How to Write values to UICR register ?

[sreehari410]

I am using nrf52832_xxaa with SDK v11.0. I have a requirement to write into UICR register APPROTECT to set its value to 0x00. Is it possible?If yes, please provide a sample code.

[Ole Saether]

Yes, it's possible. Try this code:

NRF_NVMC->CONFIG = (NVMC_CONFIG_WEN_Wen << NVMC_CONFIG_WEN_Pos);
while (NRF_NVMC->READY == NVMC_READY_READY_Busy) {}
NRF_UICR->APPROTECT = 0xFFFFFF00;
while (NRF_NVMC->READY == NVMC_READY_READY_Busy) {}
NRF_NVMC->CONFIG = (NVMC_CONFIG_WEN_Ren << NVMC_CONFIG_WEN_Pos);
while (NRF_NVMC->READY == NVMC_READY_READY_Busy){}

Or with nrfjprog:

nrfjprog --memwr 0x10001208 --val 0xffffff00

[endnode]

(also note that UICR registers are loaded at the start-up so to make it effective you need to reset the chip at least once, whatever method you use...)