atahost_top.vhd

硬盘接口的硬件实现

		PIO_cmdport_T4,
		PIO_cmdport_Teoc    : buffer unsigned(7 downto 0);
		PIO_cmdport_IORDYen : out std_logic;

		-- data-port0 timing registers
		PIO_dport0_T1,
		PIO_dport0_T2,
		PIO_dport0_T4,
		PIO_dport0_Teoc    : buffer unsigned(7 downto 0);
		PIO_dport0_IORDYen : out std_logic;

		-- data-port1 timing registers
		PIO_dport1_T1,
		PIO_dport1_T2,
		PIO_dport1_T4,
		PIO_dport1_Teoc    : buffer unsigned(7 downto 0);
		PIO_dport1_IORDYen : out std_logic;

		-- DMA device0 timing registers
		DMA_dev0_Tm,
		DMA_dev0_Td,
		DMA_dev0_Teoc    : buffer unsigned(7 downto 0);

		-- DMA device1 timing registers
		DMA_dev1_Tm,
		DMA_dev1_Td,
		DMA_dev1_Teoc    : buffer unsigned(7 downto 0)
	);
	end component atahost_wb_slave;


	component atahost_controller is
	generic(
		TWIDTH : natural := 8;                        -- counter width

		-- PIO mode 0 settings (@100MHz clock)
		PIO_mode0_T1 : natural := 6;                  -- 70ns
		PIO_mode0_T2 : natural := 28;                 -- 290ns
		PIO_mode0_T4 : natural := 2;                  -- 30ns
		PIO_mode0_Teoc : natural := 23                -- 240ns ==> T0 - T1 - T2 = 600 - 70 - 290 = 240
	);
	port(
		clk : in std_logic;                           -- master clock in
		nReset : in std_logic := '1';                 -- asynchronous active low reset
		rst : in std_logic := '0';                    -- synchronous active high reset
		
		irq : out std_logic;                          -- interrupt request signal

		-- control / registers
		IDEctrl_rst,
		IDEctrl_IDEen : in std_logic;

		-- PIO registers
		PIO_cmdport_T1,
		PIO_cmdport_T2,
		PIO_cmdport_T4,
		PIO_cmdport_Teoc : in unsigned(7 downto 0);   -- PIO command timing
		PIO_cmdport_IORDYen : in std_logic;

		PIOreq : in std_logic;                        -- PIO transfer request
		PIOack : buffer std_logic;                    -- PIO transfer ended
		PIOa   : in unsigned(3 downto 0);             -- PIO address
		PIOd   : in std_logic_vector(15 downto 0);    -- PIO data in
		PIOq   : out std_logic_vector(15 downto 0);   -- PIO data out
		PIOwe  : in std_logic;                        -- PIO direction bit '1'=write, '0'=read

		-- ATA signals
		RESETn : out std_logic;
		DDi  	 : in  std_logic_vector(15 downto 0);
		DDo    : out std_logic_vector(15 downto 0);
		DDoe   : out std_logic;
		DA     : out unsigned(2 downto 0);
		CS0n   : out std_logic;
		CS1n   : out std_logic;

		DIORn	: out std_logic;
		DIOWn	: out std_logic;
		IORDY	: in  std_logic;
		INTRQ	: in  std_logic
	);
	end component atahost_controller;

	-- asynchronous reset signal
	signal arst_signal : std_logic;

	-- primary address decoder
	signal PIOsel  : std_logic;  -- controller select, IDE devices select
	
	-- registers
	signal IDEctrl_IDEen, IDEctrl_rst: std_logic;
	signal PIO_cmdport_T1, PIO_cmdport_T2, PIO_cmdport_T4, PIO_cmdport_Teoc : unsigned(7 downto 0);
	signal PIO_cmdport_IORDYen : std_logic;
	signal PIOack : std_logic;
	signal PIOq : std_logic_vector(15 downto 0);

	signal irq : std_logic; -- ATA bus IRQ signal

begin
	-- generate asynchronous reset level
	arst_signal <= arst_i xor ARST_LVL;

	--
	-- hookup wishbone slave
	--
	u0: atahost_wb_slave 
		generic map(
			DeviceID   => DeviceID,
			RevisionNo => RevisionNo,

