library ieee;
use ieee.std_logic_1164.all;
use ieee.std_logic_arith.all;
use ieee.std_logic_unsigned.all;

entity RAM9X8_PWM is	
	generic(
		PWM_BASE_ADDRESS : integer := 16;		
		
		DATA_BUS_WIDTH : integer := 8;
		ADDRESS_BUS_WIDTH : integer := 9
	);
	
	port(
		clk : in std_logic;
		
		data : inout std_logic_vector(DATA_BUS_WIDTH - 1 downto 0);
		address : in std_logic_vector(ADDRESS_BUS_WIDTH - 1 downto 0);
		we : in std_logic;
		oe : in std_logic;
		ce : in std_logic;	
	
		tk : out std_logic_vector(31 downto 0) := (others => '1');
		interrupt : out std_logic := '1';
		pwm : in std_logic_vector(5 downto 0);
		error : in std_logic
	);
end entity;

architecture behavorial of RAM9X8_PWM is

signal PWM_MODE_CONTROL_LOWER : integer := PWM_BASE_ADDRESS;
signal PWM_MODE_CONTROL_UPPER : integer := PWM_BASE_ADDRESS + 1;
signal PWM_MASK_2_LOWER : integer := PWM_BASE_ADDRESS + 2;
signal PWM_MASK_2_UPPER : integer := PWM_BASE_ADDRESS + 3;
signal PWM_MASK_1_LOWER : integer := PWM_BASE_ADDRESS + 4;
signal PWM_MASK_1_UPPER : integer := PWM_BASE_ADDRESS + 5;
signal PWM_DIRECT_CONTROL_2_LOWER : integer := PWM_BASE_ADDRESS + 6;
signal PWM_DIRECT_CONTROL_2_UPPER : integer := PWM_BASE_ADDRESS + 7;
signal PWM_DIRECT_CONTROL_1_LOWER : integer := PWM_BASE_ADDRESS + 8;
signal PWM_DIRECT_CONTROL_1_UPPER : integer := PWM_BASE_ADDRESS + 9;
signal PWM_PERIOD_LOWER : integer := PWM_BASE_ADDRESS + 10;
signal PWM_PERIOD_UPPER : integer := PWM_BASE_ADDRESS + 11;
signal PWM_DIRECTION_2_LOWER : integer := PWM_BASE_ADDRESS + 12;
signal PWM_DIRECTION_2_UPPER : integer := PWM_BASE_ADDRESS + 13;
signal PWM_DIRECTION_1_LOWER : integer := PWM_BASE_ADDRESS + 14;
signal PWM_DIRECTION_1_UPPER : integer := PWM_BASE_ADDRESS + 15;
signal PWM_CHANNEL_LOWER : integer := PWM_BASE_ADDRESS + 16;
signal PWM_CHANNEL_UPPER : integer := PWM_BASE_ADDRESS + 17;
signal PWM_TIMING_LOWER : integer := PWM_BASE_ADDRESS + 18;
signal PWM_TIMING_UPPER : integer := PWM_BASE_ADDRESS + 19;
signal PWM_CMD_LOWER : integer := PWM_BASE_ADDRESS + 20;
signal PWM_CMD_UPPER : integer := PWM_BASE_ADDRESS + 21;
signal PWM_CONTROL_LOWER : integer := PWM_BASE_ADDRESS + 22;
signal PWM_CONTROL_UPPER : integer := PWM_BASE_ADDRESS + 23;

signal modeBuf : std_logic_vector(15 downto 0) := (others => '0');
signal maskBuf : std_logic_vector(31 downto 0) := (others => '1');
signal directControlBuf : std_logic_vector(31 downto 0) := (others => '1');
signal periodBuf : std_logic_vector(15 downto 0) := (others => '0');
signal directionBuf : std_logic_vector(31 downto 0) := (others => '0');
signal channelBuf : std_logic_vector(15 downto 0) := (others => '0');
signal cmdBuf : std_logic_vector(15 downto 0) := (others => '0');
signal controlBuf : std_logic_vector(15 downto 0) := (others => '0');

