JetsonTX2 HDMI Compliance Test ID 7-2:TMDS-VL Fail

Robotics & Edge Computing Jetson & Embedded Systems Jetson TX2
1

We tested the HDMI Compliance Test ID 7-2 using DevKit.
But, The single-ended low level output voltage is not match the test specification. (2.60V < VL < 2.90V @1080p60Hz)
Is there any way to pass the Compliance Test?

HDMI_CTS_7-2_Fail.jpg
HDMI_CTS_7-2_Fail.jpg1184×800 269 KB

HDMI_CTS_7-2_Fail.jpg
HDMI_CTS_7-2_Fail.jpg1184×800 269 KB

2

Hi, why are you testing this on DevKit? DevKit is validated and should not be used to mass product.

3

Hi Trunmany

Thank you for your replay.
Now, we are developing our custom board.
At first, we tested our custom board, but Test ID 7-2 was failed.
So we tested DevKit, and the same Test ID 7-2 was faild.
I think that the drive strength of display port is missmatch…
Is this correct?

TX2-TX2i_DisplayPort_Tuning_AN.pdf (1.23 MB)

4

Please refer to the HDMI chapter in this app note: [url]http://developer.nvidia.com/embedded/dlc/tx2-series-interface-tuning-compliance-testing-guide[/url]

5

Hi Trumany,

Thank you.
Which parameter should be tune? DRIVE_CURRENT or PREEMPHASIS?

6

Please try tuning all possible registers as said in app note and also please refer to TRM for more detail.

7

Hi Trumany,

When I changed DRIVE_CURRENT(Address:0x15580138) by devmem2, the output voltage of TMDS also changed.
I will adjust the best value.

Thank you for your support!!