Adding sc_attribute of type user-defined Class to an sc_object

[OMark]

Hello,

I have defined one class "Class A" and when creating instances of that class e.g.  A* instA1 = new A ();

I want to attach the instA1 object to an sc_in port of my SystemC module as an attribute of that port.

- Can I use for that purpose the add_attribute function?

- How safe is that?

- Are there any other recommended mechanisms (as alternatives)?

Thanks.

[Eyck]

Basically yes but just add_attribute is not enough. From the top of my head: you need to declare in your sc_module:

  sc_core::sc_attribute<A*> attr{"attr", nullptr};
  sc_core::sc_in<bool> pin{"pin"};

in the constructor of your sc_module you need to add the attribute to the sc_object/sc_port:

  pin.add_attribute(attr);

via

  attr.value = new A();

you can assign a value. This way the attribute can be found e.g. via the SystemC object tree (sc_core::sc_get_top_level_objects() ).

Alternatives depend of your goal. One option would be to use CCI, esp. cci_param. But again, it depends what you want to achieve...

[OMark]

Hello,

I tried out your method as follows:

sc_object* test_object_find = sc_core::sc_find_object(port_name);
sc_core::sc_object& obj = dynamic_cast <sc_core::sc_object&>(*test_object_find);

PortElement<sc_logic>* PE = new PortElement<sc_logic>(count,hierarchical_name,port_name,obj);

sc_core::sc_attribute<PortElement<sc_logic>*> attr{"PortElement", nullptr};

 attr.value = PE;

Until here, I am capable to build and run without issue.

Then when I follow up the above lines of code with this one:

obj.add_attribute(attr);

I can build, but when I run the simulation it crashes suddenly.

Which failure did I make when adding the attribute to the port object?

Thanks for your help.

 

 

 

On 8/4/2020 at 8:11 PM, Eyck said:

 

 

[Eyck]

Do you have an error message or stacktrace (gdb)? 'simulation [...] crashes suddenly' is very generic and can have manifold root causes...

Where do you execute the code? You can only create sc_object based elements during elaboration. But if PortElement is a plain C++ class I have no idea why it fails...