> Hmm, why do you try to generate it completely with digital means I'd
> create a rough waveform and send it through a VC-slewlimiter, where the
> slew rate is depending on the frequency of the intended waveform. The CV
> for the slewlimiter would be created by the uP itself. A D/A-converter,
> a Demux, and a S&H is assumingly already on board.

Good idea. I'll see if it's a practicable solution. It would require a
voltage controlled current source to charge/discharge the capacitor. As long
as the frequency is stable it should work. But if the frequency (CV resp.)
changes it may take some cycles until the waveform output is correct. We
will see if it works.

Best wishes
Dieter Doepfer