+package era.mi.logic.wires;
+
+import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.Iterator;
+import java.util.List;
+
+import era.mi.logic.Bit;
+import era.mi.logic.Simulation;
+import era.mi.logic.Util;
+
+/**
+ * Represents an array of wires that can store n bits of information.
+ *
+ * @author Fabian Stemmler
+ *
+ */
+public class Wire
+{
+ private Bit[] values;
+ public final int travelTime;
+ private List<WireArrayObserver> observers = new ArrayList<WireArrayObserver>();
+ public final int length;
+ private List<WireEnd> inputs = new ArrayList<WireEnd>();
+
+ public Wire(int length, int travelTime)
+ {
+ if (length < 1)
+ throw new IllegalArgumentException(
+ String.format("Tried to create an array of wires with length %d, but a length of less than 1 makes no sense.", length));
+ this.length = length;
+ this.travelTime = travelTime;
+ initValues();
+ }
+
+ private void initValues()
+ {
+ values = Bit.U.makeArray(length);
+ }
+
+ private void recalculateSingleInput()
+ {
+ WireEnd input = inputs.get(0);
+ if (!Arrays.equals(input.getInputValues(), values))
+ {
+ Bit[] oldValues = values.clone();
+ System.arraycopy(input.getInputValues(), 0, values, 0, length);
+ notifyObservers(oldValues);
+ }
+ }
+
+ private void recalculateMultipleInputs()
+ {
+ Iterator<WireEnd> it = inputs.iterator();
+ Bit[] newValues = it.next().inputValues.clone();
+
+ while (it.hasNext())
+ {
+ WireEnd input = it.next();
+ Bit[] bits = input.getInputValues();
+ 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))
+ {
+ Bit[] oldValues = values;
+ values = newValues;
+ notifyObservers(oldValues);
+ }
+ }
+
+ private void recalculate()
+ {
+ switch (inputs.size())
+ {
+ case 0:
+ return;
+ case 1:
+ recalculateSingleInput();
+ break;
+ default:
+ recalculateMultipleInputs();
+ }
+ }
+
+ /**
+ * The {@link Wire} 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)
+ {
+ if (b != Bit.ZERO && b != Bit.ONE)
+ return false;
+ }
+ return true;
+ }
+
+ /**
+ * The {@link Wire} is interpreted as an unsigned integer with n bits.
+ *
+ * @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.
+ *
+ * @author Fabian Stemmler
+ */
+ public long getUnsignedValue()
+ {
+ 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;
+ }
+
+ /**
+ * The {@link Wire} is interpreted as a signed integer with n bits.
+ *
+ * @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.
+ *
+ * @author Fabian Stemmler
+ */
+ public long getSignedValue()
+ {
+ long val = getUnsignedValue();
+ long mask = 1 << (length - 1);
+ if ((mask & val) != 0)
+ {
+ int shifts = 64 - length;
+ return (val << shifts) >> shifts;
+ }
+ return val;
+ }
+
+ public Bit getValue()
+ {
+ return getValue(0);
+ }
+
+ 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;
+ }
+
+ public Bit[] getValues()
+ {
+ return values.clone();
+ }
+
+ /**
+ * Adds an {@link WireArrayObserver}, who will be notified when the value of the {@link Wire} 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(Bit[] oldValues)
+ {
+ for (WireArrayObserver o : observers)
+ o.update(this, oldValues);
+ }
+
+ /**
+ * Create and register a {@link WireEnd} object, which is tied to this {@link Wire}.
+ */
+ public WireEnd createEnd()
+ {
+ return new WireEnd();
+ }
+
+ private void registerInput(WireEnd toRegister)
+ {
+ inputs.add(toRegister);
+ }
+
+ /**
+ * A {@link WireEnd} feeds a constant signal into the {@link Wire} it is tied to. The combination of all inputs determines the
+ * {@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 and 1 turn into X when they are mixed
+ *
+ * @author Fabian Stemmler
+ */
+ public class WireEnd
+ {
+ private boolean open;
+ private Bit[] inputValues;
+
+ private WireEnd()
+ {
+ super();
+ open = true;
+ initValues();
+ registerInput(this);
+ }
+
+ private void initValues()
+ {
+ inputValues = Bit.Z.makeArray(length);
+ }
+
+ /**
+ * Sets the wires values. This takes up time, as specified by the {@link Wire}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(
+ String.format("Attempted to input %d bits instead of %d bits.", newValues.length, length));
+ }
+
+ /**
+ * Sets values of a subarray of wires. This takes up time, as specified by the {@link Wire}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)
+ {
+ if (!open)
+ throw new RuntimeException("Attempted to write to closed WireArrayEnd.");
+ 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(
+ String.format("Attempted to input bits from index %d to %d when there are only %d wires.", startingBit,
+ exclLastIndex - 1, length));
+ if (!Arrays.equals(inputValues, startingBit, exclLastIndex, newValues, 0, newValues.length))
+ {
+ System.arraycopy(newValues, 0, inputValues, startingBit, newValues.length);
+ Wire.this.recalculate();
+ }
+ }
+
+ /**
+ * @return The value (of bit 0) the {@link WireEnd} is currently feeding into the associated {@link Wire}.
