era.mi/src/era/mi/logic/components/TriStateBuffer.java

   1 package era.mi.logic.components;\r
   2 \r
   3 import java.util.List;\r
   4 \r
   5 import era.mi.logic.types.Bit;\r
   6 import era.mi.logic.wires.Wire.ReadEnd;\r
   7 import era.mi.logic.wires.Wire.ReadWriteEnd;\r
   8 \r
   9 public class TriStateBuffer extends BasicComponent\r
  10 {\r
  11         ReadEnd in, enable;\r
  12         ReadWriteEnd out;\r
  13 \r
  14         public TriStateBuffer(int processTime, ReadEnd in, ReadWriteEnd out, ReadEnd enable)\r
  15         {\r
  16                 super(processTime);\r
  17                 if (in.length() != out.length())\r
  18                         throw new IllegalArgumentException(\r
  19                                         "Tri-state output must have the same amount of bits as the input. Input: " + in.length() + " Output: " + out.length());\r
  20                 if (enable.length() != 1)\r
  21                         throw new IllegalArgumentException("Tri-state enable must have exactly one bit, not " + enable.length() + ".");\r
  22                 this.in = in;\r
  23                 in.addObserver(this);\r
  24                 this.enable = enable;\r
  25                 enable.addObserver(this);\r
  26                 this.out = out;\r
  27         }\r
  28 \r
  29         @Override\r
  30         protected void compute()\r
  31         {\r
  32                 if (enable.getValue() == Bit.ONE)\r
  33                         out.feedSignals(in.getValues());\r
  34                 else\r
  35                         out.clearSignals();\r
  36         }\r
  37 \r
  38         @Override\r
  39         public List<ReadEnd> getAllInputs()\r
  40         {\r
  41                 return List.of(in, enable);\r
  42         }\r
  43 \r
  44         @Override\r
  45         public List<ReadWriteEnd> getAllOutputs()\r
  46         {\r
  47                 return List.of(out);\r
  48         }\r
  49 \r
  50 }\r