Read values of UICR in Application

RE: Read values of UICR in Application

Simon_89 — Thu, 21 Sep 2023 14:23:31 GMT

Hi Einar

Thank you very much for the perfect answer, that solved the issue!

Could that be integrated into the official documentation? This one is only referring to writing, but I could not find anything referring to reading...

Thanks,

Simon

RE: Read values of UICR in Application

Einar Thorsrud — Thu, 21 Sep 2023 08:48:26 GMT

Hi,

You cannot use fstorage in this case. To read data from the UICR (or any other fixed address in flash for that matter), just read it directly. Example:

uint32_t reg_val = *(volatile uint32_t *) 0x10001090;

Here, the content of CUSTOMER[4] will be copied to the variable reg_val. You could also make a pointer and use that. For example, like this:

volatile uint32_t * p_my_uicr_reg = (volatile uint32_t *) 0x10001090;
NRF_LOG_INFO("Val: %08X", *p_my_uicr_reg);

RE: Read values of UICR in Application

JamesDougherty — Wed, 20 Sep 2023 16:13:29 GMT

Hello,

No worries, I'll leave that there just in case someone asks about it and is using Zephyr / nRF Connect SDK.

RE: Read values of UICR in Application

Simon_89 — Wed, 20 Sep 2023 16:11:16 GMT

Hi,

I'm sorry, I'm still using the old framework, nrf5 sdk for thread and zigbee which in our case is used together with FreeRTOS

RE: Read values of UICR in Application

JamesDougherty — Wed, 20 Sep 2023 16:06:27 GMT

Are you using Zephyr? Here is how I did it in Zephyr. Hopefully it helps some.

I have an enum to easily select which UICR value I want to interact with:

typedef enum flash_uicr_register {
    fur_01,
    fur_02,
    ...
    fur_30,
    fur_31,
    fur_32,
} flash_uicr_register_t;

Then I wrote a simple helper function to easily compute the offsets:

static off_t compute_uicr_offset(const flash_uicr_register_t uicr_register)
{
    //
    // The UICR base address is 0x10001000
    // The UICR registers start at 0x080
    //
    // This calculation calculates the offset based off of the passed in register ordinal.
    //
    // Examples:
    //     fur_01: 0x10001000 + (0x080 + (0 << 2)) = 0x10001080 (0x080)
    //     fur_02: 0x10001000 + (0x080 + (1 << 2)) = 0x10001084 (0x084)
    //     fur_nn: ...
    //     fur_31: 0x10001000 + (0x080 + (30 << 2)) = 0x100010F8 (0x0F8)
    //     fur_32: 0x10001000 + (0x080 + (31 << 2)) = 0x100010FC (0x0FC)
    //
    // See: https://infocenter.nordicsemi.com/topic/ps_nrf52840/uicr.html
    //

    return (off_t)NRF_UICR + (0x080 + (uicr_register << 2));
}

Then I use the Zephyr's flash driver to interact with it. Here is a simplified version:

uint32_t flash_read_uicr(const flash_uicr_register_t uicr_register)
{
    __ASSERT_NO_MSG(uicr_register >= fur_01 && uicr_register <= fur_32);

    static uint32_t value = 0;

    int error = flash_read(mDevice, compute_uicr_offset(uicr_register), &value, sizeof(uint32_t));

    if (error != 0)
    {
        LOG_FLASH_E("Error reading from the UICR (Error: %d - %s)", error, errno_to_str(error));
        return false;
    }

    return value;
}

bool flash_write_uicr(const flash_uicr_register_t uicr_register, const uint32_t value)
{
    __ASSERT_NO_MSG(uicr_register >= fur_01 && uicr_register <= fur_32);

    int error = flash_write(mDevice, compute_uicr_offset(uicr_register), &value, sizeof(uint32_t));

    if (error != 0)
    {
        LOG_FLASH_E("Error writing to the UICR (Error: %d - %s)", error, errno_to_str(error));
        return false;
    }

    return true;
}

bool flash_write_verify_uicr(const flash_uicr_register_t uicr_register, const uint32_t value)
{
    return flash_write_uicr(uicr_register, value) &&
           flash_read_uicr(uicr_register) == value;
}

bool flash_erase_uicr(void)
{
    int error = flash_erase(mDevice, (off_t)NRF_UICR, sizeof(*NRF_UICR));

    if (error != 0)
    {
        LOG_FLASH_E("Error erasing the UICR memory (Error: %d - %s)", error, errno_to_str(error));
        return false;
    }

    return true;
}

Here is what mDevice is:

const struct device *const mDevice = DEVICE_DT_GET(DT_CHOSEN(zephyr_flash_controller));