Forum Discussion

Altera_Forum's avatar
Altera_Forum
Icon for Honored Contributor rankHonored Contributor
10 years ago

Optimisation issues

Hi, is there any way to find out WHY Quartus is optimising away stuff? I know I've almost certainly got something wrong in my VHDL, but I've found that several of my signals/registers are 'missing' o...
Altera_Forum's avatar
Altera_Forum
Icon for Honored Contributor rankHonored Contributor
10 years ago

That's the first thing I did - there's nothing at all with the signal name in the synthesizer output :-(

Now, it might be that it's not optimising the registers/signals away, but there's some other reason SignalTap can't find them. If I search for 'all signals' then they're there, but not if I search in post-fitting. If I select one in 'all signals', then it appears in red, which I guess means that it can't display its contents.

(It's not working in the programmed FPGA either, where other, similar constructs are, which, along with not appearing in SignalTap may have made me come to the wrong conclusion)