net.mograsim.logic.core/src/net/mograsim/logic/core/wires/Wire.java

   1 package net.mograsim.logic.core.wires;\r
   2 \r
   3 import static net.mograsim.logic.core.types.Bit.U;\r
   4 import static net.mograsim.logic.core.types.Bit.Z;\r
   5 \r
   6 import java.util.ArrayList;\r
   7 import java.util.List;\r
   8 \r
   9 import net.mograsim.logic.core.LogicObservable;\r
  10 import net.mograsim.logic.core.LogicObserver;\r
  11 import net.mograsim.logic.core.timeline.Timeline;\r
  12 import net.mograsim.logic.core.types.Bit;\r
  13 import net.mograsim.logic.core.types.BitVector;\r
  14 import net.mograsim.logic.core.types.BitVector.BitVectorMutator;\r
  15 \r
  16 /**\r
  17  * Represents an array of wires that can store n bits of information.\r
  18  * \r
  19  * @author Fabian Stemmler\r
  20  *\r
  21  */\r
  22 public class Wire\r
  23 {\r
  24         public final String name;\r
  25         private BitVector values;\r
  26         public final int travelTime;\r
  27         private List<ReadEnd> attached = new ArrayList<>();\r
  28         public final int length;\r
  29         List<ReadWriteEnd> inputs = new ArrayList<>();\r
  30         Timeline timeline;\r
  31 \r
  32         public Wire(Timeline timeline, int length, int travelTime)\r
  33         {\r
  34                 this(timeline, length, travelTime, null);\r
  35         }\r
  36 \r
  37         public Wire(Timeline timeline, int length, int travelTime, String name)\r
  38         {\r
  39                 if (length < 1)\r
  40                         throw new IllegalArgumentException(\r
  41                                         String.format("Tried to create an array of wires with length %d, but a length of less than 1 makes no sense.", length));\r
  42                 this.name = name;\r
  43                 this.timeline = timeline;\r
  44                 this.length = length;\r
  45                 this.travelTime = travelTime;\r
  46                 initValues();\r
  47         }\r
  48 \r
  49         private void initValues()\r
  50         {\r
  51                 values = U.toVector(length);\r
  52         }\r
  53 \r
  54         private void recalculateSingleInput()\r
  55         {\r
  56                 setNewValues(inputs.get(0).getInputValues());\r
  57         }\r
  58 \r
  59         private void recalculateMultipleInputs()\r
  60         {\r
  61                 BitVectorMutator mutator = BitVectorMutator.empty();\r
  62                 for (ReadWriteEnd wireArrayEnd : inputs)\r
  63                         mutator.join(wireArrayEnd.getInputValues());\r
  64                 setNewValues(mutator.get());\r
  65         }\r
  66 \r
  67         private void setNewValues(BitVector newValues)\r
  68         {\r
  69                 if (values.equals(newValues))\r
  70                         return;\r
  71 //              BitVector oldValues = values;\r
  72                 values = newValues;\r
  73                 notifyObservers();\r
  74         }\r
  75 \r
  76         void recalculate()\r
  77         {\r
  78                 switch (inputs.size())\r
  79                 {\r
  80                 case 0:\r
  81                         return;\r
  82                 case 1:\r
  83                         recalculateSingleInput();\r
  84                         break;\r
  85                 default:\r
  86                         recalculateMultipleInputs();\r
  87                 }\r
  88         }\r
  89 \r
  90         /**\r
  91          * The {@link Wire} is interpreted as an unsigned integer with n bits.\r
  92          * \r
  93          * @return <code>true</code> if all bits are either <code>Bit.ONE</code> or <code>Bit.ZERO</code> (they do not all have to have the same\r
  94          *         value), not <code>Bit.X</code> or <code>Bit.Z</code>. <code>false</code> is returned otherwise.\r
  95          * \r
  96          * @author Fabian Stemmler\r
  97          */\r
  98         public boolean hasNumericValue()\r
  99         {\r
 100                 for (Bit b : values)\r
 101                 {\r
 102                         if (b != Bit.ZERO && b != Bit.ONE)\r
 103                                 return false;\r
 104                 }\r
 105                 return true;\r
 106         }\r
 107 \r
 108         /**\r
 109          * The {@link Wire} is interpreted as an unsigned integer with n bits.\r
 110          * \r
 111          * @return The unsigned value of the {@link Wire}'s bits, where value 0 corresponds with 2^0, value 1 is 2^1 and so on.\r
 112          * \r
 113          * @author Fabian Stemmler\r
 114          */\r
 115         public long getUnsignedValue()\r
 116         {\r
 117                 long val = 0;\r
 118                 long mask = 1;\r
 119                 for (Bit bit : values)\r
 120                 {\r
 121                         switch (bit)\r
 122                         {\r
 123                         default:\r
 124                         case Z:\r
