see 25.5 uvm_reg_field, configure for the function input descriptions.
example of it in use:
http://cluelogic.com/2012/10/uvm-tutorial-for-candy-lovers-register-abstraction/
Keisuke specifically mentions that bit in this example:
http://cluelogic.com/2013/02/uvm-tutorial-for-candy-lovers-register-access-methods/
configure is just a function of uvm_reg_field, not a phase… you confused me :)