There are two automatic input selection modes that can be set by register: Auto Revertive and Auto Non-Revertive.
- Auto Revertive: In this mode, the DPLL automatically selects the valid input with the highest configured priority. If a clock with higher priority becomes valid, the DPLL will automatically switch over to that clock immediately.
- Auto Non-Revertive: In this mode, the DPLL automatically selects the highest priority input that is valid. If a higher priority input because valid, the DPLL will not switch-over until the currently selected input becomes invalid.