APB2ENR
| SYSCFGEN | SYSCFG clock enable |
| FIREWALLEN | Firewall clock enable |
| SDMMCEN | SDMMC clock enable |
| TIM1EN | TIM1 timer clock enable |
| SPI1EN | SPI1 clock enable |
| USART1EN | USART1clock enable |
| TIM15EN | TIM15 timer clock enable |
| TIM16EN | TIM16 timer clock enable |
| SAI1EN | SAI1 clock enable |