(Zybo Z7-10) Connecting HDMI sink causes "done" LED to light up

[aytli]

I'm working with a computer that has a DVI video port, which I want to route into the HDMI sink of my Zybo Z7-10. I've tried using a passive splitter (DVI to DVI+HDMI) to capture the video signal going to the monitor, as a DVI to HDMI adapter to directly feed the video signal into my board. When I connect either of these to the HDMI sink, the DONE LED (LD12) on my board will light up (it looks dim, and it gets dimmer when I use the adapter instead of the splitter). This will happen even when I flip the power switch off and unplug everything including the power cable. Nothing else on the board seems to be powered.

Here are the two connection configurations I mentioned above:

Computer (DVI) --> Splitter -----> Monitor (DVI)
                             \\
                              ---> FPGA (HDMI)
and

Computer (DVI) --> Adapter --> FPGA (HDMI)

The board is still fully functional, and this effect doesn't seem to happen with any other video source. I'm looking at the schematic for this board and there appears to be no connection between the HDMI sink plug and the power rail.

What could be causing this issue?

[jpeyron]

Hi @aytli,

The HDMI connection to the board can back power the FPGA and potentially cause issues during power on. We suggest that either you power on the board before the monitor is turned on or not have the hdmi connected until it is powered. Sorry for the inconvenience. 

thank you,

Jon