Honored ContributorHi I'm new to QuartusII and also VHDL, I'm trying to compile an IIR filter for a MAXII device (EPM1270F256C5), but I'm getting this error:
"Error (10414): VHDL Unsupported Feature error at filter.vhd(34): cannot synthesize non-constant real objects or values" The file that I'm trying to compile is:
Honored ContributorYour code has floating point type, which is more for DSP processors. You have to use fixed-point to approximate the REAL value.
Honored Contributorhow can I convert floating point to fixed point?
Honored ContributorYou can manually convert them
OR Write Matlab script to do that Either case, you need to determine how may bits you need to use for. But this is a topic for DSP. Once you setting down on number of bit in the system. You need to run simulation probably in Matlab to verify the filter response.Honored ContributorI got it now, thanks.
Honored Contributoryou can also take a look at the VHDL-2008 fixed point package. there's a version floating around that compiles in QII in VHDL-1993 mode. the package has features to convert float data to fixed point
Honored ContributorSorry, I am not that experienced with VHDL-2008. Thanks for bring that up. Quartus II 9.1 SP1 or later supports VHDL-2008. I don't know if it supports the WHOLE VHDL-2008 yet.
