/**
* Represents an array of wires that can store n bits of information.
+ *
* @author Fabian Stemmler
*
*/
public class WireArray
{
- private Bit[] values;
- public final int travelTime;
- private List<WireArrayObserver> observers = new ArrayList<WireArrayObserver>();
- public final int length;
- private List<WireArrayInput> inputs = new ArrayList<WireArrayInput>();
-
- public WireArray(int length, int travelTime)
+ private Bit[] values;
+ public final int travelTime;
+ private List<WireArrayObserver> observers = new ArrayList<WireArrayObserver>();
+ public final int length;
+ private List<WireArrayInput> inputs = new ArrayList<WireArrayInput>();
+
+ public WireArray(int length, int travelTime)
+ {
+ if (length < 1)
+ throw new IllegalArgumentException("Tried to create an array of wires with length " + length
+ + ", but a length of less than 1 makes no sense.");
+ this.length = length;
+ this.travelTime = travelTime;
+ initValues();
+ }
+
+ private void initValues()
+ {
+ values = new Bit[length];
+ for (int i = 0; i < length; i++)
+ values[i] = Bit.Z;
+ }
+
+ private void recalculateSingleInput()
+ {
+ WireArrayInput input = inputs.get(0);
+ if (!Arrays.equals(input.getValues(), values))
{
- if(length < 1)
- throw new IllegalArgumentException("Tried to create an array of wires with length " + length + ", but a length of less than 1 makes no sense.");
- this.length = length;
- this.travelTime = travelTime;
- initValues();
+ System.arraycopy(input.getValues(), 0, values, 0, length);
+ notifyObservers();
}
-
- private void initValues()
+ }
+
+ private void recalculateMultipleInputs()
+ {
+ Iterator<WireArrayInput> it = inputs.iterator();
+ Bit[] newValues = it.next().values.clone();
+
+ while (it.hasNext())
{
- values = new Bit[length];
- for(int i = 0; i < length; i++)
- values[i] = Bit.Z;
+ WireArrayInput input = it.next();
+ Bit[] bits = input.getValues();
+ for (int i = 0; i < length; i++)
+ {
+ if (Bit.Z.equals(bits[i]) || newValues[i].equals(bits[i]))
+ continue;
+ else if (Bit.Z.equals(newValues[i]))
+ newValues[i] = bits[i];
+ else
+ newValues[i] = Bit.X;
+ }
}
-
- private void recalculateSingleInput()
+
+ if (!Arrays.equals(newValues, values))
{
- WireArrayInput input = inputs.get(0);
- if(!Arrays.equals(input.getValues(), values))
- {
- System.arraycopy(input.getValues(), 0, values, 0, length);
- notifyObservers();
- }
+ notifyObservers();
+ values = newValues;
}
-
- private void recalculateMultipleInputs()
+ }
+
+ private void recalculate()
+ {
+ switch (inputs.size())
{
- Iterator<WireArrayInput> it = inputs.iterator();
- Bit[] newValues = it.next().values.clone();
-
- while(it.hasNext())
- {
- WireArrayInput input = it.next();
- Bit[] bits = input.getValues();
- for(int i = 0; i < length; i++)
- {
- if(Bit.Z.equals(bits[i]) || newValues[i].equals(bits[i]))
- continue;
- else if(Bit.Z.equals(newValues[i]))
- newValues[i] = bits[i];
- else
- newValues[i] = Bit.X;
- }
- }
-
- if(!Arrays.equals(newValues, values))
- {
- notifyObservers();
- values = newValues;
- }
+ case 0:
+ return;
+ case 1:
+ recalculateSingleInput();
+ break;
+ default:
+ recalculateMultipleInputs();
}
+ }
- private void recalculate()
+ /**
+ * The WireArray is interpreted as an unsigned integer with n bits.
+ *
+ * @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 value),
+ * not <code>Bit.X</code> or <code>Bit.Z</code>. <code>false</code> is
+ * returned otherwise.
