Example code to write to UICR

[rmarques]

I am trying to store data to the UICR using SDK16, mesh SDK 4.2.0 and the nRF52840 chip.

I want to write to the UICR once on runtime and never again. To avoid messing with the softdevice, I am trying to write to the UICR before calling ble_stack_init() and after __LOG_INIT to get logs working.

This is the code:

NRF_NVMC->CONFIG = NVMC_CONFIG_WEN_Wen;
while (NRF_NVMC->READY == NVMC_READY_READY_Busy){}

uint32_t * consumer0 = (uint32_t *) 0x10001080;
*consumer0 = 0x00000005;

NRF_NVMC->CONFIG = NVMC_CONFIG_WEN_Ren;
while (NRF_NVMC->READY == NVMC_READY_READY_Busy){}
__LOG(LOG_SRC_APP, LOG_LEVEL_INFO, "%d\n", *consumer0);

NVIC_SystemReset();

So we put the NVMC in Write enable, wait for it to be ready, write to consumer0, put it in Read enable, wait for it to be ready and reset the device. I can see 5 logged to Segger console.

Then I comment what I don't need:

//NRF_NVMC->CONFIG = NVMC_CONFIG_WEN_Wen;
//while (NRF_NVMC->READY == NVMC_READY_READY_Busy){}

uint32_t * consumer0 = (uint32_t *) 0x10001080;
//*consumer0 = 0x00000005;

//NRF_NVMC->CONFIG = NVMC_CONFIG_WEN_Ren;
//while (NRF_NVMC->READY == NVMC_READY_READY_Busy){}
__LOG(LOG_SRC_APP, LOG_LEVEL_INFO, "%d\n", *consumer0);

//NVIC_SystemReset();

And I see -1 logged to Segger console, meaning the flash still has the 0xFFFF on that position. I can confirm it on Segger Memory explorer that 10001080 is never filled with the data I wanted. Am I doing something wrong?

[dgerman]

Beware that sometimes Flash memory is cached by Segger and does not exactly show what you expect. I refer explicitly to 

exec SetAllowFlashCache =0   

Have you tried exiting Segger and starting it again to see if flash isn really set?

In addition add a check in your coded to see what the value is.

Finally choose your values wisely since if there PREVIOUS value of customer[0] was FFFFFFFF this will work BUT if the previous value was 05000000 it will not since write to flash can only reset bits. It is necessary to erase flash to set it to FFFFFFF

[rmarques]

I tried exiting Segger and rechecking the memory, all was the same. I also added a small check for looking for the change in the flash like so:

//NRF_NVMC->CONFIG = NVMC_CONFIG_WEN_Wen;
//while (NRF_NVMC->READY == NVMC_READY_READY_Busy){}

uint32_t * consumer0 = (uint32_t *) 0x10001080;
//*consumer0 = 0x00000005;
if(*consumer0 == 5){
    __LOG(LOG_SRC_APP, LOG_LEVEL_INFO, "*consumer0 = 5\n");
}
else {
    __LOG(LOG_SRC_APP, LOG_LEVEL_INFO, "Flash not correct, *consumer0 = %d\n", *consumer0);
}

//NRF_NVMC->CONFIG = NVMC_CONFIG_WEN_Ren;
//while (NRF_NVMC->READY == NVMC_READY_READY_Busy){}

//NVIC_SystemReset();

As soon as I comment the lines commented in the code I get the second __LOG: Flash not correct, *consumer0 = -1

[Einar Thorsrud]

Yes, that looks correct (note that if you want to debug/program after step 3, it is a requirement that the firmware continues to enable debugger access. That is the default behavior with the SDK though, so it should be good).

I forgot about this post before, but you can read a bit more in Working with the nRF52 Series' improved APPROTECT if you want more details.

[Learner]

Thank you for sharing the link.

Einar Thorsrud said:

note that if you want to debug/program after step 3, it is a requirement that the firmware continues to enable debugger access. That is the default behavior with the SDK though, so it should be good).

Understood. The three steps mentioned above are for a production environment. We do all development and debugging in Segger Embedded Studio. 

Kind regards

Mohamed

[Learner]

Hi Thorsrud,

I have installed nrfjprog v10:15 on another machine running Windows 10 64-bits and I am running into this problem,

C:\>nrfjprog -v
ERROR: JLinkARM DLL is invalid. Please reinstall latest JLinkARM DLL.
NOTE: For additional output, try running again with logging enabled (--log).
NOTE: Any generated log error messages will be displayed.

C:\>nrfjprog -v --log
WARNING: Logging is unavailable. nrfjprog.exe does not have write
WARNING: permission for the log file
ERROR: JLinkARM DLL is invalid. Please reinstall latest JLinkARM DLL.
NOTE: For additional output, try running again with logging enabled (--log).
NOTE: Any generated log error messages will be displayed.

He has installed it twice but he is still facing the same problem.

Thank you for your help.

Kind regards

Mohamed

[Einar Thorsrud]

Hi,

I am not immediately able to explain that. Please open a new question/thread for this as it is not directly related to the original topic in this thread.

[Learner]

Good Morning Einar,

We managed to solve the problem by just installing nRF Connect for Desktop on the new machine.

Thank you for your support.

Kind regards

Mohamed