GPIO port mode register
| MODER0 | Port x configuration bits (y = 0…15) |
| MODER1 | Port x configuration bits (y = 0…15) |
| MODER2 | Port x configuration bits (y = 0…15) |
| MODER3 | Port x configuration bits (y = 0…15) |
| MODER4 | Port x configuration bits (y = 0…15) |