pong.vhd

Pong is a mixed schematic, VHDL, Verilog project featuring the PS2 and VGA monitor connections of

-- Scott  Campbell
-- Xilinx Applications
-- CPLD Project
-- PONG Game

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

entity cntrl is Port (
	CLK : 	in std_logic;
	RESET: 	in std_logic;
	DATA_L:	in std_logic_vector( 6 downto 0 );
	DATA_R:	in std_logic_vector( 6 downto 0 );
	SERVE:	in std_logic;
	WRITE: 	out std_logic;
	HSYNCH:  out std_logic;
	VSYNCH:	out std_logic;
	COLOR:	out std_logic_vector( 1 downto 0 )
	);
end cntrl;

architecture static_display of cpld_top is

component vgacore is Port ( 
	CLK : 	in std_logic;
	RESET: 	in std_logic;
	HSYNCH:  out std_logic;
	VSYNCH:	out std_logic;
	VBLANK: 	out std_logic;
	HBLANK: 	out std_logic;
	LINE: 	out std_logic_vector(5 downto 0);
	PIXEL: 	out std_logic_vector(6 downto 0)
	);
end component;

component testram is Port ( 
	clk: 		in std_logic;
	address: in std_logic_vector( 6 downto 0 );
	data: 	out std_logic_vector( 3 downto 0 )
	);
end component;

signal	number_data: std_logic_vector( 3 downto 0 );
signal   number_address: std_logic_vector( 6 downto 0 );
signal   temp_data: std_logic;
signal	enable: std_logic;

signal	LINE:	 	std_logic_vector( 5 downto 0 );
signal	PIXEL: 	std_logic_vector( 6 downto 0 );
signal	VBLANK: 	std_logic;
signal	HBLANK: 	std_logic;

--signal   MODE: std_logic;
signal	next_HSYNCH:	std_logic;
signal	next_VSYNCH:	std_logic;
signal	VCLK: std_logic;
signal   next_COLOR: 	std_logic_vector( 1 downto 0 );

constant ball_height: integer := 1;
constant ball_width: integer := 2;

constant paddle_height: integer := 8;
constant paddle_heighta: integer := 4;	-- defines top 1/4 of paddle
constant paddle_heightb: integer := 6;	-- defines middle 1/2 of paddle
constant paddle_heightc: integer := 8;	-- defines bottom 1/4 of paddle
constant paddle_width: integer := 2;		-- defines width of paddle

constant wall_height: integer := 1;
constant wall_top: integer := 9;
constant wall_bottom: integer := 58;
constant right_wall: integer := 77;
constant left_wall: integer := 2;

constant right_score_x: integer:= 64;
constant right_score_y: integer:= 4;
constant left_score_x: integer:= 16;
constant left_score_y: integer:= 4;
constant score_width: integer := 4;
constant score_height: integer := 4;

constant right_x: integer := 72;
constant left_x: integer := 8;

signal ball_xdir, ball_ydir: std_logic;
signal ball_x: integer range 0 to 80;
signal ball_y: integer range 0 to 60;
signal ball_yrate: integer range 0 to 3;

signal left_y: std_logic_vector( 5 downto 0);
signal right_y: std_logic_vector( 5 downto 0);
signal nextleft_y: std_logic_vector( 5 downto 0);
signal nextright_y: std_logic_vector( 5 downto 0);

signal lscore, rscore: integer range 0 to 9;

begin

-- Signal Assignments for Testing Purposes

--right_y <= 60;
--left_y <= 60;

-- VGA CORE Instantiation
VGA1: vgacore port map (
	CLK => CLK,
	RESET=> RESET,
	HSYNCH=> next_HSYNCH,
	VSYNCH=> next_VSYNCH,
	VBLANK=> VBLANK,
	HBLANK=> HBLANK,
	LINE=> LINE,
	PIXEL=> PIXEL
	);

-- Character generator memory instantiation
CGEN1: testram port map ( 
	clk		=> clk,
	address	=> number_address ,
	data		=> number_data
	);

-- Pipeline the control signals to account for Game Delay
pipeline: process ( clk, pixel, line)
begin
	if ( clk = '1' and clk'event ) then
		VSYNCH <= next_VSYNCH;
		VCLK <= next_VSYNCH;
		HSYNCH <= next_HSYNCH;
		WRITE <= VBLANK;
		if ( HBLANK = '1' ) then
			color <= "00";
		else
			color <= next_COLOR;
		end if;
	end if;
end process;

