char_generator.vhd

这个是国外大学的项目代码

------------------------------------------------------------------------
--  char_generator.vhd -- 
------------------------------------------------------------------------
--  Authors : Albert Zemba & Mihai Cucicea
------------------------------------------------------------------------
-- Software version: Xilinx ISE 7.1i 
--                   WebPack
------------------------------------------------------------------------
-- This source file contains the char_generator component
------------------------------------------------------------------------
--  Behavioral description
-- The main view of this component is that at a certain position, 
-- defined by pixel_row, pixel_col(the pixel coordinates on vga)
-- it returns the RBG which is transmitted to the vga(640x480 pixels)
-- Each of the "rom_char" components (16x16 pixels) returns an RGB, 
-- and the correct one is selected with char
-- The mux8_1_3bits uses only 4 of 8 inputs the other ones 
-- are left for later developement (more characters)
------------------------------------------------------------------------

library IEEE;
use IEEE.STD_LOGIC_1164.ALL;
use IEEE.STD_LOGIC_ARITH.ALL;
use IEEE.STD_LOGIC_UNSIGNED.ALL;

entity char_generator is
	port(
			posR, posC: in std_logic_vector(5 downto 0);
			char:in std_logic_vector(2 downto 0);
			pixel_row,pixel_col:in std_logic_vector(9 downto 0);
			RGB:out std_logic_vector (2 downto 0)
	);
end char_generator;

architecture Behavioral of char_generator is
------------------------------------------------------------------------
-- A representation of a door
------------------------------------------------------------------------
component rom_door_char is
	port(line, col : in std_logic_vector(3 downto 0); 
			color : out std_logic_vector(2 downto 0)
	);
end component rom_door_char;
------------------------------------------------------------------------
-- A representation of an empty spot(black on vga)
------------------------------------------------------------------------
component rom_empty_char is
	port(line, col : in std_logic_vector(3 downto 0); 
			color : out std_logic_vector(2 downto 0)
	);
end component rom_empty_char;
------------------------------------------------------------------------
-- A representation of wall
------------------------------------------------------------------------
component rom_wall_char is
	port(line, col : in std_logic_vector(3 downto 0); 
			color : out std_logic_vector(2 downto 0)
	);
end component rom_wall_char;
------------------------------------------------------------------------
-- A representation of the actual player(a happy face on vga)
------------------------------------------------------------------------
component rom_human_char is
	port(line, col : in std_logic_vector(3 downto 0); 
			color : out std_logic_vector(2 downto 0)
	);
end component rom_human_char;
------------------------------------------------------------------------
-- The mux
------------------------------------------------------------------------
component mux8_1_3bits is
	port(a,b,c,d,e,f,g,h:in std_logic_vector(2 downto 0);
			s:in std_logic_vector(2 downto 0);
			o:out std_logic_vector(2 downto 0)
	);
end component mux8_1_3bits;

signal p_r_mod8,p_c_mod8:std_logic_vector(3 downto 0);
signal s_mux,empty_out,full_out:std_logic_vector(2 downto 0);
signal people_out,door_out:std_logic_vector(2 downto 0);

begin
		empty : rom_empty_char 
			port map (line=>p_r_mod8, col=>p_c_mod8, color=>empty_out);

		wall : rom_wall_char 
			port map (line=>p_r_mod8, col=>p_c_mod8, color=>full_out);

		human : rom_human_char 
			port map (line=>p_r_mod8, col=>p_c_mod8, color=>people_out);
		
		door : rom_door_char 
			port map (line=>p_r_mod8, col=>p_c_mod8, color=>door_out);
		
		mux : mux8_1_3bits port map (a=>empty_out, b=>full_out, 
			c=>door_out, d=>people_out, e=>"000", 
			f=>"000", g=>"000", h=>"000", s=>s_mux, o=>RGB
		);
		process (pixel_row,pixel_col)
		variable p_r_div8,p_c_div8:std_logic_vector(6 downto 0);
		begin
------------------------------------------------------------------------
-- Because each character is 16x16 pixels, the current pixel 
-- in a character is determined by (pixel_row mod 16, pixel_col mod 16)
------------------------------------------------------------------------
			p_r_mod8 <= 
				conv_std_logic_vector(conv_integer(pixel_row) mod 16,4);
			p_c_mod8 <= 
				conv_std_logic_vector(conv_integer(pixel_col) mod 16,4);
			p_r_div8 := 
				conv_std_logic_vector(conv_integer(pixel_row) / 16,7);
			p_c_div8 := 
				conv_std_logic_vector(conv_integer(pixel_col) / 16,7);
------------------------------------------------------------------------
-- if posR, posC (the current position of the player) corespond 
-- to the current pixel position, than the rom_human_char is 
-- selected on mux
------------------------------------------------------------------------
			if ((p_r_div8=posR) and (p_c_div8=posC)) then s_mux<="011";
			else s_mux<=char;
			end if;
		end process;
end Behavioral;