UVM object: set_inst_override_by_type not working

UVM
, ,
1

Hi all,

I have the two following classes:

class base_obj extends uvm_object;
  `uvm_object_utils(base_obj)
  
  function new(string name = "base_obj");
    super.new(name);
  endfunction
  
  virtual function display();
    `uvm_info(get_type_name(), $sformatf("inside base_obj"), UVM_LOW);
  endfunction
  
endclass

class child_obj extends base_obj;
  `uvm_object_utils(child_obj)
  
  function new(string name = "child_obj");
    super.new(name);
  endfunction
  
  function display();
    `uvm_info(get_type_name(), "inside child_obj", UVM_LOW);
  endfunction
  
endclass

In my test, I’m instantiating an object of type base_obj, and I’m using the set_inst_override_by_type to override it type with child_obj:

class my_test extends uvm_test;
  `uvm_component_utils(my_test)

  base_obj obj_b;
  
  function new(string name = "my_test", uvm_component parent = null);
    super.new(name, parent);
  endfunction
  
  function void build_phase(uvm_phase phase);
    super.build_phase(phase);
    set_inst_override_by_type("obj_b", base_obj::get_type(), child_obj::get_type());
    obj_b = base_obj::type_id::create("obj_b");
  endfunction
     
  task run_phase(uvm_phase phase);
    super.run_phase(phase);
    obj_b.display();
  endtask

endclass

It did not worked:

UVM_INFO testbench.sv(14) @ 0: reporter [base_obj] inside base_obj

Using

set_type_override("base_obj", "child_obj");

have worked but I would like to override only the specific obj_b instance. What am I missing?

Thanks,
Ruben

2

In reply to rubendah:

The issue is that uvm_objects do not exist in the UVM hierarchy, hence you can’t use the set_inst_override_by_type. You can only use the set_type_override().

If you extend from uvm_component(), your example will work.

3

In reply to rubendah:

Try the following in my_test ::


function void build_phase(uvm_phase phase);
    super.build_phase(phase);
    set_inst_override_by_type("obj_b", base_obj::get_type(), child_obj::get_type());

    obj_b = base_obj::type_id::create("obj_b",this); //  Added 2nd  argument ' this ' 
  endfunction

In your code , for instance obj_b the ’ parent ’ would be uvm_root .