[CYW43907] wl commands for CE RF certification

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JoLE_3168931
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Level 3
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Hello,

in order to obtain the CE marking for our product, which is based on CYW43907 SoC (module 1GC), we need to pass some RF tests to be compliant with the ETSI 301 893 V2.1.1 standard (we don't use the 2.4Ghz band).

As the module is already pre-certified (I have already got the reports from Murata), only a subset of the RF certification process has to be done.

Especially, the RF laboratory has listed these tests:

  - RF output power (5.4.4)

  - Transmitter unwanted emissions (5.4.5/5.4.6)

  - Receiver spurious emissions (Radiated, 5.4.7)

To be able to perform these tests, a dedicated WLAN firmware is used, as well as a tests application, mfg_tests (+ wl43909B0.exe PC utility).

Some scripts to be used with the wl utility can be found on the WICED SDK directory, but the "WICED Development System Manufacturing Test User Guide" documentation is somewhat light.

So, could you provide the wl commands to use to be able to pass the required tests?

The RF lab asks to transmit at full power on each used channel, and with all supported modulations.

In case of output power being too high, I suppose that we can use the txpwr1 wl command to reduce the TX power output to pass the RF test, but how can we set the new value permanent on the final product with the operational WLAN firmware?

Also, to disable the 2.4Ghz band, we use the command wwd_wifi_change_band(1), is it enough?

Thank you.

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Murali_R
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250 sign-ins 250 replies posted 100 solutions authored

Hello JoLE_3168931

If you don't want 2.4GHz, you can ask murata to submit a request to cypress to disable the 2.4G band for the  CLM BLOB that you will be using. Also can you let me know where you found the API wwd_wifi_change_band. I'm Unable to find it. Not sure if i am missing anything.

You can also set the band using wl command or by setting the band in wifi_config_dct.h

https://www.cypress.com/documentation/application-notes/an225347-cypress-wi-fi-clm-regulatory-manual The manual at this link talks in depth about the certifications that you need and the command sequences using the wl tool. For the list of wl commands available you can refer to WL Tool for Embedded 802.11 Systems: CYW43xx Technical Information

Yes, the txpwr1 command can be used to vary the output power, but you should be careful to ensure that the power transmitted won't exceed the regulatory limits of the region that you are shipping to. This can be done via the NVRAM parameters or getting an updated CLM BLOB which has the power numbers withing the regulatory limits of that particular country.

Thanks

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Murali_R
Moderator
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250 sign-ins 250 replies posted 100 solutions authored

Hello JoLE_3168931

If you don't want 2.4GHz, you can ask murata to submit a request to cypress to disable the 2.4G band for the  CLM BLOB that you will be using. Also can you let me know where you found the API wwd_wifi_change_band. I'm Unable to find it. Not sure if i am missing anything.

You can also set the band using wl command or by setting the band in wifi_config_dct.h

https://www.cypress.com/documentation/application-notes/an225347-cypress-wi-fi-clm-regulatory-manual The manual at this link talks in depth about the certifications that you need and the command sequences using the wl tool. For the list of wl commands available you can refer to WL Tool for Embedded 802.11 Systems: CYW43xx Technical Information

Yes, the txpwr1 command can be used to vary the output power, but you should be careful to ensure that the power transmitted won't exceed the regulatory limits of the region that you are shipping to. This can be done via the NVRAM parameters or getting an updated CLM BLOB which has the power numbers withing the regulatory limits of that particular country.

Thanks

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Hello MuraliR_36,

and thank you for your quick reply.

I had forgotten that the wwd_wifi_change_band() function was not a native WWD function, it comes from this thread.

I just found the CLM regulatory and WL tool manuals one hour ago, they indeed give much more information.

To obtain an updated CLM blob, after the RF testing, should I make a request in this forum?

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JoLE_3168931 if you are using Murata's 1GC module, then you need to request Murata to get an updated BLOB. They should intern raise a request with cypress and we will deliver the BLOB.

Looks like that API works. But it may not have gone through standard testing procedures.

I need to test if using wwd_wifi_turn_off_roam and wiced_wifi_scan_networks_ex() and wiced_join_ap_specific() are enough.

But if you are sure that you need only the mentioned channels, please contact Murata and let them know your requirements and get it updated in the BLOB.

PS: Wi-Fi CLM Regulatory Policy for Module Vendor Customers - KBA229113

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And I forgot to mention that we only want to use the following 5Ghz channels: 36, 40, 44 and 48.

How to be sure that the WLAN module doesn't transmit any data on the other channels?

For now, we disabled roaming (wwd_wifi_turn_off_roam()) and we manage the scan/connect process manually by using the wiced_wifi_scan_networks_ex() and wiced_join_ap_specific() functions with the specific channel parameters set to these allowed channels.

Is it enough?

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Adding RuRa_2181051​ from Murata Europe and ChristianH_71​ from Cypress Europe.

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Hello,

I just realized that we are still using the original wifi_nvram_image.h file coming from the CYW43907AEVAL1F platform.

In addition to the swdiv_en entry (to disable antenna diversity), should we modify this file for an EU product?

It is stated in several documents that this file shall be provided by the module manufacturer, I didn't find any information on the Murata website.

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JoLE_3168931 Please contact Murata and they should be able to provide you with the NVRAM file and check with them before modifying any NVRAM parameters. Why this is so, is because the NVRAM file will be optimised for each Eval board and using the NVRAM file of that particular board brings out the best performance.