Forum Discussion
Honored ContributorVGA to PAL converter ?
Hi,
I use a vga ouput to display video from a camera (see attached picture). I would like to add PAL output. I wonder if a single chip which converts vga (analog, digitial ?) to pal exists ? thanks.5 Replies
Altera_ForumThe 17.734Mhz oscillator frequency needs to be precise, so if you can't hit it with the Cyclone PLL then you'll need to find an external oscillator chip.
- Altera_Forum
I think the AD725 could do what I want.
I am not familiar with PAL video : does the clock (4fsc) could be generated with a cyclone II ? the datasheet specifies 17.734 475MHz and it is quit hard to obtain from a cyclone II... is it possible to generate 4fsc with a cyclone II ? if not which oscillator can be used ? thanks. - Altera_Forum
For a "quick and dirty" solution the chips you call out (AD723, ...) may be the best solution. These take analog RGB and convert to PAL or NTSC. Another solution might make use of a digital format converter IC, progressive scan digital RGB to PAL or NTSC. These tend to be hard to obtain in small quantitites as they're geared for the consumer market. If you've got the time and inclination you can create your own PAL encoder in the FPGA as mentioned above. This will require converting from progressive scan to interlaced mode first.
- Altera_Forum
my board is a custom daughter card for evaluation kit (with a hsmc connector).
my current project is something like that : camera => raw data => ping pong ddr => vga The PAL output feature is for an other project so I was hopping to find a solution with a few harware modifications and software re-use. I've just find these components => AD723/AD724/AD725. I am reading the datasheet... - Altera_Forum
is the video from the camera not pal already?
Otherwise, you can write a standard converter if you have some external memory for the frame buffering.
