Please confirm the following is correct for nRF52840 (per PS v1.1)
1. The firmware doesn't have to enable internal pull-up when the pin reset is configured (it's done automatically by nRF52840)
2. There is no need for off-chip pull-up resistor. (Note: For improved noise immunity some may choose to lower the pull-up resistance; any issues?)
3. Per parameter 't_PINR', the on chip pull-up resistance is about ~10's of kOhm (same pull-up HW as all other GPIO). Is it the 13 kOhm as used in other pull-ups?
The closest information I find is symbol t_PINR, which only gives the reset time for two capacitances (500nF,10uF). It's not clear if this is equal to 1x RC time constant or for example 3xRC.
