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Hi 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:Link Copied
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Your code has floating point type, which is more for DSP processors. You have to use fixed-point to approximate the REAL value.
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how can I convert floating point to fixed point?
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You 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.- Mark as New
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I got it now, thanks.
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you 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
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Sorry, 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.

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