Example code to store a 9 digits serial number in UICR

[Learner]

Hello,

I would like to use the UICR customer registers to store our devices serial numbers. 

Can you please point me to some example code for nRF52833 SoC.

I am using nRF Connect SDK v1.7.0.

Thank you for your help.

Kind regards

Mohamed

[haakonsh]

#include <zephyr.h>
#include <nrfx_nvmc.h>

void main(void)
{
	nrfx_nvmc_word_write(&NRF_UICR->CUSTOMER[0], 0x00);
	
	return;
}

I believe this code snippet should write 0x00 to the first customer register in UICR. 

BTW, you can use the BLE address in DEVICEID[n] as a serial number for your devices, they are unique 64bit addresses. That way you can easily find the serial number of the device OTA. 

[Learner]

Thank you Haakonsh.

I am using NVS to access the SoC internal flash. Is there an equivalent NVS function I can use?

Thank you for the tip regarding using the BLE address as a serial number.

Kind regards

Mohamed

[Learner]

Good Morning Haakonsh,

I am now back working on the write and read of the UICR register.

I am finding I can write to and read from it but the problem each time I flash the firmware in the device I lose the content of the UICR. The next read is 0xffffffff. I expected the UICR content will remain protected until it is written to again. I am inserting snippets of the code below.

If I flash the debug build (CONFIG_DEBUG_PORT_ACCESS=y) of the firmware from SES Nordic Edition v5.60 then the UICR content is preserved. However, if I use nRF Programmer v2.3.3 then the content of the UICR being erased.

Note, when using nRF Programmer only the 'Erase & write' option is available. The 'Write' only option is disabled, see attached screen shot below.

void system_write_dev_id( uint32_t hb_id )
{
    /* Allow UICR access */
    NRF_NVMC->CONFIG = NVMC_CONFIG_WEN_Wen;
    while (NRF_NVMC->READY == NVMC_READY_READY_Busy) { }

    /* Set new value for the id */
    NRF_UICR->CUSTOMER[0] = hb_id;

    /* Disallow UICR access */
    NRF_NVMC->CONFIG = NVMC_CONFIG_WEN_Ren;
    while (NRF_NVMC->READY == NVMC_READY_READY_Busy) { }
}

/* Read the programmed UICR device id */
memcpy( &dev_id, (uint32_t*)0x10001080, 4 );

Can you spot anything I am doing missing or doing wrong?

PS Case ID: 280741 deals with the same problem but I could not find  a solution there. 

I think the problem is in the way I am flashing the target but I am not sure how to configure nRF Programmer in order NOT to erase the UICR register.

Thank you.

Kind regards

Mohamed

[Simon]

Hello Mohamed,

What is the current state on this issue?

Best regards,

Simon

[Learner]

Hi Simon,

Although I can write to and read from UICR I am still facing the problem of the UICR content being erased (on nRF52833 QDAAA0 SoC)

1- After I start a debug session in SES v5.60

2- Or use nRF Programmer v2.3.3 to flash a merged,hex image

This is now being dealt under Case ID: 290765.

Kind regards

Mohamed

[Simon]

Learner said:

This is now being dealt under Case ID: 290765.

Do you want to continue the discussion there, and close this ticket?

Best,

Simon

[Learner]

Yes, pleas close it because I don't know how to.