SPI_Test/tb/spi_tb/spi_monitor.sv

class spi_monitor;


  virtual spi_if		wif;
  virtual sram_if#(25,32)	xif;
  integer			fid;

  //collect MOSI(exp) & MISO(act)
  spi_trans			exp_trans;
  spi_trans			act_trans;


  function new();
  endfunction
  extern task collect();
  extern task do_mon();

endclass : spi_monitor 


task spi_monitor::do_mon();

    while(1) begin
      collect();
    end

endtask: do_mon




task spi_monitor::collect();
    bit		temp[$];
    int		i=0;

	@(negedge wif.csn);

	//capture cmd-words
	temp.delete();
	repeat(32) begin
	  @(posedge wif.sclk or posedge wif.csn);
	  if(wif.csn) break;
	  temp.push_back(wif.mosi);
	end

	//capture write-data or read-data
	while(1) begin
          @(posedge wif.sclk or posedge wif.csn);
          if(wif.csn) break;
	  temp.push_back(temp[0] ? wif.miso : wif.mosi);
        end
	temp.pop_back();
	
	if(!temp[0]) begin
	  exp_trans = new();
	  exp_trans.pack(temp);
	  exp_trans.print(fid);
	end  
	else begin
	  act_trans = new();
	  act_trans.pack(temp);
	  act_trans.print(fid);
	end
          

	if(!wif.csn) @(posedge wif.csn);

endtask