+-----+   +--------------+   +-----+    
      +----+       | PE1 |===|              |===| PE3 |       +----+
      | CE1+-------+     |   |              |   |     +-------+ CE3|
      +----+       +-----+   |              |   +-----+       +----+
                             |     Core     |                 
      +----+       +-----+   |              |   +-----+       +----+
      |CE2 +-------+     |   |              |   |     +-------+ CE4|
      +----+       | PE2 |===|              |===| PE4 |       +----+
                   +-----+   +--------------+   +-----+