signal tkBuf : std_logic_vector(31 downto 0) := (others => '1');

type mem is array (31 downto 0) of std_logic_vector(15 downto 0);
signal memory : mem;
signal memoryBuf : mem;

signal pwm3level : std_logic_vector(31 downto 0) := (others => '1');
signal upDown : std_logic := '0';
signal upDownPrev : std_logic := '0';
signal interruptBuf : std_logic := '0';
signal period : std_logic_vector(15 downto 0) := (others => '0');
signal counter : std_logic_vector(15 downto 0) := (others => '0');

signal enableWriteControlBuf : std_logic := '1';

begin	

	process (we, oe, ce)
		variable addr : integer range 0 to 2**ADDRESS_BUS_WIDTH - 1 := 0;
	begin
		if (ce = '0') then  -- Если микросхема выбрана
			addr := conv_integer(address);
			if (addr = PWM_MODE_CONTROL_UPPER or addr = PWM_MODE_CONTROL_LOWER
				or addr = PWM_MASK_2_UPPER or addr = PWM_MASK_2_LOWER or addr = PWM_MASK_1_UPPER or addr = PWM_MASK_1_LOWER
				or addr = PWM_DIRECT_CONTROL_2_UPPER or addr = PWM_DIRECT_CONTROL_2_LOWER or addr = PWM_DIRECT_CONTROL_1_UPPER or addr = PWM_DIRECT_CONTROL_1_LOWER
				or addr = PWM_PERIOD_UPPER or addr = PWM_PERIOD_LOWER 
				or addr = PWM_DIRECTION_2_UPPER or addr = PWM_DIRECTION_2_LOWER or addr = PWM_DIRECTION_1_UPPER or addr = PWM_DIRECTION_1_LOWER
				or addr = PWM_CHANNEL_UPPER or addr = PWM_CHANNEL_LOWER or addr = PWM_TIMING_UPPER or addr = PWM_TIMING_LOWER
				or addr = PWM_CMD_UPPER or addr = PWM_CMD_LOWER or addr = PWM_CONTROL_UPPER or addr = PWM_CONTROL_LOWER) then
				if (oe = '0' and we = '1') then  -- Если сигнал чтения активен, а записи нет	
					case addr is
						when PWM_MODE_CONTROL_UPPER =>
							data <= modeBuf(15 downto 8);
						when PWM_MODE_CONTROL_LOWER =>
							data <= modeBuf(7 downto 0);
						when PWM_MASK_2_UPPER =>
							data <= maskBuf(31 downto 24);
						when PWM_MASK_2_LOWER =>
							data <= maskBuf(23 downto 16);
						when PWM_MASK_1_UPPER =>
							data <= maskBuf(15 downto 8);
						when PWM_MASK_1_LOWER =>
							data <= maskBuf(7 downto 0);
						when PWM_DIRECT_CONTROL_2_UPPER =>
							data <= directControlBuf(31 downto 24);
						when PWM_DIRECT_CONTROL_2_LOWER =>
							data <= directControlBuf(23 downto 16);
						when PWM_DIRECT_CONTROL_1_UPPER =>
							data <= directControlBuf(15 downto 8);
						when PWM_DIRECT_CONTROL_1_LOWER =>
							data <= directControlBuf(7 downto 0);
						when PWM_PERIOD_UPPER =>
							data <= periodBuf(15 downto 8);
						when PWM_PERIOD_LOWER =>
							data <= periodBuf(7 downto 0);
						when PWM_DIRECTION_2_UPPER =>
							data <= directionBuf(31 downto 24);
						when PWM_DIRECTION_2_LOWER =>
							data <= directionBuf(23 downto 16);	
						when PWM_DIRECTION_1_UPPER =>
							data <= directionBuf(15 downto 8);
						when PWM_DIRECTION_1_LOWER =>
							data <= directionBuf(7 downto 0);							
						when PWM_CHANNEL_UPPER =>
							data <= channelBuf(15 downto 8);
						when PWM_CHANNEL_LOWER =>
							data <= channelBuf(7 downto 0);	
						when PWM_TIMING_UPPER =>
							data <= memory(conv_integer(channelBuf))(15 downto 8);
						when PWM_TIMING_LOWER =>
							data <= memory(conv_integer(channelBuf))(7 downto 0);
						when PWM_CMD_UPPER =>
							data <= cmdBuf(15 downto 8);
						when PWM_CMD_LOWER =>
							data <= cmdBuf(7 downto 0);	
						when PWM_CONTROL_UPPER =>
							data <= controlBuf(15 downto 8);	
						when PWM_CONTROL_LOWER =>
							data <= controlBuf(7 downto 0);						
						when others => 
							data <= (others => 'Z');  -- Запретить запись на шину
					end case;
						
