OZ1KLK

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(last edit: 24. september 2012)

Record

A data type that represents a set of values of different types. Used to define data structures. Not typically used to describe hardware, but useful for high level modelling.

Syntax

  type NewName is
    record
      ElementName, ... : DataType;
      ... ;
    end record [NewName];

Placement

 PACKAGE Pack IS
   ... 
 END PACKAGE Pack;

 PACKAGE BODY Pack IS
   ... 
 END PACKAGE BODY Pack;

 Blk:BLOCK 
   ... 
 BEGIN 
   ... 
 END BLOCK Blk;

 ENTITY Ent IS
   ... 
 BEGIN 
   ... 
 END ENTITY Ent;

 ARCHITECTURE Arc OF Ent IS
   ... 
 BEGIN 
   ... 
 END ARCHITECTURE Arc;

 CONFIGURATION Conf OF Ent IS
   ... 
 END CONFIGURATION Conf;

 Proc:PROCESS(...) 
   ... 
 BEGIN 
   ... 
 END PROCESS Proc;

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

 FUNCTION F(...) RETURN Tp IS
   ... 
 BEGIN
   ... 
 END FUNCTION F;

Things to remember

Not all synthesis tools support record types.

Synthesis

Values of a record types are synthesized as a bundle of wires, structured according to the elements of the record. Not all synthesis tools support records.

Tips

The values within a record can be read or written using a selected name. Use record types together with access types to create dynamic data structures for high level modelling.

Example

  type Floating is
    record
      Sign: Bit;
      Mantissa, Exponent: Integer; 
    end record;
  variable A, B: Floating;
  ...
  A.Mantissa := A.Mantissa + B.Mantissa;
  B := A;