cgales, thanks a lot for your comments.
As your comments, I specify null in my start, and then, in the sequence, I printed the m_sequencer’s full name by m_sequencer.get_full_name(), and got the result : uvm_test_top.m_env.apb.sqr, what is the sequencer in my APB agent. I think this is because I have set the sequencer like this: regmodel.default_map.set_sequencer(apb.sqr,reg2apb); I think this is not a virtual sequencer assigned by UVM. correct me, Thanks.
And if I specified the sequencer when I start the sequence like this
m_seq_mul.start(m_env.apb.sqr) ; , the m_sequencer in the sequence will not be null, but the grab will not return either.
if possible, Could you please help me about this?