git.zerfleddert.de Git - raggedstone/blob - heartbeat/source/pciwbsequ.vhd

   1 --+-------------------------------------------------------------------------------------------------+
   2 --|                                                                                                                                                                                                     |
   3 --|  File:                      pciwbsequ.vhd                                                                           |
   4 --|                                                                                                                                                                                                     |
   5 --|  Project:           pci32tlite_oc                                                                                                                                   |
   6 --|                                                                                                                                                                                                     |
   7 --|  Description:       FSM controlling PCI to Whisbone sequence.                                                                               |
   8 --|                                                                                                                                                                                                     |
   9 --+-------------------------------------------------------------------------------------------------+
  10 --|                                                                                                                                                                                                     |
  11 --|  Revision history :                                                                                                                                                         |
  12 --|  Date                 Version       Author  Description                                                                                                             |
  13 --|  2005-05-13   R00A00    PAU         First alfa revision     (eng)                                                                           |
  14 --|  2006-01-09             MS      added debug signals debug_init, debug_access                                        |                                                                                                                                                       |
  15 --|                                                                                                                                                                                                     |
  16 --|  To do:                                                                                                                                                                                     |
  17 --|                                                                                                                                                                                                     |
  18 --+-------------------------------------------------------------------------------------------------+
  19 --+-----------------------------------------------------------------+
  20 --|                                                                                                                             |
  21 --|  Copyright (C) 2005 Peio Azkarate, peio@opencores.org               |
  22 --|                                                                                                                             |
  23 --|  This source file may be used and distributed without               |
  24 --|  restriction provided that this copyright statement is not          |
  25 --|  removed from the file and that any derivative work contains        |
  26 --|  the original copyright notice and the associated disclaimer.       |
  27 --|                                                                     |
  28 --|  This source file is free software; you can redistribute it     |
  29 --|  and/or modify it under the terms of the GNU Lesser General     |
  30 --|  Public License as published by the Free Software Foundation;   |
  31 --|  either version 2.1 of the License, or (at your option) any     |
  32 --|  later version.                                                 |
  33 --|                                                                                                                             |
  34 --|  This source is distributed in the hope that it will be         |
  35 --|  useful, but WITHOUT ANY WARRANTY; without even the implied     |
  36 --|  warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR        |
  37 --|  PURPOSE.  See the GNU Lesser General Public License for more   |
  38 --|  details.                                                       |
  39 --|                                                                                                                             |
  40 --|  You should have received a copy of the GNU Lesser General      |
  41 --|  Public License along with this source; if not, download it     |
