package era.mi.logic.wires;
+import java.io.Closeable;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Iterator;
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 final int travelTime;
private List<WireArrayObserver> observers = new ArrayList<WireArrayObserver>();
public final int length;
- private List<WireArrayInput> inputs = new ArrayList<WireArrayInput>();
-
+ private List<WireArrayEnd> inputs = new ArrayList<WireArrayEnd>();
+
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.");
+ 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 = new Bit[length];
- for(int i = 0; i < length; i++)
- values[i] = Bit.Z;
+ values = Bit.U.makeArray(length);
}
-
+
private void recalculateSingleInput()
{
- WireArrayInput input = inputs.get(0);
- if(!Arrays.equals(input.getValues(), values))
+ WireArrayEnd input = inputs.get(0);
+ if (!Arrays.equals(input.getValues(), values))
{
+ Bit[] oldValues = values.clone();
System.arraycopy(input.getValues(), 0, values, 0, length);
- notifyObservers();
+ notifyObservers(oldValues);
}
}
-
+
private void recalculateMultipleInputs()
{
- Iterator<WireArrayInput> it = inputs.iterator();
- Bit[] newValues = it.next().values.clone();
-
- while(it.hasNext())
+ Iterator<WireArrayEnd> it = inputs.iterator();
+ Bit[] newValues = it.next().inputValues.clone();
+
+ while (it.hasNext())
{
- WireArrayInput input = it.next();
+ WireArrayEnd input = it.next();
Bit[] bits = input.getValues();
- for(int i = 0; i < length; i++)
+ 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;
+ newValues[i] = newValues[i].combineWith(bits[i]);
}
}
-
- if(!Arrays.equals(newValues, values))
+
+ if (!Arrays.equals(newValues, values))
{
- notifyObservers();
+ Bit[] oldValues = values;
values = newValues;
+ notifyObservers(oldValues);
}
}
private void recalculate()
{
- switch(inputs.size())
+ switch (inputs.size())
{
case 0:
return;
recalculateMultipleInputs();
}
}
-
+
/**
* 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.
+ *
+ * @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)
+ for (Bit b : values)
{
- if(b != Bit.ZERO && b != Bit.ONE)
+ if (b != Bit.ZERO && b != Bit.ONE)
return false;
}
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
{
long val = 0;
long mask = 1;
- for(int i = 0; i < length; i++)
+ for (int i = 0; i < length; i++)
{
- switch(values[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?
+ return 0; // TODO: Proper handling for getUnsignedValue(), if not all bits are 1 or 0;
+ // Random number?
case ONE:
val |= mask;
break;
}
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
{
long val = getUnsignedValue();
long mask = 1 << (length - 1);
- if((mask & val) != 0)
+ if ((mask & val) != 0)
{
int shifts = 64 - length;
return (val << shifts) >> shifts;
}
return val;
}
-
+
/**
* Included for convenient use on {@link WireArray}s of length 1.
+ *
* @return The value of bit 0.
*
* @author Fabian Stemmler
{
return getValue(0);
}
-
+
/**
*
* @param index Index of the requested bit.
{
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);
+ 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.
*
{
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
*
{
return observers.add(ob);
}
-
- private void notifyObservers()
+
+ private void notifyObservers(Bit[] oldValues)
{
- for(WireArrayObserver o : observers)
- o.update(this);
+ for (WireArrayObserver o : observers)
+ o.update(this, oldValues);
}
-
- public WireArrayInput createInput()
+
+ /**
+ * Create and register a {@link WireArrayEnd} object, which is tied to this {@link WireArray}.
+ */
+ public WireArrayEnd createInput()
{
- return new WireArrayInput(this);
+ return new WireArrayEnd(this);
}
-
- private void registerInput(WireArrayInput toRegister)
+
+ private void registerInput(WireArrayEnd toRegister)
{
inputs.add(toRegister);
}
-
- public class WireArrayInput {
+
+ /**
+ * A {@link WireArrayEnd} 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 WireArrayEnd implements Closeable
+ {
public final WireArray owner;
- private Bit[] values;
-
- private WireArrayInput(WireArray owner) {
+ private boolean open;
+ private Bit[] inputValues;
+
+ private WireArrayEnd(WireArray owner)
+ {
super();
this.owner = owner;
+ open = true;
initValues();
owner.registerInput(this);
}
-
+
private void initValues()
{
- values = new Bit[length];
- for(int i = 0; i < length; i++)
- values[i] = Bit.Z;
+ inputValues = Bit.U.makeArray(length);
}
-
+
/**
* 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)
+ if (newValues.length == length)
{
feedSignals(0, newValues);
- }
- else
- throw new IllegalArgumentException("Attempted to input " + newValues.length + " bits instead of " + length + " bits.");
+ } 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 WireArray}s travel time.
- * @param newValues The new values the wires should take on.
+ *
+ * @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("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))
+ 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, values, startingBit, newValues.length);
+ System.arraycopy(newValues, 0, inputValues, startingBit, newValues.length);
owner.recalculate();
}
}
-
+
+ /**
+ * Returns a copy (safe to modify) of the values the {@link WireArrayEnd} is currently feeding into the associated
+ * {@link WireArray}.
+ */
public Bit[] getValues()
{
- return values.clone();
+ return inputValues.clone();
}
-
+
+ /**
+ * {@link WireArrayEnd} now feeds Z into the associated {@link WireArray}.
+ */
public void clearSignals()
{
- Bit[] bits = new Bit[length];
- for(int i = 0; i < length; i++)
- bits[i] = Bit.Z;
- feedSignals(bits);
+ feedSignals(Bit.Z.makeArray(length));
}
+
+ public Bit[] wireValuesExcludingMe()
+ {
+ Bit[] bits = Bit.Z.makeArray(length);
+ for (WireArrayEnd wai : inputs)
+ {
+ if (wai == this)
+ continue;
+ Util.combineInto(bits, wai.getValues());
+ }
+ return bits;
+ }
+
+ public Bit getWireValue()
+ {
+ return owner.getValue();
+ }
+
+ public Bit[] getWireValues()
+ {
+ return owner.getValues();
+ }
+
+ @Override
+ public String toString()
+ {
+ return Arrays.toString(inputValues);
+ }
+
+ @Override
+ public void close()
+ {
+ inputs.remove(this);
+ open = false;
+ }
+ }
+
+ @Override
+ public String toString()
+ {
+ return String.format("wire 0x%08x value: %s inputs: %s", hashCode(), Arrays.toString(values), inputs);
+ }
+
+ public static WireArrayEnd[] extractInputs(WireArray[] w)
+ {
+ WireArrayEnd[] inputs = new WireArrayEnd[w.length];
+ for (int i = 0; i < w.length; i++)
+ inputs[i] = w[i].createInput();
+ return inputs;
}
-}
+}
\ No newline at end of file
projects / Mograsim.git / blobdiff