CODEWITHSUNDEEP
vhdl
ted
ted

Reputation: 4975

Using records in type generics

I am striving to use generics to define a record for the interface(port) of a component. In an older question I have been pointed to using type generics. however I do not know how to access the fields of the records. Here is an answer were the use of records with type generics is promoted

Assuming the following component:

entity genericInput is
    generic(
        type recordType
    );
    port(
            result: integer;
        port: in recordType
    );
end entity;

architecture behav of genericInput is
begin
    result <= port.part1;
end architecture;

And this instantiation:

type myRecord is record
    part1: integer;
    part2: std_logic_vector(1 to 100)
end record;

inst: genericInput 
    generic map(recordType <= myRecord)
    port map(...)

i get a compilation error from modelsim:

** Error: ****.vhd(21): Unknown expanded name. --line on which i attempt port.part1
** Error: ****.vhd(22): VHDL Compiler exiting

How do I access the fields of a record supplied by generics, assuming the Record always has a field of that name (vhdl2008 is available)? (I wan't to vary the widths of the vectors in the record)?

Reworded Question: What is the best way to integrate a record with generic width vectors into the ports of an entity?

Upvotes: 0

Views: 864

Answers (1)

Philippe
Philippe

Reputation: 3730

First:

  • PORT is a keyword. You cannot use it as a name for your ports. If you trim your code before posting on a forum, it is greatly appreciated if you test it too. (Make it VETSMOD)
  • Which version of ModelSim are you using? Are you sure it supports VHDL 2008? Are you sure it supports generics in entities?

Answering your question:

Inside the entity (and architecture), nothing is known about the data type. You can only access it through functions or procedurs that you pass as generic parameters. Not sure how much of this is really supported by ModelSim at this time, though.

Upvotes: 1

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