waveform modeling

as well as your are a ATE engineer, you may very familiar with the ATE test pattern formats that can transfer the waveform info into sample digital codes.
this is  a very example code for req/grant test case.

// timing modeling
task req_grant_00();                                                                                                                                                                 
  m_vif.REQ   <= 0;
  m_vif.GRANT <= 0;
  @(posedge m_vif.CLK);
endtask : req_grant_00

task req_grant_01();
  m_vif.REQ   <= 0;
  m_vif.GRANT <= 1;
  @(posedge m_vif.CLK);
endtask : req_grant_01

task req_grant_10();
  m_vif.REQ   <= 1;
  m_vif.GRANT <= 0;
  @(posedge m_vif.CLK);
endtask : req_grant_10

task req_grant_11();
  m_vif.REQ   <= 1;
  m_vif.GRANT <= 1;
  @(posedge m_vif.CLK);
endtask : req_grant_1

task

task wave_gen();
  list = {`ON_OFF, `ON_ON, `OFF_ON, `OFF_OFF};

  foreach(list[i]) begin
    case(list[i])
      `ON_OFF : req_grant_10();
      `ON_ON  : req_grant_11();
      `OFF_OFF: req_grant_00();
      `OFF_ON : req_grant_01();
    endcase
  end 
endtask