Clock control register
| MSION | MSI clock enable  |  
| MSIRDY | MSI clock ready flag  |  
| MSIPLLEN | MSI clock PLL enable  |  
| MSIRGSEL | MSI clock range selection  |  
| MSIRANGE | MSI clock ranges  |  
| HSION | HSI clock enable  |  
| HSIKERON | HSI always enable for peripheral kernels  |  
| HSIRDY | HSI clock ready flag  |  
| HSIASFS | HSI automatic start from Stop  |  
| HSEON | HSE clock enable  |  
| HSERDY | HSE clock ready flag  |  
| HSEBYP | HSE crystal oscillator bypass  |  
| CSSON | Clock security system enable  |  
| PLLON | Main PLL enable  |  
| PLLRDY | Main PLL clock ready flag  |  
| PLLSAI1ON | SAI1 PLL enable  |  
| PLLSAI1RDY | SAI1 PLL clock ready flag  |  
| PLLSAI2ON | SAI2 PLL enable  |  
| PLLSAI2RDY | SAI2 PLL clock ready flag  |