  42 --|  from http://www.opencores.org/lgpl.shtml                       |
  43 --|                                                                                                                             |
  44 --+-----------------------------------------------------------------+
  45
  46
  47 --+-----------------------------------------------------------------------------+
  48 --|                                                                     LIBRARIES                                                                       |
  49 --+-----------------------------------------------------------------------------+
  50
  51 library ieee;
  52 use ieee.std_logic_1164.all;
  53
  54
  55 --+-----------------------------------------------------------------------------+
  56 --|                                                                     ENTITY                                                                          |
  57 --+-----------------------------------------------------------------------------+
  58
  59 entity pciwbsequ is
  60 port (
  61
  62         -- General
  63     clk_i               : in std_logic;
  64         nrst_i          : in std_logic;
  65         -- pci
  66         --adr_i
  67         cmd_i                   : in std_logic_vector(3 downto 0);
  68         cbe_i                   : in std_logic_vector(3 downto 0);
  69         frame_i                 : in std_logic;
  70         irdy_i          : in std_logic;
  71         devsel_o                : out std_logic;
  72         trdy_o          : out std_logic;
  73         -- control
  74         adrcfg_i                : in std_logic;
  75         adrmem_i                : in std_logic;
  76         pciadrLD_o              : out std_logic;
  77         pcidOE_o                : out std_logic;
  78         parOE_o                 : out std_logic;
  79         wbdatLD_o       : out std_logic;
  80         wbrgdMX_o       : out std_logic;
  81         wbd16MX_o       : out std_logic;
  82         wrcfg_o                 : out std_logic;
  83         rdcfg_o                 : out std_logic;
  84         -- whisbone
  85         wb_sel_o                : out std_logic_vector(1 downto 0);
  86         wb_we_o                 : out std_logic;
  87         wb_stb_o                : inout std_logic;
  88         wb_cyc_o                : out std_logic;
  89         wb_ack_i                : in std_logic;
  90         wb_err_i                : in std_logic;
  91         -- debug signals
  92         debug_init       : out std_logic;
  93         debug_access : out std_logic
  94 );
  95 end pciwbsequ;
  96
  97
  98 architecture rtl of pciwbsequ is
  99
 100
 101 --+-----------------------------------------------------------------------------+
 102 --|                                                                     COMPONENTS                                                                      |
 103 --+-----------------------------------------------------------------------------+
 104 --+-----------------------------------------------------------------------------+
 105 --|                                                                     CONSTANTS                                                                       |
 106 --+-----------------------------------------------------------------------------+
 107 --+-----------------------------------------------------------------------------+
 108 --|                                                                     SIGNALS                                                                         |
 109 --+-----------------------------------------------------------------------------+
 110
 111         type PciFSM is ( PCIIDLE, B_BUSY, S_DATA1, S_DATA2, TURN_AR );
 112         signal pst_pci          : PciFSM;
 113         signal nxt_pci          : PciFSM;
 114
 115         signal sdata1           : std_logic;
 116         signal sdata2           : std_logic;
 117         signal idleNX           : std_logic;
 118         signal sdata1NX         : std_logic;
 119         signal sdata2NX         : std_logic;
 120         signal turnarNX         : std_logic;
 121         signal idle                     : std_logic;
 122         signal devselNX_n       : std_logic;
 123         signal trdyNX_n         : std_logic;
 124         signal devsel           : std_logic;
 125         signal trdy                     : std_logic;
 126         signal adrpci           : std_logic;
 127         signal acking           : std_logic;
 128         signal rdcfg            : std_logic;
 129         signal targOE           : std_logic;
 130         signal pcidOE           : std_logic;
 131
 132
 133 begin
 134
 135     --+-------------------------------------------------------------------------+
 136     --|  PCI-Whisbone Sequencer                                                                                                 |
 137     --+-------------------------------------------------------------------------+
 138
 139
 140     --+-------------------------------------------------------------+
 141         --|  FSM PCI-Whisbone                                                                                   |
 142     --+-------------------------------------------------------------+
 143
 144         PCIFSM_CLOCKED: process( nrst_i, clk_i, nxt_pci )
