Lpc2000

Could you possibly use LPCs PWM for vertical and horizontal sync 
generation ?

bob


--- In lpc2000@yahoogroups.com, "donhamilton2002" <hamilton@d...> 
wrote:
>
> --- In lpc2000@yahoogroups.com, "rodboyce70" <rodboyce70@y...> 
wrote:
> > <snip>
> > 
> > There are 50 frames a second transmitted but each frame is an
> > interlace.  So video output is even number scan lines in the frame
> > then odd numbered scan lines.  A video scan line is 62.5uS 
including
> > the sync-pluse.  I think that from memory the total sync pulse 
width
> > in 12.5uS this leave 50uS of screen data.  So by dividing this 
50uS
> > into as many sections is you like you get a pixel width.  There 
are
> 
> AFAIR this is correct.
> 
> Pixel width is the main factor in a project like this.
> 
> For the sake of argument, lets say the display is 50 pixels across.
> That means every one uSec a transition may accure. Using an 
interrupt
> set to one uSec would make the cpu very busy. No time left to do 
much
> of anything. Software loop means nothing else will ever be done. 
Even
> at 60 Mhz what would be the overhead ?
> 
> So unless you want a seperate LPC cpu to control just the video
> (overkill as stated in another post) just use a seperate controller 
(
> pick your favrite design).
> 
> This is a great academic question, but has little practical value.
> 
> donhamilton
> 
> 
> > 625 lines in a frame and I think 100 or so of them are take up 
with
> > vertial refresh this leaves 525 for display.  So a counter that
> 
> PS: Your software can not stop, ever !!
>