+ *
+ * @author Fabian Stemmler
+ */
+ public boolean hasNumericValue()
+ {
+ for (Bit b : values)
{
- switch(inputs.size())
- {
- case 0:
- return;
- case 1:
- recalculateSingleInput();
- break;
- default:
- recalculateMultipleInputs();
- }
+ if (b != Bit.ZERO && b != Bit.ONE)
+ return false;
}
-
- /**
- * The WireArray is interpreted as an unsigned integer with n bits.
- * @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 value), not <code>Bit.X</code> or <code>Bit.Z</code>. <code>false</code> is returned otherwise.
- *
- * @author Fabian Stemmler
- */
- public boolean hasNumericValue()
+ return true;
+ }
+
+ /**
+ * The WireArray is interpreted as an unsigned integer with n bits.
+ *
+ * @return The unsigned value of the {@link WireArray}'s bits, where value 0
+ * corresponds with 2^0, value 1 is 2^1 and so on.
+ *
+ * @author Fabian Stemmler
+ */
+ public long getUnsignedValue()
+ {
+ long val = 0;
+ long mask = 1;
+ for (int i = 0; i < length; i++)
{
- for(Bit b : values)
- {
- if(b != Bit.ZERO && b != Bit.ONE)
- return false;
- }
- return true;
+ switch (values[i])
+ {
+ default:
+ case Z:
+ case X:
+ return 0; // TODO: Proper handling for getUnsignedValue(), if not all bits are 1 or 0;
+ // Random number?
+ case ONE:
+ val |= mask;
+ break;
+ case ZERO:
+ }
+ mask = mask << 1;
}
-
- /**
- * The WireArray is interpreted as an unsigned integer with n bits.
- * @return The unsigned value of the {@link WireArray}'s bits, where value 0 corresponds with 2^0, value 1 is 2^1 and so on.
- *
- * @author Fabian Stemmler
- */
- public long getUnsignedValue()
+ return val;
+ }
+
+ /**
+ * The WireArray is interpreted as a signed integer with n bits.
+ *
+ * @return The signed value of the {@link WireArray}'s bits, where value 0
+ * corresponds with 2^0, value 1 is 2^1 and so on.
+ *
+ * @author Fabian Stemmler
+ */
+ public long getSignedValue()
+ {
+ long val = getUnsignedValue();
+ long mask = 1 << (length - 1);
+ if ((mask & val) != 0)
{
- long val = 0;
- long mask = 1;
- for(int i = 0; i < length; i++)
- {
- switch(values[i])
- {
- default:
- case Z:
- case X:
- return 0; //TODO: Proper handling for getUnsignedValue(), if not all bits are 1 or 0; Random number?
- case ONE:
- val |= mask;
- break;
- case ZERO:
- }
- mask = mask << 1;
- }
- return val;
+ int shifts = 64 - length;
+ return (val << shifts) >> shifts;
}
-
- /**
- * The WireArray is interpreted as a signed integer with n bits.
- * @return The signed value of the {@link WireArray}'s bits, where value 0 corresponds with 2^0, value 1 is 2^1 and so on.
- *
- * @author Fabian Stemmler
- */
- public long getSignedValue()
+ return val;
+ }
+
+ /**
+ * Included for convenient use on {@link WireArray}s of length 1.
+ *
+ * @return The value of bit 0.
+ *
+ * @author Fabian Stemmler
+ */
+ public Bit getValue()
+ {
+ return getValue(0);
+ }
+
+ /**
+ *
+ * @param index Index of the requested bit.
+ * @return The value of the indexed bit.
+ *
+ * @author Fabian Stemmler
+ */
+ public Bit getValue(int index)
+ {
+ return values[index];
+ }
+
+ public Bit[] getValues(int start, int end)
+ {
+ int length = end - start;
+ Bit[] bits = new Bit[length];
+ System.arraycopy(values, start, bits, 0, length);
+ return bits;
+ }
+
+ /**
+ * @return An array of length n containing the values of the n bits in the
+ * {@link WireArray}. Can be safely modified.
