Clock control register
| HSI16ON | 16 MHz high-speed internal clock enable |
| HSI16KERON | High-speed internal clock enable bit for some IP kernels |
| HSI16RDYF | Internal high-speed clock ready flag |
| HSI16DIVEN | HSI16DIVEN |
| HSI16DIVF | HSI16DIVF |
| HSI16OUTEN | 16 MHz high-speed internal clock output enable |
| MSION | MSI clock enable bit |
| MSIRDY | MSI clock ready flag |
| HSEON | HSE clock enable bit |
| HSERDY | HSE clock ready flag |
| HSEBYP | HSE clock bypass bit |
| CSSLSEON | Clock security system on HSE enable bit |
| RTCPRE | TC/LCD prescaler |
| PLLON | PLL enable bit |
| PLLRDY | PLL clock ready flag |