© LRS - UNI Erlangen-Nuremberg

2.2 Subprogram body

...
ENTITY e IS
    ...
 BEGIN
    ...
END e ;

...
ARCHITECTURE a OF e IS
    ...
BEGIN
    ...
END a ;

...
CONFIGURATION c
        OF e IS
    ...
    ...
    ...
END


...
PACKAGE pkg IS
    ...
    ...
    ...
END pkg ;

subprogram_body ::=

 subprogram_specification is
     subprogram_declarative_part
begin
     subprogram_statement_part
end [ subprogram_kind ] [ designator ] ;


..
PACKAGE BODY pck
        IS
    ...
    ...
    ...
 END pck ;

...
b: BLOCK IS
    ...
 BEGIN
    ...
END BLOCK b ;

FUNCTION f (...)
    RETURN r IS
    ...
 BEGIN
    ...
END f ;

PROCEDURE p (...) IS
    ...
 BEGIN
    ...
END p ;

p : PROCESS
    ...
 BEGIN
    ...
END PROCESS p ;

2.2.1 Further definitions

subprogram_specification ::=
    procedure designator [ ( formal_parameter_list ) ]
    | [ pure | impure ] function designator [ ( formal_parameter_list ) ]
        return type_mark

subprogram_declarative_part ::=
    { subprogram_declarative_item }

subprogram_statement_part ::=
    { sequential_statement }

subprogram_kind ::= procedure | function

designator ::= identifier | operator_symbol

2.2.2 Comment

2.2.3 Examples

PROCEDURE thank_you IS
BEGIN
    ASSERT false
   REPORT "Thank You !"
   SEVERITY note ;
END thank_you ;

Definition of the procedure thank_you .

If the condition false is not fulfilled
"Thank You !" is reported as note in the severity level.
FUNCTION convert(B : Bit ) RETURN fuzzy_bit IS
    VARIABLE v : fuzzy_bit ;
BEGIN
    IF B = '1' THEN
       v := High ;
   ELSE
       v := Low ;
   END IF ;
   RETURN v ;
END convert ;

Definition of the function convert with the transfer
value B and the result type fuzzy_bit .


In the If-loop the variable v is assigned the value
High or Low depending on the value of B .

v is transferred as transfer value.
PROCEDURE regist(
   SIGNAL D : IN Bit ;
   SIGNAL CK : IN Bit ;
   SIGNAL Q : OUT Bit ) IS
BEGIN
    LOOP
       WAIT ON CK ;
      IF CK = '1' THEN
          Q <= D AFTER 1 ns ;
      END IF ;
   END LOOP ;
END regist ;

Definition of the procedure regist with the
transfer values of the signals D , CK and Q .



Within the endless loop (LOOP) a register
is declared which takes on the value of input D from
output Q at the positive clock-edge with a delay of 1 ns.
PROCEDURE p(
   VARIABLE COL : INOUT color ;
   CONSTANT C : IN choice ) IS
    SUBTYPE primary_color IS
       color RANGE yellow TO red ;
VARIABLE X, Y, Z : primary_color ;
BEGIN
...
...

END p ;

Definition of the procedure p; transfer values of the
variable COL and the constant C .

The subtype primary_color is declared from
the type colour with a range of yellow to red
 (from the enumeration type colour ).
The variables X , Y and Z are declared.
FUNCTION exfunc RETURN INTEGER ;

ATTRIBUTE FOREIGN OF exfunc FUNCTION
IS "C:modellib.so.0.1 ELAB:mod_lab";

The external function exfunc is declared.

The attribute FOREIGN of exfunc gets (simulator-)
program specific information.