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Thanks very much, both of you.
Now, it seems I have a basic understanding.
Let me say this way, so in VHDL design file (I mean I create a design with VHDL file), the reason I put the library command like (Library altera_mf;)
This is because in my design, I need some entity that are not in my project, with the library command, Quartus can know where to find these entity because library give the path information, right?
IEEE library is a little different, it has data type and definition of operations (I don't know whether there are entities). I am also curious where the IEEE library physically exist in my computer.
Thanks.
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On my PC the source code of built in libraries is @
altera/quartus/libraries/vhdl/std
altera/quartus/libraries/vhdl/ieee
altera/quartus/libraries/vhdl/lpm
altera/quartus/libraries/vhdl/altera_mf
and remember it is not this code that compilation looks at but its precompiled version stored as non hdl files in a different area pointed at by quartus. It is done this way may be to speed up the compilation
Honored Contributor
