src/jtag/interface.c

   1 /***************************************************************************
   2  *   Copyright (C) 2005 by Dominic Rath                                    *
   3  *   Dominic.Rath@gmx.de                                                   *
   4  *                                                                         *
   5  *   Copyright (C) 2007,2008 Øyvind Harboe                                 *
   6  *   oyvind.harboe@zylin.com                                               *
   7  *                                                                         *
   8  *   Copyright (C) 2009 SoftPLC Corporation                                *
   9  *       http://softplc.com                                                *
  10  *   dick@softplc.com                                                      *
  11  *                                                                         *
  12  *   Copyright (C) 2009 Zachary T Welch                                    *
  13  *   zw@superlucidity.net                                                  *
  14  *                                                                         *
  15  *   This program is free software; you can redistribute it and/or modify  *
  16  *   it under the terms of the GNU General Public License as published by  *
  17  *   the Free Software Foundation; either version 2 of the License, or     *
  18  *   (at your option) any later version.                                   *
  19  *                                                                         *
  20  *   This program is distributed in the hope that it will be useful,       *
  21  *   but WITHOUT ANY WARRANTY; without even the implied warranty of        *
  22  *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the         *
  23  *   GNU General Public License for more details.                          *
  24  *                                                                         *
  25  *   You should have received a copy of the GNU General Public License     *
  26  *   along with this program; if not, write to the                         *
  27  *   Free Software Foundation, Inc.,                                       *
  28  *   59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.             *
  29  ***************************************************************************/
  30 #ifdef HAVE_CONFIG_H
  31 #include "config.h"
  32 #endif
  33
  34 #include "jtag.h"
  35 #include "interface.h"
  36
  37 /**
  38  * @see tap_set_state() and tap_get_state() accessors.
  39  * Actual name is not important since accessors hide it.
  40  */
  41 static tap_state_t state_follower = TAP_RESET;
  42
  43 void tap_set_state_impl( tap_state_t new_state )
  44 {
  45         /* this is the state we think the TAPs are in now, was cur_state */
  46         state_follower = new_state;
  47 }
  48
  49 tap_state_t tap_get_state()
  50 {
  51         return state_follower;
  52 }
  53
  54 /**
  55  * @see tap_set_end_state() and tap_get_end_state() accessors.
  56  * Actual name is not important because accessors hide it.
  57  */
  58 static tap_state_t end_state_follower = TAP_RESET;
  59
  60 void tap_set_end_state( tap_state_t new_end_state )
  61 {
  62         /* this is the state we think the TAPs will be in at completion of the
  63            current TAP operation, was end_state
  64         */
  65         end_state_follower = new_end_state;
  66 }
  67
  68 tap_state_t tap_get_end_state()
  69 {
  70         return end_state_follower;
  71 }
  72
  73
  74 int tap_move_ndx( tap_state_t astate )
  75 {
  76         /* given a stable state, return the index into the tms_seqs[] array within tap_get_tms_path() */
  77
  78         int ndx;
  79
  80         switch( astate )
  81         {
  82         case TAP_RESET:         ndx = 0;                        break;
  83         case TAP_DRSHIFT:       ndx = 2;                        break;
  84         case TAP_DRPAUSE:       ndx = 3;                        break;
  85         case TAP_IDLE:          ndx = 1;                        break;
  86         case TAP_IRSHIFT:       ndx = 4;                        break;
  87         case TAP_IRPAUSE:       ndx = 5;                        break;
  88         default:
  89                 LOG_ERROR( "fatal: unstable state \"%s\" used in tap_move_ndx()", tap_state_name(astate) );
  90                 exit(1);
  91         }
  92
  93         return ndx;
  94 }
  95
  96
  97 /* tap_move[i][j]: tap movement command to go from state i to state j
  98  * 0: Test-Logic-Reset
  99  * 1: Run-Test/Idle
 100  * 2: Shift-DR
 101  * 3: Pause-DR
 102  * 4: Shift-IR
 103  * 5: Pause-IR
 104  *
 105  * DRSHIFT->DRSHIFT and IRSHIFT->IRSHIFT have to be caught in interface specific code
 106  */
 107 struct tms_sequences
 108 {
 109         uint8_t bits;
 110         uint8_t bit_count;
 111
 112 };
 113
 114 /*
 115  * These macros allow us to specify TMS state transitions by bits rather than hex bytes.
