---------------------------------------------------------------------
-- Test Bench for JK flip-flop (ESD 2.3.1)
-- 
-- we use another process to offer the concurrent clock signal
---------------------------------------------------------------------

library ieee;
use ieee.std_logic_1164.all;

entity jkff_TB is			-- entity declaration
end jkff_TB;

---------------------------------------------------------------------

architecture TB of jkff_TB is

    signal T_J, T_K: 	std_logic;
    signal T_clock:	std_logic;
    signal T_reset:	std_logic;
    signal T_Q, T_Qbar:	std_logic;
	
    component JK_FF is
    port (	clock:		in std_logic;
		J, K:		in std_logic;
		reset:		in std_logic;
		Q, Qbar:	out std_logic
    );
    end component;
		
begin

    U_JKFF: JK_FF port map (T_clock, T_J, T_K, T_reset, T_Q, T_Qbar);

    -- concurrent process to offer clock signal	
    process
    begin
	T_clock <= '0';
	wait for 5 ns;
	T_clock <= '1';
	wait for 5 ns;
    end process;
	
    process

	variable err_cnt: integer := 0;

    begin
		
    	T_reset <= '1';
	wait for 25 ns;

	T_reset <= '0';
	wait for 10 ns;

	-- case 1
	T_J <= '0';
	T_K <= '1';
	wait for 15 ns;
	assert (T_Q='0') report "Error1!" severity error; 
	if (T_Q/='0') then
	    err_cnt := err_cnt + 1;
	end if;

	-- case 2
	wait for 5 ns;
	T_J <= '1';
	T_K <= '0';
	wait for 15 ns;
	assert (T_Q='1') report "Error2!" severity error; 
	if (T_Q/='0') then
	    err_cnt := err_cnt + 1;
	end if;

	-- case 3
	wait for 5 ns;
	T_J <= '1';
	T_K <= '1';
	wait for 15 ns;
	assert (T_Q='0') report "Error3!" severity error;
	if (T_Q/='0') then
	    err_cnt := err_cnt + 1;
	end if;
		
	-- summary of all the tests
	if (err_cnt=0) then 			
	    assert false 
	    report "Testbench of Adder completed successfully!" 
	    severity note; 
	else 
	    assert true 
	    report "Something wrong, try again" 
	    severity error; 
	end if; 

 	wait;

    end process;

end TB;

--------------------------------------------------------------------
configuration CFG_TB of jkff_TB is
	for TB
	end for;
end CFG_TB;
---------------------------------------------------------------------