Merged logic into master

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

diff --git a/era.mi/src/era/mi/logic/components/Mux.java b/era.mi/src/era/mi/logic/components/Mux.java
new file mode 100644 (file)
index 0000000..aea7116
--- /dev/null
+++ b/era.mi/src/era/mi/logic/components/Mux.java
@@ -0,0 +1,93 @@
+package era.mi.logic.components;
+
+import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.Collections;
+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 Mux extends BasicComponent
+{
+       private WireEnd select;
+       private WireEnd out;
+       private WireEnd[] inputs;
+       private final int outputSize;
+
+       /**
+        * 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, WireEnd out, WireEnd select, WireEnd... inputs)
+       {
+               super(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;
+       }
+
+       public WireEnd getOut()
+       {
+               return out;
+       }
+
+       public WireEnd getSelect()
+       {
+               return select;
+       }
+
+       @Override
+       public void compute()
+       {
+               int selectValue;
+               if (!select.hasNumericValue() || (selectValue = (int) select.getUnsignedValue()) >= inputs.length)
+               {
+                       out.clearSignals();
+                       return;
+               }
+
+               WireEnd active = inputs[selectValue];
+               out.feedSignals(active.getValues());
+       }
+
+       @Override
+       public List<WireEnd> getAllInputs()
+       {
+               ArrayList<WireEnd> wires = new ArrayList<WireEnd>(Arrays.asList(inputs));
+               wires.add(select);
+               return Collections.unmodifiableList(wires);
+       }
+
+       @Override
+       public List<WireEnd> getAllOutputs()
+       {
+               return List.of(out);
+       }
+}