AHB1 peripheral clock register
| GPIOAEN | IO port A clock enable |
| GPIOBEN | IO port B clock enable |
| GPIOCEN | IO port C clock enable |
| GPIODEN | IO port D clock enable |
| GPIOEEN | IO port E clock enable |
| GPIOFEN | IO port F clock enable |
| GPIOGEN | IO port G clock enable |
| GPIOHEN | IO port H clock enable |
| GPIOIEN | IO port I clock enable |
| GPIOJEN | IO port J clock enable |
| GPIOKEN | IO port K clock enable |
| CRCEN | CRC clock enable |
| BKPSRAMEN | Backup SRAM interface clock enable |
| CCMDATARAMEN | CCM data RAM clock enable |
| DMA1EN | DMA1 clock enable |
| DMA2EN | DMA2 clock enable |
| DMA2DEN | DMA2D clock enable |
| ETHMACEN | Ethernet MAC clock enable |
| ETHMACTXEN | Ethernet Transmission clock enable |
| ETHMACRXEN | Ethernet Reception clock enable |
| ETHMACPTPEN | Ethernet PTP clock enable |
| OTGHSEN | USB OTG HS clock enable |
| OTGHSULPIEN | USB OTG HSULPI clock enable |