Analysis port in user callback class

[ManMe]

Is it possible to implement analysis port in user call back class? or is it possible to implement only in component derived from uvm_component?

Edited February 6, 2013 by ManMe

[jadec]

uvm_analysis_imp requires that the implementation be a component, but uvm_analysis_port can be instantiated outside of a component:

uvm_analysis_port #( my_obj ) myport = new( "myport", null );

It might make debugging more difficult, but the port functionality doesn't require it.

[tfitz]

While it is possible to instantiate an analysis_port outside of a component, as jadec shows, it's not recommended. Perhaps if you could describe what you're ultimately trying to achieve, we might be able to suggest a better alternative.

[basili]

Apologies for the necropost, but I'm trying to do the same the OP is doing.

I have a VIP that exposes a callback to access its internal states and I want to pack that state into a transaction and transfer it to a subscriber for some further processing.

I've described the usecase here: https://verificationacademy.com/forums/uvm/analysis-port-wrapped-callback

but unfortunately not many answers so far...

 

Anyone from this forum open to chime in?

[David Black]

If you understand SystemVerilog class-based syntax properly, you will see that you simply are describing a UVM subscriber. You could alternatively use the general purpose UVM callback mechanism.

[basili]

On 7/7/2022 at 2:48 PM, David Black said:

you simply are describing a UVM subscriber.

Hi David, I'm not entirely sure to understand what you mean. A UVM subscriber is essentially a uvm_component with an associated analysis_export at my disposal.

My VIP exposes a callback (not an analysis_port) so how can I 'attach' the analysis_export of my subscriber to my callback?

My preferred way would be to instantiate an analysis_port in my callback and have it connected to my subscriber analysis_export. Alternatively I could get the handle of subscriber in my callback and simply pass the transaction to the subscriber write function, without going through proper port connection, but I find this strategy less than ideal.

 

On 7/7/2022 at 2:48 PM, David Black said:

You could alternatively use the general purpose UVM callback mechanism.

I'm not sure what you mean by that, although I do understand what's the general purpose callback mechanism in UVM. My VIP already has a callback that's executed right before the packet is to be transmitted onto the interface and therefore it gives us the possibility to check/modify several attributes of the packet.