UVM in UVM_ config_ Use of DB in sequence

stay UVM Use in get_full_name() You can get one component Full path to , alike , This function can also be used in a sequence In the called , Try in a sequence Of body This function is called , And print out the return value , The results are as follows ：
uvm_test_top.env.i_agt.sqr.case0_sequence
This path is made up of two parts , this sequence Of sequencer The path of , Instantiate this sequence Name passed when .

stay sequence in get Parameters

//my_case0.sv

function void my_case0::build_phase(uvm_phase phase);
...
  uvm_config_db#(int)::set(this, "env.i_agt.sqr.*", "count", 9);
...
endfunction

set Wildcards appear in the second path parameter of the function , This is because sequence In instantiation, the name is usually not fixed , And sometimes unknown , So use wildcards .

stay sequence Call... In the following way config_db::get function .
//my_case0.sv

class case0_sequence extends uvm_sequence#(my_transaction);
...
  virtual task per_body();
    if(uvm_config_db#(int)::get(null, get_full_name(), "count", count)
      `uvm_info("seq0", $sformatf("get count value %0d via config_db", count), UVM_MEDIUM)
    else
      `uvm_error("seq0", "cannot get count value!")
  endtask
...
endclass

stay get In the function prototype , The first parameter must be a component, and sequence Is not a component, So you can't use this The pointer , Only use null or uvm_root::get(). I've already mentioned that , When using null yes ,UVM It will be automatically replaced with uvm_root:get(), Add the second parameter get_full_name(), You can get this completely sequence The path of , So as to get the parameters .

stay sequence in set Parameters

//my_case0.sv

class drv0_seq extends uvm_sequnece #(my_transaction);
...
  virtual task body();
    void'(uvm_config_db#(bit)::get(uvm_root::get(), get_full_name(), "first_start", first_start));
    if(first_start)
      `uvm_info("drv0_seq", "this is the first start of the sequence", UVM_MEDIUM)
    else
      `uvm_info("drv0_seq", "this is not the first start of the sequence", UVM_MEDIUM)
    uvm_config_db#(bit)::set(uvm_root::get(), "uvm_test_top.v_sqr.*", "first_start", 0);
  endtask...
endclass

It should be noted that , Because of this sequence stay virtual sequence Started in , So its get_full_name The result should be uvm_test_top.v_seq., instead of uvm_test_top.env0.i_agt.sqr., So when setting up , The second parameter should be the former .