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Altera_Forum
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15 years ago

VHDL newbie : package and "use" directive

Hi ! However hard I try to insert those 2 lines in my vhdl top level design (multiplexer.vhd) : library WORK; use WORK.multiplexer_Pkg.all; my component instantiations located in my to...
Altera_Forum's avatar
Altera_Forum
Icon for Honored Contributor rankHonored Contributor
15 years ago

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Hi,

package is for procedures and functions. (not 100% sure)

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You can put component declarations in a package, but its a habit formed a long long time ago before direct isntantiation was brought into the language (1993) and supported by the tools.

Component declarations are messy because you have to maintain essentially two copies of the same thing, and its too easy to update the entity and forget to update the component.

But It can be useful to have a package without a body. A setup package containing types and constants for example.