					if addr /= PWM_CONTROL_LOWER then
						enableWriteControlBuf <= '1';
					else
						enableWriteControlBuf <= '0';
					end if;	
				elsif (oe = '1' and we = '0') then  -- Если сигнал записи активен, а чтения нет
					case addr is
						when PWM_MODE_CONTROL_UPPER =>
							modeBuf(15 downto 8) <= data;
						when PWM_MODE_CONTROL_LOWER =>
							modeBuf(7 downto 0) <= data;
						when PWM_MASK_2_UPPER =>
							maskBuf(31 downto 24) <= data;
						when PWM_MASK_2_LOWER =>
							maskBuf(23 downto 16) <= data;
						when PWM_MASK_1_UPPER =>
							maskBuf(15 downto 8) <= data;
						when PWM_MASK_1_LOWER =>
							maskBuf(7 downto 0) <= data;
						when PWM_DIRECT_CONTROL_2_UPPER =>
							directControlBuf(31 downto 24) <= data;
						when PWM_DIRECT_CONTROL_2_LOWER =>
							directControlBuf(23 downto 16) <= data;
						when PWM_DIRECT_CONTROL_1_UPPER =>
							directControlBuf(15 downto 8) <= data;
						when PWM_DIRECT_CONTROL_1_LOWER =>
							directControlBuf(7 downto 0) <= data;
						when PWM_PERIOD_UPPER =>
							periodBuf(15 downto 8) <= data;
						when PWM_PERIOD_LOWER =>
							periodBuf(7 downto 0) <= data;
						when PWM_DIRECTION_2_UPPER =>
							directionBuf(31 downto 24) <= data;
						when PWM_DIRECTION_2_LOWER =>
							directionBuf(23 downto 16) <= data;	
						when PWM_DIRECTION_1_UPPER =>
							directionBuf(15 downto 8) <= data;
						when PWM_DIRECTION_1_LOWER =>
							directionBuf(7 downto 0) <= data;
						when PWM_CHANNEL_UPPER =>
							channelBuf(15 downto 8) <= data;
						when PWM_CHANNEL_LOWER =>
							channelBuf(7 downto 0) <= data;	
						when PWM_TIMING_UPPER =>
							memory(conv_integer(channelBuf))(15 downto 8) <= data;
						when PWM_TIMING_LOWER =>
							memory(conv_integer(channelBuf))(7 downto 0) <= data;
						when PWM_CMD_UPPER =>
							cmdBuf(15 downto 8) <= data;
						when PWM_CMD_LOWER =>
							cmdBuf(7 downto 0) <= data;	
--						when PWM_CONTROL_UPPER =>
--							controlBuf(15 downto 8) <= data;
--						when PWM_CONTROL_LOWER =>
--							controlBuf(7 downto 0) <= data;
						when others =>
							data <= (others => 'Z');  -- Запретить запись на шину
					end case;
				else
					data <= (others => 'Z');  -- Запретить запись на шину
				end if;
			else
				data <= (others => 'Z');  -- Запретить запись на шину	
			end if;
		else 
			data <= (others => 'Z');  -- Запретить запись на шину
		end if;
	end process;
	
