Fixed Merger, Mux, Splitter: onedirectional again. Tests added.

[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
index 0b19e7c..0fd7fd4 100644 (file)
--- a/era.mi/src/era/mi/logic/components/Mux.java
+++ b/era.mi/src/era/mi/logic/components/Mux.java
@@ -1,77 +1,72 @@
 package era.mi.logic.components;
 
-import era.mi.logic.Bit;
 import era.mi.logic.wires.WireArray;
+import era.mi.logic.wires.WireArray.WireArrayInput;
 
 /**
- * Models a Multiplexer. A is selected when select bit is 1, B when select bit is 0. Outputs X otherwise.
- * @author Fabian
+ * 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 Mux extends BasicComponent
 {
-       private WireArray a, b, out;
        private WireArray select;
-       private final int size;
-       
+       private WireArrayInput outI;
+       private WireArray[] inputs;
+       private final int outputSize;
        /**
-        * {@link WireArray}s a, b and out must be of uniform length, select
-        * @param a Must be of uniform length with b and out.
-        * @param b Must be of uniform length with a and out.
-        * @param select C
-        * @param out Must be of uniform length with a and b.
+        * 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 inputs One of these inputs is mapped to the output, depending on the select bits
         */
-       public Mux(int processTime, WireArray a, WireArray b, WireArray select, WireArray out)
+       public Mux(int processTime, WireArray out, WireArray select, WireArray... inputs)
        {
                super(processTime);
-               size = a.length;
-               if(b.length != out.length || b.length != size)
-                       throw new IllegalArgumentException("All MUX wire arrays must be of uniform length!");
-               this.a = a;
-               a.addObserver(this);
-               this.b = b;
-               b.addObserver(this);
-               this.select = select;
-               select.addObserver(this);
-               this.out = out;
-       }
-
-       @Override
-       protected void compute()
-       {
-               WireArray active = b;
-               switch(select.getValue())
+               outputSize = out.length;
+               
+               this.inputs = inputs.clone();
+               for(int i = 0; i < this.inputs.length; i++)
                {
-               case ONE:
-                       active = a;
-               case ZERO:
-                       out.feedSignals(active.getValues());
-                       break;
-               default:
-                       Bit[] newValues = new Bit[size];
-                       for(int i = 0; i < size; i++)
-                               newValues[i] = Bit.X;
-                       out.feedSignals(newValues);
+                       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 + ").");
+               
+               outI = out.createInput();
        }
-
-       public WireArray getA()
-       {
-               return a;
-       }
-
-       public WireArray getB()
-       {
-               return b;
-       }
-
+       
        public WireArray getOut()
        {
-               return out;
+               return outI.owner;
        }
 
        public WireArray getSelect()
        {
                return select;
        }
+
+       @Override
+       public void compute() {
+               int selectValue;
+               if(!select.hasNumericValue() || (selectValue = (int) select.getUnsignedValue()) >= inputs.length)
+               {
+                       outI.clearSignals();
+                       return;
+               }
+               
+               WireArray active = inputs[selectValue];
+               outI.feedSignals(active.getValues());
+       }
 }