RCC AHB4 Clock Register
| GPIOAEN | 0GPIO peripheral clock enable |
| GPIOBEN | 0GPIO peripheral clock enable |
| GPIOCEN | 0GPIO peripheral clock enable |
| GPIODEN | 0GPIO peripheral clock enable |
| GPIOEEN | 0GPIO peripheral clock enable |
| GPIOFEN | 0GPIO peripheral clock enable |
| GPIOGEN | 0GPIO peripheral clock enable |
| GPIOHEN | 0GPIO peripheral clock enable |
| GPIOIEN | 0GPIO peripheral clock enable |
| GPIOJEN | 0GPIO peripheral clock enable |
| GPIOKEN | 0GPIO peripheral clock enable |
| CRCEN | CRC peripheral clock enable |
| BDMAEN | BDMA and DMAMUX2 Clock Enable |
| ADC3EN | ADC3 Peripheral Clocks Enable |
| HSEMEN | HSEM peripheral clock enable |
| BKPRAMEN | Backup RAM Clock Enable |