UVM RAL · Topic
UVM RAL Prediction — Auto, Explicit & Passive Modes
How the register model stays in step with the DUT — implicit, explicit and passive prediction, and when each is the right choice.
Prediction is how the model learns what the DUT now holds. Implicit prediction updates the mirror whenever the model itself issues an access, which is simple and blind to anything else on the bus. Explicit prediction watches the monitor instead, so it also sees accesses the model did not initiate — which is the only mode that stays correct when firmware or another master is writing registers too. Choosing implicit prediction in a multi-master system produces a mirror that is confidently out of date.