LIBRARY ieee;
USE ieee.std_logic_1164.ALL;

-- Uncomment the following library declaration if using
-- arithmetic functions with Signed or Unsigned values
--USE ieee.numeric_std.ALL;

ENTITY cputest IS
END cputest;

ARCHITECTURE behavior OF cputest IS

    -- Component Declaration for the Unit Under Test (UUT)

    COMPONENT CPU
    PORT(
                Ext_Data_Bus : inout  STD_LOGIC_VECTOR (31 downto 0);
                Ext_Address_Bus : out  STD_LOGIC_VECTOR (31 downto 0);
                Ext_Address_Read : out  STD_LOGIC;
                Ext_Address_Write : out  STD_LOGIC);
    END COMPONENT;


   --Inputs
    signal databus : STD_LOGIC_VECTOR (31 downto 0) := (others => '0');

     --Outputs
    signal addressbus : STD_LOGIC_VECTOR (31 downto 0) := (others => '0');
    signal addressread : STD_LOGIC_VECTOR (31 downto 0) := (others => '0');
    signal addresswrite : STD_LOGIC_VECTOR (31 downto 0) := (others => '0');
   -- No clocks detected in port list. Replace <clock> below with
   -- appropriate port name

--   constant <clock>_period : time := 10 ns;

BEGIN

    -- Instantiate the Unit Under Test (UUT)
   uut: CPU PORT MAP (
    Ext_Data_Bus => databus;
    Ext_Address_Bus => addressbus;
    Ext_Address_Read => addressread;
    Ext_Address_Write => addresswrite;
        );

   -- Clock process definitions
--  <clock>_process :process
--   begin
--        <clock> <= '0';
--        wait for <clock>_period/2;
--        <clock> <= '1';
--        wait for <clock>_period/2;
--   end process;


   -- Stimulus process
   stim_proc: process
   begin
       while ('1' = '1') loop
        if (addressbus = "00000000000000000000000000000000") then--0
            databus <= "10001110010010110000000100101100";--LW $t3, 300($s2)
            wait 100 ns;
        elsif (addressbus = "00000000000000000000000000000100") then--4
            databus <= "10101110111011100000000110010000";--SW $t6, 400($s7)
                    wait for 100 ns;
        elsif (addressbus = "00000000000000000000000000001000") then--8
            databus <= "00000001011100010110100000100000";--add $t5, $t3, $s1)
                    wait for 100 ns;
        elsif (addressbus = "00000000000000000000000000001100") then--12
            databus <= "00010110110011010000000000110001";--bne $s6, $t5, 200
            wait for 100 ns;
        elsif (addressbus = "00000000000000000000000000010000") then--16
            databus <= "00010010111110000000000000011000";--beq $s7, $t8, 100
                wait for 100 ns;
        elsif (addressbus = "00000000000000000000000000010100") then--20
            databus <= "00110101001100100000000010100001";--ori $s2, $t1, 0xA1
                    wait for 100 ns;
       end loop;
   end process;

END;