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Altera_Forum's avatar
Altera_Forum
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11 years ago

Multiplication by constant

Hi all. Just found out that Quartus does not instantiate hard block multiplier if multiplication is done by a constant. Even if i define multstyle = "dsp", why?
Altera_Forum's avatar
Altera_Forum
Icon for Honored Contributor rankHonored Contributor
11 years ago

With a constant there are some sizable reductions that can be done during synthesis to make it more palatable in logic. That being said, if you have a DSP block available, why not use it. Perhaps try keeping the constant, e.g.

(* keep *) wire mult_const;

assign mult_const = 16'ha9a9;

I'm guessing something like that will get it to synthesize a DSP.