LMK04828: Use CLKin/Fin/FBCLKin as reference clock input for PLL2

The path you highlight is intended for use as a PLL feedback path, it would normally be used to perform 0-delay by routing an output clock back to PLL2 through an external path -- which for most purposes you can do more simply using CLKout6 or CLKout8 for 0-delay feedback internally.

While you could technically use this path for a reference, then route an output clock into OSCin to provide a feedback path (and effectively flip PLL reference and feedpath paths) - you wouldn't want to do this because it would break the VCO calibration.

If you require a method to connect CLKin1 to PLL2 reference, please consider the pin compatible and programming similar LMK04832. This allows CLKin1 to be connected to PLL2 reference. Note that output formats are a bit different between LMK04828 and LMK04832. This is really convenient on LMK04832 because these CLKin1 pins can be used as reference to PLL1, reference to PLL2, or clock distribution.

73,
Timothy