 116  * Read the bits from LSBit first to MSBit last (right-to-left).
 117  */
 118 #define HEX__(n) 0x##n##LU
 119
 120 #define B8__(x) \
 121          (((x) & 0x0000000FLU)?(1<<0):0) \
 122         +(((x) & 0x000000F0LU)?(1<<1):0) \
 123         +(((x) & 0x00000F00LU)?(1<<2):0) \
 124         +(((x) & 0x0000F000LU)?(1<<3):0) \
 125         +(((x) & 0x000F0000LU)?(1<<4):0) \
 126         +(((x) & 0x00F00000LU)?(1<<5):0) \
 127         +(((x) & 0x0F000000LU)?(1<<6):0) \
 128         +(((x) & 0xF0000000LU)?(1<<7):0)
 129
 130 #define B8(bits,count)          { ((uint8_t)B8__(HEX__(bits))), (count) }
 131
 132 static const struct tms_sequences old_tms_seqs[6][6] =          /*  [from_state_ndx][to_state_ndx] */
 133 {
 134         /* value clocked to TMS to move from one of six stable states to another.
 135          * N.B. OOCD clocks TMS from LSB first, so read these right-to-left.
 136          * N.B. These values are tightly bound to the table in tap_get_tms_path_len().
 137          * N.B. Reset only needs to be 0b11111, but in JLink an even byte of 1's is more stable.
 138          * These extra ones cause no TAP state problem, because we go into reset and stay in reset.
 139          */
 140
 141
 142
 143         /* to state: */
 144         /*      RESET                   IDLE                    DRSHIFT                 DRPAUSE                 IRSHIFT                 IRPAUSE         */              /* from state: */
 145         {       B8(1111111,7),  B8(0000000,7),  B8(0010111,7),  B8(0001010,7),  B8(0011011,7),  B8(0010110,7) },        /* RESET */
 146         {       B8(1111111,7),  B8(0000000,7),  B8(0100101,7),  B8(0000101,7),  B8(0101011,7),  B8(0001011,7) },        /* IDLE */
 147         {       B8(1111111,7),  B8(0110001,7),  B8(0000000,7),  B8(0000001,7),  B8(0001111,7),  B8(0101111,7) },        /* DRSHIFT */
 148         {       B8(1111111,7),  B8(0110000,7),  B8(0100000,7),  B8(0010111,7),  B8(0011110,7),  B8(0101111,7) },        /* DRPAUSE */
 149         {       B8(1111111,7),  B8(0110001,7),  B8(0000111,7),  B8(0010111,7),  B8(0000000,7),  B8(0000001,7) },        /* IRSHIFT */
 150         {       B8(1111111,7),  B8(0110000,7),  B8(0011100,7),  B8(0010111,7),  B8(0011110,7),  B8(0101111,7) },        /* IRPAUSE */
 151 };
 152
 153
 154
 155 static const struct tms_sequences short_tms_seqs[6][6] =                /*  [from_state_ndx][to_state_ndx] */
 156 {
 157         /* this is the table submitted by Jeff Williams on 3/30/2009 with this comment:
 158
 159                 OK, I added Peter's version of the state table, and it works OK for
 160                 me on MC1322x. I've recreated the jlink portion of patch with this
 161                 new state table. His changes to my state table are pretty minor in
 162                 terms of total transitions, but Peter feels that his version fixes
 163                 some long-standing problems.
