I am not sure there is a pull-up as they call out those situations specifically in the datasheet, but there are important remarks around setting EXTMODE and EXTPOLAR
(page29)
Software should only change a bit in this register when its interrupt is disabled in the VICIntEnable register, and should write the corresponding 1 to the EXTINT register before enabling (initializing) or re-enabling the interrupt, to clear the EXTINT bit that could be set by changing the mode
Software should only change a bit in this register when its interrupt is disabled in the VICIntEnable register, and should write the corresponding 1 to the EXTINT register before enabling (initializing) or re-enabling the interrupt, to clear the EXTINT bit that could be set by changing the polarity
Maybe that can do the trick.
regards,
Paul