perchick
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hello
i wrote a code for Tic-Tac-Toe checker for my homework assignment and i just got my grade and it is not good.
Im having some trouble understanding what is the problem with this code for this system and i was wondering if someone could explain to me what i did wrong here. my professor has an history of giving bed grads for codes he doesn't like and i just wanted to know if my code is really that awful or is it him.
the rules for the game: d_in writes x, and 0 from left to right row by row. if we have a winner the program stops. the output (stts) is "01" for x_win, "10" for o_win and "11" for a draw.
i didn't want to use components so i used functions and did all my calculation in one process. my professor hated my solution and in hes comments he wrote " doesn't look like HDL". i don't really understand what the difference if my code works (had 2 latches which i guess is not good, i mean beside that).
hope you can help me with this
my code:
i wrote a code for Tic-Tac-Toe checker for my homework assignment and i just got my grade and it is not good.
Im having some trouble understanding what is the problem with this code for this system and i was wondering if someone could explain to me what i did wrong here. my professor has an history of giving bed grads for codes he doesn't like and i just wanted to know if my code is really that awful or is it him.
the rules for the game: d_in writes x, and 0 from left to right row by row. if we have a winner the program stops. the output (stts) is "01" for x_win, "10" for o_win and "11" for a draw.
i didn't want to use components so i used functions and did all my calculation in one process. my professor hated my solution and in hes comments he wrote " doesn't look like HDL". i don't really understand what the difference if my code works (had 2 latches which i guess is not good, i mean beside that).
hope you can help me with this
my code:
Code:
library ieee;
use ieee.std_logic_1164.all;
--==========package and functions=====================================================
package TicTacToe is
constant n : integer := 3; --board size
type state is (no_win, x_win, o_win, idle) ; --FSM states
type memroy_reg is array (0 to n-1) of state; -- memory for columns
function check_win (win :state) return boolean ;
function status (d_in : std_logic_vector (1 downto 0) ; --FSM
PS : state) return state ;
end TicTacToe;
package body TicTacToe is
-------------####################################------------------------
--function that checks if we have a winner, if we do it returns a
--bolean flag which indicates the end of the game (end_game)
-------------####################################------------------------
function check_win (win :state) return boolean is
begin
if win = x_win or win = o_win then
return true;
else
return false;
end if;
end check_win;
-------------************************************------------------------
--FSM function. gets present state and d_in and returns next state
-------------************************************------------------------
function status (d_in : std_logic_vector (1 downto 0) ;
PS : state ) return state is
begin
case PS is
when idle =>
if d_in = "01" then
return x_win;
elsif d_in = "10" then
return o_win;
else
return idle;
end if;
when x_win =>
if d_in = "10" then
return no_win;
else
return x_win ;
end if;
when o_win =>
if d_in = "01" then
return no_win;
else
return o_win;
end if;
when no_win =>
return no_win;
end case;
end status;
end TicTacToe;
--========== end package and functions=====================================================
library ieee;
use ieee.std_logic_1164.all;
use work.TicTacToe.all;-- use package
entity full_TicTacToe is
port ( clk, rst_n :in std_logic ;
d_in :in std_logic_vector (1 downto 0) ;
stts :out std_logic_vector (1 downto 0) );
end full_TicTacToe;
architecture arch_full_TicTacToe of full_TicTacToe is
begin
process (d_in, clk, rst_n)
variable end_game : boolean := false;--indication for the end of the game
variable i : integer := 0; --index columns
variable j : integer := 0; --index rows
variable row_state : state := idle; --row state
variable stts_temp : std_logic_vector (1 downto 0) := "00"; --temp stts output
variable memory : memroy_reg := (others => idle) ; --column memory is vector of type state
variable diag_L2R : state := idle; --north west to south east diagonal
variable diag_R2L : state := idle; --north east to south west diagonal
begin
--reset all
if rst_n ='0' then
i :=0;
j := 0;
end_game := false;
stts_temp := "00";
row_state := idle;
memory := (others => idle);
diag_L2R := idle;
diag_R2L := idle;
--if end_game=true we do not enter the rest of the code
elsif falling_edge (clk) and end_game = false and rst_n = '1' then
if i /= n then--case i didnt reach the end of the row
row_state := status (d_in, row_state); --extracted state from status function
memory (i) := status (d_in, memory (i));
if j = n-1 then--last row
end_game := check_win (memory (i)); --check if we have a winner through function check_win
if end_game = true then--case we do have column winner, what is the output
case memory (i) is
when x_win => stts_temp := "01";
when o_win => stts_temp := "10";
when others => null;
end case;
end if;
end if;--j=n-1
if i=j then--left to right diagonal condition
diag_L2R := status (d_in, diag_L2R);
if j= n-1 and end_game = false then--check last diag squar if we still do not have a winner
end_game := check_win (diag_L2R);
if end_game = true then--case diag left to right won what's the output
case diag_L2R is
when x_win => stts_temp := "01";
when o_win => stts_temp := "10";
when others => null;
end case;
end if;
end if;--j=n-1
end if;--i=j
if (i+j = n-1) then-- diag right to left condition
diag_R2L := status (d_in, diag_R2L);
if j = n-1 and end_game = false then--case we don't have a winner yet and we at the last squar, check for winner
end_game := check_win (diag_R2L);
if end_game = true then--case we do have a winner, what's the output
case diag_R2L is
when x_win => stts_temp := "01";
when o_win => stts_temp := "10";
when others => null;
end case;
end if;
end if;--j=n-1 & end_game=false
end if;--i+j = n-1
i := i+1;
else --case i=n (if i= n meaning we're reach the end of the row, input is "11")
i := 0; --zero index row
j := j+1;--advance index column
if end_game = false then--if we don't have a winner yet, check if row won
end_game := check_win (row_state);
end if;
if end_game = true then--case row won wha's the output
case row_state is
when x_win => stts_temp := "01";
when o_win => stts_temp := "10";
when others => null;
end case;
end if;
row_state := idle;
end if;--i /=n
end if;--rst_n&rising edge&end_game
if j = n and d_in ="11" and end_game = false then-- case no one won so far and we reach the end if the board
stts_temp := "11";
end_game := true;
end if;
stts <= stts_temp;
end process;
end architecture;
