src/display.vhd

   1 library ieee;
   2 use ieee.std_logic_1164.all;
   3 use ieee.numeric_std.all;
   4 use work.gen_pkg.all;
   5 use work.textmode_vga_component_pkg.all;
   6 use work.textmode_vga_pkg.all;
   7 use work.textmode_vga_platform_dependent_pkg.all;
   8
   9 entity display is
  10         port (
  11                 sys_clk : in std_logic;
  12                 sys_res_n : in std_logic;
  13                 -- History
  14                 d_new_eingabe : in std_logic;
  15                 d_new_result : in std_logic;
  16                 d_new_bs : in std_logic;
  17                 d_zeile : out hzeile;
  18                 d_spalte : out hspalte;
  19                 d_get : out std_logic;
  20                 d_done : in std_logic;
  21                 d_char : in hbyte;
  22                 -- VGA
  23                 command : out std_logic_vector(7 downto 0);
  24                 command_data : out std_logic_vector(31 downto 0);
  25                 free : in std_logic
  26         );
  27 end entity display;
  28
  29 architecture beh of display is
  30         type DISPLAY_STATE is (SIDLE, S_NEW_BS, S_BACK, S_BLANK, S_NEW_RESULT,
  31                 S_NEW_INPUT, S_COUNTUP, S_GETCH, S_CR1, S_NL1, S_PUTCH1, S_PUTCH2,
  32                 S_WAIT, S_NOP1);
  33         signal state_int, state_next : DISPLAY_STATE;
  34         signal d_zeile_int, d_zeile_next : hzeile;
  35         signal d_spalte_int, d_spalte_next : hspalte;
  36         signal d_get_int, d_get_next : std_logic;
  37         signal command_int, command_next : std_logic_vector(7 downto 0);
  38         signal command_data_int, command_data_next : std_logic_vector(31 downto 0);
  39         signal istate_next, istate_int : signed(2 downto 0);
  40 begin
  41         d_zeile <= d_zeile_int;
  42         d_spalte <= d_spalte_int;
  43         d_get <= d_get_int;
  44         command <= command_int;
  45         command_data <= command_data_int;
  46
  47         process(sys_clk, sys_res_n)
  48         begin
  49                 if sys_res_n = '0' then
  50                         -- internal
  51                         state_int <= SIDLE;
  52                         istate_int <= (others => '0');
  53                         -- out
  54                         d_zeile_int <= (others => '0');
  55                         d_spalte_int <= (others => '0');
  56                         d_get_int <= '0';
  57                         command_int <= COMMAND_NOP;
  58                         command_data_int <= (others => '0');
  59                 elsif rising_edge(sys_clk) then
  60                         -- internal
  61                         state_int <= state_next;
  62                         istate_int <= istate_next;
  63                         -- out
  64                         d_zeile_int <= d_zeile_next;
  65                         d_spalte_int <= d_spalte_next;
  66                         d_get_int <= d_get_next;
  67                         command_int <= command_next;
  68                         command_data_int <= command_data_next;
  69                 end if;
  70         end process;
  71
  72         -- next state
  73         process(state_int, d_new_result, d_new_eingabe, d_new_bs, d_done, free,
  74                 d_spalte_int, d_char, istate_int)
  75         begin
  76                 state_next <= state_int;
  77                 istate_next <= istate_int;
  78
  79                 case state_int is
  80                         when SIDLE =>
  81                                 istate_next <= b"111"; -- default: immer wieder ins SIDLE;
  82                                 if d_new_bs = '1' then
  83                                         state_next <= S_NEW_BS;
  84                                 elsif d_new_eingabe = '1' then
  85                                         state_next <= S_NEW_INPUT;
  86                                 end if;
  87                                 if d_new_result = '1' then
  88                                         state_next <= S_NEW_RESULT;
  89                                 end if;
  90
  91                         when S_NEW_RESULT =>
  92                                 state_next <= S_CR1;
  93                         when S_NEW_INPUT =>
  94                                 state_next <= S_COUNTUP;
  95
  96                         when S_NEW_BS =>
  97                                 state_next <= S_BACK;
  98                         when S_BACK =>
  99                                 if free = '0' then
 100                                         state_next <= S_WAIT;
 101                                         case istate_int is
 102                                                 when b"111" => istate_next <= b"001"; -- => danach S_BLANK und wieder hierher
 103                                                 when others => istate_next <= b"111"; -- => danach SIDLE
 104                                         end case;
 105                                 end if;
 106                         when S_BLANK =>
 107                                 if free = '0' then
 108                                         state_next <= S_WAIT;
 109                                         istate_next <= b"010"; -- => danach S_BACK
 110                                 end if;
 111
 112                         when S_CR1 =>
 113                                 if free = '0' then
