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