 125                         case X:\r
 126                                 return 0; // TODO: Proper handling for getUnsignedValue(), if not all bits are 1 or 0;\r
 127                         case ONE:\r
 128                                 val |= mask;\r
 129                                 break;\r
 130                         case ZERO:\r
 131                         }\r
 132                         mask = mask << 1;\r
 133                 }\r
 134                 return val;\r
 135         }\r
 136 \r
 137         /**\r
 138          * The {@link Wire} is interpreted as a signed integer with n bits.\r
 139          * \r
 140          * @return The signed value of the {@link Wire}'s bits, where value 0 corresponds with 2^0, value 1 is 2^1 and so on.\r
 141          * \r
 142          * @author Fabian Stemmler\r
 143          */\r
 144         public long getSignedValue()\r
 145         {\r
 146                 long val = getUnsignedValue();\r
 147                 long mask = 1 << (length - 1);\r
 148                 if ((mask & val) != 0)\r
 149                 {\r
 150                         int shifts = 64 - length;\r
 151                         return (val << shifts) >> shifts;\r
 152                 }\r
 153                 return val;\r
 154         }\r
 155 \r
 156         public Bit getValue()\r
 157         {\r
 158                 return getValue(0);\r
 159         }\r
 160 \r
 161         public Bit getValue(int index)\r
 162         {\r
 163                 return values.getBit(index);\r
 164         }\r
 165 \r
 166         public BitVector getValues(int start, int end)\r
 167         {\r
 168                 return values.subVector(start, end);\r
 169         }\r
 170 \r
 171         public BitVector getValues()\r
 172         {\r
 173                 return values;\r
 174         }\r
 175 \r
 176         /**\r
 177          * Adds an {@link LogicObserver}, who will be notified when the value of the {@link Wire} is updated.\r
 178          * \r
 179          * @param ob The {@link LogicObserver} to be notified of changes.\r
 180          * @return true if the given {@link LogicObserver} was not already registered, false otherwise\r
 181          * \r
 182          * @author Fabian Stemmler\r
 183          */\r
 184         void attachEnd(ReadEnd end)\r
 185         {\r
 186                 attached.add(end);\r
 187         }\r
 188 \r
 189         void detachEnd(ReadEnd end)\r
 190         {\r
 191                 attached.remove(end);\r
 192         }\r
 193 \r
 194         private void notifyObservers()\r
 195         {\r
 196                 attached.forEach(r -> r.update());\r
 197         }\r
 198 \r
 199         /**\r
 200          * Create and register a {@link ReadWriteEnd} object, which is tied to this {@link Wire}. This {@link ReadWriteEnd} can be written to.\r
 201          */\r
 202         public ReadWriteEnd createReadWriteEnd()\r
 203         {\r
 204                 return new ReadWriteEnd();\r
 205         }\r
 206 \r
 207         /**\r
 208          * Create a {@link ReadEnd} object, which is tied to this {@link Wire}. This {@link ReadEnd} cannot be written to.\r
 209          */\r
 210         public ReadEnd createReadOnlyEnd()\r
 211         {\r
 212                 return new ReadEnd();\r
 213         }\r
 214 \r
 215         void registerInput(ReadWriteEnd toRegister)\r
 216         {\r
 217                 inputs.add(toRegister);\r
 218         }\r
 219 \r
 220         /**\r
 221          * A {@link ReadEnd} feeds a constant signal into the {@link Wire} it is tied to. The combination of all inputs determines the\r
 222          * {@link Wire}s final value. X dominates all other inputs Z does not affect the final value, unless there are no other inputs than Z 0\r
 223          * and 1 turn into X when they are mixed\r
 224          * \r
 225          * @author Fabian Stemmler\r
 226          */\r
 227         public class ReadEnd implements LogicObservable\r
 228         {\r
 229                 private List<LogicObserver> observers = new ArrayList<>();\r
 230 \r
 231                 ReadEnd()\r
 232                 {\r
 233                         super();\r
 234                         Wire.this.attachEnd(this);\r
 235                 }\r
 236 \r
 237                 public void update()\r
 238                 {\r
 239                         notifyObservers();\r
 240                 }\r
 241 \r
 242                 /**\r
 243                  * Included for convenient use on {@link Wire}s of length 1.\r
 244                  * \r
 245                  * @return The value of bit 0.\r
 246                  * \r
 247                  * @author Fabian Stemmler\r
 248                  */\r
 249                 public Bit getValue()\r
 250                 {\r
 251                         return Wire.this.getValue();\r
 252                 }\r
 253 \r
 254                 /**\r
 255                  * @param index Index of the requested bit.\r
