Why start_of_simulation_phase is in bottup manner..?

[dave_59]

You should only rely on the build_phase being top-down. You should assume no predefined ordering of the time-consuming task phases. Assume they get started in parallel

See some of the discussion here:

Calling of build phase?

In reply to georgean: I have attached a small example that demonstrates the calling order for some of the UVM phases given a simple hierarchy. A better term would have been depth-first traversal instead of bottom-up. Note that calling the connect() method is not the same as calling the connect_phase(). The connect() builds a database of connections to be made between components. The order that you call the connect() methods does not matter as long as both ends of the connection have been const…