+ *
+ * @author Fabian Stemmler
+ */
+ public Bit[] getValues()
+ {
+ return values.clone();
+ }
+
+ /**
+ * Adds an {@link WireArrayObserver}, who will be notified when the value of the
+ * {@link WireArray} is updated.
+ *
+ * @param ob The {@link WireArrayObserver} to be notified of changes.
+ * @return true if the given {@link WireArrayObserver} was not already
+ * registered, false otherwise
+ *
+ * @author Fabian Stemmler
+ */
+ public boolean addObserver(WireArrayObserver ob)
+ {
+ return observers.add(ob);
+ }
+
+ private void notifyObservers()
+ {
+ for (WireArrayObserver o : observers)
+ o.update(this);
+ }
+
+ /**
+ * Create and register a {@link WireArrayInput} object, which is tied to this
+ * {@link WireArray}.
+ */
+ public WireArrayInput createInput()
+ {
+ return new WireArrayInput(this);
+ }
+
+ private void registerInput(WireArrayInput toRegister)
+ {
+ inputs.add(toRegister);
+ }
+
+ /**
+ * A {@link WireArrayInput} feeds a constant signal into the {@link WireArray}
+ * it is tied to. The combination of all inputs determines the
+ * {@link WireArray}s final value. X dominates all other inputs Z does not
+ * affect the final value, unless there are no other inputs than Z 0 and 1 turn
+ * into X when they are mixed
+ *
+ * @author Fabian Stemmler
+ */
+ public class WireArrayInput
+ {
+ public final WireArray owner;
+ private Bit[] values;
+
+ private WireArrayInput(WireArray owner)
{
- long val = getUnsignedValue();
- long mask = 1 << (length - 1);
- if((mask & val) != 0)
- {
- int shifts = 64 - length;
- return (val << shifts) >> shifts;
- }
- return val;
+ super();
+ this.owner = owner;
+ initValues();
+ owner.registerInput(this);
}
-
- /**
- * Included for convenient use on {@link WireArray}s of length 1.
- * @return The value of bit 0.
- *
- * @author Fabian Stemmler
- */
- public Bit getValue()
+
+ private void initValues()
{
- return getValue(0);
+ values = new Bit[length];
+ for (int i = 0; i < length; i++)
+ values[i] = Bit.Z;
}
-
+
/**
+ * Sets the wires values. This takes up time, as specified by the
+ * {@link WireArray}s travel time.
*
- * @param index Index of the requested bit.
- * @return The value of the indexed bit.
+ * @param newValues The new values the wires should take on.
*
* @author Fabian Stemmler
*/
- public Bit getValue(int index)
- {
- return values[index];
- }
-
- public Bit[] getValues(int start, int end)
+ public void feedSignals(Bit... newValues)
{
- int length = end - start;
- Bit[] bits = new Bit[length];
- System.arraycopy(values, start, bits, 0, length);
- return bits;
+ if (newValues.length == length)
+ {
+ feedSignals(0, newValues);
+ } else
+ throw new IllegalArgumentException(
+ "Attempted to input " + newValues.length + " bits instead of " + length + " bits.");
}
-
-
+
/**
- * @return An array of length n containing the values of the n bits in the {@link WireArray}. Can be safely modified.
+ * Sets values of a subarray of wires. This takes up time, as specified by the
+ * {@link WireArray}s travel time.
*
- * @author Fabian Stemmler
- */
- public Bit[] getValues()
- {
- return values.clone();
- }
-
- /**
- * Adds an {@link WireArrayObserver}, who will be notified when the value of the {@link WireArray} is updated.
- * @param ob The {@link WireArrayObserver} to be notified of changes.
- * @return true if the given {@link WireArrayObserver} was not already registered, false otherwise
+ * @param newValues The new values the wires should take on.
+ * @param startingBit The first index of the subarray of wires.
