RCC APB1 Clock Register
| TIM2EN | TIM peripheral clock enable |
| TIM3EN | TIM peripheral clock enable |
| TIM4EN | TIM peripheral clock enable |
| TIM5EN | TIM peripheral clock enable |
| TIM6EN | TIM peripheral clock enable |
| TIM7EN | TIM peripheral clock enable |
| TIM12EN | TIM peripheral clock enable |
| TIM13EN | TIM peripheral clock enable |
| TIM14EN | TIM peripheral clock enable |
| LPTIM1EN | LPTIM1 Peripheral Clocks Enable |
| SPI2EN | SPI2 Peripheral Clocks Enable |
| SPI3EN | SPI3 Peripheral Clocks Enable |
| SPDIFRXEN | SPDIFRX Peripheral Clocks Enable |
| USART2EN | USART2 Peripheral Clocks Enable |
| USART3EN | USART3 Peripheral Clocks Enable |
| UART4EN | UART4 Peripheral Clocks Enable |
| UART5EN | UART5 Peripheral Clocks Enable |
| I2C1EN | I2C1 Peripheral Clocks Enable |
| I2C2EN | I2C2 Peripheral Clocks Enable |
| I2C3EN | I2C3 Peripheral Clocks Enable |
| CECEN | HDMI-CEC peripheral clock enable |
| DAC12EN | DAC1&2 peripheral clock enable |
| USART7EN | USART7 Peripheral Clocks Enable |
| USART8EN | USART8 Peripheral Clocks Enable |