Uvm_monitor ; how to track changes in the bus value?

UVM
1

Hi All,
I need some help with my uvm_monitor. I need to capture the “mirror_data[127:0]” and “mirror_byte_wr_en[15:0]” when “mirror_wr_addr[18:0]” changes.

mirror_wr_addr does NOT change every posedge of clk. It changes every few clocks. I need to capture the transaction only when “mirror_wr_addr” changes and “mirror_byte_wr_en > 0”. Even if “mirror_wr_addr” changes and “mirror_byte_wr_en” is at 0, I should NOT capture the transaction. The below code does not do it.

Any inputs on where I could be wrong?



task run_phase(uvm_phase phase);
    egress_transaction tr; 
    forever begin
      //@ (posedge vif.clock);
      @(vif.mirror_wr_addr) 
      @(vif.mirror_byte_wr_en);
      tr = egress_transaction ::type_id::create("tr");
      tr.mirror_data = vif.mirror_wr_data;
      tr.mirror_wr_byte_en = vif.mirror_byte_wr_en;
      tr.mirror_wr_addr = vif.mirror_wr_addr;
      `uvm_info(get_type_name(),$sformatf("mirror_data = 0x%x, mirror_byte_wr_en = 0x%x, mirror_wr_addr = 0x%x\n", 
                                 tr.mirror_data,tr.mirror_wr_byte_en, tr.mirror_wr_addr),UVM_LOW); 
    end
  endtask : run_phase

Thanks in advance!

2

In reply to Verif Engg:

Hi,

Following code, may help you.


task run_phase(uvm_phase phase);
    egress_transaction tr; 
    int  copy_mirror_wr_addr;
    byte copy_mirror_byte_wr_en;           
    forever begin
      @ (posedge vif.clock);
      
      if(copy_mirror_wr_addr != vif.mirror_wr_addr)
      begin
        if(vif.mirror_byte_wr_en > 0)
          begin
            tr = egress_transaction ::type_id::create("tr");
            tr.mirror_data = vif.mirror_wr_data;
            tr.mirror_wr_byte_en = vif.mirror_byte_wr_en;
            tr.mirror_wr_addr = vif.mirror_wr_addr;
            `uvm_info(get_type_name(),$sformatf("mirror_data = 0x%x, mirror_byte_wr_en = 0x%x, mirror_wr_addr = 0x%x\n", 
                                 tr.mirror_data,tr.mirror_wr_byte_en, tr.mirror_wr_addr),UVM_LOW);
          end
        
        //Assiging captured address for next clock comparision
        copy_mirror_wr_addr = vif.mirror_wr_addr;
      end
      
    end
  endtask : run_phase