Hi,
I am trying to maintain a single bit of information through a power-on reset event (sd_nvic_SystemReset();). I am trying to do this through the configuration of an unused I/O pin. I am setting the pin to be an output before the reset and then reading the pin-configuration after the reset:
nrf_gpio_cfg_output(23); //set pin 23 to output
sd_nvic_SystemReset(); // reset
//this appears after the reset:
SEGGER_RTT_printf(0, "pin_test = %d\n", NRF_GPIO->PIN_CNF[23]&0x01); //print direction bit for pin 23
The output of this operation is always zero (I have printed the value of the direction before the reset and it is 1). Am I correct in my understanding that the pin configuration bits should be maintained through a power-on reset? Also, I am open to other methods of carrying 1 bit of information through a reset (I would prefer to avoid the gpregret register if possible, as it is already used for a bootloader with various options).
Thanks in advance, Dave