global_stop_request() does not work in UVM?

[cliffc]

Does the global_stop_request() command still work in UVM?

I know the preferred mechanism to stop tests is to raise and drop objections.

In the test1 raise/drop objection example below, the test runs for 100ns and prints two messages.

In the test2 global_stop_request() example below, the test runs for 0ns and only prints the time-0 message.

class test1 extends uvm_test;

`uvm_component_utils(test1)

function new (string name="test1", uvm_component parent);

super.new(name, parent);

endfunction

task run_phase(uvm_phase phase);

phase.raise_objection(this);

`uvm_info("test1", "test1 started ...", UVM_MEDIUM)

#100ns;

`uvm_info("test1", "test1 ran 100ns ...", UVM_MEDIUM)

phase.drop_objection(this);

endtask

endclass

class test2 extends uvm_test;

`uvm_component_utils(test2)

function new (string name="test2", uvm_component parent);

super.new(name, parent);

endfunction

task run_phase(uvm_phase phase);

`uvm_info("test2", "test2 started ...", UVM_MEDIUM)

#100ns;

`uvm_info("test2", "test2 ran 100ns ...", UVM_MEDIUM)

global_stop_request();

endtask

endclass

Regards - Cliff Cummings

www.sunburst-design.com

[dave_59]

Hi Cliff,

Didn't you write a paper on this?

If you use stop_request() and/or global_stop_request(), then you will need to use the plusarg +UVM_USE_OVM_RUN_SEMANTIC, otherwise your testbench will end prematurely without awaiting your stop_request().

[cliffc]

Hi, Dave -

Why yes I did write a paper on this topic, but the paper was released before UVM was released, so the paper addressed OVM run-time semantics.

Thanks for the plusarg switch. I did not know that this switch existed. I will give this a try.

Thanks-much for the reply. I'm not sure where I would have found documentation on this command line switch.

Regards - Cliff

[smallnokia]

Hi cliffc,

In UVM GOLDEN Reference Guide, Page 63, it is mentioned that "UVM provides an "objection" mechanism for this purpose. Other methods of stopping simulation, which were used in OVM and UVM-EA, such as calling global_stop_request, are deprecated in UVM.

So in order to make it compatible to OVM, you should use the switch posted by dave_59, I think.

Regards,

Hi, Dave -

Why yes I did write a paper on this topic, but the paper was released before UVM was released, so the paper addressed OVM run-time semantics.

Thanks for the plusarg switch. I did not know that this switch existed. I will give this a try.

Thanks-much for the reply. I'm not sure where I would have found documentation on this command line switch.

Regards - Cliff