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