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                         setNewValues(BitVector.of(Bit.U, length));\r
  82                         break;\r
  83                 case 1:\r
  84                         recalculateSingleInput();\r
  85                         break;\r
  86                 default:\r
  87                         recalculateMultipleInputs();\r
  88                 }\r
  89         }\r
  90 \r
  91         /**\r
  92          * The {@link Wire} is interpreted as an unsigned integer with n bits.\r
  93          * \r
  94          * @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
  95          *         value), not <code>Bit.X</code> or <code>Bit.Z</code>. <code>false</code> is returned otherwise.\r
  96          * \r
  97          * @author Fabian Stemmler\r
  98          */\r
  99         public boolean hasNumericValue()\r
 100         {\r
 101                 for (Bit b : values)\r
 102                 {\r
 103                         if (b != Bit.ZERO && b != Bit.ONE)\r
 104                                 return false;\r
 105                 }\r
 106                 return true;\r
 107         }\r
 108 \r
 109         /**\r
 110          * The {@link Wire} is interpreted as an unsigned integer with n bits.\r
 111          * \r
 112          * @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
 113          * \r
 114          * @author Fabian Stemmler\r
 115          */\r
 116         public long getUnsignedValue()\r
 117         {\r
 118                 long val = 0;\r
 119                 long mask = 1;\r
 120                 for (Bit bit : values)\r
 121                 {\r
 122                         switch (bit)\r
 123                         {\r
 124                         default:\r
 125                         case Z:\r
 126                         case X:\r
 127                                 return 0; // TODO: Proper handling for getUnsignedValue(), if not all bits are 1 or 0;\r
 128                         case ONE:\r
 129                                 val |= mask;\r
 130                                 break;\r
 131                         case ZERO:\r
 132                         }\r
 133                         mask = mask << 1;\r
 134                 }\r
 135                 return val;\r
 136         }\r
 137 \r
 138         /**\r
 139          * The {@link Wire} is interpreted as a signed integer with n bits.\r
 140          * \r
 141          * @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
 142          * \r
 143          * @author Fabian Stemmler\r
 144          */\r
 145         public long getSignedValue()\r
 146         {\r
 147                 long val = getUnsignedValue();\r
 148                 long mask = 1 << (length - 1);\r
 149                 if ((mask & val) != 0)\r
 150                 {\r
 151                         int shifts = 64 - length;\r
 152                         return (val << shifts) >> shifts;\r
 153                 }\r
 154                 return val;\r
 155         }\r
 156 \r
 157         public Bit getValue()\r
 158         {\r
 159                 return getValue(0);\r
 160         }\r
 161 \r
 162         public Bit getValue(int index)\r
 163         {\r
 164                 return values.getBit(index);\r
 165         }\r
 166 \r
 167         public BitVector getValues(int start, int end)\r
 168         {\r
 169                 return values.subVector(start, end);\r
 170         }\r
 171 \r
 172         public BitVector getValues()\r
 173         {\r
 174                 return values;\r
 175         }\r
 176 \r
 177         /**\r
 178          * Adds an {@link LogicObserver}, who will be notified when the value of the {@link Wire} is updated.\r
 179          * \r
 180          * @param ob The {@link LogicObserver} to be notified of changes.\r
 181          * @return true if the given {@link LogicObserver} was not already registered, false otherwise\r
 182          * \r
 183          * @author Fabian Stemmler\r
 184          */\r
 185         void attachEnd(ReadEnd end)\r
 186         {\r
 187                 attached.add(end);\r
 188         }\r
 189 \r
 190         void detachEnd(ReadEnd end)\r
 191         {\r
 192                 attached.remove(end);\r
 193         }\r
 194 \r
 195         private void notifyObservers()\r
 196         {\r
 197                 attached.forEach(r -> r.update());\r
 198         }\r
 199 \r
 200         /**\r
 201          * Create and register a {@link ReadWriteEnd} object, which is tied to this {@link Wire}. This {@link ReadWriteEnd} can be written to.\r
