Falling Trigger selection register (EXTI_FTSR)
| FT0 | Falling trigger event configuration of line 0 |
| FT1 | Falling trigger event configuration of line 1 |
| FT2 | Falling trigger event configuration of line 2 |
| FT3 | Falling trigger event configuration of line 3 |
| FT4 | Falling trigger event configuration of line 4 |
| FT5 | Falling trigger event configuration of line 5 |
| FT6 | Falling trigger event configuration of line 6 |
| FT7 | Falling trigger event configuration of line 7 |
| FT8 | Falling trigger event configuration of line 8 |
| FT9 | Falling trigger event configuration of line 9 |
| FT10 | Falling trigger event configuration of line 10 |
| FT11 | Falling trigger event configuration of line 11 |
| FT12 | Falling trigger event configuration of line 12 |
| FT13 | Falling trigger event configuration of line 13 |
| FT14 | Falling trigger event configuration of line 14 |
| FT15 | Falling trigger event configuration of line 15 |
| FT16 | Falling trigger event configuration of line 16 |
| FT17 | Falling trigger event configuration of line 17 |
| FT19 | Falling trigger event configuration of line 19 |
| FT20 | Falling trigger event configuration of line 20 |
| FT21 | Falling trigger event configuration of line 21 |
| FT22 | Falling trigger event configuration of line 22 |