src/parser.vhd

   1 library ieee;
   2 use ieee.std_logic_1164.all;
   3 use ieee.numeric_std.all;
   4 use work.gen_pkg.all;
   5
   6 entity parser is
   7         port
   8         (
   9                 sys_clk : in std_logic;
  10                 sys_res_n : in std_logic;
  11                 -- History
  12                 p_rw : out std_logic;
  13                 p_spalte : out hspalte;
  14                 p_rget : out std_logic;
  15                 p_rdone : in std_logic;
  16                 p_read : in hbyte;
  17                 p_wtake : out std_logic;
  18                 p_wdone : in std_logic;
  19                 p_write : out hbyte;
  20                 p_finished : out std_logic;
  21                 -- ALU
  22                 opcode : out alu_ops;
  23                 op1 : out csigned;
  24                 op2 : out csigned;
  25                 op3 : in csigned;
  26                 do_calc : out std_logic;
  27                 calc_done : in std_logic;
  28                 calc_error : in std_logic;
  29                 -- Scanner
  30                 do_it : in std_logic;
  31                 finished : out std_logic
  32         );
  33 end entity parser;
  34
  35 architecture beh of parser is
  36         type PARSER_STATE is (SIDLE, SREAD_NEWNUMBER, SREAD_NEXTBYTE,
  37         SREAD_CALCNUMBER1, SREAD_CALCNUMBER2, SCALC_1, SCALC_14, SCALC_15, SCALC_2, SWRITE_CHAR1,
  38         SWRITE_CHAR2, SDONE, SERROR1, SERROR2);
  39         signal state_int, state_next : PARSER_STATE;
  40         signal z_int, z_next, strich_int, strich_next, wtmp_int, wtmp_next : csigned;
  41         signal punkt_int, punkt_next : csigned;
  42         signal rbyte_int, rbyte_next : hbyte;
  43         signal p_write_int, p_write_next : hbyte;
  44         signal p_rget_int, p_rget_next : std_logic;
  45         signal p_wtake_int, p_wtake_next : std_logic;
  46         signal p_finished_int, p_finished_next : std_logic;
  47         signal aktop_int, aktop_next : alu_ops;
  48         signal opp_int, opp_next : alu_ops;
  49         signal opcode_int, opcode_next : alu_ops;
  50         signal op1_int, op1_next : csigned;
  51         signal op2_int, op2_next : csigned;
  52         signal do_calc_int, do_calc_next : std_logic;
  53 begin
  54         p_write <= p_write_int;
  55         p_rget <= p_rget_int;
  56         p_wtake <= p_wtake_int;
  57         p_finished <= p_finished_int;
  58
  59         opcode <= opcode_int;
  60         op1 <= op1_int;
  61         op2 <= op2_int;
  62         do_calc <= do_calc_int;
  63
  64         process(sys_clk, sys_res_n)
  65         begin
  66                 if sys_res_n = '0' then
  67                         state_int <= SIDLE;
  68                         z_int <= (others => '0');
  69                         strich_int <= (others => '0');
  70                         punkt_int <= (others => '0');
  71                         wtmp_int <= (others => '0');
  72                         rbyte_int <= (others => '0');
  73                         aktop_int <= ALU_NOP;
  74                         opp_int <= ALU_NOP;
  75                         -- out ports
  76                         p_rw <= '0';
  77                         p_spalte <= (others => '0');
  78                         p_rget_int <= '0';
  79                         p_write_int <= (others => '0');
  80                         p_wtake_int <= '0';
  81                         p_finished_int <= '0';
  82                         opcode_int <= ALU_NOP;
  83                         op1_int <= (others => '0');
  84                         op2_int <= (others => '0');
  85                         do_calc_int <= '0';
  86                         finished <= '0';
  87                 elsif rising_edge(sys_clk) then
  88                         -- internal
  89                         state_int <= state_next;
  90                         z_int <= z_next;
  91                         strich_int <= strich_next;
  92                         punkt_int <= punkt_next;
  93                         wtmp_int <= wtmp_next;
  94                         rbyte_int <= rbyte_next;
  95                         aktop_int <= aktop_next;
  96                         opp_int <= opp_next;
  97                         -- out ports
  98                         p_rget_int <= p_rget_next;
  99                         p_write_int <= p_write_next;
 100                         p_wtake_int <= p_wtake_next;
 101                         p_finished_int <= p_finished_next;
 102                         opcode_int <= opcode_next;
 103                         op1_int <= op1_next;
 104                         op2_int <= op2_next;
 105                         do_calc_int <= do_calc_next;
