1. A method for modifying the function of a state machine having a programmable logic device, the method comprising: (a) modifying a high-level design of said state machine to obtain a modified high-level design of said state machine with a modified function; (b) generating a programmable logic device netlist from differences in said high-level design and said modified design; and (c) installing said modified function into said state machine by programming said programmable logic device based on said programmable logic device netlist.