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Honored Contributor
Honored ContributorAlter Beginner
Dear friends I am altera beginner,i want to know that,what is top level entity?,Then one more problem i wrote on vhdl code ,code is this library ieee; use ieee.std_logic_1164.all; entity ...
Altera_ForumHonored Contributor
Honored ContributorThink of the components as belonging to a tree (hierarchy).
xor1 and and1 are sub components of half_adder i.e. They are parts of your design and must be compiled along with the top level. If you use xor1 or and1 as your top level then they probably do not depend on any other components. For your system to compile fully, you need to compile the top level and all it's sub components. i.e. half_adder, xor1, and1
