Toggling switch button to start and pause using logic '0' or '1'

Altera_Forum · ‎01-22-2012

Hi Altera Friends,

I have an issue with design of clock. I have written a program for a clock to count from 0 to 9 and returns to zero. I use a switch as start/stop as in std_logic and i want a logic that I can use that when i press button ones, it will toggle between 1 and 0 so that the button can perform the two tasks start and stop. I will appreciate your urgent reply.

Thanks.

Altera_Forum · ‎01-23-2012

please post the code you have already done with specific questions about what the problem is.

Altera_Forum · ‎01-23-2012

PORT

(

clOCK : IN STD_LOGIC;

ce : IN STD_LOGIC;

rst : IN STD_LOGIC;

d1: BUFFER STD_LOGIC_VECTOR (3 DOWNTO 0);

clk_2: OUT STD_LOGIC

);

-- {{ALTERA_IO_END}} DO NOT REMOVE THIS LINE!

END mod_mod;

-- Architecture Body

ARCHITECTURE mod_mod_architecture OF mod_mod IS

SIGNAL M: STD_LOGIC;

BEGIN

PROCESS (clock,rst,M)

BEGIN

IF (rst = '0') THEN

d1 <= "0000";

ELSIF (clOCK 'EVENT AND clOCK='1') THEN

IF (ce = '0') THEN

d1<= "0000" ;

ELSE

d1<= d1 + '1';

M<= '0';

END IF;

IF d1= "1001" THEN

d1<= "0000";

M<= '1';

END IF;

clk_2<=M;

END PROCESS;

end mod_mod;

I want ce to perform the function of start and stop.I want it to be like if i press ce switch it should change the logic from 1 to 0 to purse and for the next state to start after pressing same ce switch.

Altera_Forum · ‎01-23-2012

Hi Ebony,

Not sure what you are referring to here. If you wanted a CE using a KEY, you could simply read the KEY press (remember in DE2 boards its active LOW) and feed it as an enable input in a tri-state buffer. When key isnt pressed the clock output will be driven to Z. Not sure if this is what you wanted!?

BP

Altera_Forum · ‎01-23-2012

if i press the switch button on the altera board down without removing hand, it will purse or stop. if i rmove my hand from the button, it will start counting. I want the state to change such that if i press the switch button and remove my hand it will purse or stop and if i press the switch button and remove my hand next it should start counting.

ce i assigned to start/stop switch.

hope you understand it?

Altera_Forum · ‎01-23-2012

if i press the switch button on the altera board down without removing hand, it will purse or stop. if i rmove my hand from the button, it will start counting. I want the state to change such that if i press the switch button and remove my hand it will purse or stop and if i press the switch button and remove my hand next it should start counting.

ce is assigned as start/stop switch button.

hope you understand it?

Altera_Forum · ‎01-23-2012

If I correctly understood your needs, you can try changing your code this way:

SIGNAL M: STD_LOGIC;
SIGNAL run: STD_LOGIC;
SIGNAL last_ce: STD_LOGIC;
PROCESS (clock,rst,M)
BEGIN
   IF (rst = '0') THEN
      d1 <= "0000";
	  run <= '0';
	  last_ce <= ce;
   ELSIF (clOCK 'EVENT AND clOCK='1') THEN
      IF (run='1') THEN
          d1<= d1 + '1';
		  M <= '0';
      END IF;
      IF d1= "1001" THEN
         d1<= "0000";
		 M <= '1';
      END IF;
	  IF (ce='1' and last_ce='0')
	      run <= not run;
      END IF;
   END IF;
   clk_2<=M;
END PROCESS;

Regards

Altera_Forum · ‎01-23-2012

still not working