 256                  * @return The value of the indexed bit.\r
 257                  * \r
 258                  * @author Fabian Stemmler\r
 259                  */\r
 260                 public Bit getValue(int index)\r
 261                 {\r
 262                         return Wire.this.getValue(index);\r
 263                 }\r
 264 \r
 265                 /**\r
 266                  * @param index Index of the requested bit.\r
 267                  * @return The value of the indexed bit.\r
 268                  * \r
 269                  * @author Fabian Stemmler\r
 270                  */\r
 271                 public BitVector getValues()\r
 272                 {\r
 273                         return Wire.this.getValues();\r
 274                 }\r
 275 \r
 276                 /**\r
 277                  * @param start Start of the wanted segment. (inclusive)\r
 278                  * @param end   End of the wanted segment. (exclusive)\r
 279                  * @return The values of the segment of {@link Bit}s indexed.\r
 280                  * \r
 281                  * @author Fabian Stemmler\r
 282                  */\r
 283                 public BitVector getValues(int start, int end)\r
 284                 {\r
 285                         return Wire.this.getValues(start, end);\r
 286                 }\r
 287 \r
 288                 /**\r
 289                  * The {@link Wire} is interpreted as an unsigned integer with n bits.\r
 290                  * \r
 291                  * @return <code>true</code> if all bits are either <code>Bit.ONE</code> or <code>Bit.ZERO</code> (they do not all have to have the\r
 292                  *         same value), not <code>Bit.X</code> or <code>Bit.Z</code>. <code>false</code> is returned otherwise.\r
 293                  * \r
 294                  * @author Fabian Stemmler\r
 295                  */\r
 296                 public boolean hasNumericValue()\r
 297                 {\r
 298                         return Wire.this.hasNumericValue();\r
 299                 }\r
 300 \r
 301                 /**\r
 302                  * The {@link Wire} is interpreted as an unsigned integer with n bits.\r
 303                  * \r
 304                  * @return The unsigned value of the {@link Wire}'s bits, where value 0 corresponds with 2^0, value 1 is 2^1 and so on.\r
 305                  * \r
 306                  * @author Fabian Stemmler\r
 307                  */\r
 308                 public long getUnsignedValue()\r
 309                 {\r
 310                         return Wire.this.getUnsignedValue();\r
 311                 }\r
 312 \r
 313                 /**\r
 314                  * The {@link Wire} is interpreted as a signed integer with n bits.\r
 315                  * \r
 316                  * @return The signed value of the {@link Wire}'s bits, where value 0 corresponds with 2^0, value 1 is 2^1 and so on.\r
 317                  * \r
 318                  * @author Fabian Stemmler\r
 319                  */\r
 320                 public long getSignedValue()\r
 321                 {\r
 322                         return Wire.this.getSignedValue();\r
 323                 }\r
 324 \r
 325                 @Override\r
 326                 public String toString()\r
 327                 {\r
 328                         return Wire.this.toString();\r
 329                 }\r
 330 \r
 331                 public void close()\r
 332                 {\r
 333                         inputs.remove(this);\r
 334                         detachEnd(this);\r
 335                         recalculate();\r
 336                 }\r
 337 \r
 338                 public int length()\r
 339                 {\r
 340                         return length;\r
 341                 }\r
 342 \r
 343                 public Wire getWire()\r
 344                 {\r
 345                         return Wire.this;\r
 346                 }\r
 347 \r
 348                 @Override\r
 349                 public void registerObserver(LogicObserver ob)\r
 350                 {\r
 351                         observers.add(ob);\r
 352                 }\r
 353 \r
 354                 @Override\r
 355                 public void deregisterObserver(LogicObserver ob)\r
 356                 {\r
 357                         observers.remove(ob);\r
 358                 }\r
 359 \r
 360                 @Override\r
 361                 public void notifyObservers()\r
 362                 {\r
 363                         observers.forEach(ob -> ob.update(this));\r
 364                 }\r
 365         }\r
 366 \r
 367         public class ReadWriteEnd extends ReadEnd\r
 368         {\r
 369                 private boolean open;\r
 370                 private BitVector inputValues;\r
 371 \r
 372                 ReadWriteEnd()\r
 373                 {\r
 374                         super();\r
 375                         open = true;\r
 376                         initValues();\r
