[UVM foundation] can only be used in build_ Research on executing instantiation action in phase

The answer is No . In addition to the build_phase Execute instantiated actions in , In fact, it can also be in new Function to execute instantiated actions .

If you can my_agent Of new Instantiation in function driver and monitor：

function new(string name, uvm_component parent);
	super.new(name, parent);
	if (is_active == UVM_ACTIVE) begin
		drv = my_driver::type_id::create("drv", this);
	end
	mon = my_monitor::type_id::create("mon", this);
endfunction

One problem caused by this is It is not possible to assign values directly to uvm_agent Pass on is_active Value . stay my_env Of build_phase（ perhaps new function ） in , towards i_agt and o_agt Of is_active assignment , It doesn't work at all . therefore i_agt and o_agt All work in active Pattern （ is_active The default value of is UVM_ACTIVE） , This is far from expected . To solve this problem , Can be in my_agent Use before instantiation config_db Statement passing is_active Value ：

class my_env extends uvm_env;
	virtual function void build_phase(uvm_phase phase);
		super.build_phase(phase);
		uvm_config_db#(uvm_active_passive_enum)::set(this, "i_agt", "is_active", UVM_ACTIVE);
		uvm_config_db#(uvm_active_passive_enum)::set(this, "o_agt", "is_active", UVM_PASSIVE);
		i_agt = my_agent::type_id::create("i_agt", this);
		o_agt = my_agent::type_id::create("o_agt", this);
	endfunction
endclass

class my_agent extends uvm_agent ;
	function new(string name, uvm_component parent);
		super.new(name, parent);
		uvm_config_db#(uvm_active_passive_enum)::get(this, "", "is_active", is_active);
		if (is_active == UVM_ACTIVE) begin
			drv = my_driver::type_id::create("drv", this);
		end
		mon = my_monitor::type_id::create("mon", this);
	endfunction
endclass

It's just UVM in What is customary is still build_phase Complete instantiation in . therefore , It is strongly recommended that only build_phase Complete instantiation in .