Non-synthesizable APIs such as posedge or value depend on the result of packed to compute their value. This is generally accurate, but has two major downsides:
Calling packed creates and connects a new signal. If a testbench calls packed (directly or indirectly) on a signal within a Module, it will generate some additional hardware (though it won't have any functional impact).
The previousValue will be null the first time it is called since packed is lazily initialized. This can cause surprising testbench failures.
To Reproduce
Call previousValue on a LogicStructure and observe that it is null.
Expected behavior
The APIs should not have side effects of creating hardware (even without functional impact) and should be functional in the same way as Logic.
Describe the bug
Non-synthesizable APIs such as
posedgeorvaluedepend on the result ofpackedto compute their value. This is generally accurate, but has two major downsides:packedcreates and connects a new signal. If a testbench callspacked(directly or indirectly) on a signal within aModule, it will generate some additional hardware (though it won't have any functional impact).previousValuewill benullthe first time it is called sincepackedis lazily initialized. This can cause surprising testbench failures.To Reproduce
Call
previousValueon aLogicStructureand observe that it isnull.Expected behavior
The APIs should not have side effects of creating hardware (even without functional impact) and should be functional in the same way as
Logic.Actual behavior
No response
Additional: Dart SDK info
No response
Additional: pubspec.yaml
No response
Additional: Context
No response