Pausing/restarting 一个序列

Pausing/restarting a sequence

我的设计需要暂停数据流量才能进入低功耗模式。有没有办法暂停流量生成序列或驱动程序以允许这种情况发生?然后在稍后恢复序列?

我目前在我设置的序列中有一个标志,告诉它打破永远循环。但是,这并不理想,因为序列完成后我必须重新启动它。

您可以从虚拟序列中锁定(或获取音序器),例如:

class virtual_seq extends uvm_sequence;

  `uvm_object_utils(virtual_zero_seq)
  `uvm_declare_p_sequencer(virtual_sequencer)

  function new(string name = "");
    super.new(name);
  endfunction: new

  task body;
    // start the normal traffic sequence
    normal_traffic_seq seq;
    seq = serial_fixed_seq::type_id::create("seq");
    if (! seq.randomize() ...
    seq.set_starting_phase(get_starting_phase());
    seq.start(p_sequencer.seqr, this);

    // when you're ready, lock the sequencer
    #12345;
    this.lock(p_sequencer.seqr);   // or grab

    // wait till you're ready to resume
    #12345; 
    // you could start another sequence on the same sequencer if you need to
    // if you do, you must input the reference to this virtual sequence in 
    // the sequence's start method, otherwise that sequence will be locked too
    // eg
    // power_down_seq.start(p_sequencer.seqr, this);
    //                                        ^^^^

    // when you're ready, start normal traffic again
    this.unlock(p_sequencer.seqr);   // or ungrab
  endtask : body

endclass : virtual_zero_seq

抓取是优先级更高的锁。如果多个虚拟序列试图锁定一个音序器,那么它们将按照请求的顺序获得访问权限。如果多个虚拟序列试图获取一个音序器,如果它已经被锁定(或获取),这些虚拟序列将以先到先得的方式访问它。