I would like to inquire about the HDMI 2.1 display capabilities on the Thor development kit and our custom platform.
Is the Thor devkit currently capable of outputting 8K@30Hz resolution via the onboard HDMI 2.1 port?
If this is a hardware-supported feature but currently limited by software, which JetPack release will officially enable it? Do we need to wait for a major update like JetPack 7.x?[ref][ref]
Additionally, we encountered issues during our custom board evaluation: We recently tested our custom board but found that it failed to output any 8K signals. Is the current software stack limited to HDMI 2.1 TMDS mode (which restricts the resolution to 4K), and requires future software adjustments/patches to switch into FRL (Fixed Rate Link) mode to achieve 8K?
For the current public Jetson Linux documentation, HDMI 8K@30 is not listed as a supported software configuration on Jetson Thor.
The r38.4 Jetson Thor Developer Guide documents the HDMI support as:
HDMI 1.4: 480p, 720p, 1080p, and 4K at 30 Hz
HDMI 2.1 TMDS: 4K at 30 Hz and 60 Hz
So yes, based on the current public software support matrix, the HDMI path is documented for HDMI 2.1 TMDS up to 4K60. HDMI FRL / 8K output is not documented there as supported, so the failure to get an 8K signal from your custom board is consistent with the current documented support scope.
For the future JetPack question, we do not have a public JetPack release number or schedule to share for HDMI FRL / 8K enablement at this time.
In principle, please align with the Jetson Linux Developer Guide for the officially supported software display matrix:
In addition, we are currently performing SI testing on our custom board. We found some issues with the HDMI eye diagram and would like to adjust the Pre-Emphasis and Pre-Shoot configurations to improve signal quality.
For the AGX Orin platform, the manual previously documented the specific addresses we could modify for tuning. However, I checked the Thor document Jetson_Thor_Series_VerificationGuide_DA-12308-001_v1.2.pdf and couldn’t find similar register information.
Could you guide us on how to perform this tuning or provide the necessary register addresses for Jetson Thor?
I understand the AGX Orin tuning guide documented SOR register fields for HDMI tuning. For Jetson Thor, please do not use the AGX Orin HDMI register addresses directly. The HDMI PHY/register settings are platform-specific, and using Orin offsets or tuning values on Thor would not be a valid method.
In the public Thor documentation, I do not see an equivalent customer-facing HDMI pre-emphasis / pre-shoot register table in the I/O Verification Guide. I need to check internally whether this tuning is exposed or supported for customer use on Thor.
Before that, could you help confirm the exact test condition?
JetPack / L4T release used for the test
HDMI mode under test, such as 4K60 TMDS or 8K/FRL
Where the eye diagram is measured, for example at the custom board HDMI connector, compliance fixture, or after the cable
Please also make sure the SI test is first validated with a mode listed in the current Jetson Linux Thor HDMI support matrix. As mentioned above, HDMI FRL / 8K is not documented as a supported software configuration in the current public guide, so an 8K/FRL eye-diagram result would not be a supported debug baseline.
Recommendation: Please validate the HDMI eye diagram using a documented TMDS mode first, and align the custom board layout with the Jetson Thor Series design guide. I will check whether there is an approved Thor-specific method for HDMI TX tuning before suggesting any register-level changes.
Thank you for looking into this internally for us. Here are the exact test conditions and details regarding our current Signal Integrity (SI) validation to help with your internal investigation:
JetPack / L4T Release: We are currently using JetPack 7.1 (L4T r38.4.0 ) for this evaluation.
HDMI Mode Under Test: Our current SI compliance testing and eye-diagram measurements are strictly focused on the officially supported HDMI 2.0 4K@60Hz TMDS mode.
Measurement Location: at the custom board HDMI connector.
Design Guide Alignment: We have strictly followed the Jetson Thor Series Product Design Guide for our custom board high-speed layout, including impedance control and trace length matching.
Since we are observing tight margins in the 4K60 TMDS eye diagram on our layout, having access to the Thor-specific HDMI TX tuning registers, Device Tree overrides, or an unreleased application note would be immensely valuable for our hardware team to pass the compliance baseline.
We look forward to your internal feedback. Thank you!
We will look forward to the outcome of your internal discussions.
Please let us know if there are any updates or if any information can be shared later on.
