How to create a vector of fifos and add new fifos values depending on an input?

[gabriel123]

Hi, im  new to systemC.

I want to know how to create a specific amount of sc_fifos<int> depending on an argument. Usually something like this is done with a vector in c++. That is why i thought that an sc_vector is appropriate here.

My original code (static). I would have to write new fifos depending on how much i need:

sc_fifo<int> *fifos1;
sc_fifo<int> *fifos2;
sc_fifo<int> *fifos3;
  
fifos1 = new sc_fifo<int>(50000);
fifos2 = new sc_fifo<int>(50000);
fifos3 = new sc_fifo<int>(50000);

 

The approach with vectors:

sc_vector< sc_fifo<int> > fifos;

fifos(outputs)
for (int i = 0; i < outputs; i++) {
	fifos[i] = new sc_fifo<int>(50000);
}

The above code doesn't work. How am i supposed to initialize the vector and add new sc_fifos?

[David Black]

SystemC FIFO's represent hardware and as such may only be created during construction of a model. After elaboration closes, you are not allowed to add more fifos. None of your code examples above are complete, so it is fairly hard to give you a complete answer. Perhaps you could put your design on https://edaplayground.com and share a link with us.

For details on phases of SystemC (e.g. elaboration) see IEEE-1666-2011.pdf, which you can obtain through Accellera.org.

 

[gabriel123]

This is all in the constructor so they are created during construction if i understand correctly. I want to know how to add members to my sc_vector. In C++ the method push_back would be used. If it isnt possible does that mean if i need 1000 fifos i would have to write the below code 1000 times?

sc_fifo<int> *fifos1;
  
fifos1 = new sc_fifo<int>(50000);

 

[Eyck]

In the constructor list you would provide a creator function. This is a functor(a function pointer, a std::function object, a Functor classinstance, a lambda function, ...) which accepts a char const* and a size_type and returns a constructed object. In your case it would look like (C++11):

class example: public sc_core::sc_module {
public:
  sc_core::sc_vector<sc_core::sc_fifo<unsigned>> fifos;
  
  example(sc_core::sc_module_name nm, unsigned outputs)
    : sc_core::sc_module(nm)
    , fifos("fifos", outputs, [](char const* name, unsigned i)->sc_core::sc_fifo<unsigned> {
        return new sc_core::sc_fifo<unsigned>(5000);
      }
  {
    // some construction code
  }
}

 

[David Black]

@eyck nailed it.

[gabriel123]

Thanks @eyck the solution worked