reset only by system reset, not reset by wakeup from Standby mode
| WKUPF1 | Wakeup pin WKUPF flag. This bit is set by hardware and cleared only by a Reset pin or by setting the WKUPCn+1 bit in the PWR wakeup clear register (PWR_WKUPCR).  |  
| WKUPF2 | Wakeup pin WKUPF flag. This bit is set by hardware and cleared only by a Reset pin or by setting the WKUPCn+1 bit in the PWR wakeup clear register (PWR_WKUPCR).  |  
| WKUPF3 | Wakeup pin WKUPF flag. This bit is set by hardware and cleared only by a Reset pin or by setting the WKUPCn+1 bit in the PWR wakeup clear register (PWR_WKUPCR).  |  
| WKUPF4 | Wakeup pin WKUPF flag. This bit is set by hardware and cleared only by a Reset pin or by setting the WKUPCn+1 bit in the PWR wakeup clear register (PWR_WKUPCR).  |  
| WKUPF5 | Wakeup pin WKUPF flag. This bit is set by hardware and cleared only by a Reset pin or by setting the WKUPCn+1 bit in the PWR wakeup clear register (PWR_WKUPCR).  |  
| WKUPF6 | Wakeup pin WKUPF flag. This bit is set by hardware and cleared only by a Reset pin or by setting the WKUPCn+1 bit in the PWR wakeup clear register (PWR_WKUPCR).  |