package era.mi.logic.components;
-import era.mi.logic.Bit;
-import era.mi.logic.wires.WireArray;
+import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.Collections;
+import java.util.List;
+
+import era.mi.logic.timeline.Timeline;
+import era.mi.logic.wires.Wire;
+import era.mi.logic.wires.Wire.ReadEnd;
+import era.mi.logic.wires.Wire.ReadWriteEnd;
/**
- * Models a Multiplexer. A is selected when select bit is 1, B when select bit is 0. Outputs X otherwise.
- * @author Fabian
+ * Models a multiplexer. Takes an arbitrary amount of input {@link Wire}s, one of which, as determined by select, is put through to the
+ * output.
+ *
+ * @author Fabian Stemmler
*
*/
public class Mux extends BasicComponent
{
- private WireArray a, b, out;
- private WireArray select;
- private final int size;
-
+ private ReadEnd select;
+ private ReadWriteEnd out;
+ private ReadEnd[] inputs;
+ private final int outputSize;
+
/**
- * {@link WireArray}s a, b and out must be of uniform length, select
- * @param a Must be of uniform length with b and out.
- * @param b Must be of uniform length with a and out.
- * @param select C
- * @param out Must be of uniform length with a and b.
+ * Input {@link Wire}s and out must be of uniform length
+ *
+ * @param out Must be of uniform length with all inputs.
+ * @param select Indexes the input array which is to be mapped to the output. Must have enough bits to index all inputs.
+ * @param inputs One of these inputs is mapped to the output, depending on the select bits
*/
- public Mux(int processTime, WireArray a, WireArray b, WireArray select, WireArray out)
+ public Mux(Timeline timeline, int processTime, ReadWriteEnd out, ReadEnd select, ReadEnd... inputs)
{
- super(processTime);
- size = a.length;
- if(b.length != out.length || b.length != size)
- throw new IllegalArgumentException("All MUX wire arrays must be of uniform length!");
- this.a = a;
- a.addObserver(this);
- this.b = b;
- b.addObserver(this);
+ super(timeline, processTime);
+ outputSize = out.length();
+
+ this.inputs = inputs.clone();
+ for (int i = 0; i < this.inputs.length; i++)
+ {
+ if (inputs[i].length() != outputSize)
+ throw new IllegalArgumentException("All MUX wire arrays must be of uniform length!");
+ inputs[i].addObserver(this);
+ }
+
this.select = select;
select.addObserver(this);
+
+ int maxInputs = 1 << select.length();
+ if (this.inputs.length > maxInputs)
+ throw new IllegalArgumentException("There are more inputs (" + this.inputs.length + ") to the MUX than supported by "
+ + select.length() + " select bits (" + maxInputs + ").");
+
this.out = out;
}
- @Override
- protected void compute()
+ public ReadEnd getOut()
{
- WireArray active = b;
- switch(select.getValue())
- {
- case ONE:
- active = a;
- case ZERO:
- out.feedSignals(active.getValues());
- break;
- default:
- Bit[] newValues = new Bit[size];
- for(int i = 0; i < size; i++)
- newValues[i] = Bit.X;
- out.feedSignals(newValues);
- }
+ return out;
}
- public WireArray getA()
+ public ReadEnd getSelect()
{
- return a;
+ return select;
}
- public WireArray getB()
+ @Override
+ public void compute()
{
- return b;
+ int selectValue;
+ if (!select.hasNumericValue() || (selectValue = (int) select.getUnsignedValue()) >= inputs.length)
+ {
+ out.clearSignals();
+ return;
+ }
+
+ ReadEnd active = inputs[selectValue];
+ out.feedSignals(active.getValues());
}
- public WireArray getOut()
+ @Override
+ public List<ReadEnd> getAllInputs()
{
- return out;
+ ArrayList<ReadEnd> wires = new ArrayList<ReadEnd>(Arrays.asList(inputs));
+ wires.add(select);
+ return Collections.unmodifiableList(wires);
}
- public WireArray getSelect()
+ @Override
+ public List<ReadWriteEnd> getAllOutputs()
{
- return select;
+ return List.of(out);
}
}