In reply to chr_sue:
spi_env_config is a class described as follow :
class spi_env_config extends uvm_object;
`uvm_object_utils(spi_env_config)
bit topcell_env=0;
bit has_scbd=1;
bit has_digital_env=1;
bit active=1;
spi_agent_config agent_config;
function new(string name="spi_env_config_i");
super.new(name);
endfunction : new
endclass
When I create the object in the test before the set, the object has the default values. I verify this with some displays.