 106                 end if;
 107         end process;
 108
 109         -- next state
 110         process(state_int, do_it, p_rdone, p_wdone, p_read, aktop_int, strich_int,
 111                 punkt_int, calc_done, wtmp_int, opp_int)
 112         begin
 113                 state_next <= state_int;
 114
 115                 case state_int is
 116                         when SIDLE =>
 117                                 if do_it = '1' then
 118                                         state_next <= SREAD_NEWNUMBER;
 119                                 end if;
 120                         when SREAD_NEWNUMBER =>
 121                                 state_next <= SREAD_NEXTBYTE;
 122                         when SREAD_NEXTBYTE =>
 123                                 if p_rdone = '1' then
 124                                         state_next <= SREAD_CALCNUMBER1;
 125                                 end if;
 126                         when SREAD_CALCNUMBER1 =>
 127                                 state_next <= SREAD_CALCNUMBER2;
 128                         when SREAD_CALCNUMBER2 =>
 129                                 if p_rdone = '0' then
 130                                         if aktop_int /= ALU_NOP then
 131                                                 state_next <= SCALC_1;
 132                                         else
 133                                                 state_next <= SREAD_NEXTBYTE;
 134                                         end if;
 135                                 end if;
 136                         when SCALC_1 =>
 137                                 if calc_done = '1' then
 138                                         case opp_int is
 139                                                 -- spezialfall: eine zwischenberechnung wird fuer diese
 140                                                 -- kombination benoetigt
 141                                                 when ALU_MUL | ALU_DIV =>
 142                                                         case aktop_int is
 143                                                                 when ALU_ADD | ALU_SUB | ALU_DONE => state_next <= SCALC_14;
 144                                                                 when others => state_next <= SCALC_2;
 145                                                         end case;
 146                                                 when others => state_next <= SCALC_2;
 147                                         end case;
 148                                 end if;
 149                         when SCALC_14 =>
 150                                 if calc_done = '0' then
 151                                         state_next <= SCALC_15;
 152                                 end if;
 153                         when SCALC_15 =>
 154                                 if calc_done = '1' then
 155                                         state_next <= SCALC_2;
 156                                 end if;
 157                         when SCALC_2 =>
 158                                 if aktop_int = ALU_DONE then
 159                                         state_next <= SWRITE_CHAR1;
 160                                 else
 161                                         state_next <= SREAD_NEWNUMBER;
 162                                 end if;
 163                         when SWRITE_CHAR1 =>
 164                                 if p_wdone = '1' then
 165                                         if strich_int < 10 then
 166                                                 state_next <= SDONE;
 167                                         else
 168                                                 state_next <= SWRITE_CHAR2;
 169                                         end if;
 170                                 end if;
 171                         when SERROR1 =>
 172                                 if p_wdone = '1' then
 173                                         -- TODO
 174                                         if strich_int < 10 then
 175                                                 state_next <= SDONE;
 176                                         else
 177                                                 state_next <= SWRITE_CHAR2;
 178                                         end if;
 179                                 end if;
 180                         when SWRITE_CHAR2 | SERROR2 =>
 181                                 if p_wdone = '0' then
 182                                         state_next <= SWRITE_CHAR1;
 183                                 end if;
 184                         when SDONE =>
 185                                 if p_wdone = '0' and do_it = '0' then
 186                                         state_next <= SIDLE;
