When P0.18 is configured as the RESETn pin, is there a pull-up enabled?
In our design we have an external CPU driving the nRF52 RESETn line.
We have a pull-down on that line (10k) and we are seeing 1.3V with a VCC of 3.3V when our CPU has that line tri-stated.
The reset pin does indeed enable a pull-up of 13k typ. This fits well with the observed 1.3V: 3.3V * 10k/23k = 1.43V.
Why do you have a pull-down on a reset line that is active low?
We have a pull-down because we want the radio(s) to stay in reset until the CPU enables them.
Where is this RESETn pull-up documented?
Is there any way to disable it?