Process ALL and Implicit Signals

Proposal Editing Information

• Who Updates: Brent Hayhoe
• Date Proposed: 2014-05-30
• Date Last Updated:
• Priority:
• Complexity:
• Focus:

Requirement Summary

The ability to include implicit signals in sensitiviy lists when using the keyword ALL.

Examples of such signals are those generated by the predefined attributes; S'DELAYED(t); S'STABLE(t); S'QUIET(t); S'TRANSACTION.

Related Issues:

Proposal

Current Situation

I often now use the ALL keyword in process sensitiviy lists when generating verification models and, quite sensibly, this replaces any sensitivity list.

However, in the verification world I often use the 'TRANSACTION attribute for control purposes and the use of the ALL keyword precludes the inclusion of this implicit signal.

Implementation details

It will require a rule change for sensitivity lists:

   process_sensitivity_list ::= all [ , implicit_sensitivity_list] | sensitivity_list

   implicit_sensitivity_list ::= implicit_signal_name { , implicit_signal_name }

Code Examples

   process my_model( all, sig'transaction) is
      ---
   begin
      ---
   end process my_model;

Use Cases

Arguments FOR

This requirement was probably just overlooked when adding the ALL keyword into the LRM.

Arguments AGAINST

General Comments

It may be beneficial to allow the ALL keyword (and implicit signals) to be used within the sensitivity clause of the ON keyword as part of the WAIT statement.

Supporters

-- Brent Hayhoe - 2014-05-30

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