Initial VGA Timing conditions

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#1
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Hi guys, have a look at this vga timing example.

 

 

So at the Start (initialisation) do I do the v-sync pulse, then begin the first line and at the end of that line is it then that I do the horizontal pules?

 

 

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I take it you have studied AtomicZombie's definitive work? Surely that illustrates everything you need to know?
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Google "lucid science vga" if you haven't.

Last Edited: Sun. Jul 8, 2018 - 07:10 PM
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I'm guessing the first thing I do is the vertical sync then do the first line and from there do the h-sync until the screen has been done.  I then I'm back to the start again doing the v-sync.

 

 

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That's pretty much it but as I say this is all explained by the master that is AtomicZombie on his lucid science pages.

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The monitor doesn’t care where you start - eventually you go full circle and it will try to sync. However, your code has to start somewhere, so the vertical sync period would be reasonable as it is the start of the frame.

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I thought it interesting that page 5 of the 16 page explanation on Lucid Science has this very diagram:

 

Figure 8 - A VGA signal is based on horizontal and vertical timing

 

The whole thing starts at:

 

http://www.lucidscience.com/pro-...

 

and shows what is possible:

 

Figure 0 - Microcontrollers are well suited to display information on analog VGA monitors

 

Of course that is running an AVR8 at and beyond the very limits. With a faster clock and more RAM I would imaging the AVR32 is easily capable of this and more.

 

BTW what the diagram in #1 calls "blanking period" (vertical/horizontal/before/after), like AtomicZombie, I would always have called Horizontal front porch, horizontal back porch, verrtical front porch and vertical back porch. Most LCD timing generators use these same terms.

Last Edited: Mon. Jul 9, 2018 - 08:11 AM