UVM/UVM Cookbook/Sequences/VirtualSequencer — различия между версиями

// Virtual sequencer class:
class virtual_sequencer extends uvm_virtual_sequencer;
 
`uvm_component_utils(virtual_sequencer)
 
// Note that the handles are in terms that the test writer understands
bus_master_sequencer bus;
gpio_sequencer gpio;
 
function new(string name = "virtual_sequencer", uvm_component parent = null);
  super.new(name, parent);
endfunction
 
endclass: virtual_sequencer
 
class env extends uvm_env;
 
// Relevant parts of the env which combines the
// virtual_sequencer and the bus and gpio agents
//
// Build:
function void build_phase( uvm_phase phase );
  m_bus_agent = bus_master_agent::type_id::create("m_bus_agent", this);
  m_gpio_agent = gpio_agent::type_id::create("m_gpio_agent", this);
  m_v_sqr = virtual_sequencer::type_id::create("m_v_sqr", this);
endfunction: build_phase
 
// Connect - where the virtual_sequencer is hooked up:
// Note that these references are constant in the context of this env
function void connect_phase( uvm_phase phase );
  m_v_sqr.bus = m_bus_agent.m_sequencer;
  m_v_sqr.gpio = m_gpio_agent.m_sequencer;
endfunction: connect_phase
 
endclass:env
 
// Virtual sequence base class:
//
class virtual_sequence_base extends uvm_sequence #(uvm_sequence_item);
 
`uvm_object_utils(virtual_sequence_base)
 
// This is needed to get to the sub-sequencers in the
// m_sequencer
virtual_sequencer v_sqr;
 
// Local sub-sequencer handles
bus_master_sequencer bus;
gpio_sequencer gpio;
 
function new(string name = "virtual_sequence_base");
  super.new(name);
endfunction
 
// Assign pointers to the sub-sequences in the base body method:
task body();
  if(!$cast(v_sqr, m_sequencer)) begin
    `uvm_error(get_full_name(), "Virtual sequencer pointer cast failed");
  end 
  bus = v_sqr.bus;
  gpio = v_sqr.gpio;
endtask: body
 
endclass: virtual_sequence_base
 
// Virtual sequence class:
//
class example_virtual_seq extends virtual_sequence_base;
 
random_bus_seq bus_seq;
random_gpio_chunk_seq gpio_seq;
 
`uvm_object_utils(example_virtual_seq)
 
function new(string name = "example_virtual_seq");
  super.new(name);
endfunction
 
task body();
  super.body; // Sets up the sub-sequencer pointers
  gpio_seq = random_gpio_chunk_seq::type_id::create("gpio_seq");
  bus_seq = random_bus_seq::type_id::create("bus_seq");
 
  repeat(20) begin 
    bus_seq.start(bus);
    gpio_seq.start(gpio);
  end 
endtask: body
 
endclass: example_virtual_seq
 
// Inside the test class:
//
task run;
  example_virtual_sequence test_seq = example_virtual_sequencer::type_id::create("test_seq");
 
  //...
  test_seq.start(m_env.m_v_sqr);
  //...
endtask: run

// Virtual sequencer from the UART env
class uart_env_virtual_sqr extends uvm_virtual_sequencer;
// ..
uart_sequencer uart;
bus_sequencer bus;
// ..
endclass: uart_env_virtual_sqr
 
// Virtual sequencer from the GPIO env
class gpio_env_virtual_sqr extends uvm_virtual_sequencer;
// ..
gpio_sequencer gpio;
bus_sequencer bus;
// ..
endclass: gpio_env_virtual_sqr
 
// Virtual sequencer from the SoC env
class soc_env_virtual_sqr extends uvm_virtual_sequencer;
//..
// Low level sequencers to support virtual sequences running across
// TB hierarchical boundaries
uart_sequencer uart;
bus_sequencer uart_bus;
gpio_sequencer gpio;
bus_sequencer gpio_bus;
 
// Virtual sequencers to support existing virtual sequences
//
uart_env_virtual_sqr uart_v_sqr;
gpio_env_virtual_sqr gpio_v_sqr;
 
// Low level sequencer pointer assignment:
// This has to be after connect because these connections are
// one down in the hierarchy
function void end_of_elaboration();
  uart = uart_v_sqr.uart;
  uart_bus = uart_v_sqr.bus;
  gpio = gpio_v_sqr.gpio;
  gpio_bus = gpio_v_sqr.bus;
endfunction: end_of_elaboration
 
endclass: soc_env_virtual_sqr

// Either inside the virtual sequence base class or in
// an extension of it that will use specific sequencers:
task body();
  if(!$cast(v_sqr, m_sequencer)) begin
    `uvm_error(get_full_name(), "Virtual sequencer pointer cast failed")
  end
  if(v_sqr.gpio == null) begin
    `uvm_fatal(get_full_name(), "GPIO sub-sequencer null pointer: this test case will fail, check config or virtual sequence")
  end
  else begin
    gpio = v_sqr.gpio;
  end
  if(v_sqr.gpio_bus == null) begin
    `uvm_fatal(get_full_name(), "BUS sub-sequencer null pointer: this test case will fail, check config or virtual sequence")
  end
  else begin
    gpio_bus = v_sqr.gpio_bus;
  end
endtask: body