 202          */\r
 203         public ReadWriteEnd createReadWriteEnd()\r
 204         {\r
 205                 return new ReadWriteEnd();\r
 206         }\r
 207 \r
 208         /**\r
 209          * Create a {@link ReadEnd} object, which is tied to this {@link Wire}. This {@link ReadEnd} cannot be written to.\r
 210          */\r
 211         public ReadEnd createReadOnlyEnd()\r
 212         {\r
 213                 return new ReadEnd();\r
 214         }\r
 215 \r
 216         void registerInput(ReadWriteEnd toRegister)\r
 217         {\r
 218                 inputs.add(toRegister);\r
 219         }\r
 220 \r
 221         /**\r
 222          * A {@link ReadEnd} feeds a constant signal into the {@link Wire} it is tied to. The combination of all inputs determines the\r
 223          * {@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
 224          * and 1 turn into X when they are mixed\r
 225          * \r
 226          * @author Fabian Stemmler\r
 227          */\r
 228         public class ReadEnd implements LogicObservable\r
 229         {\r
 230                 private List<LogicObserver> observers = new ArrayList<>();\r
 231 \r
 232                 ReadEnd()\r
 233                 {\r
 234                         super();\r
 235                         Wire.this.attachEnd(this);\r
 236                 }\r
 237 \r
 238                 public void update()\r
 239                 {\r
 240                         notifyObservers();\r
 241                 }\r
 242 \r
 243                 /**\r
 244                  * Included for convenient use on {@link Wire}s of length 1.\r
 245                  * \r
 246                  * @return The value of bit 0.\r
 247                  * \r
 248                  * @author Fabian Stemmler\r
 249                  */\r
 250                 public Bit getValue()\r
 251                 {\r
 252                         return Wire.this.getValue();\r
 253                 }\r
 254 \r
 255                 /**\r
 256                  * @param index Index of the requested bit.\r
 257                  * @return The value of the indexed bit.\r
 258                  * \r
 259                  * @author Fabian Stemmler\r
 260                  */\r
 261                 public Bit getValue(int index)\r
 262                 {\r
 263                         return Wire.this.getValue(index);\r
 264                 }\r
 265 \r
 266                 /**\r
 267                  * @param index Index of the requested bit.\r
 268                  * @return The value of the indexed bit.\r
 269                  * \r
 270                  * @author Fabian Stemmler\r
 271                  */\r
 272                 public BitVector getValues()\r
 273                 {\r
 274                         return Wire.this.getValues();\r
 275                 }\r
 276 \r
 277                 /**\r
 278                  * @param start Start of the wanted segment. (inclusive)\r
 279                  * @param end   End of the wanted segment. (exclusive)\r
 280                  * @return The values of the segment of {@link Bit}s indexed.\r
 281                  * \r
 282                  * @author Fabian Stemmler\r
 283                  */\r
 284                 public BitVector getValues(int start, int end)\r
 285                 {\r
 286                         return Wire.this.getValues(start, end);\r
 287                 }\r
 288 \r
 289                 /**\r
 290                  * The {@link Wire} is interpreted as an unsigned integer with n bits.\r
 291                  * \r
 292                  * @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
 293                  *         same value), not <code>Bit.X</code> or <code>Bit.Z</code>. <code>false</code> is returned otherwise.\r
 294                  * \r
 295                  * @author Fabian Stemmler\r
 296                  */\r
 297                 public boolean hasNumericValue()\r
 298                 {\r
 299                         return Wire.this.hasNumericValue();\r
 300                 }\r
 301 \r
 302                 /**\r
 303                  * The {@link Wire} is interpreted as an unsigned integer with n bits.\r
 304                  * \r
 305                  * @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
 306                  * \r
 307                  * @author Fabian Stemmler\r
 308                  */\r
 309                 public long getUnsignedValue()\r
 310                 {\r
 311                         return Wire.this.getUnsignedValue();\r
 312                 }\r