 164                 Jeff
 165
 166                 I added the bit count into the table, reduced RESET column to 7 bits from 8.
 167                 Dick
 168
 169                 state specific comments:
 170                 ------------------------
 171                 *->RESET                   tried the 5 bit reset and it gave me problems, 7 bits seems to
 172                                            work better on ARM9 with ft2232 driver.  (Dick)
 173
 174                 RESET->DRSHIFT add 1 extra clock cycles in the RESET state before advancing.
 175                                                 needed on ARM9 with ft2232 driver.  (Dick)
 176
 177                 RESET->IRSHIFT add 1 extra clock cycles in the RESET state before advancing.
 178                                                 needed on ARM9 with ft2232 driver.  (Dick)
 179         */
 180
 181         /* to state: */
 182         /*      RESET                   IDLE                            DRSHIFT                 DRPAUSE                 IRSHIFT                 IRPAUSE */                      /* from state: */
 183         {       B8(1111111,7),  B8(0000000,7),  B8(0010111,7),          B8(0001010,7),  B8(0011011,7),  B8(0010110,7) },        /* RESET */
 184         {       B8(1111111,7),  B8(0000000,7),  B8(001,3),                      B8(0101,4),             B8(0011,4),     B8(01011,5) },          /* IDLE */
 185         {       B8(1111111,7),  B8(011,3),              B8(00111,5),            B8(01,2),               B8(001111,6),   B8(0101111,7) },        /* DRSHIFT */
 186         {       B8(1111111,7),  B8(011,3),              B8(01,2),               B8(0,1),                B8(001111,6),   B8(0101111,7) },        /* DRPAUSE */
 187         {       B8(1111111,7),  B8(011,3),              B8(00111,5),            B8(010111,6),   B8(001111,6),   B8(01,2) },                     /* IRSHIFT */
 188         {       B8(1111111,7),  B8(011,3),              B8(00111,5),            B8(010111,6),   B8(01,2),               B8(0,1) }                       /* IRPAUSE */
 189
 190 };
 191
 192 typedef const struct tms_sequences tms_table[6][6];
 193
 194 static tms_table *tms_seqs=&short_tms_seqs;
 195
 196 int tap_get_tms_path( tap_state_t from, tap_state_t to )
 197 {
 198         return (*tms_seqs)[tap_move_ndx(from)][tap_move_ndx(to)].bits;
 199 }
 200
 201
 202 int tap_get_tms_path_len( tap_state_t from, tap_state_t to )
 203 {
 204         return (*tms_seqs)[tap_move_ndx(from)][tap_move_ndx(to)].bit_count;
 205 }
 206
 207
 208 bool tap_is_state_stable(tap_state_t astate)
 209 {
 210         bool is_stable;
 211
 212         /*      A switch() is used because it is symbol dependent
 213                 (not value dependent like an array), and can also check bounds.
 214         */
 215         switch( astate )
 216         {
 217         case TAP_RESET:
 218         case TAP_IDLE:
 219         case TAP_DRSHIFT:
 220         case TAP_DRPAUSE:
 221         case TAP_IRSHIFT:
 222         case TAP_IRPAUSE:
 223                 is_stable = true;
 224                 break;
 225         default:
 226                 is_stable = false;
 227         }
 228
 229         return is_stable;
 230 }
 231
 232 tap_state_t tap_state_transition(tap_state_t cur_state, bool tms)
 233 {
 234         tap_state_t new_state;
 235
 236         /*      A switch is used because it is symbol dependent and not value dependent
 237                 like an array.  Also it can check for out of range conditions.
