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Null object error from uvm_config.sv

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At the end of my simulation, I get a null object error from uvm_config.sv

Error-[NOA] Null object access

uvm/src/base/uvm_config.sv, 245

The object is being used before it was constructed/allocated.

Please make sure that the object is newed before using it.

#0 in \uvm_object_config_setting::value_string at


#1 in \uvm_config_setting::convert2string at


#2 in \uvm_component::check_config_usage at


#3 in \uvm_root::run_global_phase at


#4 in \uvm_root::run_test at


#5 in run_test at


#6 in unnamed$$_9 at

I am using the uvm early adapter 1.0 source code.

Can anybody help me why this happens at the end of the simulation?



Edited by suleesh
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Most likely m_value is null.

I'd place breakpoints to determine why it was null.


stop -file /blah/srajendr/UVM_SOURCE/uvm/src/base/uvm_config.sv -line 231

Might be that the object is never new'ed or it is passed a null "value" when it is created, or the assignment is not happening correctly.

More code would be useful to detemine the cause.


Edited by adielkhan
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In UVM1.0EA, the method check_config_usage() is automatically called at the end of the simulation. This prints out any configuration settings which are not matched by pathname or fieldname. It could be that an problem in one of your config settings is missed during simulation (because it is not matched) but causes an error at the end when check_config_usage() is called.

You could get a null pointer warning if you're using objects as configuration containers.

Try commenting out your configs & seeing if that fixes that problem.

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