====== Configuration ======
===== configuration_declaration =====
<code vhdl>
configuration identifier of
     entity _name is
configuration_declarative_part
 block_configuration
end [ configuration ]
        [ configuration _simple_name ] ;
</code>

===== Further definitions =====
==== identifier ====
  * [[.:bnf#basic_identifier]]
  * [[.:bnf#extended_identifier]]

==== name ====
  * [[.:bnf#simple_name]]
  * [[.:bnf#operator_symbol]]
  * [[.:bnf#selected_name]]
  * [[.:variable_declarations|indexed_name]]
  * [[.:bnf#slice_name]]
  * [[.:bnf#attribute_name]]

==== configuration_declarative_part ====
''{ [[.:bnf#configuration_declarative_item]] }''

===== block_configuration =====
''for [[.:bnf#block_specification]]'' \\
''    { [[.:bnf#use_clause]] }'' \\
''    { [[.:bnf#configuration_item]] }'' \\
''end for ;''

==== simple_name ====
  * [[.:bnf#identifier]]

===== Examples =====
Example of a default-configuration of a testbench which uses the corresponding analysed object for the architecture //arch_of_testbench// .
<code vhdl>
CONFIGURATION cfg OF testbench IS
   FOR arch_of_testbench
   END FOR ;
END cfg ;
</code>

----

The libraries //vendor// and //mylib// are published.

For the entity //example// the whole content of the library //mylib// is published, and in its architecture //structural// the entity //alu_ver_2// is used with the architecture //beh// from the library //mylib// for the instance //ALU// with the label //ALU1// . For the instances of //MUX//, labelled //mux1// , //mux2// and //mux3//, the entity //mux12345// with the architecture //rtl// from the library //vendor// is used.

For all instances of //add// the defaults are used.
<code vhdl>
LIBRARY vendor, mylib ;
CONFIGURATION cfg_of_ex OF example IS
  USE mylib.ALL ;
  FOR structural
   FOR ALU1: ALU
    USE ENTITY mylib.alu_ver_2(beh);
   END FOR ;
   FOR mux1, mux2, mux3: MUX
     USE ENTITY vendor.mux12345(rtl);
   END FOR ;
   FOR ALL : add
   END FOR ;
  END FOR ;
END cfg_of_ex ;
</code>