PIF22=B_0x0
EXTI pending register
| PIF0 | pending bit on event input 0 |
| PIF1 | pending bit on event input 1 |
| PIF2 | pending bit on event input 2 |
| PIF3 | pending bit on event input 3 |
| PIF4 | pending bit on event input 4 |
| PIF5 | pending bit on event input 5 |
| PIF6 | pending bit on event input 6 |
| PIF7 | pending bit on event input 7 |
| PIF8 | pending bit on event input 8 |
| PIF9 | pending bit on event input 9 |
| PIF10 | pending bit on event input 10 |
| PIF11 | pending bit on event input 11 |
| PIF12 | pending bit on event input 12 |
| PIF13 | pending bit on event input 13 |
| PIF14 | pending bit on event input 14 |
| PIF15 | pending bit on event input 15 |
| PIF16 | pending bit on event input 16 |
| PIF21 | pending bit on event input 21 |
| PIF22 | pending bit on event input 22 These bits are set when the selected edge event or an EXTI_SWIER software trigger arrives on the configurable event line. This bit is cleared by writing 1 to it. 0 (B_0x0): No trigger request occurred. 1 (B_0x1): Trigger request occurred. |