Lpc2000

Maybe you can use a SSP unit to generate a constant bit stream. It takes 
only 1 write to generate 16 bits, and the FIFO should make it possible 
to generate a constant bit stream. If you use the PWM to generate the 
sync signals, you may have some processing power left for a UART or USB 
routine that can communicate with the user.

I never used the SSP, so I'm not completly sure that it is possible. You 
also need to find a way to synchronize the bit stream of the SSP to the 
sync signals.

Richard.


bobtransformer wrote:

>
> 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 !!
> >