RCC AHB1 Clock Register
| DMA1EN | DMA1 Clock Enable |
| DMA2EN | DMA2 Clock Enable |
| ADC12EN | ADC1/2 Peripheral Clocks Enable |
| ARTEN | ART Clock Enable |
| ETH1MACEN | Ethernet MAC bus interface Clock Enable |
| ETH1TXEN | Ethernet Transmission Clock Enable |
| ETH1RXEN | Ethernet Reception Clock Enable |
| USB1OTGHEN | USB1OTG Peripheral Clocks Enable |
| USB1OTGHSULPIEN | USB_PHY1 Clocks Enable |
| USB2OTGHSEN | USB2OTG Peripheral Clocks Enable |