 145         begin
 146
 147         if( nrst_i = '0' ) then
 148                         pst_pci <= PCIIDLE;
 149                 elsif( rising_edge(clk_i) ) then
 150                         pst_pci <= nxt_pci;
 151         end if;
 152
 153         end process PCIFSM_CLOCKED;
 154
 155
 156         PCIFSM_COMB: process( pst_pci, frame_i, irdy_i, adrcfg_i, adrpci, acking )
 157         begin
 158
 159                 devselNX_n      <= '1';
 160                 trdyNX_n        <= '1';
 161         case pst_pci is
 162
 163                 when PCIIDLE =>
 164                         if ( frame_i = '0' ) then
 165                                         nxt_pci <= B_BUSY;
 166                                 else
 167                                         nxt_pci <= PCIIDLE;
 168                                 end if;
 169
 170             when B_BUSY =>
 171                                 if ( adrpci = '0' ) then
 172                                         nxt_pci <= TURN_AR;
 173                                 else
 174                                         nxt_pci <= S_DATA1;
 175                                         devselNX_n <= '0';
 176                                 end if;
 177
 178                     when S_DATA1 =>
 179                         if ( acking = '1' ) then
 180                                         nxt_pci         <= S_DATA2;
 181                                         devselNX_n      <= '0';
 182                                         trdyNX_n        <= '0';
 183                                 else
 184                                         nxt_pci <= S_DATA1;
 185                                         devselNX_n <= '0';
 186                                 end if;
 187
 188                     when S_DATA2 =>
 189                         if ( frame_i = '1' and irdy_i = '0' ) then
 190                                         nxt_pci <= TURN_AR;
 191                                 else
 192                                         nxt_pci <= S_DATA2;
 193                                         devselNX_n <= '0';
 194                                         trdyNX_n <= '0';
 195                                 end if;
 196
 197                         when TURN_AR =>
 198                                 if ( frame_i = '1' ) then
 199                                         nxt_pci <= PCIIDLE;
 200                                 else
 201                                         nxt_pci <= TURN_AR;
 202                                 end if;
 203
 204             end case;
 205
 206         end process PCIFSM_COMB;
 207
 208
 209     --+-------------------------------------------------------------+
 210         --|  FSM control signals                                                                                |
 211     --+-------------------------------------------------------------+
 212
 213         adrpci <= adrmem_i or adrcfg_i;
 214         acking <= '1' when ( wb_ack_i = '1' or wb_err_i = '1' ) or ( adrcfg_i = '1' and  irdy_i = '0')
 215                                   else '0';
 216
 217
 218     --+-------------------------------------------------------------+
 219         --|  FSM derived Control signals                                                                |
 220     --+-------------------------------------------------------------+
 221         idle            <= '1' when ( pst_pci = PCIIDLE ) else '0';
 222         sdata1          <= '1' when ( pst_pci = S_DATA1 ) else '0';
 223         sdata2          <= '1' when ( pst_pci = S_DATA2 ) else '0';
 224         idleNX          <= '1' when ( nxt_pci = PCIIDLE ) else '0';
 225         sdata1NX        <= '1' when ( nxt_pci = S_DATA1 ) else '0';
 226         sdata2NX        <= '1' when ( nxt_pci = S_DATA2 ) else '0';
 227         turnarNX        <= '1' when ( nxt_pci = TURN_AR ) else '0';
 228
 229
 230
 231     --+-------------------------------------------------------------+
 232         --|  PCI Data Output Enable                                                                             |
 233     --+-------------------------------------------------------------+
 234
 235         PCIDOE_P: process( nrst_i, clk_i, cmd_i(0), sdata1NX, turnarNX )
 236         begin
 237
 238         if ( nrst_i = '0' ) then
 239                         pcidOE <= '0';
 240                 elsif ( rising_edge(clk_i) ) then
 241
 242                         if ( sdata1NX = '1' and cmd_i(0) = '0' ) then
 243                                 pcidOE <= '1';
 244                         elsif ( turnarNX = '1' ) then
 245                                 pcidOE <= '0';
 246                         end if;
 247
 248         end if;
 249
 250         end process PCIDOE_P;
 251
 252         pcidOE_o <= pcidOE;
 253
 254
 255     --+-------------------------------------------------------------+
 256         --|  PAR Output Enable                                                                                  |
 257         --|  PCI Read data phase                                                                                |
 258         --|  PAR is valid 1 cicle after data is valid                                   |
 259     --+-------------------------------------------------------------+
 260
