Erasing UICR register in application code

[Dhiraj]

Hello Everyone,

I am using nrf51822 with S130. After completely erasing the chip, with the below mentioned code snippet in application code:

NRF_NVMC->CONFIG = NVMC_CONFIG_WEN_Wen << NVMC_CONFIG_WEN_Pos;

while (NRF_NVMC->READY == NVMC_READY_READY_Busy){}

*(uint32_t *)0x10001080 = hexData;

NRF_NVMC->CONFIG = NVMC_CONFIG_WEN_Ren << NVMC_CONFIG_WEN_Pos;

while (NRF_NVMC->READY == NVMC_READY_READY_Busy){}

I am able to write data in the UICR register. I tried subsequent writing to UICR using the same code in the application code, however, UICR data doesn't change. Based on further research I came to know that the entire chip needs to be erased for writing new data. However, I want to just erase UICR to rewrite new data to the UICR. Is there any way to erase the UICR registers in application code to rewrite new data?

Thanks

[John]

On the nRF51822 you cannot programatically erase the UICR. If you go to a newer variant such as the nRF52840, there is a ERASEUICR register in the NVM controller. I haven't checked the nRF52832 to see if it supports that register as well.

[Dhiraj]

Hello John,

Thank you for your reply. I tried erasing the UICR using following code:

NRF_NVMC->CONFIG = NVMC_CONFIG_WEN_Een << NVMC_CONFIG_WEN_Pos;

while (NRF_NVMC->READY == NVMC_READY_READY_Busy){}

NRF_NVMC->ERASEUICR = 1;

while (NRF_NVMC->READY == NVMC_READY_READY_Busy){}

But it doesn`t work. I followed this forum :devzone.nordicsemi.com/.../ which mentions that ERASEUICR is not available functionality on all chip configurations. It is only available when there is a pre-programmed factory code is present in the chip.