Clock control register
| MSION | MSI clock enable |
| MSIRDY | MSI clock ready flag (After reset this bit will be read 1 once the MSI is ready) |
| MSIPLLEN | MSI clock PLL enable |
| MSIRGSEL | MSI range control selection |
| MSIRANGE | MSI clock ranges |
| HSION | HSI16 clock enable |
| HSIKERON | HSI16 always enable for peripheral kernel clocks. |
| HSIRDY | HSI16 clock ready flag. (After wakeup from Stop this bit will be read 1 once the HSI16 is ready) |
| HSIASFS | HSI16 automatic start from Stop |
| HSIKERDY | HSI16 kernel clock ready flag for peripherals requests. |
| HSEON | HSE32 clock enable |
| HSERDY | HSE32 clock ready flag |
| CSSON | HSE32 Clock security system enable |
| HSEPRE | HSE32 sysclk prescaler |
| HSEBYPPWR | Enable HSE32 VDDTCXO output on package pin PB0-VDDTCXO. |
| PLLON | Main PLL enable |
| PLLRDY | Main PLL clock ready flag |