_______________________________________
                    |    |                                  |
          MSB LSB   | OP | COMBINATION RULE                 |
                    |    |                                  |
          0 0 0 0   | 0  | all zeros                        |
          0 0 0 1   | 1  | source AND destination           |
          0 0 1 0   | 2  | source AND NOT destination       |
          0 0 1 1   | 3  | source                           |
          0 1 0 0   | 4  | NOT source AND destination       |
          0 1 0 1   | 5  | destination                      |
          0 1 1 0   | 6  | source XOR destination           |
          0 1 1 1   | 7  | source OR destination            |
          1 0 0 0   | 8  | NOT source AND NOT destination   |
          1 0 0 1   | 9  | NOT source XOR destination       |
          1 0 1 0   | A  | NOT destination                  |
          1 0 1 1   | B  | source OR NOT destination        |
          1 1 0 0   | C  | NOT source                       |
          1 1 0 1   | D  | NOT source OR destination        |
          1 1 1 0   | E  | NOT source OR NOT destination    |
          1 1 1 1   | F  | all ones                         |
                    |____|__________________________________|