*
* @author Fabian Stemmler
*/
- public boolean addObserver(WireArrayObserver ob)
+ public void feedSignals(int startingBit, Bit... newValues)
{
- return observers.add(ob);
+ Simulation.TIMELINE.addEvent((e) -> setValues(startingBit, newValues), travelTime);
}
-
- private void notifyObservers()
+
+ private void setValues(int startingBit, Bit... newValues)
{
- for(WireArrayObserver o : observers)
- o.update(this);
+ int exclLastIndex = startingBit + newValues.length;
+ if (length < exclLastIndex)
+ throw new ArrayIndexOutOfBoundsException("Attempted to input bits from index " + startingBit + " to "
+ + exclLastIndex + " when there are only " + length + "wires.");
+ if (!Arrays.equals(values, startingBit, exclLastIndex, newValues, 0, newValues.length))
+ {
+ System.arraycopy(newValues, 0, values, startingBit, newValues.length);
+ owner.recalculate();
+ }
}
-
- public WireArrayInput createInput()
+
+ public Bit[] getValues()
{
- return new WireArrayInput(this);
+ return values.clone();
}
-
- private void registerInput(WireArrayInput toRegister)
+
+ public void clearSignals()
{
- inputs.add(toRegister);
+ Bit[] bits = new Bit[length];
+ for (int i = 0; i < length; i++)
+ bits[i] = Bit.Z;
+ feedSignals(bits);
}
-
- public class WireArrayInput {
- public final WireArray owner;
- private Bit[] values;
-
- private WireArrayInput(WireArray owner) {
- super();
- this.owner = owner;
- initValues();
- owner.registerInput(this);
- }
-
- private void initValues()
- {
- values = new Bit[length];
- for(int i = 0; i < length; i++)
- values[i] = Bit.Z;
- }
-
- /**
- * Sets the wires values. This takes up time, as specified by the {@link WireArray}s travel time.
- * @param newValues The new values the wires should take on.
- *
- * @author Fabian Stemmler
- */
- public void feedSignals(Bit... newValues)
- {
- if(newValues.length == length)
- {
- feedSignals(0, newValues);
- }
- else
- throw new IllegalArgumentException("Attempted to input " + newValues.length + " bits instead of " + length + " bits.");
- }
-
- /**
- * Sets values of a subarray of wires. This takes up time, as specified by the {@link WireArray}s travel time.
- * @param newValues The new values the wires should take on.
- * @param startingBit The first index of the subarray of wires.
- *
- * @author Fabian Stemmler
- */
- public void feedSignals(int startingBit, Bit... newValues)
- {
- Simulation.TIMELINE.addEvent((e) -> setValues(startingBit, newValues), travelTime);
- }
-
- private void setValues(int startingBit, Bit... newValues)
- {
- int exclLastIndex = startingBit + newValues.length;
- if(length < exclLastIndex)
- throw new ArrayIndexOutOfBoundsException("Attempted to input bits from index " + startingBit + " to "
- + exclLastIndex + " when there are only " + length + "wires.");
- if(!Arrays.equals(values, startingBit, exclLastIndex, newValues, 0, newValues.length))
- {
- System.arraycopy(newValues, 0, values, startingBit, newValues.length);
- owner.recalculate();
- }
- }
-
- public Bit[] getValues()
- {
- return values.clone();
- }
-
- public void clearSignals()
- {
- Bit[] bits = new Bit[length];
- for(int i = 0; i < length; i++)
- bits[i] = Bit.Z;
- feedSignals(bits);
- }
+
+ @Override
+ public String toString()
+ {
+ return Arrays.toString(values);
}
-}
+ }
+
+ @Override
+ public String toString()
+ {
+ return String.format("wire 0x%08x value: %s inputs: %s", hashCode(), Arrays.toString(values), inputs);
+ }
+
+ public static WireArrayInput[] extractInputs(WireArray[] w)
+ {
+ WireArrayInput[] inputs = new WireArrayInput[w.length];
+ for(int i = 0; i < w.length; i++)
+ inputs[i] = w[i].createInput();
+ return inputs;
+ }
+}
\ No newline at end of file