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                 -- TODO: 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_2, SWRITE_CHAR1, SWRITE_CHAR2, SDONE);
  38         signal state_int, state_next : PARSER_STATE;
  39         signal z_int, z_next, strich_int, strich_next, wtmp_int, wtmp_next : csigned;
  40         signal rbyte_int, rbyte_next : hbyte;
  41         signal p_write_int, p_write_next : hbyte;
  42         signal p_rget_int, p_rget_next : std_logic;
  43         signal p_wtake_int, p_wtake_next : std_logic;
  44         signal p_finished_int, p_finished_next : std_logic;
  45         signal aktop_int, aktop_next : alu_ops;
  46         signal opp_int, opp_next : alu_ops;
  47         signal opcode_int, opcode_next : alu_ops;
  48         signal op1_int, op1_next : csigned;
  49         signal op2_int, op2_next : csigned;
  50         signal do_calc_int, do_calc_next : std_logic;
  51 begin
  52         p_write <= p_write_int;
  53         p_rget <= p_rget_int;
  54         p_wtake <= p_wtake_int;
  55         p_finished <= p_finished_int;
  56
  57         opcode <= opcode_int;
  58         op1 <= op1_int;
  59         op2 <= op2_int;
  60         do_calc <= do_calc_int;
  61
  62         process(sys_clk, sys_res_n)
  63         begin
  64                 if sys_res_n = '0' then
  65                         state_int <= SIDLE;
  66                         z_int <= (others => '0');
  67                         strich_int <= (others => '0');
  68                         wtmp_int <= (others => '0');
  69                         rbyte_int <= (others => '0');
  70                         aktop_int <= ALU_NOP;
  71                         opp_int <= ALU_NOP;
  72                         -- out ports
  73                         p_rw <= '0';
  74                         p_spalte <= (others => '0');
  75                         p_rget_int <= '0';
  76                         p_write_int <= (others => '0');
  77                         p_wtake_int <= '0';
  78                         p_finished_int <= '0';
  79                         opcode_int <= ALU_NOP;
  80                         op1_int <= (others => '0');
  81                         op2_int <= (others => '0');
  82                         do_calc_int <= '0';
  83                         finished <= '0';
  84                 elsif rising_edge(sys_clk) then
  85                         -- internal
  86                         state_int <= state_next;
  87                         z_int <= z_next;
  88                         strich_int <= strich_next;
  89                         wtmp_int <= wtmp_next;
  90                         rbyte_int <= rbyte_next;
  91                         aktop_int <= aktop_next;
  92                         opp_int <= opp_next;
  93                         -- out ports
  94                         p_rget_int <= p_rget_next;
  95                         p_write_int <= p_write_next;
  96                         p_wtake_int <= p_wtake_next;
  97                         p_finished_int <= p_finished_next;
  98                         opcode_int <= opcode_next;
  99                         op1_int <= op1_next;
 100                         op2_int <= op2_next;
 101                         do_calc_int <= do_calc_next;
 102                 end if;
 103         end process;
 104
 105         -- next state
 106         process(state_int, do_it, p_rdone, p_wdone, p_read, aktop_int, strich_int,
 107                 strich_next, calc_done, wtmp_int)
 108         begin
 109                 state_next <= state_int;
 110
 111                 case state_int is
 112                         when SIDLE =>
 113                                 if do_it = '1' then
 114                                         state_next <= SREAD_NEWNUMBER;
 115                                 end if;
 116                         when SREAD_NEWNUMBER =>
 117                                 state_next <= SREAD_NEXTBYTE;
 118                         when SREAD_NEXTBYTE =>
 119                                 if p_rdone = '1' then
 120                                         state_next <= SREAD_CALCNUMBER1;
 121                                 end if;
 122                         when SREAD_CALCNUMBER1 =>
 123                                 state_next <= SREAD_CALCNUMBER2;
 124                         when SREAD_CALCNUMBER2 =>
 125                                 if aktop_int /= ALU_NOP then
 126                                         state_next <= SCALC_1;
 127                                 else
 128                                         state_next <= SREAD_NEXTBYTE;
 129                                 end if;
 130                         when SCALC_1 =>
 131                                 if calc_done = '1' then
 132                                         state_next <= SCALC_2;
 133                                 end if;
 134                         when SCALC_2 =>
 135                                 if aktop_int = ALU_DONE then
 136                                         state_next <= SWRITE_CHAR1;
 137                                 else
 138                                         state_next <= SREAD_NEWNUMBER;
 139                                 end if;
 140                         when SWRITE_CHAR1 =>
 141                                 if p_wdone = '1' then
 142                                         if strich_int < 10 then
 143                                                 state_next <= SDONE;
 144                                         else
 145                                                 state_next <= SWRITE_CHAR2;
 146                                         end if;
 147                                 end if;
 148                         when SWRITE_CHAR2 =>
 149                                 if p_wdone = '0' then
 150                                         state_next <= SWRITE_CHAR1;
 151                                 end if;
 152                         when SDONE =>
 153                                 if p_wdone = '0' and do_it = '0' then
 154                                         state_next <= SIDLE;
 155                                 end if;
 156                 end case;
 157         end process;
 158
 159         -- out
 160         process(state_int, p_read, p_write_int, z_int, rbyte_int, p_rget_int,
 161                 strich_int, aktop_int, opp_int, opcode_int, op1_int, op2_int, op3,
 162                 do_calc_int, wtmp_int)
 163                 function hbyte2csigned (x : hbyte) return csigned is
 164                         variable y : csigned;
 165                 begin
 166                         case x is
 167                                 when x"30" => y := to_signed(0, CBITS);
 168                                 when x"31" => y := to_signed(1, CBITS);
