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//

//------------------------------------------------------------------------------

//   Copyright 2007-2011 Mentor Graphics Corporation

//   Copyright 2007-2010 Cadence Design Systems, Inc.

//   Copyright 2010 Synopsys, Inc.

//   All Rights Reserved Worldwide

//

//   Licensed under the Apache License, Version 2.0 (the

//   "License"); you may not use this file except in

//   compliance with the License.  You may obtain a copy of

//   the License at

//

//       http://www.apache.org/licenses/LICENSE-2.0

//

//   Unless required by applicable law or agreed to in

//   writing, software distributed under the License is

//   distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR

//   CONDITIONS OF ANY KIND, either express or implied.  See

//   the License for the specific language governing

//   permissions and limitations under the License.

//------------------------------------------------------------------------------

//------------------------------------------------------------------------------

// CLASS: uvm_random_stimulus #(T)

//

// A general purpose unidirectional random stimulus class.

//

// The uvm_random_stimulus class generates streams of T transactions. These streams

// may be generated by the randomize method of T, or the randomize method of

// one of its subclasses.  The stream may go indefinitely, until terminated

// by a call to stop_stimulus_generation, or we may specify the maximum number

// of transactions to be generated.

//

// By using inheritance, we can add directed initialization or tidy up after

// random stimulus generation. Simply extend the class and define the run task,

// calling super.run() when you want to begin the random stimulus phase of

// simulation.

//

// While very useful in its own right, this component can also be used as a

// template for defining other stimulus generators, or it can be extended to

// add additional stimulus generation methods and to simplify test writing.

//

//------------------------------------------------------------------------------

class uvm_random_stimulus #(type T=uvm_transaction) extends uvm_component;

  const static string type_name = "uvm_random_stimulus #(T)";

  typedef uvm_random_stimulus #(T) this_type;

  `uvm_component_param_utils(this_type)

  // Port: blocking_put_port

  //

  // The blocking_put_port is used to send the generated stimulus to the rest

  // of the testbench.

  uvm_blocking_put_port #(T) blocking_put_port;

  // Function: new

  //

  // Creates a new instance of a specialization of this class.

  // Also, displays the random state obtained from a get_randstate call.

  // In subsequent simulations, set_randstate can be called with the same

  // value to reproduce the same sequence of transactions.

  function new(string name, uvm_component parent);

    super.new(name, parent);

    blocking_put_port=new("blocking_put_port", this);

    uvm_report_info("uvm_stimulus", {"rand state is ", get_randstate()});

  endfunction

  local bit m_stop;

  // Function: generate_stimulus

  //

  // Generate up to max_count transactions of type T.

  // If t is not specified, a default instance of T is allocated and used.

  // If t is specified, that transaction is used when randomizing. It must

  // be a subclass of T.

  //

  // max_count is the maximum number of transactions to be

  // generated. A value of zero indicates no maximum - in

  // this case, generate_stimulus will go on indefinitely

  // unless stopped by some other process

  //

  // The transactions are cloned before they are sent out

  // over the blocking_put_port

  virtual task generate_stimulus(T t=null, int max_count=0);

    T temp;

    if (t == null)

      t = new;

    for (int i=0; (max_count == 0 || i < max_count) && !m_stop; i++) begin

       if (! t.randomize() )

          uvm_report_warning ("RANDFL", "Randomization failed in generate_stimulus");

       $cast(temp, t.clone());

       uvm_report_info("stimulus generation", temp.convert2string());

       blocking_put_port.put(temp);

    end

  endtask

  // Function: stop_stimulus_generation

  //

  // Stops the generation of stimulus.

  // If a subclass of this method has forked additional

  // processes, those processes will also need to be

  // stopped in an overridden version of this method

  virtual function void stop_stimulus_generation;

    m_stop = 1;

  endfunction

  virtual function string get_type_name();

    return type_name;

  endfunction

endclass : uvm_random_stimulus