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=147dd7fe27df8837ee69d7fa124310b3b42514e8;hb=5606ceefa2c360772194c85ed884e5f8f06f36aa;hp=0000000000000000000000000000000000000000;hpb=002110424653b282ab9c7ea4b12f967d59e5f66a;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
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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.List;
+
+import era.mi.logic.wires.Wire;
+import era.mi.logic.wires.Wire.WireEnd;
+
+/**
+ * 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 Demux extends BasicComponent
+{
+	private final WireEnd select, in;
+	private final WireEnd[] outputs;
+	private final int outputSize;
+	private int selected = -1;
+
+	/**
+	 * Output {@link Wire}s and in must be of uniform length
+	 * 
+	 * @param in      Must be of uniform length with all outputs.
+	 * @param select  Indexes the output array to which the input is mapped. Must have enough bits to index all outputs.
+	 * @param outputs One of these outputs receives the input signal, depending on the select bits
+	 */
+	public Demux(int processTime, WireEnd in, WireEnd select, WireEnd... outputs)
+	{
+		super(processTime);
+		outputSize = in.length();
+
+		this.in = in;
+		this.outputs = outputs;
+		for (int i = 0; i < this.outputs.length; i++)
+		{
+			if (outputs[i].length() != outputSize)
+				throw new IllegalArgumentException("All DEMUX wire arrays must be of uniform length!");
+			this.outputs[i] = outputs[i];
+		}
+
+		this.select = select;
+		select.addObserver(this);
+
+		int maxInputs = 1 << select.length();
+		if (this.outputs.length > maxInputs)
+			throw new IllegalArgumentException("There are more outputs (" + this.outputs.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 >= outputs.length)
+			selectValue = -1;
+
+		if (selected != selectValue && selected != -1)
+			outputs[selected].clearSignals();
+
+		selected = selectValue;
+
+		if (selectValue != -1)
+			outputs[selectValue].feedSignals(in.getValues());
+	}
+
+	@Override
+	public List<WireEnd> getAllInputs()
+	{
+		return List.of(in, select);
+	}
+
+	@Override
+	public List<WireEnd> getAllOutputs()
+	{
+		return List.of(outputs);
+	}
+}