How to add Skyworks fem to nrf5340 audio

[LandyWang]

Hello,

I am using nrf5340 audio sample with the custom board. The nRF Connect SDK version I used is v2.7.0.

I referred to this post and tried to add skyworks fem to my nrf5340 audio application.

The following is the part I modified:

nrf5340_audio_dk_nrf5340_cpunet.overlay

/ {
    nrf_radio_fem: pa_lna {
        compatible = "skyworks,sky66112-11", "generic-fem-two-ctrl-pins";
        ctx-gpios = <&gpio1 4 GPIO_ACTIVE_HIGH>;
        ctx-settle-time-us = < 23 >;
        crx-gpios = <&gpio1 5 GPIO_ACTIVE_HIGH>;
        crx-settle-time-us = < 5 >;
        cps-gpios = <&gpio1 0 GPIO_ACTIVE_HIGH>;
        tx-gain-db = < 13 >;
        rx-gain-db = < 14 >;
    };
};
&radio {
	fem = <&nrf_radio_fem>;
};

nrf5340_audio_dk_nrf5340_cpuapp.overlay

/ {
    nrf_radio_fem: pa_lna {
        compatible = "skyworks,sky66112-11", "generic-fem-two-ctrl-pins";
        ctx-gpios = <&gpio1 4 GPIO_ACTIVE_HIGH>;
        ctx-settle-time-us = < 23 >;
        crx-gpios = <&gpio1 5 GPIO_ACTIVE_HIGH>;
        crx-settle-time-us = < 5 >;
        cps-gpios = <&gpio1 0 GPIO_ACTIVE_HIGH>;
        tx-gain-db = < 13 >;
        rx-gain-db = < 14 >;
    };
};

prj.conf

CONFIG_MPSL=y
CONFIG_MPSL_FEM_ONLY=y
CONFIG_MPSL_FEM_SIMPLE_GPIO=y

But it doesn't seem to work.

Is there any way to add skyworks fem to nrf5340 audio application?

[Elfving]

Try putting SB_CONFIG_APPROTECT_USE_UICR=y in a "sysbuild.conf" file which. I thought you additionally needed to set the same config for all images but now I don't think you do anymore, so nevermind that for now.

Try this and see if you run into the same problem.

Though if you did want to enable this in other images, just to answer that part as well (besides the main one, that you use prj.conf for), you can for instance add it to sysbuild/ipc_radio.conf. 

Regards,

Elfving

[LandyWang]

Sorry, just to clarify, I'm currently using NCS 2.7.0 and sysbuild.

I checked the release note, SB_CONFIG_APPROTECT_USE_UICR should be only available in NCS 2.8.0.

In fact, after I added SB_CONFIG_APPROTECT_USE_UICR to nrf5340_audio\sysbuild.conf with NCS 2.7.0, an unknown symbol error occurred. So this setting should not be possible with NCS 2.7.0.

I have put aside the settings of skyworks fem for now and want to make reading the TXPOWER register feasible first. Only after this problem is solved can I know whether Tx power has improved.

Is there any other way to read the TXPOWER register on nrf5340 audio application in NCS 2.7.0?

Also, the issue currently being dealt with seems to have deviated from the title skyworks fem. I am wondering whether it would be more appropriate to open a new ticket to focus on this tx power register issue.

[Elfving]

Ah I see. Sorry about that. I remember now that we were a bit back and forth regarding this. So, with 2.7 you can just use CONFIG_NRF_APPROTECT_USE_UICR, but enable it on both the app and net core.

LandyWang said:

I have put aside the settings of skyworks fem for now and want to make reading the TXPOWER register feasible first. Only after this problem is solved can I know whether Tx power has improved.

You can read what TXpower the NRF is providing by for instance reading the TXPOWER register. 

Regards,

Elfving

[LandyWang]

LandyWang said:

How to set this for both images?

Sorry I have to ask this question again.

Because I added CONFIG_NRF_APPROTECT_USE_UICR=y to nrf5340_audio\prj.conf and nrf5340_audio\sysbuild\ipc_radio\prj.conf, the following problems still occurred.

C:\WINDOWS\system32>nrfjprog --memrd 0x4000150C --log
[error] [SeggerBackend] - JLinkARM.dll ReadMem returned error 1.
[error] [SeggerBackend] - JLinkARM.dll ReadMem returned error 1.
[error] [SeggerBackend] - JLinkARM.dll ReadMem returned error 1.
[error] [SeggerBackend] - JLinkARM.dll ReadMem returned error 1.
[error] [SeggerBackend] - JLinkARM.dll ReadMem returned error 1.
[error] [  nRF53] - The read access failed due to memory protection.
ERROR: Access to the selected address is blocked by the SPU.

I want to know which files you add CONFIG_NRF_APPROTECT_USE_UICR=y to successfully read TXpower.

[Sigurd Hellesvik]

Hi,

There are two issues to reading from that registers, and none of them are related to TF-M. While it seems so from the error message related to the SPU, this is just because the SPU is in general responsible for blocking any disallowed access.

Issue 1: The ticket you got the command for is to read TXPOWER from the nRF52840. The nRF5340 has TXPOWER in another register. Specifically RADIO (0x41008000) -> TXPOWER (0x50C) = 0x4100850C

Issue 2: In the nRF5340, the TXPOWER register lives in the network core and not in the application core. nrfjprog tries to read from the application core by default. If we use "nrfjprog --help", we can see:

Try this instead:

nrfjprog --memrd 0x4100850C --coprocessor CP_NETWORK