APB1ENR register
| SPI1EN | SPI1 clock enable Set and enable by software. 0: clock disable 1: clock enable |
| ADCDIGEN | AUXADC clock enable for Aux-ADC digital clock Set and enable by software. 0: clock disable 1: clock enable |
| ADCANAEN | ADC clock enable for Aux-ADC analog clock Set and enable by software. 0: clock disable 1: clock enable |
| LPUARTEN | LPUART clock enable Set and enable by software. 0: clock disable 1: clock enable |
| USARTEN | USART clock enable Set and enable by software. 0: clock disable 1: clock enable |
| SPI3EN | SPI3 clock enable Set and enable by software. 0: clock disable 1: clock enable |
| I2C1EN | I2C1 clock enable Set and enable by software. 0: clock disable 1: clock enable |
| I2C2EN | I2C2 clock enable Set and enable by software. 0: clock disable 1: clock enable |