====== Concurrent assertion ======
===== concurrent_assertion_statement =====
  [ label : ] [ postponed ] assertion ;

===== Parents =====
  * entity_statement_part
  * architecture_statement_part
  * block_statement_part

===== Further definitions =====
==== label ====
  * [[.:bnf#identifier]]

==== assertion ====
''**assert** [[.:bnf#condition]] \\
    [ **report** [[.:bnf#expression]] ] \\
    [ **severity** expression ]''

===== Comment =====
For any concurrent assertion statement, there is an equivalent (passive) process statement.

The equivalent process statement of a concurrent assertion statement including the keyword **POSTPONED** is a postponed process.

If the concurrent assertion contains a static condition then the assertion will be executed only once at the beginning of the simulation.

===== Examples =====
These are two different examples of assertions.

One condition at a time is checked ( **ASSERT** ) and if it is not fulfilled a report is given ( **REPORT** ). The severity level determines which actions are carried out if the condition which is to be checked is not fulfilled.

<code vhdl>
ASSERT reset = '1' ;
</code>

<code vhdl>
ASSERT reset = '1'
REPORT "Reset ist aktiv !" ;
</code>

<code vhdl>
lbl :
   ASSERT reset = '1'
   REPORT "Reset ist aktiv !"
   SEVERITY warning ;
</code>

<code vhdl>
latch_check :
   ASSERT reset = '1' OR set = '1'
   REPORT "Reset und Set sind" &
          "gleichzeitig aktiv !"
   SEVERITY failure ;
</code>

<code vhdl>
lbl :
   ASSERT data = 0
   REPORT "Datum ist gleich "
         & integer_to_string ( data )
         & " !"
   SEVERITY note ;
</code>