 313 \r
 314                 /**\r
 315                  * The {@link Wire} is interpreted as a signed integer with n bits.\r
 316                  * \r
 317                  * @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
 318                  * \r
 319                  * @author Fabian Stemmler\r
 320                  */\r
 321                 public long getSignedValue()\r
 322                 {\r
 323                         return Wire.this.getSignedValue();\r
 324                 }\r
 325 \r
 326                 @Override\r
 327                 public String toString()\r
 328                 {\r
 329                         return Wire.this.toString();\r
 330                 }\r
 331 \r
 332                 public void close()\r
 333                 {\r
 334                         inputs.remove(this);\r
 335                         detachEnd(this);\r
 336                         recalculate();\r
 337                 }\r
 338 \r
 339                 public int length()\r
 340                 {\r
 341                         return length;\r
 342                 }\r
 343 \r
 344                 public Wire getWire()\r
 345                 {\r
 346                         return Wire.this;\r
 347                 }\r
 348 \r
 349                 @Override\r
 350                 public void registerObserver(LogicObserver ob)\r
 351                 {\r
 352                         observers.add(ob);\r
 353                 }\r
 354 \r
 355                 @Override\r
 356                 public void deregisterObserver(LogicObserver ob)\r
 357                 {\r
 358                         observers.remove(ob);\r
 359                 }\r
 360 \r
 361                 @Override\r
 362                 public void notifyObservers()\r
 363                 {\r
 364                         observers.forEach(ob -> ob.update(this));\r
 365                 }\r
 366         }\r
 367 \r
 368         public class ReadWriteEnd extends ReadEnd\r
 369         {\r
 370                 private boolean open, isWriting;\r
 371                 private BitVector inputValues;\r
 372 \r
 373                 ReadWriteEnd()\r
 374                 {\r
 375                         super();\r
 376                         open = true;\r
 377                         isWriting = true;\r
 378                         initValues();\r
 379                         registerInput(this);\r
 380                 }\r
 381 \r
 382                 private void initValues()\r
 383                 {\r
 384                         inputValues = U.toVector(length);\r
 385                 }\r
 386 \r
 387                 /**\r
 388                  * Sets the wires values. This takes up time, as specified by the {@link Wire}s travel time.\r
 389                  * \r
 390                  * @param newValues The new values the wires should take on.\r
 391                  * \r
 392                  * @author Fabian Stemmler\r
 393                  */\r
 394                 public void feedSignals(Bit... newValues)\r
 395                 {\r
 396                         feedSignals(BitVector.of(newValues));\r
 397                 }\r
 398 \r
 399                 public void feedSignals(BitVector newValues)\r
 400                 {\r
 401                         if (newValues.length() != length)\r
 402                                 throw new IllegalArgumentException(\r
 403                                                 String.format("Attempted to input %d bits instead of %d bits.", newValues.length(), length));\r
 404                         if (!open)\r
 405                                 throw new RuntimeException("Attempted to write to closed WireArrayEnd.");\r
 406                         timeline.addEvent(e -> setValues(newValues), travelTime);\r
 407                 }\r
 408 \r
 409                 /**\r
 410                  * Sets values of a subarray of wires. This takes up time, as specified by the {@link Wire}s travel time.\r
 411                  * \r
 412                  * @param bitVector   The new values the wires should take on.\r
 413                  * @param startingBit The first index of the subarray of wires.\r
 414                  * \r
 415                  * @author Fabian Stemmler\r
 416                  */\r
 417                 public void feedSignals(int startingBit, BitVector bitVector)\r
 418                 {\r
 419                         if (!open)\r
 420                                 throw new RuntimeException("Attempted to write to closed WireArrayEnd.");\r
