ExternalNameTypes < P1076/Ballots

P1076/Ballots Web>Vhdl2019CollectedRequirements>ExternalNameTypes (2020-02-17, JimLewis) (raw view)EditAttach
---+ External Names for Types

%TOC%

---++ Proposal Information
   * Current Owner: JimLewis, ...
   * Contributors: JimLewis, ...
   * Date Proposed: 2014-May-26
   * Date Last Updated: 2014-May-26
   * Priority:
   * Complexity:
   * Focus: Testbench
   * Related Issues: None
   * Competing Issues: None
---++ Requirement Summary

Create external names to types.

---++ Rationale

For a testbench to do actions based on the state of a statemachine requires knowledge type. Unfortunately the type is most often defined within the RTL code itself. As a result, there is currently no way to access it.

---++ Proposal

Extend external_name to include external_type_name:

<pre>external_name ::=
    external_constant_name
    | external_signal_name
    | external_variable_name
    | external_type_name
</pre>

Define external_type_name as:

<pre>external_type_name ::=  &lt;&gt;
</pre>

---++ Usage:

In some RTL block:

<pre>architecture rtl of block1 is 
  type RingType is (S0, S1, S2, S3) ; 
begin 
  ...
</pre>

In a testbench block:

<pre>architecture Test1 of Testbench is
  alias RingType is &lt;&lt;type .Testbench.U_RTL_TOP.Block1.RingType&gt;&gt;; 
...
begin
</pre>

In a package:

<pre>package TbPkg is 
  alias RingType is &lt;&lt;type .Testbench.U_RTL_TOP.Block1.RingType&gt;&gt;; 
...
end package TbPkg ;
</pre>

---++ Alternative Proposal

Directly reference into the entity - similar to a package and not similar to an elaborated path.
&nbsp; Needs syntax work, example only for concepts:<br />
<pre>package TbPkg is 
  alias RingType is EntityName.ArchName.RingType ; 
...
end package TbPkg ;
</pre>

Would create a compile dependency.
---++ Comments

-- Main.LievenLemiengre - 2015-06-04

From a compiler POV this is _extremely_ hard. You would have to do elaboration during type resolving.

---++ Supporters

Main.JimLewis

-- Main.RyanHinton - 2014-06-18

-- [[Main.BrentHahoe][Brent Hayhoe]] - 2014-06-19

-- Main.TorstenMeissner - 2016-05-18
Topic revision: r8 - 2020-02-17 - 15:34:53 - JimLewis
P1076/Ballots