HDMI DDC_SCL/SDA pull-up voltage level and abnormal signal

Jetson 35.4.1 platform
In “Jetson_Orin_NX_Series_and_Orin_Nano_Series_Design_Guide_DG-10931-001_v1.1” document, HDMI DDC signals are pulled up to 3.3V. But in “Jetson_Orin_NX_andOrin_Nano_Schematic_Checklist.nvxlsx” and “P3768_A04” demo board, HDMI DDC signals are pulled up to 1.8V. Please confirm which is correct.
In addition, I tested that abnormal pulse signals are generated on DDC signals every once in a while, I don’t know why?

It is 3.3V in checklist as below. The default design on P3768_A04 is for DP only.

Why are there abnormal signals on the DDC signals?

Please describe “abnormal signals on the DDC signals” in detail. Did you meet any issue of display? How and why did you do the test? Is it on devkit? Is it tested with DP display?

Only used as an HDMI port,connected to HDMI connector,we tested HDMI signals quality,but found even without DDC access, there were intermittent signals with amplitudes other than 3.3V on the signal lines. There is also a similar phenomenon on development kits.

Can you pls show a clear waveform of “intermittent signals with amplitudes other than 3.3V on the signal lines”?

Hi,

You didn’t mention anything before so I wonder. Are you sure your software is configured to HDMI mode already?

This topic was automatically closed 14 days after the last reply. New replies are no longer allowed.