CSSF=B_0x0, PDDS=B_0x0, STOPF=B_0x0, SVOS=B_0x0, SBF=B_0x0
PWR CPU control register
| PDDS | Power-down deepsleep selection 0 (B_0x0): Stop mode when device enters deepsleep 1 (B_0x1): Standby mode when device enters deepsleep  |  
| CSSF | Clear Standby and Stop flags (always read as 0) 0 (B_0x0): No effect 1 (B_0x1): When written, clear the CPU flags (STOPF, SBF).  |  
| STOPF | Stop flag 0 (B_0x0): System has not been in Stop mode. 1 (B_0x1): System has been in Stop mode.  |  
| SBF | Standby flag 0 (B_0x0): System has not been in Standby mode. 1 (B_0x1): System has been in Standby mode.  |  
| SVOS | System Stop mode voltage scaling selection 0 (B_0x0): SVOS low 1 (B_0x1): SVOS high (default)  |