How to set parameterized sequcence as default sequence with +uvm_set_default_sequence

UVM
, ,
1

I am trying to use +uvm_set_default_sequence to set default sequence to an parameterized sequence, but i didn’t make it. Can anyone please help and show me what went wrong?

The sequence is parameterized like below.


class seq_a #(int param = 10) extends uvm_sequence;

  //`uvm_object_utils(seq_a)
  `uvm_object_param_utils(seq_a#(param))

  function new(string name = "my_seq");
    super.new(name);
    do_not_randomize = 1'b1; // Required for ModelSim
    set_automatic_phase_objection(1);
  endfunction

  task body;
    uvm_sequence_state_enum state = get_sequence_state();
    // In UVM 1.1d: starting_phase.raise_objection(this);
    `uvm_info("SEQ_A", $sformatf("state is %s",
      state.name()), UVM_LOW);
    while ($time < 10us) begin
      #1us;
      `uvm_info("SEQ_A", $sformatf("[%d] ping at time %d", param, $time), UVM_LOW);
    end
    // In UVM 1.1d: starting_phase.drop_objection(this);
  endtask

endclass

And I added +uvm_set_default_sequence=*,main_phase,seq_a#(10) to VCS runtime option.

Unfortunately, it went wrong, and log was like below.


UVM_INFO @ 0: reporter [RNTST] Running test test...
UVM_WARNING @ 0: reporter [UnknownTypeName] find_wrapper_by_name: Type name 'seq_a#(10)' not registered with the factory.
UVM_ERROR @ 0: reporter [UVM_CMDLINE_PROC] Invalid type 'seq_a#(10)' provided to +uvm_set_default_sequence
UVM_FATAL @ 0: reporter [BUILDERR] stopping due to build errors
2

In reply to Jaor:

UVM factory registration does not allow named look-ups which is a requirement for +uvm_set_default_sequence. You can only use type look-ups when a component/object is parameterized.

Also, you should never use a default sequence. You want your test to be able to control what sequences are started. By using a default_sequence, you remove this control from your test.

3

In reply to cgales:

Thanks for the explanation, cgales. And you are right about the default sequence, I will try not using default sequence and see the difference.