X-Git-Url: https://mograsim.net/gitweb/?a=blobdiff_plain;f=era.mi%2Fsrc%2Fera%2Fmi%2Flogic%2Fwires%2FWire.java;fp=era.mi%2Fsrc%2Fera%2Fmi%2Flogic%2Fwires%2FWire.java;h=5eac8894371b687fc7f7102a507ee3ff46a5c12c;hb=c1d0ddc342c482051fa6c455bb286617135bd3c3;hp=0000000000000000000000000000000000000000;hpb=c18c04011cab0040c2287608eeefc9c3cc4536c2;p=Mograsim.git

diff --git a/era.mi/src/era/mi/logic/wires/Wire.java b/era.mi/src/era/mi/logic/wires/Wire.java
new file mode 100644
index 00000000..5eac8894
--- /dev/null
+++ b/era.mi/src/era/mi/logic/wires/Wire.java
@@ -0,0 +1,467 @@
+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