ARM ST32F400 - best way to generate a 400Hz sinewave, w/o the CPU doing it all

[langwadt]

Yes, but you must compute all, every time. The main thing was to not have to do that.
So in that case you must have these 3600 steps stored somewhere.

why bother?  a 700ns interrupt every 25us is less the 3% of the cpu

[DavidAlfa]

If it really does ok with 100 samples/wave...
And you must add the interrupt overhead too.
Anyways, in the same case, 100 samples in the dma will be a lot faster. And only requiring 400bytes of ram.