Per the subject line. I want to experiment with direct PAL video generation from a microcontroller, with the minimal number of parts. I'm thinking that a good starting place might be to use a CPU clock that's based on the PAL subcarrier frequency (4.43MHz) multiplied with a PLL+VCO+Divider to give me phase reference points, & directly generate the composite colour signal via an R2R ladder.
So, some questions:
1) Is this a reasonable concept? (I'm comfortable with per-cycle level timing & coding)2) Any tips/suggestions/thoughts as to a better approach?
3) What's a good (simple, cheap, stable) circuit to oscillate a standard 4.43MHz PAL sub-carrier xtal? (Ideally just an inverter or two)4) Suggestions for a cheap + simple PLL frequency multiplier (x8? x4?) for the above to give me multiple cycles per PAL subcarrier cycle?
5) How many analog samples do you actually /need/ to generate per subcarrier cycle to get good quality PAL colour?6) Any recommended online resources/references that cover direct digital synthesis of medium to high quality PAL colour video?
Thanks in advance for any help or advice.