-- Code to display the ball and paddles
display: process ( clk, line, pixel )
begin

	number_address(2 downto 0) <= line(2 downto 0);

--	if ( clk = '1' and clk'event ) then
		
	
	-- Display Background Color
	next_COLOR <= "00";
--	number_address <= ( others => '0' );

	-- Display the playing field top bar
		if ( line = wall_top  ) then
				next_COLOR <= "11";
		end if;

	-- Display the playing field bottom bar
		if ( line = wall_bottom ) then
				next_COLOR <= "11";
		end if;

	-- Display the left Paddle:
		if (( pixel = left_x -1)  ) then
			if ( (line >= left_y ) and (line <= (left_y + paddle_height)) ) then
				next_COLOR <= "11";
			end if;
		end if;
		
	-- Display the right Paddle:
		if ( pixel = right_x + 1 ) then
			if ( (line >= right_y) and (line <= (right_y + paddle_height)) ) then
				next_COLOR <= "11";
			end if;
		end if;

	-- Display the Ball:
		if ( (pixel = ball_x) ) then
			if ( line = ball_y ) then
				next_COLOR <= "11";
			end if;
		end if;
	
	-- Display the Left Score ( Using Std_Logic_Vectors instead of integers )
		if ( (pixel >= "0001000" ) and ( pixel <= "0001011" ) ) then
			if ( (line >= "000000" ) and (line <= "000111" ) ) then
				number_address(6 downto 3) <= CONV_STD_LOGIC_VECTOR(lscore,4); 

 			   case (pixel( 1 downto 0 )) is
					when "00" =>
						if ( number_data(3) = '1' ) then
							next_COLOR <= "10";
						end if;
					when "01" =>
						if ( number_data(2) = '1' ) then
							next_COLOR <= "10";
						end if;
					when "10" =>
						if ( number_data(1) = '1' ) then
							next_COLOR <= "10";
						end if;
					when "11" =>
						if ( number_data(0) = '1' ) then
							next_COLOR <= "10";
						end if;
					when others =>
						next_COLOR <= "00";
				end case;				
			end if;
		end if;

	-- Display the Right Score
		if ( (pixel >= "01000000" ) and ( pixel <= "01000011" ) ) then
			if ( (line >= "000000" ) and (line <= "000111" ) ) then
				number_address(6 downto 3) <= CONV_STD_LOGIC_VECTOR(rscore,4); 
 			   case (pixel( 1 downto 0 )) is
					when "00" =>
						if ( number_data(3) = '1' ) then
							next_COLOR <= "10";
						end if;
					when "01" =>
						if ( number_data(2) = '1' ) then
							next_COLOR <= "10";
						end if;
					when "10" =>
						if ( number_data(1) = '1' ) then
							next_COLOR <= "10";
						end if;
					when "11" =>
						if ( number_data(0) = '1' ) then
							next_COLOR <= "10";
						end if;
					when others =>
						next_COLOR <= "00";
				end case;				
			end if;
		end if;

--	end if;
end process;

-- Game play logic
moving_ball: process ( VCLK, ball_xdir, ball_ydir, ball_x, ball_y )
begin
	if ( reset = '1' ) then
		ball_x <= left_wall;
		ball_y <= 32;
		ball_yrate <= 1;
		lscore <= 0;
		rscore <= 0;
		enable <= '0';
	elsif ( VCLK = '1' and VCLK'event ) then
		-- Horizontal Movement ( 1 = right )
		nextleft_y <= DATA_L( 6 downto 1);
		nextright_y <= DATA_R( 6 downto 1);

		if ( SERVE = '1' ) then
			if ( enable = '0' ) then
				ball_yrate <= 0;
			end if;
			enable <= '1';
		end if;

		if ( nextleft_y < 9 ) then
			left_y <= "001001";
		elsif( nextleft_y > 50 ) then
			left_y <= "110010";
		else
			left_y <= nextleft_y;
		end if;

		if ( nextright_y < 9 ) then
			right_y <= "001001";
		elsif( nextright_y > 50 ) then
			right_y <= "110010";
		else
			right_y <= nextright_y;
		end if;

		if ( ball_xdir = '1' ) then
			if ( enable = '1' ) then
				ball_x <= ball_x + 1;
			end if;

