Simple DDS [State Variable, IIR] | Cypress Semiconductor
Simple DDS [State Variable, IIR]
Here is a DDS approach another poster turned me on to, very fascinating.
Think State Variable, second order, 2 integrators + sign change = oscillator. Or think
second order IIR with positive feedback.
Runs just from C code, 80 uS ( 12.5 Khz ), 40 samples/sine.
With optimization, conversion to fixed point, binary size elements, ASM vs C, or HW solution,
should yield much higher freq.
Add a timer to control code placed in ISR, eg. sample period, or just use a delay function to control sample rate.