 377                         registerInput(this);\r
 378                 }\r
 379 \r
 380                 private void initValues()\r
 381                 {\r
 382                         inputValues = U.toVector(length);\r
 383                 }\r
 384 \r
 385                 /**\r
 386                  * Sets the wires values. This takes up time, as specified by the {@link Wire}s travel time.\r
 387                  * \r
 388                  * @param newValues The new values the wires should take on.\r
 389                  * \r
 390                  * @author Fabian Stemmler\r
 391                  */\r
 392                 public void feedSignals(Bit... newValues)\r
 393                 {\r
 394                         feedSignals(BitVector.of(newValues));\r
 395                 }\r
 396 \r
 397                 public void feedSignals(BitVector newValues)\r
 398                 {\r
 399                         if (newValues.length() != length)\r
 400                                 throw new IllegalArgumentException(\r
 401                                                 String.format("Attempted to input %d bits instead of %d bits.", newValues.length(), length));\r
 402                         if (!open)\r
 403                                 throw new RuntimeException("Attempted to write to closed WireArrayEnd.");\r
 404                         timeline.addEvent(e -> setValues(newValues), travelTime);\r
 405                 }\r
 406 \r
 407                 /**\r
 408                  * Sets values of a subarray of wires. This takes up time, as specified by the {@link Wire}s travel time.\r
 409                  * \r
 410                  * @param bitVector   The new values the wires should take on.\r
 411                  * @param startingBit The first index of the subarray of wires.\r
 412                  * \r
 413                  * @author Fabian Stemmler\r
 414                  */\r
 415                 public void feedSignals(int startingBit, BitVector bitVector)\r
 416                 {\r
 417                         if (!open)\r
 418                                 throw new RuntimeException("Attempted to write to closed WireArrayEnd.");\r
 419                         timeline.addEvent(e -> setValues(startingBit, bitVector), travelTime);\r
 420                 }\r
 421 \r
 422                 /**\r
 423                  * Sets the values that are being fed into the {@link Wire}. The preferred way of setting {@link ReadWriteEnd} values is via\r
 424                  * feedValues(...) with a delay.\r
 425                  */\r
 426                 void setValues(int startingBit, BitVector newValues)\r
 427                 {\r
 428                         // index check covered in equals\r
 429                         if (!inputValues.equalsWithOffset(newValues, startingBit))\r
 430                         {\r
 431                                 Bit[] vals = inputValues.getBits();\r
 432                                 System.arraycopy(newValues.getBits(), 0, vals, startingBit, newValues.length());\r
 433                                 inputValues = BitVector.of(vals);\r
 434                                 Wire.this.recalculate();\r
 435                         }\r
 436                 }\r
 437 \r
 438                 /**\r
 439                  * Sets the values that are being fed into the {@link Wire}. The preferred way of setting {@link ReadWriteEnd} values is via\r
 440                  * feedValues(...) with a delay.\r
 441                  */\r
 442                 void setValues(BitVector newValues)\r
 443                 {\r
 444                         if (inputValues.equals(newValues))\r
 445                                 return;\r
 446                         inputValues = newValues;\r
 447                         Wire.this.recalculate();\r
 448                 }\r
 449 \r
 450                 /**\r
 451                  * @return The value (of bit 0) the {@link ReadEnd} is currently feeding into the associated {@link Wire}.\r
 452                  */\r
 453                 public Bit getInputValue()\r
 454                 {\r
 455                         return getInputValue(0);\r
 456                 }\r
 457 \r
 458                 /**\r
 459                  * @return The value which the {@link ReadEnd} is currently feeding into the associated {@link Wire} at the indexed {@link Bit}.\r
 460                  */\r
 461                 public Bit getInputValue(int index)\r
 462                 {\r
 463                         return inputValues.getBit(index);\r
 464                 }\r
 465 \r
 466                 /**\r
 467                  * @return A copy (safe to modify) of the values the {@link ReadEnd} is currently feeding into the associated {@link Wire}.\r
 468                  */\r
 469                 public BitVector getInputValues()\r
 470                 {\r
 471                         return getInputValues(0, length);\r
 472                 }\r
