picoblazeinput.vhd

此为VHDL实现的路口红绿灯控制例子

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-- Company:			Steepest Ascent
-- Engineer:		James A Bowman
--
-- Create Date:   
-- Design Name:   picoblaze_traffic_light  
-- Module Name:   picoblazeinput - Behavioral
-- Project Name:  XUP- PicoBlaze Traffic Light Example 
-- Target Device: XILINX Virtex II Pro XC2VP30
-- Tool versions:  
-- Description:
--
-- Dependencies:
-- 
-- Revision:		Version 1.1
-- Additional 
-- Comments:		Version 1.1 Input bus width increased to 8 Bits
-- 
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library IEEE;
use IEEE.STD_LOGIC_1164.ALL;
use IEEE.STD_LOGIC_ARITH.ALL;
use IEEE.STD_LOGIC_UNSIGNED.ALL;



entity PicoBlazeInput is
    Port ( input_0 	 : in std_logic_vector(7 downto 0);
           input_1 	 : in std_logic_vector(7 downto 0);
           input_2 	 : in std_logic_vector(7 downto 0);
           input_3    : in std_logic_vector(7 downto 0);
			  clk		    : in std_logic;
           input_id   : in std_logic_vector(7 downto 0);
           input_data : out std_logic_vector(7 downto 0));
end PicoBlazeInput;



architecture Behavioral of PicoBlazeInput is

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


begin
	-- Setup for Maximum of 4 Inputs (2 Bit Address)
	mux_input <= input_id(1 downto 0);

	process(clk)
	begin
		
		if rising_edge(clk) then
		-- Each Output is Full Data Width Wide (8 Bits)	
			MUX: case  mux_input  is
    				when "00" =>
						input_intermediate <= input_0;	
    				when "01" =>
						input_intermediate <= input_1;
					when "10" =>
						input_intermediate <= input_2;
					when "11" =>
						input_intermediate <= input_3;
    				when others =>
      				input_intermediate <= "00000000";
  				  end case;	
		end if;

	input_data <= input_intermediate;   

	end process;
	
end Behavioral;