 169                                 when x"32" => y := to_signed(2, CBITS);
 170                                 when x"33" => y := to_signed(3, CBITS);
 171                                 when x"34" => y := to_signed(4, CBITS);
 172                                 when x"35" => y := to_signed(5, CBITS);
 173                                 when x"36" => y := to_signed(6, CBITS);
 174                                 when x"37" => y := to_signed(7, CBITS);
 175                                 when x"38" => y := to_signed(8, CBITS);
 176                                 when x"39" => y := to_signed(9, CBITS);
 177                                 when others => assert(false) report "hbyte2csigned: shouldn't happen";
 178                         end case;
 179                         return y;
 180                 end function hbyte2csigned;
 181
 182                 function csigned2hbyte (x : csigned) return hbyte is
 183                         variable y : hbyte;
 184                 begin
 185                         case x is
 186                                 when x"00000000" => y := x"30";
 187                                 when x"00000001" => y := x"31";
 188                                 when x"00000002" => y := x"32";
 189                                 when x"00000003" => y := x"33";
 190                                 when x"00000004" => y := x"34";
 191                                 when x"00000005" => y := x"35";
 192                                 when x"00000006" => y := x"36";
 193                                 when x"00000007" => y := x"37";
 194                                 when x"00000008" => y := x"38";
 195                                 when x"00000009" => y := x"39";
 196                                 when others => assert(false) report "csigned2hbyte: shouldn't happen";
 197                         end case;
 198                         return y;
 199                 end function csigned2hbyte;
 200
 201                 variable multmp : signed(((2*CBITS)-1) downto 0);
 202                 variable tmp : csigned;
 203         begin
 204                 -- internal
 205                 z_next <= z_int;
 206                 strich_next <= strich_int;
 207                 wtmp_next <= wtmp_int;
 208                 rbyte_next <= rbyte_int;
 209                 aktop_next <= aktop_int;
 210                 opp_next <= opp_int;
 211                 -- signals
 212                 p_rget_next <= '0';
 213                 p_write_next <= p_write_int;
 214                 p_wtake_next <= '0';
 215                 p_finished_next <= '0';
 216                 opcode_next <= opcode_int;
 217                 op1_next <= op1_int;
 218                 op2_next <= op2_int;
 219                 do_calc_next <= '0';
 220
 221                 case state_int is
 222                         when SIDLE =>
 223                                 strich_next <= (others => '0');
 224                                 opp_next <= ALU_NOP;
 225                         when SREAD_NEWNUMBER =>
 226                                 z_next <= (others => '0');
 227                                 rbyte_next <= (others => '0');
 228                                 p_write_next <= (others => '0');
 229                                 aktop_next <= ALU_NOP;
 230                         when SREAD_NEXTBYTE =>
 231                                 p_rget_next <= '1';
 232                         when SREAD_CALCNUMBER1 =>
 233                                 case p_read is
 234                                         -- '+'
 235                                         when x"2B" =>
 236                                                 aktop_next <= ALU_ADD;
 237
 238                                         -- '\0'
 239                                         when x"00" =>
 240                                                 aktop_next <= ALU_DONE;
 241
 242                                         when others =>
 243                                                 -- TODO: check auf overflow
 244                                                 multmp := (z_int * 10) + hbyte2csigned(p_read);
 245                                                 z_next <= multmp((CBITS-1) downto 0);
 246                                 end case;
 247                         when SREAD_CALCNUMBER2 =>
 248                                 null;
 249
 250                         when SCALC_1 =>
 251                                 case opp_int is
 252                                         when ALU_NOP | ALU_ADD =>
 253                                                 op1_next <= z_int;
 254                                                 case aktop_int is
 255                                                         when ALU_ADD | ALU_SUB | ALU_NOP | ALU_DONE =>
 256                                                                 opcode_next <= ALU_ADD;
 257                                                                 op2_next <= strich_int;
 258                                                         when ALU_MUL | ALU_DIV =>
 259                                                                 opcode_next <= ALU_MUL;
 260                                                                 op2_next <= strich_int;
 261                                                         when others => assert(false) report "SCALC_1/ALU_NOP: not implemented yet";
 262                                                 end case;
 263                                                 do_calc_next <= '1';
 264                                         when others => assert(false) report "SCALC_1: not implemented yet";
 265                                 end case;
 266                         when SCALC_2 =>
 267                                 case opp_int is
 268                                         when ALU_NOP | ALU_ADD =>
 269                                                 strich_next <= op3;
 270                                         when others => assert (false) report "SCALC_2: not implemented yet";
 271                                 end case;
 272                                 opp_next <= aktop_int;
 273
 274                         when SWRITE_CHAR1 =>
 275                                 p_wtake_next <= '1';
 276                                 tmp := strich_int mod 10;
 277                                 p_write_next <= csigned2hbyte(tmp);
 278                                 wtmp_next <= strich_int / 10;
 279                         when SWRITE_CHAR2 =>
 280                                 strich_next <= wtmp_int;
 281
 282                         when SDONE =>
 283                                 p_finished_next <= '1';
 284                 end case;
 285         end process;
 286 end architecture beh;