Hi,
In our product we have a few GPIO pins that should keep their state for as long as possible through a soft reset, CPU lockup, or WDT-reset. Specifically, the pins are connected to pulldown resistors, so they go to 0V whenever the 9160 does not hold the pins high. Currently, in a minimal application, when a reset through software is triggered they stay low for a little over 250ms, we want this to be lower. The pins are set high using Zephyr's SYS_INIT with EARLY level, e.g the pins go high before Zephyr boots.
It does not seem like the nrf9160 supports pin retention through restarts, but in table 19, chapter 5.5.8 of the nrf9160 datasheet, the POWER.GPREGRET registers are described to have their values retained through soft resets. Is there a way to use this to minimize the time GPIO-pins lose their state? Or is there any other way to minimize this time?
