LIBRARY IEEE;
USE IEEE.STD_LOGIC_ARITH.ALL;
USE IEEE.STD_LOGIC_UNSIGNED.ALL;
USE IEEE.STD_LOGIC_1164.all;

ENTITY mousestream IS
	PORT(
		clk								: IN	STD_LOGIC;
		enable							: IN	STD_LOGIC;
		leftbutton						: IN	STD_LOGIC;
		rightbutton						: IN	STD_LOGIC;
		middlebutton					: IN	STD_LOGIC;
		xsign							: IN	STD_LOGIC;
		ysign							: IN	STD_LOGIC;
		xmove							: IN	STD_LOGIC_VECTOR(7 DOWNTO 0);
		ymove							: IN	STD_LOGIC_VECTOR(7 DOWNTO 0);
		clk_10k							: INOUT	STD_LOGIC;
		clk_20k							: OUT	STD_LOGIC;
		MOUSE_DATA						: INOUT STD_LOGIC);

END mousestream;

ARCHITECTURE a OF mousestream IS
	TYPE STATE_TYPE IS (INIT_STATE, STREAM_MODE, MOUSEDATA, LOAD_COMMAND1, LOAD_COMMAND2, 
						WAIT_OUTPUT_READY, WAIT_OUTPUT_PAUSE);

	SIGNAL mouse_state : STATE_TYPE;
	SIGNAL ClkDivisor_10k							: STD_LOGIC_VECTOR(10 DOWNTO 0);
	SIGNAL Clk_10k_buff								: STD_LOGIC;
	SIGNAL Clk_20k_buff								: STD_LOGIC;
	SIGNAL COUNT_STREAM								: STD_LOGIC_VECTOR(16 DOWNTO 0);
--	SIGNAL Clk_100_buff								: STD_LOGIC;
	SIGNAL MOUSE_DATA_DIR							: STD_LOGIC;
	SIGNAL MOUSE_DATA_BUF							: STD_LOGIC;
	SIGNAL MOUSE_CLK_DIR							: STD_LOGIC;
	SIGNAL STREAMMODE								: STD_LOGIC;
	SIGNAL SEND_DATA, output_ready,IREADY_SET		: STD_LOGIC;
	SIGNAL SEND_CHAR, READ_CHAR, SEND_UPDATE		: STD_LOGIC;
	SIGNAL RECEIVE_DATA								: STD_LOGIC;
	SIGNAL OUTCNT									: STD_LOGIC_VECTOR(3 DOWNTO 0);
	SIGNAL INCNT									: STD_LOGIC_VECTOR(3 DOWNTO 0);
	SIGNAL CHARIN, CHAROUT							: std_logic_vector(7 DOWNTO 0);
	SIGNAL SHIFTIN 									: std_logic_vector(8 DOWNTO 0);
	SIGNAL SHIFTOUT 								: std_logic_vector(10 DOWNTO 0);
	SIGNAL PACKET_COUNT 							: std_logic_vector(1 DOWNTO 0);
	SIGNAL PACKET_CHAR1, PACKET_CHAR2, PACKET_CHAR3 : std_logic_vector(7 DOWNTO 0);
	SIGNAL PAUSETIME								: std_logic_vector(12 DOWNTO 0);
	SIGNAL COUNT_CLICKS								: std_logic_vector(3 DOWNTO 0); 
	SIGNAL xmovement								: std_logic_vector(7 DOWNTO 0); 
	SIGNAL ymovement								: std_logic_vector(7 DOWNTO 0);
	

BEGIN

	MOUSE_DATA <= 'Z' WHEN MOUSE_DATA_DIR = '0' ELSE MOUSE_DATA_BUF;
	clk_10k <= 'Z' WHEN MOUSE_CLK_DIR = '0' ELSE Clk_10k_buff;
	clk_20k <= clk_20k_buff;