+ */
+ public Bit getInputValue()
+ {
+ return getInputValue(0);
+ }
+
+ /**
+ * @return The value which the {@link WireEnd} is currently feeding into the associated {@link Wire} at the indexed {@link Bit}.
+ */
+ public Bit getInputValue(int index)
+ {
+ return inputValues[index];
+ }
+
+ /**
+ * @return A copy (safe to modify) of the values the {@link WireEnd} is currently feeding into the associated
+ * {@link Wire}.
+ */
+ public Bit[] getInputValues()
+ {
+ return getInputValues(0, length);
+ }
+
+ public Bit[] getInputValues(int start, int end)
+ {
+ int length = end - start;
+ Bit[] bits = new Bit[length];
+ System.arraycopy(inputValues, start, bits, 0, length);
+ return bits;
+ }
+
+ /**
+ * {@link WireEnd} now feeds Z into the associated {@link Wire}.
+ */
+ public void clearSignals()
+ {
+ feedSignals(Bit.Z.makeArray(length));
+ }
+
+ public Bit[] wireValuesExcludingMe()
+ {
+ Bit[] bits = Bit.Z.makeArray(length);
+ for (WireEnd wai : inputs)
+ {
+ if (wai == this)
+ continue;
+ Util.combineInto(bits, wai.getInputValues());
+ }
+ return bits;
+ }
+
+ /**
+ * Included for convenient use on {@link Wire}s of length 1.
+ *
+ * @return The value of bit 0.
+ *
+ * @author Fabian Stemmler
+ */
+ public Bit getValue()
+ {
+ return Wire.this.getValue();
+ }
+
+ /**
+ * @param index Index of the requested bit.
+ * @return The value of the indexed bit.
+ *
+ * @author Fabian Stemmler
+ */
+ public Bit getValue(int index)
+ {
+ return Wire.this.getValue(index);
+ }
+
+ /**
+ * @param index Index of the requested bit.
+ * @return The value of the indexed bit.
+ *
+ * @author Fabian Stemmler
+ */
+ public Bit[] getValues()
+ {
+ return Wire.this.getValues();
+ }
+
+ /**
+ * @param start Start of the wanted segment. (inclusive)
+ * @param end End of the wanted segment. (exclusive)
+ * @return The values of the segment of {@link Bit}s indexed.
+ *
+ * @author Fabian Stemmler
+ */
+ public Bit[] getValues(int start, int end)
+ {
+ return Wire.this.getValues(start, end);
+ }
+
+
+ /**
+ * The {@link Wire} 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 Wire.this.hasNumericValue();
+ }
+
+ /**
+ * The {@link Wire} is interpreted as an unsigned integer with n bits.
+ *
+ * @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.
+ *
+ * @author Fabian Stemmler
+ */
+ public long getUnsignedValue()
+ {
+ return Wire.this.getUnsignedValue();
+ }
+
+ /**
+ * The {@link Wire} is interpreted as a signed integer with n bits.
+ *
+ * @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.
+ *
+ * @author Fabian Stemmler
+ */
+ public long getSignedValue()
+ {
+ return Wire.this.getSignedValue();
+ }
+
+ @Override
+ public String toString()
+ {
+ return Arrays.toString(values);
+ //return String.format("%s \nFeeding: %s", WireArray.this.toString(), Arrays.toString(inputValues));
+ }
+
+ public void disconnect()
+ {
+ inputs.remove(this);
+ open = false;
+ }
+
+ public int length()
+ {
+ return length;
+ }
+
+ public boolean addObserver(WireArrayObserver ob)
+ {
+ return Wire.this.addObserver(ob);
+ }
+
+ public Wire getWire()
+ {
+ return Wire.this;
+ }
+ }
+
+ @Override
+ public String toString()
+ {
+ return String.format("wire 0x%08x value: %s inputs: %s", hashCode(), Arrays.toString(values), inputs);
+ //Arrays.toString(values), inputs.stream().map(i -> Arrays.toString(i.inputValues)).reduce((s1, s2) -> s1 + s2)
+ }
+
+ public static WireEnd[] extractEnds(Wire[] w)
+ {
+ WireEnd[] inputs = new WireEnd[w.length];
+ for (int i = 0; i < w.length; i++)
+ inputs[i] = w[i].createEnd();
+ return inputs;
+ }
+}
\ No newline at end of file
projects / Mograsim.git / commitdiff