Subprogram body

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

• entity_declarative_part
• architecture_declarative_part
• package
• package_body
• block_declarative_part
• process_declarative_part

procedure designator [ ( formal_parameter_list ) ]

[ pure | impure ] function designator [ ( formal_parameter_list ) ]
return type_mark

{ subprogram_declarative_item }

{ sequential_statement }

• procedure
• function

• identifier
• operator_symbol

• The declaration of a subprogram is optional. The subprogram specification can act as the declaration.
• Shared variables must not be declared in subprograms.
• A “foreign subprogram” is a subprogram with the attribute FOREIGN . The value of the attribute (a string) can contain implementation specific information for linking the external program (see example below).
• A pure function must not contain a reference to an explicitly declared file object.
• A pure function must not be the parent of an impure function.

Definition of the procedure thank_you .

If the condition false is not fulfilled “Thank You !” is reported as note in the severity level.

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

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.

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 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 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 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.

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 ;

The external function exfunc is declared.

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

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