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Altera_Forum's avatar
Altera_Forum
Icon for Honored Contributor rankHonored Contributor
14 years ago

I have a problem....

Hi.. i am beginner in quartus..

i learned the integer method.. so i used it!

the code is this and this works very well.

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

Library ieee;

use ieee.std_logic_1164;

Entity adder_4b is

port(

cin : in integer range 0 to 1;

astring : in integer range 0 to 15;

bstring : in integer range 0 to 15;

sum_string : out integer range 0 to 31

);

end adder_4b;

architecture arc of adder_4b is

begin

sum_string <= astring + bstring + cin;

end arc;

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

the problem is .... when i simulate this file,

i can't increase my input numer one by one.

( radix is hexadecimal , clock - cin = 100, astring = 200, bstring = 400

and i don't touch anything.)

how can i increase my input numer one by one...?

i attach the simulation ficture..

( i am foreigner so.. i am not good at english.. sorry.)

1 Reply

  • Altera_Forum's avatar
    Altera_Forum
    Icon for Honored Contributor rankHonored Contributor
    14 years ago

    you need to make a synchrnous counter. What you have is just an adder. You will need to store the previous value of the counter in a signal, and have a clock input.

    heres an example: 

    
use ieee.numeric_std.all;
signal count : unsigned(7 downto 0);
process(clk, reset)
begin
  if reset =  '1' then
    count <= (others => '0');
  elsif rising_edge(clk) then
    count <= count + 1;
  end if;
end process;
    ;