HDMI drive strength control and pixel clock change

[ani10c89]

Hi,

We are facing issues with HDMI port during EMI test. Can you please let us know documentation to change the drive strength and pixel clock for HDMI interface.

Regards,

Anirudha

[b36401]

Actually pixel clock depends of FPS and the resolution. Please refer to table 15-6 of i.MX8M Reference Manual
https://www.nxp.com/docs/en/reference-manual/IMX8MDQLQRM.pdf

As for drive strength it can be changed with HDMI firmware.
Please refer to section 6.1.6.2 "HDMI image boot up" of the Reference Manual for the details.
However it is not supported with our BSP.

Have a great day,
Victor

-----------------------------------------------------------------------------------------------------------------------
Note: If this post answers your question, please click the Correct Answer button. Thank you!
-----------------------------------------------------------------------------------------------------------------------

[ani10c89]

Hi Victor,

Can you please help to change the drive strength in BSP. Please provide the documentation on how HDMI booting can be enabled in BSP.

This is very critical to resolve the HDMI EMI issues.

Regards,

Anirudha

[b36401]

The drive strength can not be changed in BSP. You need to update HDMI firmware.

[sandeep_yenugul]

Hi Victor,

I have got a binary of HDMI firmware in imx-boot/0.2-r0/git/iMX8M/signed_hdmi_imx8m.bin. But from where can I get source code for same so that I can edit the drive-strength in it, recompile and test it.

[ani10c89]

Can you provide details or documentation for it which can help us control the drive strength.

Can you please provide the support for this as it is critical for EMI testing.

Regards,

Anirudha

[ani10c89]

Hi,

Any update.

Regards,

Anirudha