AHB peripheral clock enable in low power mode register
| GPIOALPEN | IO port A clock enable during Sleep mode |
| GPIOBLPEN | IO port B clock enable during Sleep mode |
| GPIOCLPEN | IO port C clock enable during Sleep mode |
| GPIODLPEN | IO port D clock enable during Sleep mode |
| CRCLPEN | CRC clock enable during Sleep mode |
| FLITFLPEN | FLITF clock enable during Sleep mode |
| SRAMLPEN | SRAM clock enable during Sleep mode |
| DMALPEN | DMA1 clock enable during Sleep mode |