X-Git-Url: https://mograsim.net/gitweb/?a=blobdiff_plain;f=era.mi%2Fsrc%2Fera%2Fmi%2Flogic%2Fcomponents%2FDemux.java;fp=era.mi%2Fsrc%2Fera%2Fmi%2Flogic%2Fcomponents%2FDemux.java;h=e5f49f419c997251f0283a4f9ff5fb7e6186588c;hb=bcf8d773c7a836c2ee17e17a49c296ebf31d2777;hp=0000000000000000000000000000000000000000;hpb=7f37c7b2431309e49a0ee116d1ee6c173272e926;p=Mograsim.git

diff --git a/era.mi/src/era/mi/logic/components/Demux.java b/era.mi/src/era/mi/logic/components/Demux.java
new file mode 100644
index 00000000..e5f49f41
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+++ b/era.mi/src/era/mi/logic/components/Demux.java
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+package era.mi.logic.components;
+
+import java.util.Arrays;
+import java.util.Collections;
+import java.util.List;
+
+import era.mi.logic.wires.WireArray;
+import era.mi.logic.wires.WireArray.WireArrayInput;
+
+/**
+ * Models a multiplexer. Takes an arbitrary amount of input {@link WireArray}s, one of which,
+ * as determined by select, is put through to the output.
+ * @author Fabian Stemmler
+ *
+ */
+public class Demux extends BasicComponent
+{
+	private final WireArray select, in;
+	private final WireArray[] outputs;
+	private final WireArrayInput[] outputsI;
+	private final int outputSize;
+	private int selected = -1;
+	
+	/**
+	 * Input {@link WireArray}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 outputs One of these inputs is mapped to the output, depending on the select bits
+	 */
+	public Demux(int processTime, WireArray in, WireArray select, WireArray... outputs)
+	{
+		super(processTime);
+		outputSize = in.length;
+		
+		this.in = in;
+		this.outputs = outputs;
+		this.outputsI = new WireArrayInput[outputs.length];
+		for(int i = 0; i < this.outputsI.length; i++)
+		{
+			if(outputs[i].length != outputSize)
+				throw new IllegalArgumentException("All DEMUX wire arrays must be of uniform length!");
+			this.outputsI[i] = outputs[i].createInput();
+		}
+		
+		this.select = select;
+		select.addObserver(this);
+		
+		int maxInputs = 1 << select.length;
+		if(this.outputsI.length > maxInputs)
+			throw new IllegalArgumentException("There are more outputs ("
+					+ this.outputsI.length + ") to the DEMUX than supported by "
+					+ select.length + " select bits (" + maxInputs + ").");
+		in.addObserver(this);
+	}
+
+	@Override
+	public void compute() {
+		int selectValue = select.hasNumericValue() ? (int) select.getUnsignedValue() : -1;
+		if(selectValue >= outputsI.length)
+			selectValue = -1;
+		
+		if(selected != selectValue && selected != -1)
+			outputsI[selected].clearSignals();
+		
+		selected = selectValue;
+		
+		if(selectValue != -1)
+			outputsI[selectValue].feedSignals(in.getValues());
+	}
+
+	@Override
+	public List<WireArray> getAllInputs()
+	{
+		return Collections.unmodifiableList(Arrays.asList(in, select));
+	}
+
+	@Override
+	public List<WireArray> getAllOutputs()
+	{
+		return Collections.unmodifiableList(Arrays.asList(outputs));
+	}
+}