entity identifier is entity_header entity_declarative_part [ begin entity_statement_part ] end [ entity ] [ entity _simple_name ] ;
[ formal _generic_clause ]
[ formal _port_clause ]
{ entity_statement }
Example of a testbench which possesses neither inputs nor outputs.
ENTITY testbench IS END testbench ;
Entity for a 2-Bit-fulladder.
ENTITY fulladder IS PORT (X,Y,Cin : IN Bit; Cout, Sum : OUT Bit); END fulladder ;
Entity with several features:
Definition of procedure init with signal transfer. Seizing of b4 with several `1` is carried out only after delay .
Instructions within the entity:
ENTITY big_example IS GENERIC (m : Positive); PORT (b1,b2 : IN Bit; b3: OUT Bit_Vector(1 to m)); TYPE byte IS ARRAY (1 TO 8) OF Bit; USE work.timing_library.all; CONSTANT setuptime : Time := 12 ns; PROCEDURE init ( SIGNAL b4 : OUT byte) IS BEGIN b4 <= ( OTHERS => '1') AFTER delay; END init; BEGIN ASSERT b4' DELAYED'STABLE (5 ns) REPORT "Error occured!" SEVERITY Error; passive_procedure(b2,delay); END big_example ;