UVM · Topic
UVM Phases — Build, Connect, Run & Objections
The UVM phase machine — build and connect order, the run-phase family, objections, and why a test ends when it does.
Phasing exists to solve an ordering problem that has no good manual answer: every component must be constructed before any component is connected, and connection must finish before anything runs. UVM enforces that top-down/bottom-up order so a testbench assembles correctly regardless of the order components were declared. The part engineers meet as a bug is objections — the run phase ends when the last objection drops, so a component that forgets to raise one lets the test finish before its work does, and the symptom is a test that passes having checked almost nothing.