Hello everyone!

I am looking at using an 8052/FPGA combination to provide a colour OSD overlay onto a video signal. I would like the system to display at least up to 256 colours on the screen at any one time.

Many video applications using an FPGA that I have seen, use resistor networks to convert the digital outputs of the FPGA into appropriate RGB levels. These designs tend to use 2-bits per pixel, allowing (2^2)^3=64 colours to be displayed. This colour 'palette' is fixed.

I was thinking of using a RAMDAC in my design, similar to the ones found on older PC vga cards. Of course, these days, modern graphics intergrate the RAMDAC and controller into a single package, so I am finding it difficult locating such a device in discrete form.

Anybody know of a chip I can use? Maximum pixel clock freq. in my application will be around 30MHz.

Matt.