I have a design that does a fair amount of multiplications. As far as I can see Quartus uses both DSP slices and ALMs to implement those, as the DSP report only shows a small fraction of all multiplications.
My problem is, that even though there are free ALMs, Quartus reports around 50% ALM and LAB usage, Quartus tries to use more DSP slices than available on the chip.
Is there any setting I am missing? How is this happening?
Do you have IPs in your design? Quartus use DSP blocks to execute some IPs. How do you do multiplications? Maybe you can use same IP instead of multiple IPs. This can solve your problem.