Hatem,

If an audio freq. generator (other than a "spot frequency" standard) is what you intend to implement. Look at the many DTMF examples to learn about Phase Accumulator approaches to waveform generation.

There is no reason that you couldn't select a u-controller with all necessary resources already integrated into the micro. I have done this many time with DACs from 6-16 bits.

If you will "digitally" control the amplitude of the waveform you will need a fairly wide DAC 14-16 bits (driven by your spec of course). If your amplitude is set externally you can use fewer bit's and increase the waveform quality using outboard filters (which would have to track the Fz).

The Freq. resolution will drive the width of your Phase Accumulator.

The Freq. Span (low/high Fz.) will drive the micro/sample clock rate.

Your "jitter" specification will drive the method by which you implement the Phase Accum approach (interrupt vs. fixed length code path).

regards,
p