+--+   +--+ +--+   +--+
      |  |   |  | |  |   |  |
      |IR|   |IR| |IR|   |IR|
      |  |   |  | |  |   |  |
      +-++XXX++-+ +-++XXX++-+
        |     |     |     |
        |     |     |     |
+---+ +-v-XXX-v-+ +-v-XXX-v-+ +-----+ +-----+ +-----+ +-----+ +-----+
|   | |         | |         | |Class| |Class| |Class| |Class| |Class|
|CDT| | Class A | | Class B | | BE4 | | BE3 | | BE2 | | BE1 | | BE0 |
|   | |         | |         | |     | |     | |     | |     | |     |
+-+-+ +----+----+ +----+----+ +--+--+ +--+--+ +--+--+ +--+--+ +--+--+
  |        |           |         |       |       |       |       |
  |      +-v-+       +-v-+       |       |       |       |       |
  |      |CBS|       |CBS|       |       |       |       |       |
  |      +-+-+       +-+-+       |       |       |       |       |
  |        |           |         |       |       |       |       |
+-v--------v-----------v---------v-------V-------v-------v-------v--+
|                     Strict Priority selection                     |
+--------------------------------+----------------------------------+
                                 |
                                 V