architecture studentVersion of ex_24_1_5 is

  signal running : std_ulogic;
  signal deccel : std_ulogic;
  signal counter : unsigned(speedBitNb/2-1 downto 0);
  signal accumulator : unsigned(speedBitNb-1 downto 0);

begin
  process(clock, reset) begin
    if reset = '1' then

      running <= '0';
      deccel <= '0';
      counter <= (others => '0');
      accumulator <= (others => '0');
      speed <= (others => '0');
      done <= '0';
    
    elsif rising_edge(clock) then 
      
      if start = '1' then
        running <= '1';
        deccel <= '0';
        counter <= (others => '0');
        accumulator <= (others => '0'); -- Comment this line if you want 2 accel without overflow (l.38-39)
      end if;

      if running = '1' then
        if deccel = '0' then
          counter <= counter + 1;
        else
          counter <= counter - 1;
        end if;
        accumulator <= accumulator + counter;
        speed <= accumulator;    
      end if;

      --if ((counter = 2**(speedBitNb/2-1)) and (deccel = '0')) then -- For 2 accel without overflow
      if ((counter = 2**((speedBitNb/2))-2) and (deccel = '0')) then -- For best fit for only one acceleration
        deccel <= '1';
        done <= '1';
      else
        done <= '0';
      end if;

      if ((deccel = '1') and (counter = 0)) then
        running <= '0';
      end if;

    end if;
  end process;
end studentVersion;