 187                                 end if;
 188                 end case;
 189         end process;
 190
 191         -- out
 192         process(state_int, p_read, p_write_int, z_int, rbyte_int, p_rget_int,
 193                 strich_int, aktop_int, opp_int, opcode_int, op1_int, op2_int, op3,
 194                 do_calc_int, wtmp_int, punkt_int)
 195                 function hbyte2csigned (x : hbyte) return csigned is
 196                         variable y : csigned;
 197                 begin
 198                         case x is
 199                                 when x"30" => y := to_signed(0, CBITS);
 200                                 when x"31" => y := to_signed(1, CBITS);
 201                                 when x"32" => y := to_signed(2, CBITS);
 202                                 when x"33" => y := to_signed(3, CBITS);
 203                                 when x"34" => y := to_signed(4, CBITS);
 204                                 when x"35" => y := to_signed(5, CBITS);
 205                                 when x"36" => y := to_signed(6, CBITS);
 206                                 when x"37" => y := to_signed(7, CBITS);
 207                                 when x"38" => y := to_signed(8, CBITS);
 208                                 when x"39" => y := to_signed(9, CBITS);
 209                                 when others => assert(false) report "hbyte2csigned: shouldn't happen";
 210                         end case;
 211                         return y;
 212                 end function hbyte2csigned;
 213
 214                 function csigned2hbyte (x : csigned) return hbyte is
 215                         variable y : hbyte;
 216                 begin
 217                         case x is
 218                                 when x"00000000" => y := x"30";
 219                                 when x"00000001" => y := x"31";
 220                                 when x"00000002" => y := x"32";
 221                                 when x"00000003" => y := x"33";
 222                                 when x"00000004" => y := x"34";
 223                                 when x"00000005" => y := x"35";
 224                                 when x"00000006" => y := x"36";
 225                                 when x"00000007" => y := x"37";
 226                                 when x"00000008" => y := x"38";
 227                                 when x"00000009" => y := x"39";
 228                                 when others => assert(false) report "csigned2hbyte: shouldn't happen";
 229                         end case;
 230                         return y;
 231                 end function csigned2hbyte;
 232
 233                 variable multmp : signed(((2*CBITS)-1) downto 0);
 234                 variable tmp : csigned;
 235         begin
 236                 -- internal
 237                 z_next <= z_int;
 238                 strich_next <= strich_int;
 239                 punkt_next <= punkt_int;
 240                 wtmp_next <= wtmp_int;
 241                 rbyte_next <= rbyte_int;
 242                 aktop_next <= aktop_int;
 243                 opp_next <= opp_int;
 244                 -- signals
 245                 p_rget_next <= '0';
 246                 p_write_next <= p_write_int;
 247                 p_wtake_next <= '0';
 248                 p_finished_next <= '0';
 249                 opcode_next <= opcode_int;
 250                 op1_next <= op1_int;
 251                 op2_next <= op2_int;
 252                 do_calc_next <= '0';
 253
 254                 case state_int is
 255                         when SIDLE =>
 256                                 strich_next <= (others => '0');
 257                                 punkt_next <= (0 => '1', others => '0');
 258                                 opp_next <= ALU_NOP;
 259                         when SREAD_NEWNUMBER =>
 260                                 z_next <= (others => '0');
 261                                 rbyte_next <= (others => '0');
 262                                 p_write_next <= (others => '0');
 263                                 aktop_next <= ALU_NOP;
 264                         when SREAD_NEXTBYTE =>
 265                                 p_rget_next <= '1';
 266                         when SREAD_CALCNUMBER1 =>
 267                                 case p_read is
 268                                         -- '+'
 269                                         when x"2B" =>
 270                                                 aktop_next <= ALU_ADD;
 271                                         -- '-'
 272                                         when x"2D" =>
 273                                                 -- TODO: sign check beim ersten byte lesen!
