Spartan® Family FPGAs

[ciobanescu_elena]

i`m read all the document i can find about video transmitter via hdmi(tmds), i tried to implement the xilinx`s design but without any succes.the curious is that the program doesn`t have any error but when i try to conect my pc to tv`s hdmi it doesn`t work.Please help!!

[joelby]

Could you describe exactly what you're trying to do and what went wrong? Many of us have successfully implemented XAPP495.

I just got some HDMI cables in the mail, so right this very minute I have:

• created a new ISE project
• added all of the .v files from XAPP495
• added vtc_demo.ucf
• set vtc_demo as the top module
• generated a programming file
• programmed it in to my Digilent Atlys board

I can successfully see the colour bars and change the resolution using the switches.

Are you trying to use dvi_demo or vtc_demo? If it's dvi_demo, you'll need to connect some signal sources to the HDMI inputs on your development board.

[ciobanescu_elena]

i'm trying to use  dvi_demo.so far i could implement the vtc_demo and i can see the bars.with dvi_demo i have problems.i have conected into my hdmi in port a cable that comes from my pc(the pc has a dvi output-i use a dvi-hdmi cable) and from atlys board i conected a cable into my tv`s hdmi in port.doesn`t work :(... 

[joelby]

Have you tried all combinations of settings for sw0 and sw1?

[ciobanescu_elena]

of course!...i don`t get it..did you try to implement it?

[joelby]

Unfortunately I don't have any HDMI sources to test it with. Are any of your status LEDs lit? If you have a valid HDMI source, some of them should come on (check the very last line in dvi_demo.v). If not, try connecting something else as a test, or perhaps adjust the output resolution on your PC to something more conservative.

[ciobanescu_elena]

I tried almost all valid relosution. the led doesn`t lit that means that the problems is in rx component. 

[joelby]

If no LEDs are lit, it would indeed seem like the receiver is having trouble.

If you don't have any other HDMI sources, you could try things like:

• Probing the HDMI input with a fast oscilloscope to ensure that your PC is actually outputting a signal
• Probing the dvi_decoder's PLL lock output with Chipscope or an LED.
• Probing other dvi_decoder and des_0 signals to see where the hold-up is.

[gszakacs · Accepted solution]

Normally PC graphics cards use the EEPROM attached to a digital monitor to detect the

type of the monitor and its capabilities.  If your board does not implement the monitor

detection system, then the graphics card won't drive the signal.  Depending on the

graphics card, there may be some way to circumvent this behavior and force the

transmitter to run regardless of the monitor.  Another solution is to buy a DVI splitter.

These devices are made to drive more than one monitor.  Then you can plug a

real monitor on the primary port of the splitter and the graphics card will transmit

video based on the capabilities of that monitor.  The secondary output port(s)

will then also provide video.  The nice thing about this setup is that you can

see the video that is being sent.

HTH,

Gabor

[eteam00]

Normally PC graphics cards use the EEPROM attached to a digital monitor to detect the type of the monitor and its capabilities.

The technical term for this is "EDID".  You have to dig and dig for information on EDID, and the description(s) aren't as concise and specific as I would have preferred... but life isn't fair.

There are windows apps you can download to display the EDID of DVI/HDMI monitors connected to your Windows PC.  You can reverse engineer these for your own design...   or even clone one as a temporary workaround until you get your own EDID configuration set up.

-- Bob Elkind