RCC AHB1 Clock Register
| DMA1EN | DMA1 Clock Enable |
| DMA2EN | DMA2 Clock Enable |
| ADC12EN | ADC1/2 Peripheral Clocks Enable |
| ETH1MACEN | Ethernet MAC bus interface Clock Enable |
| ETH1TXEN | Ethernet Transmission Clock Enable |
| ETH1RXEN | Ethernet Reception Clock Enable |
| USB1OTGEN | USB1OTG Peripheral Clocks Enable |
| USB1ULPIEN | USB_PHY1 Clocks Enable |
| USB2OTGEN | USB2OTG Peripheral Clocks Enable |
| USB2ULPIEN | USB_PHY2 Clocks Enable |