added demux; added getAllInputs() and getAllOutputs() for all components

[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..e5f49f4
--- /dev/null
+++ b/era.mi/src/era/mi/logic/components/Demux.java
@@ -0,0 +1,83 @@
+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));
+       }
+}