APB2 peripheral clock enable in low power mode register
| SYSCFGLPEN | System configuration controller clock enable during Sleep mode |
| TIM9LPEN | TIM9 timer clock enable during Sleep mode |
| TIM10LPEN | TIM10 timer clock enable during Sleep mode |
| TIM11LPEN | TIM11 timer clock enable during Sleep mode |
| ADC1LPEN | ADC1 interface clock enable during Sleep mode |
| SPI1LPEN | SPI 1 clock enable during Sleep mode |
| USART1LPEN | USART1 clock enable during Sleep mode |