 473 \r
 474                 public BitVector getInputValues(int start, int end)\r
 475                 {\r
 476                         return inputValues.subVector(start, end);\r
 477                 }\r
 478 \r
 479                 /**\r
 480                  * {@link ReadEnd} now feeds Z into the associated {@link Wire}.\r
 481                  */\r
 482                 public void clearSignals()\r
 483                 {\r
 484                         feedSignals(Z.toVector(length));\r
 485                 }\r
 486 \r
 487                 public BitVector wireValuesExcludingMe()\r
 488                 {\r
 489                         BitVectorMutator mutator = BitVectorMutator.empty();\r
 490                         for (ReadWriteEnd wireEnd : inputs)\r
 491                         {\r
 492                                 if (wireEnd == this)\r
 493                                         continue;\r
 494                                 mutator.join(wireEnd.inputValues);\r
 495                         }\r
 496                         return mutator.get();\r
 497                 }\r
 498 \r
 499                 @Override\r
 500                 public String toString()\r
 501                 {\r
 502                         return inputValues.toString();\r
 503                 }\r
 504         }\r
 505 \r
 506         @Override\r
 507         public String toString()\r
 508         {\r
 509                 String name = this.name == null ? String.format("0x%08x", hashCode()) : this.name;\r
 510                 return String.format("wire %s value: %s inputs: %s", name, values, inputs);\r
 511         }\r
 512 \r
 513         public static ReadEnd[] extractEnds(Wire[] w)\r
 514         {\r
 515                 ReadEnd[] inputs = new ReadEnd[w.length];\r
 516                 for (int i = 0; i < w.length; i++)\r
 517                         inputs[i] = w[i].createReadWriteEnd();\r
 518                 return inputs;\r
 519         }\r
 520 \r
 521         /**\r
 522          * @formatter:off\r
 523          * Fuses the selected bits of two wires together. If the bits change in one Wire, the other is changed accordingly immediately.\r
 524          * Warning: The bits are permanently fused together.\r
 525          * @formatter:on\r
 526          * @param a The {@link Wire} to be (partially) fused with b\r
 527          * @param b The {@link Wire} to be (partially) fused with a\r
 528          * @param fromA The first bit of {@link Wire} a to be fused\r
 529          * @param fromB The first bit of {@link Wire} b to be fused\r
 530          * @param length The amount of bits to fuse\r
 531          */\r
 532         public static void fuse(Wire a, Wire b, int fromA, int fromB, int length)\r
 533         {\r
 534                 ReadWriteEnd rA = a.createReadWriteEnd(), rB = b.createReadWriteEnd();\r
 535                 rA.setValues(BitVector.of(Bit.Z, a.length));\r
 536                 rB.setValues(BitVector.of(Bit.Z, b.length));\r
 537                 rA.registerObserver(new Fusion(rB, fromA, fromB, length));\r
 538                 rB.registerObserver(new Fusion(rA, fromB, fromA, length));\r
 539         }\r
 540 \r
 541         /**\r
 542          * @formatter:off\r
 543          * Fuses the selected bits of two wires together. If the bits change in one Wire, the other is changed accordingly immediately.\r
 544          * Warning: The bits are permanently fused together.\r
 545          * @formatter:on\r
 546          * @param a The {@link Wire} to be fused with b\r
 547          * @param b The {@link Wire} to be fused with a\r
 548          */\r
 549         public static void fuse(Wire a, Wire b)\r
 550         {\r
 551                 fuse(a, b, 0, 0, a.length);\r
 552         }\r
 553 \r
 554         private static class Fusion implements LogicObserver\r
 555         {\r
 556                 private ReadWriteEnd target;\r
 557                 int fromSource, fromTarget, length;\r
 558 \r
 559                 public Fusion(ReadWriteEnd target, int fromSource, int fromTarget, int length)\r
 560                 {\r
 561                         this.target = target;\r
 562                         this.fromSource = fromSource;\r
 563                         this.fromTarget = fromTarget;\r
 564                         this.length = length;\r
 565                 }\r
 566 \r
 567                 @Override\r
 568                 public void update(LogicObservable initiator)\r
 569                 {\r
 570                         ReadWriteEnd source = (ReadWriteEnd) initiator;\r
 571                         BitVector targetInput = (source.getWire().inputs.size() > 1)\r
 572                                         ? source.wireValuesExcludingMe().subVector(fromSource, fromSource + length)\r
 573                                         : BitVector.of(Bit.Z, length);\r
 574                         target.setValues(fromTarget, targetInput);\r
 575                 }\r
 576         }\r
 577 }