Question about grab/ungrab for interrupt

[yyn]

Dear all,

I made interrupt sequence. For interrupt opeartion, I use grab/ungrab function from UVM.

But I have a problem not to grab.

My testbench has 4 sequencers from interface UVC, so virtual sequence handles this.

My interrupt sequence is based on uvm_reg_sequence.

And I start the interrupt sequence in virtual sequence class and this virtual sequence is started in virtual sequencer.

#--------------

class int_seq_c extends uvm_reg_sequence;

... ...

virutal task body();

forever begin

@(posedge interrupt);

grab(regmodel.default_map.get_sequencer()); // Sequencer of AXI bus is get.

// clear interrupt

ungrab(regmodel.default_map.get_sequencer());

end

endtask

endclass

class int_virt_seq_c extends uvm_sequence;

int_seq_c int_seq;

virutal task body();

int_seq = int_seq_c::type_id::create("int_seq");

int_seq.start(null);

endtask

endclass

class my_virtual_sequencer extends uvm_sequencer;

... ...

virtual task run_phase(uvm_phase phase);

int_virt_seq = int_virt_seq_c::type_id::create("int_virt_seq");

fork

int_virt_seq.start(this);

join_none

endtask

endclass

I checked grab startus in int_seq_c class using "is_grabbed()" function after executing "grab()" task.

But 0 value is returned.

What is my problem?

How can I fix my problem?

Thanks and Regards,

// yyn

[jadec]

Even though grab has the highest priority, it still goes through arbitration logic. You might need to wait a bit before the is_grabbed state happens.