[Openchrome-devel] Fix vt1625 output sensing

Xavier Bachelot xavier at bachelot.org
Thu Nov 22 05:28:05 PST 2012

Hi Harry,

On 11/22/2012 02:01 PM, Harry de Boer wrote:
> Hi,
> I recently upgraded my Via machine to the latest Ubuntu and I couldn't
> get my tv-output to work again. Last night I decided to dive into the
> code a bit. The first thing I noticed was that vt1625 output sensing
> seemed broken. Attached is a patch that should fix that.
> I haven't got it working again yet so there's more to be done. If there
> is anything I should know before continuing or have any tips please let
> me know.
Thanks for the patch. There's someone with issue with the TV out on an 
EX board on the -users mailing list and he has trouble with probing the 
TV out too, so it comes right to the point ;-)

There are 2 variant of the VT1625 (VT1625 and VT1625S) out in the wild 
and it seems there are subtle differences between them. One of the 
difference is one has 4 DACs and the other has 6. They are sharing the 
same idea so I don't know of a good way to tell one from the other.
Fortunately, there are datasheets available for both, it might help you 
get the TV out working.
See http://www.openchrome.org/trac/wiki/Development#TVencoders

Out of curiosity, I do have an EX board too (for testing purpose) and 
mine is using a VT1625S. What's the flavor on yours ?

> A little about me: I am a computing science student from the
> Netherlands, I have a Via EPIA EX10000EG Mini-ITX board which has a
> CX700 chip. It's mainly used as a server and for its tv-out.
Glad to meet you and welcome on board :-)

> Cheers,
> Harry
> NB, the mailing list link on the openchrome.org front page is still
> linking to the old mailing lists, I first sent this message there by
> accident.
Thanks for the heads up, I'll fix that tonight. Both the old mailing 
lists and new ones are still working though, so we've got 2 copies of 
your mail. I've dropped the first one from the queue.
Btw, consider subscribing to the list if you don't want your mails to be 
stuck in the moderation queue until someone let them in ;-)


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