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Altera_Forum
Honored Contributor
Honored ContributorDevide in VHLD
I want to implement this function : A<= B/x"A", when I compile, the Quartus put a notice: "/" used but didn't declare. When I try with "*" (multiply) or "+" (add), it is ok. I don't know this er...
Altera_ForumHonored Contributor
Honored Contributor --- Quote Start --- Dear FvM I want to implement Multiplication command in VHDL. Because Modelsim does not support for LPM library. And when I use multiply command directly, the result's not true with the negative number. In this method, I multiply two positive number, and use sign<=A(15)xor B(15); to check the sign of A and B. If sign=0 => the result's positive. else the result's negative. When I simulate with the waveforms, it appear strange value. I did not understand it. Do you have other idea for this? --- Quote End --- You can precompile most libraries in Modelsim. Usually altera_modelsim will have these lpm/altera_mf libraries ready from installation. Otherwise you can precompile as follows: go to modelsim => compile => set library name to lpm => navigate to altera folders that contain 220pack.vhd/220model.vhd. select them and compile.
