21c

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

entity timer is
  Port(
    clk, mux, time_clk : in std_logic;
    start_in, reset_in : in std_logic;
    led : out std_logic;
    time_prec : in 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, led_counter, 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";

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_clk;
      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_counter <= 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_counter <= '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
          if (t_prec = '1') then
            if (seconds_10 > 0) then
              dspA <= '1';
              dspB <= '1';
            else
              dp <= '1';
            end if;
            if (delta_time = '1') then
              adress <= dmseconds_10;
            else
              adress <= mseconds_10;
            end if;
          else
            if (minutes_10 > 0) then
              dspA <= '1';
              dspB <= '1';
            else
              dp <= '1';
            end if;
            if (delta_time = '1') then
              adress <= dseconds_1;
            else
              adress <= seconds_1;
            end if;
          end if;
        --------------------------------------------------------------------------------------------------
        elsif (display = 1) then
          dspA <= '0';
          dspB <= '0';
          if (t_prec='1' and ((mseconds_100 > 0) or (seconds_1 > 0) or (seconds_10 > 0))) then
            if (delta_time = '1') then
              adress <= dmseconds_100;
            else
              adress <= mseconds_100;
            end if;
          elsif (t_prec='0' and ((seconds_10 > 0) or (minutes_1 > 0) or (minutes_10 > 0))) then
            if (delta_time = '1') then
              adress <= dseconds_10;
            else
              adress <= seconds_10;
            end if;
          end if;
        --------------------------------------------------------------------------------------------------
        elsif (display = 2) then
          if (t_prec='1') then
            if ((mseconds_100 > 0) or (seconds_1 > 0) or (seconds_10 > 0)) then
              dspA <= '1';
              dspB <= '0';
            end if;
            if ((seconds_1 > 0) or (seconds_10 > 0)) then
              if (delta_time = '1') then
                adress <= dseconds_1;
              else
                adress <= seconds_1;
              end if;
            else
              adress <= "1111";
            end if;
          else
            if ((seconds_10 > 0) or (minutes_1 > 0) or (minutes_10 > 0)) then
              dspA <= '1';
              dspB <= '0';
            end if;
            if ((minutes_1 > 0) or (minutes_10 > 0)) then
              if (delta_time = '1') then
                adress <= dminutes_1;
              else
                adress <= minutes_1;
              end if;
            else
              adress <= "1111";
            end if;
          end if;
        --------------------------------------------------------------------------------------------------
        elsif (display = 3) then
          dspA <= '0';
          dspB <= '1';
          dp <= '1';
          if (t_prec='1' and (seconds_10 > 0)) then
            if (delta_time = '1') then
              adress <= dseconds_10;
            else
              adress <= seconds_10;
            end if;
          elsif (minutes_10 > 0) then
            if (delta_time = '1') then
              adress <= dminutes_10;
            else
              adress <= minutes_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",
      "0000000" when "1111",
      "-------" 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_counter;
      end if;
    end if;
  end process;
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_clk 0 0, 1 500 -r 1000
--force -freeze sim:/timer/start_in 0 0, 1 100
--force -freeze sim:/timer/reset_in 0 0
--force -freeze sim:/timer/time_prec 0 0
--run 500000