 421                         timeline.addEvent(e -> setValues(startingBit, bitVector), travelTime);\r
 422                 }\r
 423 \r
 424                 /**\r
 425                  * Sets the values that are being fed into the {@link Wire}. The preferred way of setting {@link ReadWriteEnd} values is via\r
 426                  * feedValues(...) with a delay.\r
 427                  */\r
 428                 void setValues(int startingBit, BitVector newValues)\r
 429                 {\r
 430                         // index check covered in equals\r
 431                         if (!inputValues.equalsWithOffset(newValues, startingBit))\r
 432                         {\r
 433                                 Bit[] vals = inputValues.getBits();\r
 434                                 System.arraycopy(newValues.getBits(), 0, vals, startingBit, newValues.length());\r
 435                                 inputValues = BitVector.of(vals);\r
 436                                 Wire.this.recalculate();\r
 437                         }\r
 438                 }\r
 439 \r
 440                 /**\r
 441                  * Sets the values that are being fed into the {@link Wire}. The preferred way of setting {@link ReadWriteEnd} values is via\r
 442                  * feedValues(...) with a delay.\r
 443                  */\r
 444                 void setValues(BitVector newValues)\r
 445                 {\r
 446                         if (inputValues.equals(newValues))\r
 447                                 return;\r
 448                         inputValues = newValues;\r
 449                         Wire.this.recalculate();\r
 450                 }\r
 451 \r
 452                 /**\r
 453                  * @return The value (of bit 0) the {@link ReadEnd} is currently feeding into the associated {@link Wire}.\r
 454                  */\r
 455                 public Bit getInputValue()\r
 456                 {\r
 457                         return getInputValue(0);\r
 458                 }\r
 459 \r
 460                 /**\r
 461                  * @return The value which the {@link ReadEnd} is currently feeding into the associated {@link Wire} at the indexed {@link Bit}.\r
 462                  */\r
 463                 public Bit getInputValue(int index)\r
 464                 {\r
 465                         return inputValues.getBit(index);\r
 466                 }\r
 467 \r
 468                 /**\r
 469                  * @return A copy (safe to modify) of the values the {@link ReadEnd} is currently feeding into the associated {@link Wire}.\r
 470                  */\r
 471                 public BitVector getInputValues()\r
 472                 {\r
 473                         return getInputValues(0, length);\r
 474                 }\r
 475 \r
 476                 public BitVector getInputValues(int start, int end)\r
 477                 {\r
 478                         return inputValues.subVector(start, end);\r
 479                 }\r
 480 \r
 481                 /**\r
 482                  * {@link ReadEnd} now feeds Z into the associated {@link Wire}.\r
 483                  */\r
 484                 public void clearSignals()\r
 485                 {\r
 486                         feedSignals(Z.toVector(length));\r
 487                 }\r
 488 \r
 489                 public BitVector wireValuesExcludingMe()\r
 490                 {\r
 491                         BitVectorMutator mutator = BitVectorMutator.empty();\r
 492                         for (ReadWriteEnd wireEnd : inputs)\r
 493                         {\r
 494                                 if (wireEnd == this)\r
 495                                         continue;\r
 496                                 mutator.join(wireEnd.inputValues);\r
 497                         }\r
 498                         return mutator.get();\r
 499                 }\r
 500 \r
 501                 @Override\r
 502                 public String toString()\r
 503                 {\r
 504                         return inputValues.toString();\r
 505                 }\r
 506 \r
 507                 @Override\r
 508                 public void close()\r
 509                 {\r
 510                         super.close();\r
 511                         open = false;\r
 512                 }\r
 513 \r
 514                 void setWriting(boolean isWriting)\r
 515                 {\r
 516                         if (this.isWriting != isWriting)\r
 517                         {\r
 518                                 this.isWriting = isWriting;\r
