RCC Domain 3 Kernel Clock Configuration Register
| LPUART1SRC | LPUART1 kernel clock source selection |
| I2C4SRC | I2C4 kernel clock source selection |
| LPTIM2SRC | LPTIM2 kernel clock source selection |
| LPTIM345SRC | LPTIM3,4,5 kernel clock source selection |
| ADCSRC | SAR ADC kernel clock source selection |
| SAI4ASRC | Sub-Block A of SAI4 kernel clock source selection |
| SAI4BSRC | Sub-Block B of SAI4 kernel clock source selection |
| SPI6SRC | SPI6 kernel clock source selection |