uvm_task_phase

Base class for all task phases.  It forks a call to uvm_phase::exec_task() for each component in the hierarchy.

The completion of the task does not imply, nor is it required for, the end of phase.  Once the phase completes, any remaining forked uvm_phase::exec_task() threads are forcibly and immediately killed.

By default, the way for a task phase to extend over time is if there is at least one component that raises an objection.

class my_comp extends uvm_component;
   task main_phase(uvm_phase phase);
      phase.raise_objection(this, "Applying stimulus")
      ...
      phase.drop_objection(this, "Applied enough stimulus")
   endtask
endclass

There is however one scenario wherein time advances within a task-based phase without any objections to the phase being raised.  If two (or more) phases share a common successor, such as the uvm_run_phase and the uvm_post_shutdown_phase sharing the uvm_extract_phase as a successor, then phase advancement is delayed until all predecessors of the common successor are ready to proceed.  Because of this, it is possible for time to advance between uvm_component::phase_started and uvm_component::phase_ended of a task phase without any participants in the phase raising an objection.

Summary
uvm_task_phase
Base class for all task phases.
Class Hierarchy
uvm_void
uvm_object
uvm_phase
uvm_task_phase
Class Declaration
virtual class uvm_task_phase extends uvm_phase
Methods
newCreate a new instance of a task-based phase
traverseTraverses the component tree in bottom-up order, calling execute for each component.
executeFork the task-based phase phase for the component comp.

Methods

new

function new( string  name )

Create a new instance of a task-based phase

traverse

virtual function void traverse( uvm_component  comp,
uvm_phase  phase,
uvm_phase_state  state )

Traverses the component tree in bottom-up order, calling execute for each component.  The actual order for task-based phases doesn’t really matter, as each component task is executed in a separate process whose starting order is not deterministic.

execute

protected virtual function void execute( uvm_component  comp,
uvm_phase  phase )

Fork the task-based phase phase for the component comp.

The uvm_void class is the base class for all UVM classes.
virtual class uvm_object extends uvm_void
The uvm_object class is the base class for all UVM data and hierarchical classes.
class uvm_phase extends uvm_object
This base class defines everything about a phase: behavior, state, and context.
virtual class uvm_task_phase extends uvm_phase
Base class for all task phases.
function new( string  name )
Create a new instance of a task-based phase
virtual function void traverse( uvm_component  comp,
uvm_phase  phase,
uvm_phase_state  state )
Traverses the component tree in bottom-up order, calling execute for each component.
protected virtual function void execute( uvm_component  comp,
uvm_phase  phase )
Fork the task-based phase phase for the component comp.
virtual task exec_task( uvm_component  comp,
uvm_phase  phase )
Implements the functor/delegate functionality for a task phase type comp - the component to execute the functionality upon phase - the phase schedule that originated this phase call
class uvm_run_phase extends uvm_task_phase
Stimulate the DUT.
class uvm_post_shutdown_phase extends uvm_task_phase
After things have settled down.
class uvm_extract_phase extends uvm_bottomup_phase
Extract data from different points of the verficiation environment.
virtual function void phase_started ( uvm_phase  phase )
Invoked at the start of each phase.
virtual function void phase_ended ( uvm_phase  phase )
Invoked at the end of each phase.