Merged logic into master

[Mograsim.git] / era.mi / src / era / mi / logic / components / Demux.java

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 (file)
index 0000000..147dd7f
--- /dev/null
+++ b/era.mi/src/era/mi/logic/components/Demux.java
@@ -0,0 +1,80 @@
+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);
+       }
+}