18.5.1 PPS One-Way Lock
The PPS1WAY Configuration bit can also be used to prevent inadvertent modification to the PPS selection registers.
When the PPS1WAY bit is set (PPS1WAY = 1), the PPSLOCKED bit can only be set one time after a device
         Reset. Once the PPSLOCKED bit has been set, it cannot be cleared again unless a device
         Reset is executed.
When the PPS1WAY bit is clear (PPS1WAY = 0), the PPSLOCKED
         bit can be set or cleared as needed; however, the PPS lock/unlock sequences must be
         executed.
