-- 
-- (c) 2010 Igor Kalnitsky <igor@kalnitsky.org>
--

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

entity top_testbench is
	generic (
	    n : integer := 8
	);
end top_testbench;

architecture top_testbench_arch of top_testbench is  

    component top is
        generic (
            n : integer
        );
        port (
            clk : in std_logic;
            rst : in std_logic;
            d1 : in std_logic_vector (n-1 downto 0);
            d2 : in std_logic_vector (n-1 downto 0);
            operation : in std_logic;
            result : out std_logic_vector (2*n-1 downto 0)
        );
    end component;

    signal clk : std_logic;
    signal rst : std_logic;
	signal operation : std_logic;
    signal d1 : std_logic_vector (n-1 downto 0);
    signal d2 : std_logic_vector (n-1 downto 0);
    signal result : std_logic_vector (2*n-1 downto 0);

begin

    TESTUNIT : top generic map (n => n)
                   port map (clk => clk,
                             rst => rst,
                             d1  => d1,
                             d2  => d2,
                             operation => operation,
                             result => result);

    clock_process : process
    begin
        clk <= '0';
        wait for 5 ns;
        clk <= '1';
        wait for 5 ns;
    end process;

    data_process : process
    begin       
                      
	    ------------------------------------------------------------------
        -- Unsigned multiplication 
        ------------------------------------------------------------------
		
		-- test case #1	
	   	operation <= '0';
		
        rst <= '1';
        wait for 5 ns;
        rst <= '0';
        wait for 5 ns;
		
		d1 <= std_logic_vector(to_unsigned(60, d1'length));
		d2 <= std_logic_vector(to_unsigned(12, d2'length));
		wait for 360 ns;
		
		assert (result = std_logic_vector(to_unsigned(720, result'length)))
			report "Test case #1 failed" severity error; 
            
		-- test case #2	
	   	operation <= '0';
		
        rst <= '1';
        wait for 5 ns;
        rst <= '0';
        wait for 5 ns;
		
		d1 <= std_logic_vector(to_unsigned(55, d1'length));
		d2 <= std_logic_vector(to_unsigned(1, d2'length));
		wait for 360 ns;
		
		assert (result = std_logic_vector(to_unsigned(55, result'length)))
			report "Test case #2 failed" severity error;
            
		-- test case #3	
	   	operation <= '0';
		
        rst <= '1';
        wait for 5 ns;
        rst <= '0';
        wait for 5 ns;
		
		d1 <= std_logic_vector(to_unsigned(1, d1'length));
		d2 <= std_logic_vector(to_unsigned(178, d2'length));
		wait for 360 ns;
		
		assert (result = std_logic_vector(to_unsigned(178, result'length)))
			report "Test case #3 failed" severity error;
        
		-- test case #4	
	   	operation <= '0';
		
        rst <= '1';
        wait for 5 ns;
        rst <= '0';
        wait for 5 ns;
		
		d1 <= std_logic_vector(to_unsigned(202, d1'length));
		d2 <= std_logic_vector(to_unsigned(0, d2'length));
		wait for 360 ns;
		
		assert (result = std_logic_vector(to_unsigned(0, result'length)))
			report "Test case #4 failed" severity error;
            
		-- test case #5	
	   	operation <= '0';
		
        rst <= '1';
        wait for 5 ns;
        rst <= '0';
        wait for 5 ns;
		
		d1 <= std_logic_vector(to_unsigned(0, d1'length));
		d2 <= std_logic_vector(to_unsigned(105, d2'length));
		wait for 360 ns;
		
		assert (result = std_logic_vector(to_unsigned(0, result'length)))
			report "Test case #5 failed" severity error;        
            
            
    	------------------------------------------------------------------
        -- Signed multiplication 
        ------------------------------------------------------------------
        
		-- test case #6	
	   	operation <= '1';
		
        rst <= '1';
        wait for 5 ns;
        rst <= '0';
        wait for 5 ns;
		
		d1 <= std_logic_vector(to_signed(60, d1'length));
		d2 <= std_logic_vector(to_signed(12, d2'length));
		wait for 360 ns;
		
		assert (result = std_logic_vector(to_signed(720, result'length)))
			report "Test case #6 failed" severity error; 
            
		-- test case #7	
	   	operation <= '1';
		
        rst <= '1';
        wait for 5 ns;
        rst <= '0';
        wait for 5 ns;
		
		d1 <= std_logic_vector(to_signed(55, d1'length));
		d2 <= std_logic_vector(to_signed(1, d2'length));
		wait for 360 ns;
		
		assert (result = std_logic_vector(to_signed(55, result'length)))
			report "Test case #7 failed" severity error;
            
		-- test case #8	
	   	operation <= '1';
		
        rst <= '1';
        wait for 5 ns;
        rst <= '0';
        wait for 5 ns;
		
		d1 <= std_logic_vector(to_signed(-24, d1'length));
		d2 <= std_logic_vector(to_signed(3, d2'length));
		wait for 360 ns;
		
		assert (result = std_logic_vector(to_signed(-72, result'length)))
			report "Test case #8 failed" severity error;
        
		-- test case #9	
	   	operation <= '1';
		
        rst <= '1';
        wait for 5 ns;
        rst <= '0';
        wait for 5 ns;
		
		d1 <= std_logic_vector(to_signed(202, d1'length));
		d2 <= std_logic_vector(to_signed(0, d2'length));
		wait for 360 ns;
		
		assert (result = std_logic_vector(to_signed(0, result'length)))
			report "Test case #9 failed" severity error;
            
		-- test case #10	
	   	operation <= '1';
		
        rst <= '1';
        wait for 5 ns;
        rst <= '0';
        wait for 5 ns;
		
		d1 <= std_logic_vector(to_signed(0, d1'length));
		d2 <= std_logic_vector(to_signed(105, d2'length));
		wait for 360 ns;
		
		assert (result = std_logic_vector(to_signed(0, result'length)))
			report "Test case #10 failed" severity error; 
            
		              
		-- test case #11	
	   	operation <= '1';
		
        rst <= '1';
        wait for 5 ns;
        rst <= '0';
        wait for 5 ns;
		
		d1 <= std_logic_vector(to_signed(-26, d1'length));
		d2 <= std_logic_vector(to_signed(-10, d2'length));
		wait for 360 ns;
		
		assert (result = std_logic_vector(to_signed(260, result'length)))
			report "Test case #11 failed" severity error;   
            
    end process;

end top_testbench_arch;

configuration testbench_for_top of top_testbench is
	for top_testbench_arch
		for TESTUNIT : top
			use entity work.top(top_arch);
		end for;
	end for;
end testbench_for_top;