	PROCESS (clk, enable)
	BEGIN
		IF clk'event AND clk = '1' THEN
			IF(ClkDivisor_10k = "10011100001") then
--			IF(ClkDivisor_10k = "00011111001") then
				Clk_20k_buff <= NOT Clk_20k_buff;
				ClkDivisor_10k <= "00000000000";
				Clk_10k_buff <= NOT CLK_10k_buff;
			ELSIF (ClkDivisor_10k = "1001110000") THEN
--			ELSIF (ClkDivisor_10k = "0001111100") THEN
				Clk_20k_buff <= NOT Clk_20k_buff;
				clkDivisor_10k <= clkDivisor_10k + 1;
			ELSE
				clkDivisor_10k <= clkDivisor_10k + 1;
			END IF;
			IF (enable = '1') THEN
				COUNT_STREAM <= "00000000000000001";
			END IF;
			IF COUNT_STREAM = "00010101101101100" THEN
				COUNT_STREAM <= "00000000000000000";
			ELSIF (COUNT_STREAM > "00000000000000000") THEN
				COUNT_STREAM <= COUNT_STREAM + 1;
			END IF;
		END IF;
	END PROCESS;

	PROCESS(enable, COUNT_STREAM)
	BEGIN
		IF (COUNT_STREAM = "00010101101101100") THEN
			SEND_UPDATE <= '0';
		ELSIF (enable'event AND enable = '1') THEN
			IF ((STREAMMODE = '1') AND (mouse_state = STREAM_MODE)) THEN
				SEND_UPDATE <= '1';
				PACKET_CHAR1 <= "00" & ysign & xsign & '1' & middlebutton & rightbutton & leftbutton;
				PACKET_CHAR2 <= xmove;
				PACKET_CHAR3 <= ymove;
			END IF;
		END IF;
	END PROCESS;

	PROCESS (clk)
	BEGIN
		IF clk'EVENT AND clk = '1' THEN
			CASE mouse_state IS
				WHEN INIT_STATE =>
					PACKET_COUNT <= "11";
					STREAMMODE <= '1';
					SEND_DATA <= '0';
					RECEIVE_DATA <= '1';
					mouse_state <= STREAM_MODE;

				WHEN STREAM_MODE =>
					IF (SEND_UPDATE = '1') THEN
						IF (clk_10k_buff = '1' and Clk_20k_buff = '1') THEN
							mouse_state <= MOUSEDATA;
						ELSE
							mouse_state <= STREAM_MODE;
						END IF;
					ELSE
						mouse_state <= STREAM_MODE;
					END IF;

				WHEN MOUSEDATA =>
					IF (PACKET_COUNT = "00") THEN
						PACKET_COUNT <= "11";
						mouse_state <= STREAM_MODE;
					ELSIF (PACKET_COUNT = "01") THEN
						PACKET_COUNT <= PACKET_COUNT - 1;
						CHAROUT <= PACKET_CHAR3;
						mouse_state <= LOAD_COMMAND1;
					ELSIF (PACKET_COUNT = "10") THEN
						PACKET_COUNT <= PACKET_COUNT - 1;
						CHAROUT <= PACKET_CHAR2;
						mouse_state <= LOAD_COMMAND1;
					ELSIF (PACKET_COUNT = "11") THEN
						PACKET_COUNT <= PACKET_COUNT - 1;
						CHAROUT <= PACKET_CHAR1;
						mouse_state <= LOAD_COMMAND1;
					END IF;			

				WHEN LOAD_COMMAND1 	=>
					SEND_DATA <= '1';
					mouse_state <= LOAD_COMMAND2;

				WHEN LOAD_COMMAND2 	=>
					SEND_DATA <= '1';
					mouse_state <= WAIT_OUTPUT_READY;

				WHEN WAIT_OUTPUT_READY =>
					SEND_DATA <= '0';
					IF (output_ready = '1') THEN
						mouse_state <= WAIT_OUTPUT_PAUSE;
					ELSE
						mouse_state <= WAIT_OUTPUT_READY;
					END IF;

				WHEN WAIT_OUTPUT_PAUSE =>
					IF(PAUSETIME = "1110101001011") THEN
--					IF(PAUSETIME = "0010011100001") THEN 
						IF (Clk_10k_buff = '1' and Clk_20k_buff = '1') THEN
							PAUSETIME <= "0000000000000";
							mouse_state <= MOUSEDATA;
						ELSE
							mouse_state <= WAIT_OUTPUT_PAUSE;
						END IF;
					ELSE
						PAUSETIME <= PAUSETIME + 1;
						mouse_state <= WAIT_OUTPUT_PAUSE;
					END IF;

			END CASE;
		END IF;
	END PROCESS;

