hw/dv/sv/dv_lib/dv_base_reg.sv

// Copyright lowRISC contributors.
// Licensed under the Apache License, Version 2.0, see LICENSE for details.
// SPDX-License-Identifier: Apache-2.0
//
// base register class which will be used to generate the reg
class dv_base_reg extends uvm_reg;

  function new(string       name = "",
               int unsigned n_bits,
               int          has_coverage);
    super.new(name, n_bits, has_coverage);
  endfunction : new

  // get_n_bits will return number of all the bits in the csr
  // while this function will return actual number of bits used in reg field
  function uint get_n_used_bits();
    uvm_reg_field fields[$];
    get_fields(fields);
    foreach (fields[i]) get_n_used_bits += fields[i].get_n_bits();
  endfunction

  // loop all the fields to find the msb position of this reg
  function uint get_msb_pos();
    uvm_reg_field fields[$];
    get_fields(fields);
    foreach (fields[i]) begin
      uint field_msb_pos = fields[i].get_lsb_pos() + fields[i].get_n_bits() - 1;
      if (field_msb_pos > get_msb_pos) get_msb_pos = field_msb_pos;
    end
  endfunction
endclass