I'm following along with the instruction provided on the GitHub ( to test the functionality of the Zybo board's HDMI ports. I followed the instruction to the T but cannot seem to get a signal to pass through. At first, I connected my cable box to the HDMI Rx and then I switched to my laptop. In both instances, not only did my TV monitor not detect a signal, but the output on the sdk terminal was that the HDMI-in was unplugged (see first attached photo). The HDP / LD9 LED near the HDMI port turns on, telling me it is detecting a signal. Using the Zybo-Z7 reference manual, I deduced that it might be due to an issue with resolution, but if I try to change the resolution, I get 'stuck' in that menu (see second attached photo) and have to restart the processes by clicking run-as -> Launch on Hardware. I also notice the clock frequency is set to 0, but I'm not exactly sure what could be the issue. I have also attached the block design and xdc file as I'm assuming the issue could be there since the pixel clock isn't running.



design_1.pdf Zybo-Z7-Master.xdc

Edited by J995
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Hi @J995,

Based on the readme you attached, I'm guessing you are using Vivado/SDK 2018.2 and the 2018.2-2 release of the Zybo Z7-10 HDMI demo?

A co-worker of mine tested the 2018.2-2 release and found that if they start the demo with the HDMI TX unplugged, and then start the demo, they receive the same HDMI unplugged message and upon attempting to change the resolution, the application freezes. If they plug in the cable, the unplugged message does not go away. They were able to get the pre-programmed static images (the blended test pattern and color bar test) to run with the TX cable attached before launching the demo (the RX HDMI cable was unplugged the entire time).

However, they are also finding that the HPD interrupt is not firing so the RX portion of the HDMI is not working as expected, so they are going to look further into this. I recall that both I and the co-worker had this demo working correctly on separate computers at some point (and I had made a point of trying to break the demo before it got released), though I don't remember if it was for this particular release or for a different version of Vivado.

Thank you,

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