This discussion just to share what i've experienced on the 56F84xxx family : it could be a bug in the silicon or an error in the reference manual .
On the reference manual of this family ( i.e. : MC56F8455x - Reference Manual see ) there is the following sentence ( page 983 ) :
"• Individual pull resistor type selection for each pin in either peripheral mode or GPIO mode"
However, I've experienced that, when a pin is in peripheral mode ( correspondig GPIOx_PER is set ) , setting the corresponding bit of GPIOx_PUR doesn't pull the pin up ..
The pull-up seems to be effective only in GPIO mode .
Has anyone here that have experienced such erratic behaviour ?