			-- PIO mode 0 settings
			PIO_mode0_T1 => PIO_mode0_T1,
			PIO_mode0_T2 => PIO_mode0_T2,
			PIO_mode0_T4 => PIO_mode0_T4,
			PIO_mode0_Teoc => PIO_mode0_Teoc,

			-- Multiword DMA mode 0 settings
			-- OCIDEC-1 does not support DMA, set registers to zero
			DMA_mode0_Tm   => 0,
			DMA_mode0_Td   => 0,
			DMA_mode0_Teoc => 0
		)
		port map(
			-- WISHBONE SYSCON signals
			clk_i => wb_clk_i,
			arst_i => arst_signal,
			rst_i  => wb_rst_i,

			-- WISHBONE SLAVE signals
			cyc_i => wb_cyc_i,
			stb_i => wb_stb_i,
			ack_o => wb_ack_o,
			err_o => wb_err_o,
			adr_i => wb_adr_i,
			dat_i => wb_dat_i,
			dat_o => wb_dat_o,
			sel_i => wb_sel_i,
			we_i  => wb_we_i,
			inta_o => wb_inta_o,

			-- PIO control input
			--	PIOtip is only asserted during a PIO transfer (No shit! ;)
			--	Since it is impossible to read the status register and access the PIO registers at the same time
			--	this bit is useless (besides using-up resources)
			PIOtip     => '0',
			PIOack     => PIOack,
			PIOq       => PIOq,
			PIOsel     => PIOsel,
			PIOpp_full => '0', -- OCIDEC-1 does not support PIO-write PingPong, negate signal
			irq        => irq,

			-- DMA control inputs (negate all of them)
			DMAtip     => '0',
			DMAack     => '0',
			DMARxEmpty => '0',
			DMATxFull  => '0',
			DMA_dmarq  => '0',
			DMAq       => x"00000000",

			-- outputs
			-- control register outputs
			IDEctrl_rst   => IDEctrl_rst,
			IDEctrl_IDEen => IDEctrl_IDEen,

			-- CMD port timing registers
			PIO_cmdport_T1 => PIO_cmdport_T1,
			PIO_cmdport_T2 => PIO_cmdport_T2,
			PIO_cmdport_T4 => PIO_cmdport_T4,
			PIO_cmdport_Teoc => PIO_cmdport_Teoc,
			PIO_cmdport_IORDYen => PIO_cmdport_IORDYen
		);

	--
	-- hookup controller section
	--
	u1: atahost_controller
		generic map(
			TWIDTH         => TWIDTH,
			PIO_mode0_T1   => PIO_mode0_T1,
			PIO_mode0_T2   => PIO_mode0_T2,
			PIO_mode0_T4   => PIO_mode0_T4,
			PIO_mode0_Teoc => PIO_mode0_Teoc
		)
		port map(
			clk    => wb_clk_i,
			nReset => arst_signal,
			rst    => wb_rst_i,
			irq    => irq,
			IDEctrl_rst         => IDEctrl_rst,
			IDEctrl_IDEen       => IDEctrl_IDEen,
			PIO_cmdport_T1      => PIO_cmdport_T1,
			PIO_cmdport_T2      => PIO_cmdport_T2,
			PIO_cmdport_T4      => PIO_cmdport_T4,
			PIO_cmdport_Teoc    => PIO_cmdport_Teoc,
			PIO_cmdport_IORDYen => PIO_cmdport_IORDYen, 
			PIOreq => PIOsel,
			PIOack => PIOack,
			PIOa   => wb_adr_i(5 downto 2),
			PIOd   => wb_dat_i(15 downto 0),
			PIOq   => PIOq,
			PIOwe  => wb_we_i,
			RESETn => resetn_pad_o,
			DDi    => dd_pad_i,
			DDo    => dd_pad_o,
			DDoe   => dd_padoe_o,
			DA     => da_pad_o,
			CS0n   => cs0n_pad_o,
			CS1n   => cs1n_pad_o,
			DIORn  => diorn_pad_o,
			DIOWn  => diown_pad_o,
			IORDY  => iordy_pad_i,
			INTRQ  => intrq_pad_i
		);

end architecture structural;