			-- check for hit on upper 1/4 of right paddle
			if  ((ball_x = right_x) and ( ball_y >= right_y - ball_height ) and ( ball_y < right_y + paddle_heighta) ) then
				ball_xdir <= '0';
				-- if ball is going down
				if ( ball_ydir = '0' ) then 
					if ( ball_yrate > 0 ) then
						ball_yrate <= ball_yrate - 1;
					else
						ball_yrate <= 1;
						ball_ydir <= '1';
					end if;

				-- if ball is going up
			  	else
					if ( ball_yrate < 2 ) then
						ball_yrate <= ball_yrate + 1;
					else
						ball_yrate <= 2;
					end if;
				end if;

			elsif  ((ball_x = right_x) and ( ball_y >= right_y + paddle_heighta) and ( ball_y < right_y + paddle_heightb) ) then
				ball_xdir <= '0';

			-- check for hit on lower half of right paddle
			elsif  ((ball_x = right_x) and ( ball_y >= right_y + paddle_heightb) and ( ball_y <= right_y + paddle_heightc) ) then
					ball_xdir <= '0';
				-- if ball is going down
				if ( ball_ydir = '0' ) then 
					if ( ball_yrate < 2 ) then
						ball_yrate <= ball_yrate + 1;
					else
						ball_yrate <= 2;
					end if;
				-- if ball is going up
			  	else
					if ( ball_yrate > 0 ) then
						ball_yrate <= ball_yrate - 1;
					else
						ball_ydir <= '0';
						ball_yrate <= 1;
					end if;
				end if;
					
			-- Score for left team
			else
				if ( ball_x = right_wall ) then			
					ball_xdir <= '0';	
					if ( enable = '1' ) then
						if ( lscore = 9 ) then
							lscore <= 0;
						else 
							lscore <= lscore + 1;
						end if;
					end if;
					enable <= '0';
				end if;
			end if;

		-- Ball going left
		else 
			-- in middle of playing field
			if ( enable = '1' ) then
				ball_x <= ball_x - 1;
			end if;

			if ( ball_x = left_x ) then

			-- upper portion of paddle
				if (( ball_y >= left_y ) and ( ball_y < left_y + paddle_heighta )) then
					ball_xdir <= '1';
					-- if ball is going down
					if ( ball_ydir = '0' ) then 
						if ( ball_yrate > 0 ) then
							ball_yrate <= ball_yrate - 1;
						else
							ball_ydir <= '1';
							ball_yrate <= 1;
						end if;
					-- if ball is going up
				  	else
						if ( ball_yrate < 2 ) then
							ball_yrate <= ball_yrate + 1;
						else
							ball_yrate <= 2;
						end if;
					end if;

				-- lower portion of paddle
				elsif  ( ( ball_y >= left_y + paddle_heightb) and ( ball_y <= left_y + paddle_heightc) ) then
					ball_xdir <= '1';
					-- if ball is going down
					if ( ball_ydir = '0' ) then 
						if ( ball_yrate < 2 ) then
							ball_yrate <= ball_yrate + 1;
						else
							ball_yrate <= 2;
						end if;
					-- if ball is going up
				  	else
						if ( ball_yrate > 0 ) then
							ball_yrate <= ball_yrate - 1;
						else
							ball_ydir <= '0';
							ball_yrate <= 1;
						end if;
					end if;				
				elsif (( ball_y >= left_y + paddle_heighta) and ( ball_y < left_y + paddle_heightb)) then
					ball_xdir <= '1';				
				end if;

			-- Score for right team
			else
				if ( ball_x = left_wall ) then	
					ball_xdir <= '1';		
					if ( enable = '1' ) then
						if ( rscore = 9 ) then
							rscore <= 0;
						else
							rscore <= rscore + 1;
						end if;
					end if;
				enable <= '0';
				end if;
			end if;
		end if;

		-- Vertical Movement ( 1 = up )
		if ( ball_ydir = '1' ) then
			if ( (ball_y = wall_top )or (ball_y = wall_top + 1 )) then
				ball_ydir <= '0';
			else
				ball_y <= ball_y - ball_yrate;
			end if;
		else 
			if (( ball_y = wall_bottom ) or ( ball_y = wall_bottom-1 )) then
				ball_ydir <= '1';
			else
				ball_y <= ball_y + ball_yrate;
			end if;
		end if;

	end if;
end process;

end static_display;