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Re: Project: HDMI/DVI out for STFM

Posted: 30 Nov 2018 10:29
by Smonson

Re: Project: HDMI/DVI out for STFM

Posted: 30 Nov 2018 10:47
by exxos
Program doesn't seem to be doing anything ?

IMG_3627.JPG

Re: Project: HDMI/DVI out for STFM

Posted: 30 Nov 2018 10:53
by exxos
Tried in medium res..

now just stuck on this...

IMG_3628.JPG

Re: Project: HDMI/DVI out for STFM

Posted: 30 Nov 2018 11:08
by Smonson
Doing nothing is good, it means it's only reading zeroes (or 1 in medium). Like me, your machine works with the mod for some unknown reason.

Re: Project: HDMI/DVI out for STFM

Posted: 30 Nov 2018 11:15
by exxos
I removed the cap I added and this is what happens to the video...

( still get nothing in that program with the cap removed)




IMG_3630.JPG

Video is fine with the cap.

Re: Project: HDMI/DVI out for STFM

Posted: 30 Nov 2018 11:33
by exxos
Smonson wrote: 30 Nov 2018 08:27 My observations:
  • The latching behaviour is only level-sensitive, so high-frequency noise around the transitions shouldn't cause glitches
  • The values that are being read seem very non-random, in the sense that either reads the whole word perfectly, or else it reads it with 8-12 wrong bits. It never reads just one wrong bit here and there. The pattern of bits is also very uniform, e.g. 0xb479 comes up a lot (see video and screenshot posted by Icky above)
  • The reason I don't think it's clock related is that both Icky and Troed have the same behaviour, and Troed is using a totally different clock.

Could you get your program to output in binary instead ? Then be easier for people to see if any particular bit(s) are having issues...

Re: Project: HDMI/DVI out for STFM

Posted: 30 Nov 2018 11:39
by Smonson
That's more good evidence that the register read problem isn't related to clock stability :dualthumbup:

The line of Xs is the value in binary.

Re: Project: HDMI/DVI out for STFM

Posted: 30 Nov 2018 11:44
by Smonson
Icky wrote: 22 Nov 2018 11:01
^ This is what it looks like on Icky's machine while running the test program.

Each line represents a read off the resolution register (the whole 16bit word) that differs from the previous value.

Re: Project: HDMI/DVI out for STFM

Posted: 30 Nov 2018 11:56
by exxos
Smonson wrote: 30 Nov 2018 11:44 ^ This is what it looks like on Icky's machine while running the test program.

Each line represents a read off the resolution register (the whole 16bit word) that differs from the previous value.
So what motherboard revisions are people using then ?

This is mine..
IMG_3631.JPG

Different boards tend to have different "faults".

Is everyone's HDMI board exactly like the one I have ?

Re: Project: HDMI/DVI out for STFM

Posted: 30 Nov 2018 12:06
by Smonson
Mine's a C103414-001 rev 1.1.

The HDMI boards are all the same, unless I'm misremembering (V4).