--------------------------------------------------------------------------
--------------------------------------------------------------------------
--	File Name 	: blackjack.v
--	Author(s)	: Mitchel D. Horton
--	Affiliation	: Laboratory for Digital Design Environments
--			  Department of Electrical & Computer Engineering
--			  University of Cincinnati
--	Date Created	: June, 1991.
--	Introduction	: Behavioral description for the black-jack m/c
--			  written in a synthesizable subset of VHDL.
--
--	Source		: Textual description compiled from the book
--		          F. Prosser and D. Winkel,
--			  ``The Art of Digital Design'',
--			  Prentice-Hall, 1987.
--
--
--	Modified For Synthesis by Jay(anta) Roy, University of Cincinnati.
--	Date Modified	: Sept, 91.
--
--	Disclaimer	: This comes with absolutely no guarantees of any
--			  kind (just stating the obvious ...)
--
--      Acknowledgement : The Distributed Synthesis Systems research at 
--                        the Laboratory for Digital Design Environments,
--                        University of Cincinnati, is sponsored in part 
--                        by the Defense Advanced Research Projects Agency 
--                        under order number 7056 monitored by the Federal 
--                        Bureau of Investigation under contract number 
--                        J-FBI-89-094.
--
--------------------------------------------------------------------------
--------------------------------------------------------------------------
-- 
use Work.functions.all;

entity blackjack is end blackjack;

architecture behavior of blackjack is

  type CARDDECK is array(0 to 51) of BIT_VECTOR(3 downto 0);

  signal card        : BIT_VECTOR(3 downto 0);
  signal score       : INTEGER                   :=   0;
  signal state       : BIT_VECTOR(1 downto 0)    :=  "00";
  signal card_number : INTEGER                   :=   0;
  signal deck        : CARDDECK := ("1011", "1011", "1011", "1011",
                                    "1010", "1010", "0111", "0100",
                                    "1010", "1010", "0111", "0100",
                                    "1010", "1010", "0111", "0100",
                                    "1010", "1010", "0111", "0100",
                                    "1010", "1001", "0110", "0011",
                                    "1010", "1001", "0110", "0011",
                                    "1010", "1001", "0110", "0011",
                                    "1010", "1001", "0110", "0011",
                                    "1010", "1000", "0101", "0010",
                                    "1010", "1000", "0101", "0010",
                                    "1010", "1000", "0101", "0010",
                                    "1010", "1000", "0101", "0010");

begin  

  bj : process

  begin

    -- CARD GRABBING LOOP
    Loop1 : while (bits_to_int(state) < 1) loop

      -- GRAB NEXT CARD OFF THE DECK
      card <= deck(card_number);

      -- UPDATE NUMBER OF CARDS IN THIS HAND
      card_number <= card_number + 1;

      -- UPDATE SCORE
      score <= score + bits_to_int(card);

      -- IF SCORE GT 15 THEN
      if score > 15 then

        -- IF SCORE LT 22 THEN
        if score < 22 then

          -- STAY
          state <= "10";

        -- ELSE; SCORE GT 22
        else

          -- IF ACE THEN
          if card = "1011" then

            -- ENHANCE VALUE OF ACE FROM 11 TO 1
            score <= score - 10;

            -- IF SCORE GT 15 THEN
            if score > 15 then

              -- STAY
              state <= "10";

            -- ELSE; SCORE LT 16
            else

              -- HIT ME
              state <= "00";
            end if;

          -- ELSE; CARD NOT ACE
          else

            -- BUST
            state <= "01";
          end if;
        end if;

      -- ELSE; SCORE LT 16
      else

        -- HIT ME
        state <= "00";
      end if;
    end loop;
  end process;
end behavior;