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One more set of comments on DDS waveform generation.
1) Jitter is related to not only the clock, but other interrupt related processes. So if
you use a timer, to set sample rate, with an ISR, you need to be concerned with jitter
of clock, and ISR machine behaviour and priority.
2) Table depth controls waveform "fidelity", reproduction, hence harmonic distortion.
There is at least one paper, to the best of my limited knowledge, in IEEE archives, that
discusses this. Not public domain unless you are a member. I have used 32 entry sine
tables, and on a spectrum analyzer they are close to 40 db down on harmonics. Larger
table size diminishing returns/bit. As to be expected. I will go out on a limb and state you
are not going to get 60 db perfromance in a PSOC solution. Unless lots of external filtering.
3) PSOC limited to 8 bit DAC, unless you resort to other techniques, like bit dithering, PWM generation,
etc.. Translate even lower max frequency generation capabilities.
http://www.cypress.com/?rID=51137
Regards, Dana.
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