HDMI settings (frequency for EMC tests)

Hello,

we are using a NVIDIA Jetson Xaviar AGX in our device. During a electromagnetic compatibility test a problem encountered if the HDMI interface was connected to the touch screen. The EMC test results are promising if we don’t use the HDMI connection.

Is there a way to manipulate the frequencies of the HDMI interface?
Is is possible to enable frequency spreading on HDMI?

Thanks

There is a tuning guide doc in DLC, you can check that first.
https://developer.nvidia.com/jetson-agx-xavier-series-tuning-and-compliance-guide-application-note

Thanks for the really interesting document.

Is there a DLC or some “How-To” that explains how to set the register values for HDMI (Table 17/18)?

Hi,

Do you mean you want to fix this value after kernel is up? If so, there is a prod setting in device tree.

hardware/nvidia/soc/t19x/kernel-dts/tegra194-soc/tegra194-soc-prod.dtsi

You need to firstly download the kernel source from our DLC and then rebuild the dts file to dtb.

As far as I understand is the tuning guide about HDMI Signal compliance, not about the EMI compliance.

We are still struggling with EMI issues due to HDMI on NVIDIA Xavier AGX.

Hi, what is your requirement on this? Are you using a devkit or custom design? Xavier devkit should not be used for a product. If a custom design, the PCB layout should follow the design guide well.

Our main requirement is, that we can pass the EN 61000-6-3. That norm defines the emitted interference. We are currently around 13dB above the maximum allowed peak.

We are not using the NVIDIA DevKit, we are using the Rogue Carrier board from ConnectTech.

Please check with carrier board vendor first. Assume the board should have well followed layout guideline in OEM DG.