UVM reg model mask

Hi,

I have a 32 bit register in which some of the bits are reserved. I have added the mask in the register model. But the reserved bits are also read/writable.

I only wont to write to the bits which are not reserved.

    foreach (rg[i]) begin
           foreach (fields[j]) begin
         if (fields[j].get_name() == "UNUSED" ) begin
            $display("UNUSED field= %s",fields[j].get_name());
             end
          else begin
                    fields[j].write(status, wdata,.parent(this));
        end  
 end

I tried the obove solution, but it writes for every field which is slowing me down.

Is their a way i can get the mask from the register model? Or any other solution?

Thanks