 114                                         state_next <= S_WAIT;
 115                                         istate_next <= b"000"; -- => danach S_NL1
 116                                 end if;
 117                         when S_NL1 =>
 118                                 if free = '0' then
 119                                         state_next <= S_WAIT;
 120                                         istate_next <= b"111"; -- => wieder nach SIDLE
 121                                 end if;
 122
 123                         when S_COUNTUP =>
 124                                 state_next <= S_GETCH;
 125                         when S_GETCH =>
 126                                 if free = '1' and d_done = '1' and d_new_result = '0' and d_new_eingabe = '0' then
 127                                         state_next <= S_PUTCH1;
 128                                 end if;
 129                         when S_PUTCH1 =>
 130                                 state_next <= S_PUTCH2;
 131                         when S_PUTCH2 =>
 132                                 if free = '0' or (free = '1' and d_char = x"00") then
 133                                         state_next <= S_WAIT;
 134                                 end if;
 135                         when S_WAIT =>
 136                                 if free = '1' and d_done = '0' then
 137                                         state_next <= S_NOP1;
 138                                 end if;
 139                         when S_NOP1 =>
 140                                 if free = '1' then
 141                                         case istate_int is
 142                                                 when b"000" => state_next <= S_NL1;
 143                                                 when b"001" => state_next <= S_BLANK;
 144                                                 when b"010" => state_next <= S_BACK;
 145                                                 when others => state_next <= SIDLE;
 146                                         end case;
 147                                 end if;
 148                 end case;
 149         end process;
 150
 151         -- out
 152         process(state_int, d_zeile_int, d_spalte_int, d_get_int, command_int,
 153                 command_data_int, d_char)
 154         begin
 155                 d_zeile_next <= d_zeile_int;
 156                 d_spalte_next <= d_spalte_int;
 157                 d_get_next <= '0';
 158                 command_next <= command_int;
 159                 command_data_next <= command_data_int;
 160
 161                 case state_int is
 162                         when SIDLE =>
 163                                 null;
 164                         when S_NEW_RESULT =>
 165                                 d_spalte_next <= (others => '0');
 166                                 case d_zeile_int is
 167                                         when "11111" => d_zeile_next <= "00000";
 168                                         when others => d_zeile_next <= std_logic_vector(unsigned(d_zeile_int) + 1);
 169                                 end case;
 170                         when S_NEW_INPUT =>
 171                                 null;
 172
 173                         when S_NEW_BS =>
 174                                 -- underflow check schon im history modul
 175                                 d_spalte_next <= std_logic_vector(unsigned(d_spalte_int) - 1);
 176                         when S_BACK =>
 177                                 -- einen schritt zurueck
 178                                 command_next <= COMMAND_SET_CURSOR_COLUMN;
 179                                 command_data_next <= x"ffffff" & '0' & std_logic_vector(unsigned(d_spalte_int));
 180                         when S_BLANK =>
 181                                 command_next <= COMMAND_SET_CHAR;
 182                                 command_data_next <= x"ffffff" & x"20"; -- white space
 183
 184                         when S_CR1 =>
 185                                 command_next <= COMMAND_SET_CHAR;
 186                                 command_data_next <= x"ffffff" & x"0d"; -- carrige return
 187                         when S_NL1 =>
 188                                 command_next <= COMMAND_SET_CHAR;
 189                                 command_data_next <= x"ffffff" & x"0a"; -- newline
 190
 191                         when S_COUNTUP =>
 192                                 d_get_next <= '1';
 193                                 d_spalte_next <= std_logic_vector(unsigned(d_spalte_int) + 1);
 194                         when S_GETCH =>
 195                                 d_get_next <= '1';
 196                         when S_PUTCH1 =>
 197                                 if d_char /= x"00" then
 198                                         command_next <= COMMAND_SET_CHAR;
 199                                         command_data_next <= x"ffffff" & std_logic_vector(d_char);
 200                                 end if;
 201                         when S_PUTCH2 => null;
 202                         when S_WAIT | S_NOP1 =>
 203                                 command_next <= COMMAND_NOP;
 204                                 command_data_next <= x"00000000";
 205                 end case;
 206         end process;
 207 end architecture beh;