Clocked video output

Hmm, this is strange

I've used this test pattern generator with clocked video output and it worked ok.

I loaded the predefined NTSC configuration to ensure the sync signals were correct, and they use F Falling Edge line 1 instead of 4.

It's like the ADV7171 isn't recognizing the signal. Do you know if it has any status registers?

The configuration registers are all correct to accept your data? For example, I've seen that it can use or not external sync signals, I don't know if it's expecting them, this must be register configured.

The data valid signal should be always '1' (you could check that with signaltap), so you don't need to worry about it

What are you using as 27MHz clock source?

No, for this test you don't need a frame buffer.

I don't think that the f0 or f1 sync is going to make any difference too. I used f0 in my tests though.

A good thing you could do is signaltap all the outputs and check if they are ok (try to use the predefined NTSC config in the clocked video output).

Look for the TRS Symbols, see if they are ok.

After that, check the config registers on the ADV7171.

If they are also ok and you have an oscilloscope, check if the signals are getting to the ADV7171 pins correctly

I hope this is helpful

Regards

Thiago