Consider failure operation of DUV

In reply to chr_sue:

In reply to thanhnguyen.jg:
You should ask the designer what the intention of the FF is (it switches between the 2 slaves. But is there more behind?
Olease consider this is an UVM forum and not a common design or verification forum.

This lab is base on the sample project. We got the request to verify this DUV by UVM. During the project , the design have been updated by designer.
=> Verifier should estimate the potential bug with each modification and create pattern to check it.

That is the reason why I put my question in UVM forum.