 238         */
 239
 240         if (tms)
 241         {
 242                 switch (cur_state)
 243                 {
 244                 case TAP_RESET:
 245                         new_state = cur_state;
 246                         break;
 247                 case TAP_IDLE:
 248                 case TAP_DRUPDATE:
 249                 case TAP_IRUPDATE:
 250                         new_state = TAP_DRSELECT;
 251                         break;
 252                 case TAP_DRSELECT:
 253                         new_state = TAP_IRSELECT;
 254                         break;
 255                 case TAP_DRCAPTURE:
 256                 case TAP_DRSHIFT:
 257                         new_state = TAP_DREXIT1;
 258                         break;
 259                 case TAP_DREXIT1:
 260                 case TAP_DREXIT2:
 261                         new_state = TAP_DRUPDATE;
 262                         break;
 263                 case TAP_DRPAUSE:
 264                         new_state = TAP_DREXIT2;
 265                         break;
 266                 case TAP_IRSELECT:
 267                         new_state = TAP_RESET;
 268                         break;
 269                 case TAP_IRCAPTURE:
 270                 case TAP_IRSHIFT:
 271                         new_state = TAP_IREXIT1;
 272                         break;
 273                 case TAP_IREXIT1:
 274                 case TAP_IREXIT2:
 275                         new_state = TAP_IRUPDATE;
 276                         break;
 277                 case TAP_IRPAUSE:
 278                         new_state = TAP_IREXIT2;
 279                         break;
 280                 default:
 281                         LOG_ERROR( "fatal: invalid argument cur_state=%d", cur_state );
 282                         exit(1);
 283                         break;
 284                 }
 285         }
 286         else
 287         {
 288                 switch (cur_state)
 289                 {
 290                 case TAP_RESET:
 291                 case TAP_IDLE:
 292                 case TAP_DRUPDATE:
 293                 case TAP_IRUPDATE:
 294                         new_state = TAP_IDLE;
 295                         break;
 296                 case TAP_DRSELECT:
 297                         new_state = TAP_DRCAPTURE;
 298                         break;
 299                 case TAP_DRCAPTURE:
 300                 case TAP_DRSHIFT:
 301                 case TAP_DREXIT2:
 302                         new_state = TAP_DRSHIFT;
 303                         break;
 304                 case TAP_DREXIT1:
 305                 case TAP_DRPAUSE:
 306                         new_state = TAP_DRPAUSE;
 307                         break;
 308                 case TAP_IRSELECT:
 309                         new_state = TAP_IRCAPTURE;
 310                         break;
 311                 case TAP_IRCAPTURE:
 312                 case TAP_IRSHIFT:
 313                 case TAP_IREXIT2:
 314                         new_state = TAP_IRSHIFT;
 315                         break;
 316                 case TAP_IREXIT1:
 317                 case TAP_IRPAUSE:
 318                         new_state = TAP_IRPAUSE;
 319                         break;
 320                 default:
 321                         LOG_ERROR( "fatal: invalid argument cur_state=%d", cur_state );
 322                         exit(1);
 323                         break;
 324                 }
 325         }
 326
 327         return new_state;
 328 }
 329
 330 const char* tap_state_name(tap_state_t state)
 331 {
 332         const char* ret;
 333
 334         switch( state )
 335         {
 336         case TAP_RESET:         ret = "RESET";                  break;
 337         case TAP_IDLE:          ret = "RUN/IDLE";               break;
 338         case TAP_DRSELECT:      ret = "DRSELECT";               break;
 339         case TAP_DRCAPTURE: ret = "DRCAPTURE";          break;
 340         case TAP_DRSHIFT:       ret = "DRSHIFT";                        break;
 341         case TAP_DREXIT1:       ret = "DREXIT1";                        break;
 342         case TAP_DRPAUSE:       ret = "DRPAUSE";                        break;
 343         case TAP_DREXIT2:       ret = "DREXIT2";                        break;
 344         case TAP_DRUPDATE:      ret = "DRUPDATE";               break;
 345         case TAP_IRSELECT:      ret = "IRSELECT";               break;
 346         case TAP_IRCAPTURE: ret = "IRCAPTURE";          break;
 347         case TAP_IRSHIFT:       ret = "IRSHIFT";                        break;
 348         case TAP_IREXIT1:       ret = "IREXIT1";                        break;