WITH mouse_state SELECT

		MOUSE_DATA_DIR 	<=	'0'	WHEN INIT_STATE,
							'0'	WHEN STREAM_MODE,
							'0'	WHEN MOUSEDATA,
							'1'	WHEN LOAD_COMMAND1,
							'1'	WHEN LOAD_COMMAND2,
							'1'	WHEN WAIT_OUTPUT_READY,
							'0'	WHEN WAIT_OUTPUT_PAUSE;

	WITH mouse_state SELECT
		MOUSE_CLK_DIR 	<=	'0'	WHEN INIT_STATE,
							'0'	WHEN STREAM_MODE,
							'0'	WHEN MOUSEDATA,
							'1'	WHEN LOAD_COMMAND1,
							'1'	WHEN LOAD_COMMAND2,
							'1'	WHEN WAIT_OUTPUT_READY,
							'0' WHEN WAIT_OUTPUT_PAUSE;
		
	PROCESS (SEND_DATA, clk_20k_buff)
	BEGIN
		IF SEND_DATA = '1' THEN
			OUTCNT <= "0000";
    		SEND_CHAR <= '1';
			OUTPUT_READY <= '0';
			-- Send out Start Bit(0) + Command(F4) + Parity  Bit(0) + Stop Bit(1)
			SHIFTOUT(8 DOWNTO 1) <= CHAROUT ;
			-- START BIT
			SHIFTOUT(0) <= '0';
			-- COMPUTE ODD PARITY BIT
			SHIFTOUT(9) <=  not (charout(7) xor charout(6) xor charout(5) xor 
							charout(4) xor Charout(3) xor charout(2) xor charout(1) xor 
							charout(0));
			-- STOP BIT 
			SHIFTOUT(10) <= '1';
			-- Data Available Flag to Mouse
			-- Tells mouse to clock out command data (is also start bit)
    		MOUSE_DATA_BUF <= '0';

		ELSIF((clk_20k_buff'event) and (clk_20k_buff = '1')) THEN
			
			IF MOUSE_DATA_DIR='1' AND clk_10k = '1' THEN
			-- SHIFT OUT NEXT SERIAL BIT
  				IF SEND_CHAR = '1' THEN
				-- Loop through all bits in shift register
        			IF OUTCNT <= "1001" THEN
         				OUTCNT <= OUTCNT + 1;
						-- Shift out next bit to mouse
         				SHIFTOUT(9 DOWNTO 0) <= SHIFTOUT(10 DOWNTO 1);
		 				SHIFTOUT(10) <= '1';
         				MOUSE_DATA_BUF <= SHIFTOUT(1);
		 				OUTPUT_READY <= '0';
						-- END OF CHARACTER
	 				ELSE
     					SEND_CHAR <= '0';
						OUTPUT_READY <= '1';
						-- Signal the character has been output
						OUTCNT <= "0000";
					END IF;
  				END IF;
			END IF;
		END IF;
	END PROCESS;

	PROCESS(RECEIVE_DATA, clk_10k)
	BEGIN
		IF (RECEIVE_DATA = '1') THEN
   			IREADY_SET <= '0';
			INCNT <= "0000";
			READ_CHAR <= '0';
			CHARIN <= "00000000";
		ELSE
			IF clk_10k'event and clk_10k ='1' THEN
				IF MOUSE_DATA_DIR ='0' THEN
 					IF MOUSE_DATA ='0' AND READ_CHAR='0' THEN
						READ_CHAR <= '1';
	    				IREADY_SET<= '0';
						INCNT <= "0000";
		 			ELSE
						-- SHIFT IN NEXT SERIAL BIT
				  		IF READ_CHAR = '1' THEN
							IF INCNT < "1001" THEN
								INCNT <= INCNT + 1;
								SHIFTIN(7 DOWNTO 0) <= SHIFTIN(8 DOWNTO 1);
								SHIFTIN(8) <= MOUSE_DATA;
								IREADY_SET <= '0';
								-- END OF CHARACTER
							ELSE
								CHARIN <= SHIFTIN(7 DOWNTO 0);
								READ_CHAR <= '0';
								IREADY_SET <= '1';
								INCNT <= conv_std_logic_vector(0,4);
  							END IF;
	  					END IF;
		 			END IF;
				END IF;
 			END IF;
		END IF;
	END PROCESS;

END a;