Does this resistor pull down automatically?
This is a very good question.
Register 0x05:04 is described as GPIO_PULL_EN - GPIO Drive Strength and Pull Control
But the details of that register are “Register file: 0x05 – GPIO control and status, sub-register 0x04 can be used to lower the drive strength of the GPIOs. Setting to 0 will lower the drive strength.”
No mention at all of any pull down enable / disable.
Doing a quick search of the DW3000 driver code I can’t see any mention of pull down control. Register GPIO_PULL_EN isn’t even in the list of defined registers.