Question

Using Quartus to design a stopwatch that can display tenths of seconds, minutes, and hours, with the gaps between HEX displays splitting the time units (i.e. minutes on HEX[5..4], hours on HEX[7..6]). Have the stopwatch cycle through 3 states of a state machine with a pushbutton. The 3 states are counter-clear, counter-start, and counter-stop

Answer 1

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

entity real_time_clock is
port (clk1 : in std_logic;
seconds : out std_logic_vector(5 downto 0);
minutes : out std_logic_vector(5 downto 0);
miliseconds: out std_logic_vector(4 downto 0);
hex0,hex1,hex2,hex3,hex5,hex5 (o to 6)
);
end real_time_clock ;

architecture Behavioral of real_time_clock is
signal sec,min,mili : integer range 0 to 60 :=0;
signal count : integer :=1;
signal clk : std_logic :='0';
begin
seconds <= conv_std_logic_vector(sec,6);
minutes <= conv_std_logic_vector(min,6);
miliseconds<= conv_std_logic_vector(mili,5);

--clk generation.For 100 MHz clock this generates 1 Hz clock.
process(clk1)
begin
if(clk1'event and clk1='1') then
count <=count+1;
if(count = 50000000) then
clk <= not clk;
count <=1;
end if;
end if;
end process;

process(clk) --period of clk is 1 second.
begin

if(clk'event and clk='1') then
sec <= sec+ 1;
if(sec = 59) then
sec<=0;
min <= min + 1;
if(min = 59) then
hour <= hour + 1;
min <= 0;
if(hour = 23) then
hour <= 0;
end if;
end if;
end if;
end if;

end process;

end Behavioral;