The reference manual seems to be pretty good at telling me _how_ to configure the features...but cautions that the features may only be supported on selected pins. How do I determine which selected pins?
I intend to configure two pins as GPIO (with internal pull-ups) and just shorting jumpers connected to the pins. Open=high input, jumpered = low input.
I think you will find almost all I/O pins share full functionality, unless the 'signal multiplexing' or 'Chip Configuration/GPIO Configuration' sections state specifically otherwise (like for a shared crystal pin or such). One bit of warning: The internal pull-ups are called out as 20K to 50K, and 50K may be a little 'high' for jumper access.