Hello Christian,
I believe the latency between the ADC input and the DSP core is about two samples. So, you need to wait at least that long after switching your multiplexer for the input of the auxiliary ADC to be read in the DSP core. You would need to follow this procedure in your system:
- Switch your external multiplexer to select a new input
- Wait at least two samples
- Read the value in the DSP core using the DSP readback cell
- Write that value to the target DC source cell
- Switch your external multiplexer to select the next input
- Repeat from step 2
Thanks,
Brett