--------------------------------------------------------------------------------
-- Company: 
-- Engineer:
--
-- Create Date:   17:33:47 06/05/2007
-- Design Name:   eval_ac
-- Module Name:   E:/work/VHDL/eval_ac/tb_eval_ac.vhd
-- Project Name:  ac_out
-- Target Device:  
-- Tool versions:  
-- Description:   
-- 
-- VHDL Test Bench Created by ISE for module: ac_out
--
-- Dependencies:
-- 
-- Revision:
-- Revision 0.01 - File Created
-- Additional Comments:
--
-- Notes: 
-- This testbench has been automatically generated using types std_logic and
-- std_logic_vector for the ports of the unit under test.  Xilinx recommends 
-- that these types always be used for the top-level I/O of a design in order 
-- to guarantee that the testbench will bind correctly to the post-implementation 
-- simulation model.
--------------------------------------------------------------------------------
LIBRARY ieee;
USE ieee.std_logic_1164.ALL;
USE ieee.numeric_std.ALL;

ENTITY tb_ac97_wb IS
END tb_ac97_wb;

ARCHITECTURE behavior OF tb_ac97_wb IS 

	constant SYS_CLK_PERIOD : time := 10 ns;
	CONSTANT BIT_CLK_PERIOD : time := 100 ns;
--	constant BIT_CLK_PERIOD : time := 81.38 ns;
	
	signal CLK_O	: std_logic := '1';
	signal RST_O	: std_logic := '1';
	signal CYC_O	: std_logic := '0';
	signal STB_O	: std_logic := '0';
	signal WE_O		: std_logic := '0';
	signal ACK_I	: std_logic;
	signal MRDY_O	: std_logic := '1';
	signal SRDY_I	: std_logic;
	signal INT_I	: std_logic;
	signal ADDR_O	: unsigned(31 downto 0) := (others => '-');
	signal DAT_I	: unsigned(31 downto 0);
	signal DAT_O	: unsigned(31 downto 0) := (others => '-');

	signal dout_rst			: std_logic := '0';
	signal dout_reg			: unsigned(31 downto 0);
	signal dout_cnt			: natural range 0 to 255;

	SIGNAL ac97_bit_clk		:  std_logic := '0';
	SIGNAL ac97_reset_n		:  std_logic;
	SIGNAL ac97_sdata_out	:  std_logic;
	SIGNAL ac97_ssync		:  std_logic;
	SIGNAL ac97_sdata_in	:  std_logic;

BEGIN

	-- Instantiate the Unit Under Test (UUT)
uut : entity work.ac97_wb
	GENERIC MAP
	(
		fifo_depth		=> 4
	)
	PORT MAP
	(
		-- J-Bus domain
		CLK_I			=> CLK_O,
		RST_I			=> RST_O,
		CYC_I			=> CYC_O,
		STB_I			=> STB_O,
		WE_I			=> WE_O,
		ACK_O			=> ACK_I,
		SRDY_O			=> SRDY_I,
		MRDY_I			=> MRDY_O,
		ADDR_I			=> ADDR_O,
		DAT_I			=> DAT_O,
		DAT_O			=> DAT_I,
		INT_O			=> INT_I,

		-- AC97 domain
		ac97_sdata_in	=> ac97_sdata_in,
		ac97_bit_clk	=> ac97_bit_clk,          
		ac97_reset_n	=> ac97_reset_n,
		ac97_sdata_out	=> ac97_sdata_out,
		ac97_ssync		=> ac97_ssync		
	);

	
	ac97_sdata_in <= ac97_sdata_out;
	
CLK_GEN: process
	begin
		wait for SYS_CLK_PERIOD/2;
		CLK_O <= not CLK_O;
	end process;

	bit_clk_gen : PROCESS
	begin
		if (ac97_reset_n = '0') then
			ac97_bit_clk <= '0';
			wait until ac97_reset_n = '1';
			wait for 150 us;
		end if;	
		wait for BIT_CLK_PERIOD/2;
		ac97_bit_clk <= not ac97_bit_clk;
	END PROCESS;

STIMULUS: process

	begin

		wait for 3*SYS_CLK_PERIOD;
		RST_O <= '0';

		wait for 200 us;
		wait until rising_edge(CLK_O);

		CYC_O	<= '1';
		STB_O	<= '1';
		WE_O	<= '0';
		DAT_O	<= X"0000_0000";
		ADDR_O	<= X"0000_0000";
		wait until rising_edge(CLK_O);
		STB_O	<= '0';
		wait until rising_edge(CLK_O) and ACK_I = '1';
		CYC_O	<= '0';

		wait until rising_edge(CLK_O);

		CYC_O	<= '1';
		STB_O	<= '1';
		WE_O	<= '1';
		DAT_O	<= X"5555_1000";
		ADDR_O	<= X"0000_0800";
		wait until rising_edge(CLK_O);
		DAT_O	<= X"5555_1001";
		wait until rising_edge(CLK_O);
		STB_O	<= '0';
		CYC_O	<= '0';

		WAIT;
	END PROCESS;
END;