 519                                 if (isWriting)\r
 520                                         inputs.add(this);\r
 521                                 else\r
 522                                         inputs.remove(this);\r
 523                                 Wire.this.recalculate();\r
 524                         }\r
 525                 }\r
 526 \r
 527                 boolean isWriting()\r
 528                 {\r
 529                         return isWriting;\r
 530                 }\r
 531         }\r
 532 \r
 533         @Override\r
 534         public String toString()\r
 535         {\r
 536                 String name = this.name == null ? String.format("0x%08x", hashCode()) : this.name;\r
 537                 return String.format("wire %s value: %s inputs: %s", name, values, inputs);\r
 538         }\r
 539 \r
 540         public static ReadEnd[] extractEnds(Wire[] w)\r
 541         {\r
 542                 ReadEnd[] inputs = new ReadEnd[w.length];\r
 543                 for (int i = 0; i < w.length; i++)\r
 544                         inputs[i] = w[i].createReadWriteEnd();\r
 545                 return inputs;\r
 546         }\r
 547 \r
 548         // TODO Fix ReadWriteEnd feeding signals to entire Wire (Z) instead of only selected Bits\r
 549         /**\r
 550          * Fuses the selected bits of two wires together. If the bits change in one Wire, the other is changed accordingly immediately. Warning:\r
 551          * The bits are permanently fused together.\r
 552          * \r
 553          * @param a      The {@link Wire} to be (partially) fused with b\r
 554          * @param b      The {@link Wire} to be (partially) fused with a\r
 555          * @param fromA  The first bit of {@link Wire} a to be fused\r
 556          * @param fromB  The first bit of {@link Wire} b to be fused\r
 557          * @param length The amount of bits to fuse\r
 558          */\r
 559         public static void fuse(Wire a, Wire b, int fromA, int fromB, int length)\r
 560         {\r
 561                 ReadWriteEnd rA = a.createReadWriteEnd(), rB = b.createReadWriteEnd();\r
 562                 rA.setWriting(false);\r
 563                 rB.setWriting(false);\r
 564                 rA.setValues(BitVector.of(Bit.Z, a.length));\r
 565                 rB.setValues(BitVector.of(Bit.Z, b.length));\r
 566                 Fusion aF = new Fusion(rB, fromA, fromB, length), bF = new Fusion(rA, fromB, fromA, length);\r
 567                 rA.registerObserver(aF);\r
 568                 rB.registerObserver(bF);\r
 569                 aF.update(rA);\r
 570                 bF.update(rB);\r
 571         }\r
 572 \r
 573         /**\r
 574          * \r
 575          * Fuses two wires together. If the bits change in one Wire, the other is changed accordingly immediately. Warning: The bits are\r
 576          * permanently fused together.\r
 577          * \r
 578          * @param a The {@link Wire} to be fused with b\r
 579          * @param b The {@link Wire} to be fused with a\r
 580          */\r
 581         public static void fuse(Wire a, Wire b)\r
 582         {\r
 583                 fuse(a, b, 0, 0, a.length);\r
 584         }\r
 585 \r
 586         private static class Fusion implements LogicObserver\r
 587         {\r
 588                 private ReadWriteEnd target;\r
 589                 int fromSource, fromTarget, length;\r
 590 \r
 591                 public Fusion(ReadWriteEnd target, int fromSource, int fromTarget, int length)\r
 592                 {\r
 593                         this.target = target;\r
 594                         this.fromSource = fromSource;\r
 595                         this.fromTarget = fromTarget;\r
 596                         this.length = length;\r
 597                 }\r
 598 \r
 599                 @Override\r
 600                 public void update(LogicObservable initiator)\r
 601                 {\r
 602                         ReadWriteEnd source = (ReadWriteEnd) initiator;\r
 603                         if (source.getWire().inputs.size() - (source.isWriting() ? 1 : 0) == 0)\r
 604                                 target.setWriting(false);\r
 605                         else\r
 606                         {\r
 607                                 target.setWriting(true);\r
 608                                 BitVector targetInput = source.wireValuesExcludingMe().subVector(fromSource, fromSource + length);\r
 609                                 target.setValues(fromTarget, targetInput);\r
 610                         }\r
 611                 }\r
 612         }\r
 613 }