 274                                                 aktop_next <= ALU_SUB;
 275                                         -- '*'
 276                                         when x"2A" =>
 277                                                 aktop_next <= ALU_MUL;
 278                                         -- '/'
 279                                         when x"2F" =>
 280                                                 aktop_next <= ALU_DIV;
 281
 282                                         -- '\0'
 283                                         when x"00" =>
 284                                                 aktop_next <= ALU_DONE;
 285
 286                                         when others =>
 287                                                 -- TODO: check auf overflow
 288                                                 multmp := (z_int * 10) + hbyte2csigned(p_read);
 289                                                 z_next <= multmp((CBITS-1) downto 0);
 290                                 end case;
 291                         when SREAD_CALCNUMBER2 =>
 292                                 null;
 293
 294                         when SCALC_1 =>
 295                                 case opp_int is
 296                                         when ALU_NOP | ALU_ADD | ALU_SUB =>
 297                                                 case opp_int  is
 298                                                         when ALU_SUB => op1_next <= (not z_int) + 1;
 299                                                         when others => op1_next <= z_int;
 300                                                 end case;
 301                                                 case aktop_int is
 302                                                         when ALU_ADD | ALU_SUB | ALU_DONE =>
 303                                                                 opcode_next <= ALU_ADD;
 304                                                                 op2_next <= strich_int;
 305                                                         when ALU_MUL | ALU_DIV =>
 306                                                                 opcode_next <= ALU_MUL;
 307                                                                 op2_next <= punkt_int;
 308                                                         when others => assert(false) report "SCALC_1/1: shouldn't happen!";
 309                                                 end case;
 310
 311                                         when ALU_MUL | ALU_DIV =>
 312                                                 case aktop_int is
 313                                                         when ALU_ADD | ALU_SUB | ALU_DONE | ALU_MUL | ALU_DIV =>
 314                                                                 op1_next <= punkt_int;
 315                                                                 opcode_next <= opp_int;
 316                                                                 op2_next <= z_int;
 317                                                         when others => assert(false) report "SCALC_1/2: shouldn't happen!";
 318                                                 end case;
 319                                         when others => assert(false) report "SCALC_1/3: shouldn't happen!";
 320                                 end case;
 321                                 do_calc_next <= '1';
 322
 323                         when SCALC_14 =>
 324                                 -- ueberpruefung kann man sich sparen, da diese ohnehin in
 325                                 -- nextstate gemacht wird.
 326                                 op1_next <= op3;
 327                                 do_calc_next <= '0';
 328
 329                         when SCALC_15 =>
 330                                 -- ueberpruefung kann man sich sparen, da diese ohnehin in
 331                                 -- nextstate gemacht wird.
 332                                 opcode_next <= ALU_ADD;
 333                                 op2_next <= strich_int;
 334                                 punkt_next <= (0 => '1', others => '0');
 335                                 do_calc_next <= '1';
 336
 337                         when SCALC_2 =>
 338                                 case opp_int is
 339                                         when ALU_NOP | ALU_ADD | ALU_SUB | ALU_MUL | ALU_DIV =>
 340                                                 case aktop_int is
 341                                                         when ALU_ADD | ALU_SUB | ALU_DONE =>
 342                                                                 strich_next <= op3;
 343                                                         when ALU_MUL | ALU_DIV =>
 344                                                                 punkt_next <= op3;
 345                                                         when others => assert (false) report "SCALC_2/1: shouldn't happen!";
 346                                                 end case;
 347                                         when others => assert (false) report "SCALC_2/2: shouldn't happen!";
 348                                 end case;
 349                                 -- aktuelle rechenoperation fuer naechste 'runde' uebernehmen
 350                                 opp_next <= aktop_int;
 351
 352                         when SWRITE_CHAR1 =>
 353                                 p_wtake_next <= '1';
 354                                 tmp := strich_int mod 10;
 355                                 p_write_next <= csigned2hbyte(tmp);
 356                                 wtmp_next <= strich_int / 10;
 357                         when SWRITE_CHAR2 =>
 358                                 strich_next <= wtmp_int;
 359
 360                         when SERROR1 =>
 361                                 -- TODO
 362                                 null;
 363                         when SERROR2 =>
 364                                 -- TODO
 365                                 null;
 366
 367                         when SDONE =>
 368                                 p_finished_next <= '1';
 369                 end case;
 370         end process;
 371 end architecture beh;