I continued digging a little, the vid_control module has vid_clock as
an input, module video_wrapper uses this module and also has
vid_clock as an input. Right now, the s3_top_level maps vid0_clock or
vid1_clock to these inputs, but these signals are somewhat odd;
BUFG Vid0_BUFG (
.I(vid0_clock_ext),
.O(vid0_clock)
);
vid0_clock_ext is once again, an input:
// Tempory hack to make everything pass synthesis
input mem_clock_ext,
input vid0_clock_ext,
input vid1_clock_ext,
Am I deducting correctly that this comment is an elegant "TODO", and
the clocks aren't dynamic yet?
On 4 Mar 2008, at 02:24, Timothy Normand Miller wrote:
The simplest way is to have a high frequency into a divider. But
that's kinda limited. Another thing you can do is take the DCM
output, run that through a divider, and then use the output of that as
feedback.
The problem is that the frequencies needed don't really have a common
divider, unless you start running several GHz. Say, for example, we
want some basic ones;
640x480 @ 60Hz = 25.175 MHz (say 25, works just as fine)
800x600 @ 60Hz = 40 MHz
1024x768 @ 60Hz = 65 MHz
I guess we could do something like, run at 130 MHz. Then we get
640x480 - divide by 5.2 (count to 5, every fifth time count to 6?)
800x600 - divide by 3.25 (count to 3, every fourth time count to 4?)
1024x768 - divide by 2
Correcting the clock like that all the time is bound to give odd
display results. So I don't know how to do it, but a divider sounds
imho impossible.
I think. I'm really not sure how Howard did it.
On 3/3/08, Michael Meeuwisse <[EMAIL PROTECTED]> wrote:
Quick question.
Cheers,
Michael
www.projectvga.org
_______________________________________________
Open-graphics mailing list
[email protected]
http://lists.duskglow.com/mailman/listinfo/open-graphics
List service provided by Duskglow Consulting, LLC (www.duskglow.com)
