In short: Callbacks and the factory both help you reuse UVM code, but they solve different problems. A callback adds a small piece of behaviour at a fixed point inside a component you keep as-is, which is ideal for error injection or a locked third-party VIP. A factory override swaps a whole component or object…
In short: A UVM callback lets you change what a component (like a driver or monitor) does at chosen points, without touching that component’s source code. You define an empty hook method inside the component, register it, then plug in your own class later to inject errors, add checks, or collect coverage. It is the…
In short: Both are handles that a sequence uses to reach its sequencer, but they differ in type. m_sequencer is the general handle of type uvm_sequencer_base that every sequence always has. p_sequencer is a typed handle to your specific sequencer class, created by the `uvm_declare_p_sequencer macro. Use m_sequencer for the normal item handshake; use p_sequencer…
In short: uvm_config_db and uvm_resource_db are two ways to pass settings and handles across a UVM testbench without wiring them through every constructor. uvm_config_db is the everyday choice: it stores a value against a path and a name, and a component lower down reads it back. uvm_resource_db is the lower layer underneath it, used when…
In short: A fork…join block runs its statements in parallel. The three flavours differ in when the parent thread continues: join waits for all spawned threads, join_any waits for the first one to finish, and join_none waits for none and moves on at once. Two helpers go with them: wait fork blocks until all child…
In short: When several sequences run on one sequencer at the same time, the sequencer must decide whose item goes to the driver next. That decision is arbitration. UVM offers six built-in policies, set with set_arbitration, ranging from strict round-robin to weighted and priority-based schemes. Sequences can also raise their priority, or use lock and…
In short: UVM TLM lets components talk by passing whole transactions through ports instead of wiggling signals. One component owns a port (the caller), another owns an imp that holds the real method, and connect() joins them in the environment. A uvm_analysis_port is the one-to-many version used to broadcast, for example from a monitor to…
In short: A shallow copy duplicates only the top-level fields of an object. If the object holds a handle to another object, the copy shares that same inner object, so changing it through one handle affects both. A deep copy duplicates the top-level fields and also builds fresh copies of every nested object, so the…
In short: The this keyword is a built-in handle that refers to the current object, the specific instance whose method is running. Its most common use is inside a constructor or method when a parameter has the same name as a class field: this.x = x; means “set this object’s field x to the parameter…
In short: The driver and sequencer talk through a pair of matching ports: the driver has a seq_item_port, the sequencer has a seq_item_export, and connect_phase joins them. The driver pulls one item with get_next_item, drives it onto the pins, then calls item_done to release the sequence. That get, drive, done handshake is the heartbeat of…