 349         case TAP_IRPAUSE:       ret = "IRPAUSE";                        break;
 350         case TAP_IREXIT2:       ret = "IREXIT2";                        break;
 351         case TAP_IRUPDATE:      ret = "IRUPDATE";               break;
 352         default:                                ret = "???";
 353         }
 354
 355         return ret;
 356 }
 357
 358 tap_state_t tap_state_by_name(const char *name)
 359 {
 360         tap_state_t x;
 361
 362         for( x = 0 ; x < TAP_NUM_STATES ; x++ ){
 363                 /* be nice to the human */
 364                 if( 0 == strcasecmp( name, tap_state_name(x) ) ){
 365                         return x;
 366                 }
 367         }
 368         /* not found */
 369         return TAP_INVALID;
 370 }
 371
 372 #ifdef _DEBUG_JTAG_IO_
 373
 374 #define JTAG_DEBUG_STATE_APPEND(buf, len, bit) \
 375                 do { buf[len] = bit ? '1' : '0'; } while(0)
 376 #define JTAG_DEBUG_STATE_PRINT(a, b, astr, bstr) \
 377                 DEBUG_JTAG_IO("TAP/SM: %9s -> %5s\tTMS: %s\tTDI: %s", \
 378                         tap_state_name(a), tap_state_name(b), astr, bstr)
 379
 380 tap_state_t jtag_debug_state_machine(const void *tms_buf, const void *tdi_buf,
 381                 unsigned tap_bits, tap_state_t next_state)
 382 {
 383         const uint8_t *tms_buffer;
 384         const uint8_t *tdi_buffer;
 385         unsigned tap_bytes;
 386         unsigned cur_byte;
 387         unsigned cur_bit;
 388
 389         unsigned tap_out_bits;
 390         char tms_str[33];
 391         char tdi_str[33];
 392
 393         tap_state_t last_state;
 394
 395         // set startstate (and possibly last, if tap_bits == 0)
 396         last_state = next_state;
 397         DEBUG_JTAG_IO("TAP/SM: START state: %s", tap_state_name(next_state));
 398
 399         tms_buffer = (const uint8_t *)tms_buf;
 400         tdi_buffer = (const uint8_t *)tdi_buf;
 401
 402         tap_bytes = TAP_SCAN_BYTES(tap_bits);
 403         DEBUG_JTAG_IO("TAP/SM: TMS bits: %u (bytes: %u)", tap_bits, tap_bytes);
 404
 405         tap_out_bits = 0;
 406         for(cur_byte = 0; cur_byte < tap_bytes; cur_byte++)
 407         {
 408                 for(cur_bit = 0; cur_bit < 8; cur_bit++)
 409                 {
 410                         // make sure we do not run off the end of the buffers
 411                         unsigned tap_bit = cur_byte * 8 + cur_bit;
 412                         if (tap_bit == tap_bits)
 413                                 break;
 414
 415                         // check and save TMS bit
 416                         tap_bit = !!(tms_buffer[cur_byte] & (1 << cur_bit));
 417                         JTAG_DEBUG_STATE_APPEND(tms_str, tap_out_bits, tap_bit);
 418
 419                         // use TMS bit to find the next TAP state
 420                         next_state = tap_state_transition(last_state, tap_bit);
 421
 422                         // check and store TDI bit
 423                         tap_bit = !!(tdi_buffer[cur_byte] & (1 << cur_bit));
 424                         JTAG_DEBUG_STATE_APPEND(tdi_str, tap_out_bits, tap_bit);
 425
 426                         // increment TAP bits
 427                         tap_out_bits++;
 428
 429                         // Only show TDO bits on state transitions, or
 430                         // after some number of bits in the same state.
 431                         if ((next_state == last_state) && (tap_out_bits < 32))
 432                                 continue;
 433
 434                         // terminate strings and display state transition
 435                         tms_str[tap_out_bits] = tdi_str[tap_out_bits] = 0;
 436                         JTAG_DEBUG_STATE_PRINT(last_state, next_state, tms_str, tdi_str);
 437
 438                         // reset state
 439                         last_state = next_state;
 440                         tap_out_bits = 0;
 441                 }
 442         }
 443
 444         if (tap_out_bits)
 445         {
 446                 // terminate strings and display state transition
 447                 tms_str[tap_out_bits] = tdi_str[tap_out_bits] = 0;
 448                 JTAG_DEBUG_STATE_PRINT(last_state, next_state, tms_str, tdi_str);
 449         }
 450
 451         DEBUG_JTAG_IO("TAP/SM: FINAL state: %s", tap_state_name(next_state));
 452
 453         return next_state;
 454 }
 455 #endif // _DEBUG_JTAG_IO_
 456
 457 void tap_use_new_tms_table(bool use_new)
 458 {
 459         tms_seqs = use_new ? &short_tms_seqs : &old_tms_seqs;
 460 }
 461 bool tap_uses_new_tms_table(void)
 462 {
 463         return tms_seqs == &short_tms_seqs;
 464 }
 465