uppgift21b

library IEEE;
use IEEE.STD_LOGIC_1164.ALL;
use IEEE.STD_LOGIC_UNSIGNED.ALL;

entity timer is
  Port(
    clk, mux, time : in std_logic;
    start_in, reset_in : in std_logic;
    time_prec : in std_logic;
    led : out std_logic;
    a, b, c, d, e, f, g, dp, dspA, dspB : out std_logic);
end timer;

architecture atimer of timer is
  signal en_p, en_t, en_p_plus, en_t_plus, start, reset, start_plus, reset_plus : std_logic := '0';
  signal adress, seconds_1, seconds_10, minutes_1, minutes_10 : std_logic_vector(3 downto 0) := "0000";
  signal mseconds_1, mseconds_10, mseconds_100 : std_logic_vector(3 downto 0) := "0000";
  signal dmseconds_1, dmseconds_10, dmseconds_100, dseconds_1, dseconds_10, dminutes_1, dminutes_10 : std_logic_vector(3 downto 0) := "0000";
  signal t_prec, delta_time : std_logic := '0';
  signal count_enable : std_logic := '0';
  signal display : std_logic_vector(1 downto 0) := "00";
  signal data : std_logic_vector(6 downto 0) := "0000000";
  signal led_count : std_logic;

begin

  -- Klocka insignaler
  process(clk) begin
    if rising_edge(clk) then
      en_p <= en_p_plus;
      en_t <= en_t_plus;
      en_p_plus <= mux;
      en_t_plus <= time;
      start <= start_plus;
      reset <= reset_plus;
      start_plus <= start_in;
      reset_plus <= reset_in;
      t_prec <= time_prec;
    end if;
  end process;

  -- Räkna upp
  process(clk) begin
    if rising_edge(clk) then
      if (start='0' and start_plus='1') then
        count_enable <= not count_enable;
        led_count <= not count_enable;
      elsif (reset='0' and reset_plus='1' and count_enable='0') then
        seconds_1 <= "0000";
        seconds_10 <= "0000";
        minutes_1 <= "0000";
        minutes_10 <= "0000";
      elsif (reset='0' and reset_plus='1' and (count_enable='1' or (count_enable='0' and delta_time='1'))) then
        dmseconds_1 <= mseconds_1;
        dmseconds_10 <= mseconds_10;
        dmseconds_100 <= mseconds_100;
        dseconds_1 <= seconds_1;
        dseconds_10 <= seconds_10;
        dminutes_1 <= minutes_1;
        dminutes_10 <= minutes_10;
        count_enable <= '0';
        led_count <= '0';
        delta_time <= '1';
      elsif (en_t = '0' and en_t_plus = '1' and count_enable = '1') then
        mseconds_1 <= mseconds_1 + 1;
        if (mseconds_100 = 9 and mseconds_10 = 9 and mseconds_1 = 8 and seconds_1 = 9 and seconds_10 = 5 and minutes_1 = 9 and minutes_10 = 5) then
          count_enable <= '0';
        elsif (mseconds_100 = 9 and mseconds_10 = 9 and mseconds_1 = 9 and seconds_1 = 9 and seconds_10 = 5 and minutes_1 = 9) then
          minutes_10 <= minutes_10 + 1;
          minutes_1 <= "0000";
          seconds_10 <= "0000";
          seconds_1 <= "0000";
          mseconds_100 <= "0000";
          mseconds_10 <= "0000";
          mseconds_1 <= "0000";
        elsif (mseconds_100 = 9 and mseconds_10 = 9 and mseconds_1 = 9 and seconds_1 = 9 and seconds_10 = 5) then
          minutes_1 <= minutes_1 + 1;
          seconds_10 <= "0000";
          seconds_1 <= "0000";
          mseconds_100 <= "0000";
          mseconds_10 <= "0000";
          mseconds_1 <= "0000";
        elsif (mseconds_100 = 9 and mseconds_10 = 9 and mseconds_1 = 9 and seconds_1 = 9) then
          seconds_10 <= seconds_10 + 1;
          seconds_1 <= "0000";
          mseconds_100 <= "0000";
          mseconds_10 <= "0000";
          mseconds_1 <= "0000";
        elsif (mseconds_100 = 9 and mseconds_10 = 9 and mseconds_1 = 9) then
          seconds_1 <= seconds_1 + 1;
          mseconds_100 <= "0000";
          mseconds_10 <= "0000";
          mseconds_1 <= "0000";
        elsif (mseconds_10 = 9 and mseconds_1 = 9) then
          mseconds_100 <= mseconds_100 + 1;
          mseconds_10 <= "0000";
          mseconds_1 <= "0000";
        elsif(mseconds_1 = 9) then
          mseconds_10 <= mseconds_10 + 1;
          mseconds_1 <= "0000";
        end if;
      end if;
    end if;
  end process;

