DE2 Quartus debounced circuit

Hello,

I made a simplest program for hex counter it supposed to count push-button clicks.

It present the result on a single 7seg display and 4 LEDs, unfortunately I've got a bouncing problem.

I'm using a Altera Cyclone II BAIXUN ASK2CB dev. board it has on board push-button

Can you please suggest how can i debounce it, so the bits go one by one?

Here is my code:

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library IEEE;

use IEEE.STD_LOGIC_1164.ALL;

use IEEE.STD_LOGIC_ARITH.ALL;

use IEEE.STD_LOGIC_UNSIGNED.ALL;

entity test is

port (Y : out std_logic_vector (6 downto 0); -- 7 seg digit

B : out std_logic;

pb : in std_logic;

count : out std_logic_vector(3 downto 0);

reset :in std_logic

);

end entity test;

architecture Behavioral of test is

signal c: std_logic_vector(3 downto 0) :=(others => '0'); --initializing count to zero.

begin

counting: process(pb,reset) is

begin

if rising_edge (pb) then

if(c = "1111") then -- when count reaches its maximum(that is 15) reset it to 0

c <="0000";

end if;

c <= c+'1'; --increment count at every positive edge of clk.

end if;

if(reset='0') then --when reset equal to '0' make count equal to 0.

c <=(others => '0'); -- c ="0000"

end if;

case c is

when "0000"=>Y<="1000000";-- 0

when "0001"=>Y<="1111001";-- 1

when "0010"=>Y<="0100100";-- 2

when "0011"=>Y<="0110000";-- 3

when "0100"=>Y<="0011001";-- 4

when "0101"=>Y<="0010010";-- 5

when "0110"=>Y<="0000010";-- 6

when "0111"=>Y<="1111000";-- 7

when "1000"=>Y<="0000000";-- 8

when "1001"=>Y<="0010000";-- 9

when "1010"=>Y<="0001000";-- A

when "1011"=>Y<="0000011";-- b

when "1100"=>Y<="1000110";-- C

when "1101"=>Y<="0100001";-- d

when "1110"=>Y<="0000110";-- E

when "1111"=>Y<="0001110";-- F

when others=>Y<="1111111";-- in other cases balnk

end case;

end process counting;

B<='0';

count<=c;

end architecture Behavioral;

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