Write MAC to OTP over RTT

[Roman Veselskyi]

I have a custom board with the nRF9160 and nRF7200 connected.

I was able to build the radio_test sample to check if everything is working, and for now, it seems to be fine. Here are the PHY stats:

************* PHY STATS ***********
rssi_avg = -86 dBm
ofdm_crc32_pass_cnt=0
ofdm_crc32_fail_cnt=2
dsss_crc32_pass_cnt=2
dsss_crc32_fail_cnt=0

Next, I tried to program the MAC using this command:

wifi_radio_ficr_prog otp_write_params 0x120 arg1=0x23f4a7f8 arg2=0x06ce

However, I got the following errors:

rtt:~$ wifi_radio_ficr_prog otp_write_params 0x120 arg1=0x23f4a7f8 arg2=0x06ce
OTP Region is open for R/W

Invalid MAC address. MAC address cannot be all 0's, broadcast or multicast address
rtt:~$ wifi_radio_ficr_prog otp_write_params 0x120 arg1=0x23F4A7F8 arg2=0x06CE
OTP Region is open for R/W

Invalid MAC address. MAC address cannot be all 0's, broadcast or multicast address

After that, I tried writing a command to unlock the OTP:

wifi_radio_ficr_prog otp_write_params 0x100 arg=0x50FA50FA

Unfortunately, the issue now is that it writes 0 to all the registers and locks the OTP. The output shows:

rtt:~$ wifi_radio_ficr_prog otp_write_params 0x100 arg=0x50FA50FA
OTP Region is open for R/W

Finished Writing OTP params
rtt:~$ [00:48:13.181,640] <inf> otp_prog: Written REGION_PROTECT0 (0x100) : 0x0000
rtt:~$ [00:48:13.181,671] <inf> otp_prog: Written REGION_PROTECT1 (0x104) : 0x0000
rtt:~$ [00:48:13.181,671] <inf> otp_prog: Written REGION_PROTECT2 (0x108) : 0x0000
rtt:~$ [00:48:13.181,671] <inf> otp_prog: Written REGION_PROTECT3 (0x10c) : 0x0000
rtt:~$ rtt:~$ wifi_radio_ficr_prog otp_write_params 0x120 arg1=0x23f4a7f8 arg2=0x06ce
OTP Region is locked!!!

USER Region is not Writeable

I am now unable to unlock the chip because all the arguments are being sent as 0, no matter what I try to write.

I also tried this commands:

wifi_radio_ficr_prog otp_write_params 0x100 arg=0x50FA50FA

wifi_radio_ficr_prog otp_write_params 0x100 arg='0x50FA50FA'

wifi_radio_ficr_prog otp_write_params 0x100 0x50FA50FA

wifi_radio_ficr_prog otp_write_params 0x100 1358582010

For me the issue is that arg always equal to 0 if I send them over RTT.
For sending I use the J-Link RTT Viewer V7.94e

[Vidar Berg]

Hello,

The arguments should be passed like this: 'wifi_radio_ficr_prog otp_write_params 0x120 0x23f4a7f8 0x06ce', without 'arg1=' and 'arg2='. I see that the protection bits were set after you ran the 'wifi_radio_ficr_prog otp_write_params 0x100 arg=0x50FA50FA' command, which unfortunately means the FICR can no longer be updated. Do you have another board you can test this on? Also, which SDK version are you on?

Best regards,

Vidar

[Roman Veselskyi]

Hi Vidar Berg 

Thanks, I already figure out that I did send command in the wrong order. Fortunately, I ordered 3 boards and blocked only one of them.

As I understand there's a way to set MAC from the firmware and not from the OTP as now I have only 0s there and it will not work. By the way we will use nRF7200 only for scan and WIFI location does it also require the MAC address? 

I am using SDK 2.6.1

[Vidar Berg]

Hi,

Roman Veselskyi said:

As I understand there's a way to set MAC from the firmware and not from the OTP as now I have only 0s there and it will not work.

There is the CONFIG_WIFI_FIXED_MAC_ADDRESS Kconfig symbol that you can use to override the MAC address stored in OTP. However, this is intended only for testing purposes.

Only passive scanning is used for Wi-Fi locationing, so the MAC address will not be transmitted.

Best regards,

Vidar

[Roman Veselskyi]

 Vidar Berg thanks,

I have 1 more question regarding the MAC write operation.

I tried to use the next MAC f2:01:d5:50:6f:52

This is the command I send over RTT

 wifi_radio_ficr_prog otp_write_params 0x120 0x50d501f2 0x526f

But when I read values, I see that it shows another MAC

MAC0.ADDRESS = f0:01:d4:00:4e:02

rtt:~$ rtt:~$ wifi_radio_ficr_prog otp_write_params 0x120 0x50d501f2 0x526f
OTP Region is open for R/W

Finished Writing OTP params
rtt:~$ [00:22:05.303,131] <inf> otp_prog: mac addr 0 : Reg1 (0x120) = 0x50d501f2
rtt:~$ [00:22:05.303,741] <inf> otp_prog: mac addr 0 : Reg2 (0x124) = 0x526f
rtt:~$ [00:22:05.304,077] <inf> otp_prog: Written MAC address 0
rtt:~$ [00:22:05.304,077] <inf> otp_prog: Written REGION_DEFAULTS (0x154) : 0xfffffffd
rtt:~$ rtt:~$ wifi_radio_ficr_prog otp_read_params
OTP Region is open for R/W

...

MAC0.ADDRESS0 = 0x00d401f0
MAC0.ADDRESS1 = 0x0000024e
MAC0.ADDRESS = f0:01:d4:00:4e:02

MAC1.ADDRESS0 = 0xffffffff
MAC1.ADDRESS1 = 0xffffffff
MAC1.ADDRESS = ff:ff:ff:ff:ff:ff

CALIB.XO = 0xff
REGION_DEFAULTS = 0xfffffffd

rtt:~$ 

[Vidar Berg]

The registers are one-time programmable, so they can't be written to more than once. You can try writing this address to the second MAC address register.