 261         PAROE_P: process( nrst_i, clk_i, cmd_i(0), sdata2NX, turnarNX )
 262         begin
 263
 264         if ( nrst_i = '0' ) then
 265                         parOE_o <= '0';
 266                 elsif ( rising_edge(clk_i) ) then
 267
 268                         if ( ( sdata2NX = '1' or turnarNX = '1' ) and cmd_i(0) = '0' ) then
 269                                 parOE_o <= '1';
 270                         else
 271                                 parOE_o <= '0';
 272                         end if;
 273
 274         end if;
 275
 276         end process PAROE_P;
 277
 278
 279     --+-------------------------------------------------------------+
 280         --|  Target s/t/s signals OE control                                                    |
 281     --+-------------------------------------------------------------+
 282
 283 --      targOE <= '1' when ( idle = '0' and adrpci = '1' ) else '0';
 284         TARGOE_P: process( nrst_i, clk_i, sdata1NX, idleNX )
 285         begin
 286
 287         if ( nrst_i = '0' ) then
 288                         targOE <= '0';
 289                 elsif ( rising_edge(clk_i) ) then
 290
 291                         if ( sdata1NX = '1' ) then
 292                                 targOE <= '1';
 293                         elsif ( idleNX = '1' ) then
 294                                 targOE <= '0';
 295                         end if;
 296
 297         end if;
 298
 299         end process TARGOE_P;
 300
 301
 302     --+-------------------------------------------------------------------------+
 303     --|  WHISBONE outs                                                                                                                  |
 304     --+-------------------------------------------------------------------------+
 305
 306         wb_cyc_o <= '1' when ( adrmem_i = '1' and sdata1 = '1' ) else '0';
 307     wb_stb_o <= '1' when ( adrmem_i = '1' and sdata1 = '1' and irdy_i = '0' ) else '0';
 308
 309         -- PCI(Little endian) to WB(Big endian)
 310         wb_sel_o(1) <= (not cbe_i(0)) or (not cbe_i(2));
 311         wb_sel_o(0) <= (not cbe_i(1)) or (not cbe_i(3));
 312         --
 313         wb_we_o <= cmd_i(0);
 314
 315
 316     --+-------------------------------------------------------------------------+
 317         --|  Syncronized PCI outs                                                                                                       |
 318     --+-------------------------------------------------------------------------+
 319
 320         PCISIG: process( nrst_i, clk_i, devselNX_n, trdyNX_n)
 321         begin
 322
 323                 if( nrst_i = '0' ) then
 324                         devsel          <= '1';
 325                         trdy            <= '1';
 326                 elsif( rising_edge(clk_i) ) then
 327
 328                         devsel          <= devselNX_n;
 329                         trdy            <= trdyNX_n;
 330
 331                 end if;
 332
 333         end process PCISIG;
 334
 335         devsel_o <= devsel when ( targOE = '1' ) else 'Z';
 336         trdy_o   <= trdy   when ( targOE = '1' ) else 'Z';
 337
 338
 339     --+-------------------------------------------------------------------------+
 340         --|  Other outs                                                                                                                         |
 341     --+-------------------------------------------------------------------------+
 342
 343         --  rd/wr Configuration Space Registers
 344         wrcfg_o <= '1' when ( adrcfg_i = '1' and cmd_i(0) = '1' and sdata2 = '1' ) else '0';
 345         rdcfg <= '1' when ( adrcfg_i = '1' and cmd_i(0) = '0' and ( sdata1 = '1' or sdata2 = '1' ) ) else '0';
 346         rdcfg_o <= rdcfg;
 347
 348         -- LoaD enable signals
 349         pciadrLD_o <= not frame_i;
 350         wbdatLD_o  <= wb_ack_i;
 351
 352         -- Mux control signals
 353         wbrgdMX_o <= not rdcfg;
 354         wbd16MX_o <= '1' when ( cbe_i(3) = '0' or cbe_i(2) = '0' ) else '0';
 355
 356     --+-------------------------------------------------------------------------+
 357         --|  debug outs                                                                                                                         |
 358     --+-------------------------------------------------------------------------+
 359
 360         process (nrst_i, clk_i)
 361         begin
 362                 if ( nrst_i = '0' ) then
 363                         debug_init <= '0';
 364                         elsif clk_i'event and clk_i = '1' then
 365                                 if devsel = '0' then
 366                                         debug_init <= '1';
 367                                 end if;
 368                 end if;
 369         end process;
 370
 371         process (nrst_i, clk_i)
 372         begin
 373                 if ( nrst_i = '0' ) then
 374                         debug_access <= '0';
 375                         elsif clk_i'event and clk_i = '1' then
 376                                 if wb_stb_o = '1' then
 377                                         debug_access <= '1';
 378                                 end if;
 379                 end if;
 380         end process;
 381
 382 end rtl;