Arty Z7-20 HDMI pass through

[random_cat]

Hi all,

I am trying to make a simple hdmi pass through between hdmi in and hdmi out with Arty Z7-20 board. Attached is my design block. The problem is it does not work, regardless of video resolution, I tried from 800x600 up to full hd. Any idea why? On a previous design, without axi converters, just dvi2rgb connected to rgb2dvi, it works, hdmi signal passes through. clk_out1 is 200mhz, both axi interfaces works in independent clock mode and dvi2rgb outputs valid signal, I have a lock signal at output.

Thank you.

[jpeyron]

Hi @random_cat,

I am not very experienced with HDMI. I have reached out to more experienced co-workers about this thread. Also have you looked at the HDMI-IN and HDMI-OUT examples for the Arty Z7 on the Arty Z7's resource page here?

thank you,

Jon

[sbobrowicz]

Couple of possibilities:

1) Are you meeting intraclock timing? 200 MHz is kinda fast for an AXI stream bus, you might be going faster than the fabric can handle. You can try to clock the axi stream bus directly from the pixel clock, or from a slower clock (but faster than the pixel clock) generated from the clocking wizard.

2) Make sure the buffers in the converter cores are at least as wide as the maximum resolution's width (2048 will do it if you are doing 1080p).

3) Is your stream-2-video core in master or slave mode? Maybe try whichever one you are not doing. I believe if you are in master mode you need to use the vtg_ce signal to pause the vtiming bus. This might mean that a processor and a VTC core would be necessary. Checkout the stream-2-video IP core product guide for more info on this.

[random_cat]

Thank you. I've managed to make it work with the adding of a video timing generator. Otherwise, it supports 200mhz clock for dvi2rgb, all other clocks are now connected to pixelclk.