINX Virtex II Pro XC2VP30
-- Tool versions:  
-- Description:
--
-- Dependencies:
-- 
-- Revision:		Version 1.0
-- Additional 
-- Comments:		None
-- 
--------------------------------------------------------------------------------
library IEEE;
use IEEE.STD_LOGIC_1164.ALL;
use IEEE.STD_LOGIC_ARITH.ALL;
use IEEE.STD_LOGIC_UNSIGNED.ALL;


entity PicoBlazeOutput is
    Port ( output_data 	: in std_logic_vector(7 downto 0);
           clk 			: in std_logic;	 		  
			  output_0 		: out std_logic_vector(7 downto 0);
			  output_1		: out	std_logic_vector(7 downto 0);
	 	 	  output_2 		: out std_logic_vector(7 downto 0);
			  output_3 		: out std_logic_vector(7 downto 0);
           output_id 	: in std_logic_vector(7 downto 0);
           output_we 	: in std_logic);
end PicoBlazeOutput;


architecture Behavioral of PicoBlazeOutput is

signal data_intermediate : std_logic_vector(7 downto 0):= "00000000";
signal mux_input         : std_logic_vector(1 downto 0):= "00";


begin

	-- Setup for Maximum of 4 Ouputs (2 Bit Address)
	mux_input <= output_id(1 downto 0);

	process(clk)
	begin
		
		if rising_edge(clk) then
			-- Each Output is Full Data Width Wide (8 Bits)
			if (output_we = '1') then
				if mux_input ="00" then
					output_0 <= output_data;
				end if;
				if mux_input ="01" then
					output_1 <= output_data;
				end if;
				if mux_input ="10" then
					output_2 <= output_data;
				end if;
				if mux_input ="11" then
					output_3 <= output_data;
				end if;
			end if;  		
		end if;

	end process;

end Behavioral;