	process(clk) is
	begin
		if rising_edge(clk) then
			if upDown = '0' then
				if conv_integer(counter) < conv_integer(period) then
					counter <= counter + 1;
				else
					counter <= period;
					updown <= '1';
				end if;
			else
				if conv_integer(counter) > 0 then
					counter <= counter - 1;
				else
					counter <= (others => '0');
					upDown <= '0';
				end if;
			end if;
			upDownPrev <= upDown;
		end if;
	end process;
	
	process(clk) is
		variable count : integer range 0 to 7 := 0;
	begin
		if rising_edge(clk) then
			if upDown /= upDownPrev then
				count := 0;
				if cmdBuf(14) = '0' then
					interrupt <= '1';
				else 
					if updown = '0' then
						interrupt <= '1';
						interruptBuf <= '1';
						period <= periodBuf;							-- новый период грузится сразу во время начала подъема пилы
					end if;
				end if;
			else
				if count < 7 then
					count := count + 1;
				else 
					interrupt <= '0';
					interruptBuf <= '0';
				end if;
			end if;	
		end if;
	end process;
	
	process(interruptBuf) is
	begin
		if interruptBuf = '0' then
			for i in 0 to 31 loop
				memoryBuf(i) <= memory(i);							-- а вот новые значения таймингов загрузяться только после счетчика. Но зато могут грузиться дважды за период, если выбран соответствующий тип формирования прерывания
			end loop;
		end if;
	end process;
	
	process(clk) is
	begin
		if rising_edge(clk) then
			for i in 0 to 11 loop
				if(conv_integer(memoryBuf(i)) > counter) then
					if(directionBuf(i) = '0') then
						pwm3level(i) <= '0';
					else 
						pwm3level(i) <= '1';
					end if;
				else
					if(directionBuf(i) = '0') then
						pwm3level(i) <= '1';
					else 
						pwm3level(i) <= '0';
					end if;
				end if;
			end loop;
			
			for i in 12 to 15 loop
				if(conv_integer(memoryBuf(i)) > counter) then
					pwm3level(i) <= '0';
				else 
					pwm3level(i) <= '1';				
				end if;
			end loop;	
			
			for i in 16 to 27 loop
				if(conv_integer(memoryBuf(i)) > counter) then
					if(directionBuf(i) = '0') then
						pwm3level(i) <= '0';
					else 
						pwm3level(i) <= '1';
					end if;
				else
					if(directionBuf(i) = '0') then
						pwm3level(i) <= '1';
					else 
						pwm3level(i) <= '0';
					end if;
				end if;
			end loop;
			
			for i in 28 to 31 loop
				if(conv_integer(memoryBuf(i)) > counter) then
					pwm3level(i) <= '0';
				else 
					pwm3level(i) <= '1';				
				end if;
			end loop;
		end if;
	end process;

	process(clk) is
	begin
		if rising_edge(clk) then
			case modeBuf is
				when x"0000" => 
					tkBuf <= pwm3level;
				when x"0001" => 
					tkBuf <= (others => '1');
					tkBuf(5 downto 0) <= pwm;
				when x"0002" =>	
					tkBuf <= pwm3level;
				when x"0003" =>
					tkBuf <= directControlBuf;
				when others =>
					tkBuf <= (others => '1');
			end case;	
		end if;
	end process;

	process(clk) is
	begin
		if rising_edge(clk) then
			if cmdBuf(15) = '1' and error = '1' then
				tk <= tkBuf or maskBuf;
			else 
				tk <= (others => '1');
			end if;	
		end if;
	end process;
	
	process(clk) is
	begin
		if rising_edge(clk) then
			if enableWriteControlBuf = '1' then
				controlBuf <= counter;
			end if;	
		end if;
	end process;
  
	
end behavorial;