Different approach to implementing multi-monitor - single scoreboard than using the macro `uvm__analysis_imp_decl

By _ default blog

October 26, 2023

INTRODUCTION:

We all know that whenever there are multiple monitors connected to a single scoreboard, we do the connection as mentioned in UVM Cookbook or uvm_user_guide by using the inbuild macro `uvm_analysis_imp_decl(_<string>) and then writing another analysis imp inside the scoreboard with the same name passed in the arg of the above macro

DRAWBACK:

The drawback of the above implementation is that going forward if my num of monitors increases then I need to make changes to my scoreboard file,

I now need to declare the macro also need to add one more imp port inside the scoreboard file and inside the environment newly created imp port needs to be connected.

This goes against the principle of not touching a good working code.

SOLUTION:

The solution I propose here is very simple,

What I am proposing is to declare a string orig_component, dest_component inside the uvm_seq_item class.

Before calling the write method from the monitor do the following assignment

Inside the scoreboard declare a single imp port

uvm_analysis_imp #(my_seq_item, my_scbd) mon_imp;

Inside the function write () we basically check who is the orig_component and based on that we take the action. Don't forget to declare it as virtual as going forward you can extend the base scoreboard and implement more logic to it

Below is the extended scoreboard

From the testcase, you can now override the extended scoreboard to the base scoreboard

ADVANTAGE:

The advantage of this implementation is now your base_scoreboard need not be touched nor your env class. You can extend the scoreboard and do your implementation for any newly added monitor and override the base_scoreboard with extend_scoreboard from your testcase.

The code inside the environment and agent remains the same.

Let me know if you like this method, if any issues you see in the above implementation please do let me know.