RE: Invalid default MAC at first read - nRF7002

Antoine.B — Wed, 10 Jun 2026 10:17:48 GMT

Hi Marte,

Thank you for your response ! I just test it and it work fine after adding the reboot !

Is that a recent update of the documentation ? Using nRF7002 from another lot (one year ago), this reboot was not mandatory as the production went fine without it.

Best regards,

Antoine

RE: Invalid default MAC at first read - nRF7002

Marte Myrvold — Wed, 10 Jun 2026 09:29:07 GMT

Hi Antoine,

The main difference between the two tests is this:

RX: OTP Region is unprogrammed - program to enable R/W

RX: OTP Region is open for R/W

So in the first test, the REGION.PROTECT registers are in the unprogrammed/disabled state (0xFFFFFFFF), which means that neither read nor write access is enabled for the customer-programmable region. Therefore, when otp_read_params() is called, the MAC and CALIB registers cannot be read, and return 0x00000000 instead of the actual OTP content.

As stated in the OTP memory programming documentation, a reboot is required after writing 0x50FA50FA. So the required programming sequence is:

Set the protection registers with wifi_radio_ficr_prog otp_write_params 0x100 0x50FA50FA
Reboot the device
Write MAC / read OTP

So the fix is to add a device reboot step in your test sequence after otp_write_params 0x100 0x50FA50FA and before otp_read_params.

Best regards,
Marte