  -- Sätt adress för PROMen samt välja display-segment
  process(clk) begin
    if rising_edge(clk) then
      if (en_p='0' and en_p_plus='1') then
        display <= display + 1;
        dp <= '0';
        if (display = 0) then
          dspA <= '1';
          dspB <= '1';
          if (t_prec = '0') then
            if (delta_time = '1') then
              adress <= dseconds_1;
            else
              adress <= seconds_1;
            end if;
          else
            if (delta_time = '1') then
              adress <= dmseconds_10;
            else
              adress <= mseconds_10;
            end if;
          end if;
        elsif (display = 1) then
          dspA <= '0';
          dspB <= '0';
          if (t_prec = '0') then
            if (delta_time = '1') then
              adress <= dseconds_10;
            else
              adress <= seconds_10;
            end if;
          else
            if (delta_time = '1') then
              adress <= dmseconds_100;
            else
              adress <= mseconds_100;
            end if;
          end if;
        elsif (display = 2) then
          dspA <= '1';
          dspB <= '0';
          dp <= '1';
          if (t_prec = '0') then
            if (delta_time = '1') then
              adress <= dminutes_1;
            else
              adress <= minutes_1;
            end if;
          else
            if (delta_time = '1') then
              adress <= dseconds_1;
            else
              adress <= seconds_1;
            end if;
          end if;
        elsif (display = 3) then
          dspA <= '0';
          dspB <= '1';
          if (t_prec = '0') then
            if (delta_time = '1') then
              adress <= dminutes_10;
            else
              adress <= minutes_10;
            end if;
          else
            if (delta_time = '1') then
              adress <= dseconds_10;
            else
              adress <= seconds_10;
            end if;
          end if;
          display <= "00";
        end if;
      end if;
    end if;
  end process;

  -- Översätt tal till display
  with adress select
    data <= "1111110" when "0000",
      "0110000" when "0001",
      "1101101" when "0010",
      "1111001" when "0011",
      "0110011" when "0100",
      "1011011" when "0101",
      "1011111" when "0110",
      "1110000" when "0111",
      "1111111" when "1000",
      "1111011" when "1001",
      "-------" when others;

  -- Sätt outputs
  process(clk) begin
    if (en_p='0' and en_p_plus='1') then
      if rising_edge(clk) then
        a <= data(6);
        b <= data(5);
        c <= data(4);
        d <= data(3);
        e <= data(2);
        f <= data(1);
        g <= data(0);
        led <= led_count;
      end if;
    end if;
  end process;

  -- Lagra föregående klockpuls

end atimer;

--vsim timer
--add wave sim:/timer/*
--restart -force
--force -freeze sim:/timer/clk 0 0, 1 4 -r 8
--force -freeze sim:/timer/mux 0 0, 1 50 -r 100
--force -freeze sim:/timer/time 0 0, 1 50 -r 100
--force -freeze sim:/timer/start_in 0 0, 1 100
--force -freeze sim:/timer/reset_in 0 0
--force -freeze sim:/timer/time_prec 1 0
--run 500000